Introduction to Diseases, Diagnosis, and Management of Dogs and Cats

Approx.330 pages

• Discusses clinical diseases of dogs and cats including those that impact major systems in the body, specimen collection, clinical examination, diagnosis, and medical interventions
• Covers the etiology and epidemiology, physical examination abnormalities, pathogenesis, clinical signs, diagnosis, treatment and prognosis, immunity and vaccination, and prevention of infectious diseases
• Explores advances in diagnosis and treatment including molecular diagnostic techniques and therapies

• Language: English
• Publisher: Academic Press
• Release date: Nov 15, 2023
• ISBN: 9780443185496

Book preview

Chapter 1 General aspects of introduction to diseases, diagnosis, and management of dogs and cats

Ranbir Singh Jatava; Aditya Pratapa; Nitin Vaishnava; Neha Sharmab    a Department of Veterinary Medicine, College of Veterinary Science and Animal Husbandry, Nanaji Deshmukh Veterinary Science University, Jabalpur, Madhya Pradesh, India

b Department of Veterinary Surgery and Radiology, College of Veterinary Science and Animal Husbandry, Nanaji Deshmukh Veterinary Science University, Jabalpur, Madhya Pradesh, India

Abstract

Animal-human companionship bonding represents a highly dynamic relationship that offers emotional fortification and mutual support. Animal illnesses encompass deviations from the normal physiological state of animals, impacting their essential functions. Concerns about animal ailments have persisted since the early interactions between humans and animals. A disease can be defined as a detrimental deviation from normal physiological condition, resulting in discernible signs or symptoms. Different breeds of dogs and cats can have varying susceptibilities to certain diseases due to genetic predispositions and physiological differences. Dogs and cats can suffer from a range of diseases, whether infectious or noninfectious in nature. Diagnosing these ailments involves a comprehensive approach, encompassing the owner’s observations, the animal’s history, initial examination details, clinical findings derived from body system assessments, results of specific laboratory tests, and modern veterinary diagnostics. Contemporary issues affecting dogs and cats often arise from a combination of factors, such as nutrition, environment, management, and genetics. Certain infections, notably those propagated through airborne pathogens, present a challenge to control despite substantial preventive measures. Vaccinations play a pivotal role in safeguarding dogs from numerous infections, including parvo, distemper, rabies, leptospirosis, kennel cough, and corona, while also shielding cats from rhinotracheitis, calicivirus, and panleukopenia. By implementing appropriate preventive measures, diagnostic methodologies, and management techniques, one can effectively promote the health and well-being of both dogs and cats, mitigating the impact of various diseases.

Keywords

Diseases; Dogs and cats; Infection; Diagnosis; Health; Treatment

1 Introduction

Since the beginning of human civilization, cats and dogs have been companions to people as per the references in the ancient scriptures and the Vedas. Animal illness is an alteration to an animal’s normal state that affects or disrupts vital functioning. Since the very first interactions between humans and animals, there has been a concern with animal ailments, which is mirrored in early conceptions of religion and magic. Animal diseases continue to be a problem, mostly because of the financial harm they may do and the possibility that they could spread to people or animals. The disease can be described as a harmful divergence from an organism’s normal physiological condition that is significant enough to result in overt signs or symptoms. The deviation may be a functional problem with hidden organic changes, or it may be an evident organic change in the tissue making up an organ. The degree of the alterations that take place in cells and tissues exposed to harmful chemicals depends on the sensitivity of the tissue in question as well as the type and duration of the agent.

Treatment of dog and cats, that is suspected of having a disease, includes a description of the animal (age, species, sex, and breed), the animal’s history, a description of the preliminary examination, clinical findings from a review of the body systems, results of particular laboratory tests, prognosis, case progress, termination, and, if necessary, the use of scientific references.

As it is evident that the veterinarian cannot question the animal, he must make a diagnosis of a disease based on a number of examinations and tests. Inspection, which involves a visual examination of the animal, palpation, which involves applying firm pressure with the fingers to tissues to assess characteristics like abnormal shapes and potential tumors, the presence of pain, and tissue consistency, percussion, which involves applying a brief, sharp blow to tissue to elicit an audible response from body parts beneath, and auscultation, which entails listening for sounds that are abnormal or unusual, are all techniques used in the preparation of a diagnosis.

The first symptom of illness may be a raised temperature, or fever, brought on by the proliferation of disease-causing microbes. The body’s defenses against foreign invaders are activated by the rise in body temperature. Knowing the characteristics of the heartbeat and the circulatory system can be done by taking the pulse.

In addition to the tests already mentioned, the modern veterinary diagnostic laboratory also performs tests on bone marrow cells, specific organ functions (liver, kidney, pancreas, thyroid, adrenal, and pituitary glands, etc.), radioisotope tests, tissue biopsies, and histochemical analyses, as well as tests on blood coagulation and body fluids.

Problems in dogs and cats are now often multifactorial in nature with nutritional, environmental, managemental, and genetic undercurrents. Many infectious diseases are ubiquitous worldwide and airborne pathogens are difficult to control even after the adoption of very good preventive measures.

Vaccinations protect dogs and cats from some of the most serious diseases. Prevention through vaccination is essential since these diseases are difficult, if not treated. Vaccinations are the best gift you can give to your pet. All dogs and cats should be vaccinated; even indoor pets that never go outdoors. No vaccination confers lifetime immunity. However, a vaccine is effective in preventing the disease in people if it is administered soon after their possible exposure. No diagnostic test is identified as the gold standard for diseases in dogs and cats.

2 Diagnosis and management of various diseases of dog and cat

2.1 General systemic condition

The general systemic condition can be defined as the general body condition of dogs or cats which are abnormal or not in a normal physiological limit. They contribute to the pathogenesis of various diseases, either directly or indirectly, like fever is recorded in the majority of infectious diseases. Some most important systemic body conditions are fever, hypothermia, hyperthermia, shock, heat stroke, toxemia, septicemia, stress, allergy (anaphylactic reaction), etc. The knowledge of these systemic states is prerequisite to understand better the pathophysiology of various systemic infections.

History, characteristic clinical findings like sudden onset, rise of body temperature, anorexia, dullness, depression, lymphadenopathy specially splenomegaly, and marked change in total leucocyte count may play a role in the diagnosis of general systemic body condition.

In the case of hyperthermia plasma concentration of muscle enzymes, ALT, AST, LDH, and CPK are elevated due to muscle exertion.

The presence of petechial hemorrhage in mucosa and conjunctiva may suggest the occurrence of septicemia.

Changes in total and differential leukocyte number occur in endotoxemia. Leukocytosis and neutrophilia occur with mild endotoxemia.

A condition of stress can be directly detected by the assay of plasma ACTH and indirectly by cortisol. In chronic stress, there are marked lymphopenia, eosinopenia, and neutrophilia.

Clinically allergy is a state of recognizable hypersensitivity. When there is exposure of an animal to antigen, in consequence of this, there is a state of increased reactivity of the animal and a specific immune response is achieved. Diagnosis of an anaphylactic reaction is based on the history of injecting foreign protein substance within the preceding hour, characteristic clinical signs, increased blood histamine level, and increased eosinophil count. Nowadays serological tests to detect the presence of antibodies to plant proteins in the diet have been used. Management of diseases is crucial for maximizing the quality of life of both affected dogs and cats for a long and pain-free life and to minimize genetic and lifestyle risk factors.

2.2 Diseases of cardiovascular system

The cardiovascular system is comprised of the heart, the veins, and the arteries. The atrioventricular and the semilunar valves keep blood flowing in one direction through the heart. Valves in large veins keep blood flowing back toward the heart. Evaluation of the heart is performed via assessment of heart sounds, murmurs, arterial pulses, electrocardiography, radiography, etc.

There are various mechanisms that can result in different abnormalities related to a cardiovascular system like a failure of closing and opening of cardiac valves, inadequate contraction and relaxation of heart muscles, irregularity in heartbeats, abnormal communication between chambers of the left side and right side of the heart, etc. These abnormalities cause various diseases like valvular disease, myocardial disease, arrhythmias, vascular disease, cardiac shunts, heart failure, congestive heart failure, failing heart, etc.

Most senior-aged small dogs have a heart murmur. Heart murmurs are a very common aging change that is most often related to mitral valve degeneration. A murmur can be diagnosed with a stethoscope by your veterinarian. Heart murmurs are often associated with and worsened by severe dental disease. Bacteria from the mouth enter the bloodstream and stick to the heart valves where it grows and causes the valves to malfunction. This is one reason why it is very important to have your pet’s teeth cleaned regularly to prevent plaque and tartar buildup as well as gum disease. This means that the valve separating the top and bottom chambers of the heart on the left side becomes diseased and does not close like it should normally. This allows for a backflow of blood into the upper chamber of the heart.

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Electrocardiography of a dog suspected of cardiac problem.

Degenerative valve disease is the most common heart disease in dogs and accounts for about 75% of cardiovascular diseases in this species. This disease is characterized by thickening of the heart valves. It most commonly affects the mitral or tricuspid valve. The disease is age and breed related. In dogs, there are no signs during the early stages of the disease, although a heart murmur can be heard. Fainting may also occur due to decreased blood flow or arrhythmia. A veterinarian can often diagnose degenerative valve disease based on physical examination findings and appropriate imaging procedures, which may include chest X-rays and echocardiography (ultrasonography). Because X-rays can be inconclusive, your veterinarian may recommend the pet owner to count the number of times their dog breathes within a minute while it sleeps. If your dog’s sleeping respiratory rate is elevated, it may have abnormal fluid buildup within the lungs (pulmonary edema). Regular monitoring of the sleeping respiratory rate can also help assess your dog’s response to treatments. Arrhythmias may develop as the disease progresses and can be detected with electrocardiography. In addition, a blood test called an NT-proBNP may be helpful for diagnosis.

Diagnosis of cardiovascular disease is based on history, physical examination, i.e., inspection, auscultation and palpation, cardiac biomarkers, radiography, electrocardiography, and echocardiography.

In the case of infectious endocarditis, various blood samples may be needed for diagnosis and to monitor the effects of the infection. X-rays may show enlargement of a heart chamber or evidence of heart failure; however, echocardiography (ultrasonography) is the diagnostic test of choice for most veterinarians, because blood tests are positive in only 50%–90% of dogs. Electrocardiography (recording electrical activity of the heart) may show arrhythmias.

In the case of pericardial diseases, veterinarians may notice a swollen jugular vein, muffled heart sounds, and pulse abnormalities during the examination of the dog. X-rays may show an enlarged or abnormally shaped heart. In most cases, an electrocardiogram is normal or just shows an increased heart rate. The echocardiography (ultrasonography) examination is the most sensitive and specific test for the detection of cardiac tamponade. It may also reveal a tumor, if it is the cause of the disease.

ECG is a useful diagnostic tool and has added an additional dimension in the patient evaluation not only for cardiovascular diseases but also for other diseases that affect the heart secondarily. The ECG has its own limitations, and therefore, its findings should be correlated with the clinical findings of patients. It is a graphical representation of the electric events produced by the cardiac muscle cells during depolarization and repolarization. ECG in dogs is taken in a standing position or lateral recumbency (right side down). Standardization of the ECG paper is made at 10 mm or 1 mv with a paper speed of 25 mm per second.

Echocardiography is a technique that utilizes short pulses of ultrasound at a frequency of 2–5 MHz to image the heart and great vessels. Sounds waves are produced by a piezoelectric crystal incorporated into a transducer that converts electrical energy into mechanical (sound) energy and vice versa. It can also diagnose the presence of a tumor mass in the heart or ductal presence or pericardial or pleural effusion.

Doppler echocardiography is a technique for the assessment of the velocity and turbulence of blood flow within the heart. A frequency change is produced when ultrasound waves strike moving red blood cells, this can be measured and analyzed.

Blood pressure is not routinely measured in animals except racehorses, because it is virtually not possible to relax animals to obtain satisfactory basal pressure readings. The rate of disappearance of intravenously injected Evans blue from the circulation is an accurate method for measuring blood volume. While measuring it, the age and recent physical activity of animals must be taken into consideration. Dogs with extremely high blood pressure may have no signs that are visible to the owner. Sudden blindness is the most common sign. Blood tests may help with the diagnosis of the cause of high blood pressure.

2.3 Diseases of digestive system

The primary function of the mouth is to introduce food into the digestive tract, prehension, digestion, and absorption of food and water. When any of these become compromised through disease or trauma, malnutrition and dehydration may result. Dehydration is the major effect in acute diseases and shock is an important physiological disturbance in per acute diseases. Some degree of abdominal pain is usual in most diseases of the alimentary tract. Other abnormalities include vomiting, diarrhea, hemorrhage, constipation, and scanty defecation.

A complete blood count (CBC), serum biochemistry profile, and urinalysis can help differentiate primary GI (gastrointestinal) disease from non-GI disease and can identify metabolic derangements resulting from GI disease. Additional testing, such as liver function tests or an adrenocorticotropic hormone stimulation test, may be warranted depending on the clinical findings and initial test results.

Abdominal radiographs generally do not help diagnose GI ulceration, but they can help exclude GI obstruction, intussusceptions, and peritonitis.

Abdominal ultrasonography may show abnormalities in GI wall thickness or the presence of a mass, but its primary utility is the identification of non-GI lesions.

Endoscopy allows visualization of the esophagus, stomach, duodenum, and colon and identification of mucosal lesions and ulcers. Endoscopy also allows for fine needle aspirates of lesions or collection of biopsy samples, although full-thickness surgical biopsies may be required to identify infiltrative disease and tumors. Ulcerated areas should be biopsied only on the periphery to avoid perforation. Gastric fluid can be tested for pH to help diagnose hypersecretory states.

Selective culture for fecal pathogens (e.g., Clostridium spp., Salmonella spp., Yersinia spp., Clostridium spp., Campylobacter spp., enterotoxigenic Escherichia coli, etc.) and evaluation for Clostridium spp. enterotoxin by fecal ELISA can be considered.

Chronic diarrhea and weight loss are nonspecific signs common to a variety of systemic and metabolic diseases, as well as malabsorption, although, typically, systemic diseases cause anorexia. A thorough diagnostic approach in dogs and cats with signs suggestive of malabsorption is, therefore, needed to help exclude association with possible underlying systemic or metabolic disease. A precise diagnosis is also important to determine treatment and prognosis.

Multisector CT imaging, available in specialty referral practices and university teaching hospitals, can distinguish mass lesions, detect changes in the structure of hepatic parenchyma and the biliary system, identify choleliths, detect abnormal hepatic perfusion (involving the portal vein, hepatic artery, or hepatic vein), and portal thrombi and can detail the extent of traumatic hepatobiliary injuries.

Percussion of the right side of the abdomen may reveal the presence of intestinal tympany and enlargement of the liver. Auscultation can give an idea about the state of intestinal activity and abnormal sounds arising from a distended organ.

2.4 Diseases of respiratory system

Large and small airways, as well as the lungs, make up the respiratory system. Air that is inhaled by a dog through its mouth or nose passes into the trachea, which separates into the right and left bronchi, and then into the bronchioles, which are the lungs’ smaller airways. A thin membrane acts as a barrier between the air and the blood in the tiny sacs known as alveoli where the bronchioles terminate. In the alveoli, oxygen and carbon dioxide are exchanged. The animal can get gravely ill when this exchange breaks down or becomes ineffective as a result of illness. The respiratory system warms, humidifies, and filters out pollutants to preserve its own sensitive airways.

In dogs, respiratory conditions are typical. Although respiratory tract issues are the most typical source of symptoms like coughing and hard breathing, other organ system ailments like congestive heart failure can also result in these symptoms. The most common respiratory diseases are rhinitis, sinusitis, tracheobronchitis, bronchopneumonia, pneumonia, aspiration pneumonia, pleural effusion, pyothorax, pneumothorax, etc.

Most serious upper respiratory infections are caused by feline rhinotracheitis virus, feline calicivirus, and chlamydia (pneumonitis). Signs and severe symptoms of these highly contagious diseases may last up to 6 weeks.

Native commensal bacteria, such as Pasteurella multocida, Bordetella bronchiseptica, streptococci, staphylococci, pseudomonads, and coliform bacteria, typically live in the lungs, upper trachea, nasopharynx, and nasal passages of dogs and cats without causing any symptoms. Infection with a primary pathogen (such as distemper, parainfluenza, or canine type 2 adenovirus in dogs, or rhinotracheitis virus or calicivirus in cats), other insults (such as inhaling smoke or noxious gases), or diseases like congestive heart failure and pulmonary neoplasia may impair the respiratory defense mechanisms, leading to opportunistic infections by these bacteria.

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Auscultation in dog.

Evidently, diagnostic tests are necessary to establish the presence of numerous respiratory illnesses in small animals. Unfortunately, veterinary medicine’s specialization in respiratory medicine is underdeveloped, and the practitioner has access to only a small number of advanced tests that can accurately detect particular pulmonary illnesses. Diagnosis is completely depending on the history and physical examination done by veterinarians. This will help to determine the possible cause and site of respiratory disease.

When obstructive upper airway disease or airway obstruction is suspected, chest and neck X-rays may be beneficial. Dogs with lower respiratory symptoms including coughing, quick shallow breathing, or hard breathing are frequently given chest X-rays. The amount of oxygen in the blood is measured by blood gas analysis or pulse oximetry, which may be used to determine whether an animal with extremely laborious breathing needs oxygen therapy.

The diagnosis of fungal pneumonia frequently makes use of fine needle aspirates of the lungs. A sample of the accumulated fluid is frequently taken from dogs with fluid buildup in the chest cavity using a needle (thoracocentesis), allowing microscopic examination of the fluid. Ultrasonography through the chest wall can be used to diagnose diseases that develop surrounding the lungs (pleural disorders) and lung disease that occurs close to the chest walls.

Runny nose, sneezing, or both may appear out of the blue in adult dogs and may indicate a viral or bacterial infection—both extremely rare—or a foreign object lodged in the nose. A sample of nasal tissue, computed tomography (CT), an endoscopic examination, or other testing may be necessary for persistent instances. Fungal infections may be diagnosed by microscopic examination of the nasal tissue; however, the majority of canine bacterial nasal infections are brought on by other nasal disorders. Sometimes in addition to other tests and examinations, blood tests are performed to diagnose fungal respiratory infections.

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CT scan of dog at veterinary clinical complex.

Unless the vet instructs otherwise, animals with respiratory conditions should typically receive plenty of water. It could be simpler to remove airway secretions if the air has more humidity. Expectorants, which thin secretions and make them simpler for animals to cough up, are occasionally employed, although they are rarely effective. Large amounts of secretions may need to be gently suctioned away by the veterinarian if the airway obstruction is severe.

2.5 Diseases of urinary system

The kidneys, ureters (tubes connecting the kidneys to the bladder), the bladder, and the urethra are all parts of the urinary system or tract (the tube through which urine exits the body). The urinary system serves a number of crucial purposes. It eliminates the waste materials produced when food is converted into energy. Also, it keeps the electrolytes (salts) and water in the cells of the body in the proper proportion. The creation of the hormones erythropoietin and renin, which are crucial for maintaining appropriate blood pressure, generating blood cells, and properly absorbing salt, is another crucial task.

The majority of bacterial infections that affect the urinary system in small animals are aerobic. Escherichia coli, Staphylococcus, Enterococcus, and Streptococcus are examples of typical microorganisms. Infection-causing bacteria that are less frequent include Klebsiella, Proteus, and Pseudomonas. Cats are more likely than dogs to contract Pasteurella. A rare cause of urinary tract infections, mycoplasma is typically discovered in conjunction with other microorganisms. By infecting the kidney and numerous other organs, filamentous bacteria that cause leptospirosis spread throughout the world. Rarely do parasites, yeast, or fungi invade the urinary system.

Urinary tract bacterial infections often progress from the urethra into the bladder and, in some cases, the kidneys. Unusual urine flow (such as urine retention), diminished urothelial defenses, diminished systemic immunological defenses, or insufficient urine concentration are all predisposing factors. With the exception of older, uncastrated male dogs who develop bacterial prostatitis, female dogs are more prone to urinary tract infections than male dogs. Dogs that also have other disorders, such as chronic renal disease or hyperadrenocorticism, are more vulnerable.

Feline urological syndrome (FUS) is a disease complex of the urinary system. Causes of this disease include diet, urinary pH (acidity), bacteria, viruses, urinary habits, and other factors. Signs of FUS include frequent urination (spending an unusual amount of time in the litter box), urinary accidents, straining with urination, blood in the urine, pain in the abdomen, and increased irritability of the cat. Diagnosis should be made by a veterinarian who can test the urine. Regular visits to the veterinarian are important to prevent or correct serious health problems. To provide proper cat care, be aware of serious health threats and use preventive measures.

Compared to dogs, cats are more resilient to bacterial cystitis. Fewer than 2% of cats aged 1–10 with symptoms of the lower urinary tract have a positive bacterial infection culture. The most common noninfectious causes of lower urinary tract pain and inflammation in adult cats are idiopathic cystitis, interstitial cystitis, or urinary bladder stones.

A thorough urinalysis that includes physical and chemical assessments, as well as microscopic examination of preparation of unstained, moist urine may imply a probable UTI diagnosis, enabling prompt treatment of a painful and potentially life-threatening illness. Microscopical detection of bacteria does not necessarily indicate a urinary tract infection (UTI). For a UTI to be diagnosed, there must be consistent clinical symptoms, a history of infection, or other evidence of infection, such as pyuria or hematuria on microscopic examination. Apart from bacterial infections, other conditions can also cause inflammation. For instance, patients with urolithiasis or tumors may have inflammatory cells in their urine without also having bacterial infections at the same time. If a urinalysis finds protein in the urine, an additional urine test called a urine protein/creatinine ratio may be necessary.

In the case of bladder stones in dogs, X-rays are the most commonly utilized diagnostic tool that veterinarians use to confirm a dog has bladder stones. A small percentage of bladder stones, however, such as urate stones or any stone that is tiny, do not reflect X-rays well and show up best on an ultrasound. Surgery to remove the stones is the most commonly used treatment for bladder stones that cannot be dissolved or in emergency cases where a stone has blocked the urethra and the dog is not able to urinate. Most dogs do very well and recover rapidly after a cystostomy.

In the event of a urinary issue, a veterinarian may carry out a variety of further tests. They consist of biopsies, blood tests, blood pressure checks, urinalysis, and other urine examinations, X-rays, contrast X-rays (tests where a specific dye is administered to highlight the urinary tract on the X-ray), ultrasonography, and cystoscopic examinations. In a cystoscopic test, the urethra is entered and a tiny tube containing a camera is inserted.

2.6 Diseases of nervous system

Disease in the central nervous system or the peripheral nervous system might alter an animal’s capacity to feel its surroundings. Behavioral changes, seizures, tremors, discomfort, numbness, lack of coordination, and weakness or paralysis of one or more legs are among the main symptoms of nervous system problems. Depending on where and how severe the injury is, sensory and motor functions may be affected.

Depending on which portion of the brain is injured, different outcomes follow from brain injuries. A brain stem injury may result in loss of balance, limb weakness, overactive reflexes, stupor, or coma. Tremors, a loss of balance, and head-to-leg coordination are all symptoms of cerebellar damage. Complete or partial blindness, loss of smell, seizures, comas, stupor, pacing or circling behavior, and the inability to recognize an owner are all symptoms of cerebrum damage.

Below the level of the injury, a spinal cord injury can result in paralysis and a loss of feeling. Minor spinal cord injuries may cause awkward movement and slight limb weakness. More limb weakness can result from moderate spinal cord injury. A complete lack of movement (paralysis) and sensation can occur in severe spinal cord injuries. Paralysis is not a common result of spinal cord injury, though. For instance, a lower back spinal cord injury can cause loss of bladder control instead of limb paralysis.

Certain viruses or bacteria are the culprits behind nervous system infections. The body’s own overactive immune system can induce other inflammations, such as some types of meningitis. All of them are autoimmune illnesses. Many substances have the potential to harm the neurological system. Some examples of these are rat poison, antifreeze, chocolate, and sedatives. Several medications can be harmful to the neurological system when used in high dosages. In addition to coral and tiger snake venom, botulism, tetanus, and tick bites can all impact the neurological system and result in paralysis.

The presence of a brain tumor is confirmed using a range of tests. Nervous system tumors can be identified by plain X-rays, myelography, scintigraphy, computed tomography scans, and magnetic resonance imaging. Analyses of the cerebrospinal fluid may also be helpful.

A myelogram is an X-ray examination in which the spinal fluid surrounding the spinal cord is dyed with a particular substance. On a standard X-ray, the spinal cord cannot be seen. By injecting this dye, the spinal cord is highlighted and becomes apparent on X-rays. This dye may be injected into the spinal fluid in the neck region (cisternal myelogram) or lower back region (lumbar myelogram). A sample of the patient’s spinal fluid is taken right before the dye injection and sent to the laboratory for evaluation. Myelograms are a challenging and delicate diagnostic procedure that is best handled by a veterinary specialist. The procedure requires general anesthesia.

In computed tomography (CT), an X-ray tube moves around the body and continuously projects a thin fan of X-rays through the body. Detectors opposite the tube continuously monitor the X-ray and its angle for developing a proper image. Veterinary CT scans for pets are similar to humans and have the same advantages. It allows for a more detailed look into the health of tissues and organs and provides a three-dimensional image of the internal organs.

Magnetic resonance imaging (MRI) is the newest form of diagnostic imaging being used for both human and veterinary medicine. Dog MRI equipment generates a very powerful magnetic field, resulting in detailed anatomic images of whatever part of a dog’s body is being scanned. It is used to diagnose problems with the brain and spinal cord after other tests fail to determine the cause of the animal’s illness. Brain diseases diagnosed with an MRI include tumors, infarcts (lack of blood to an area of the brain), abscesses, epilepsy, and inflammation of the brain’s covering (meninges).

2.7 Deficiency diseases

While many other disorders of this sort are caused by a lack or unbalance of the dietary elements needed by the animal for maintenance, development, reproduction, and physical activity, other metabolic problems in dogs and cats are caused by inherited defects. Yet, more often than not, nutritional deficiencies are the direct result of an insufficient supply of the necessary nutrients in the diet. Sometimes, nutritional deficiencies are a complication of other illnesses that interfere with the appropriate digestion and utilization of nutritive elements.

Although numerous researches have been conducted on the dietary needs of dogs and the consequences of particular nutritional deficiencies, little is known about the nutritional needs or nutritional illnesses of cats. But because the diets of the wild cats and dogs are somewhat comparable, it is hypothesized that the two species are likely to experience comparable deficiency illnesses. What little is known about the nutritional illnesses that affect cats supports this view.

The most commonly occurring errors in the diet of domestic pet animals are deficiencies in vitamins, minerals, and proteins of good quality. Except in the case of rickets, a positive diagnosis of which can be made by means of the X-ray, some information concerning the previous diet of the animal is often essential in diagnosing a disease of nutritional origin. Also, the characteristic effects of specific deficiencies usually occur in combination with nonspecific symptoms which may be induced by one or more of several causes. The most common of these nonspecific symptoms is the retardation of growth, which may result from simple starvation, inadequate proteins of good quality, deficient or unbalanced calcium or phosphorus, or a deficiency of one or more of several vitamins. Likewise, a degeneration of the central and peripheral (outer) nervous system, with resulting in coordination of movements, may occur as a result of vitamin A deficiency or some type of vitamin B deficiency.

Typically, rickets is described as any alteration in the mineral metabolism that leads to faulty or aberrant calcification, or hardening, of developing bones. Lethargy and listlessness, an arched neck, a hunched posture, knobby and malformed joints, bowed legs, and flabby muscles are some of the clinical signs of rickets.

Female dogs and cats occasionally have eclampsia just before, during, or right after giving birth to a litter of young. It appears to be caused by a calcium shortage, which may be accompanied by vitamin D insufficiency. Females who are nursing large litters are more likely to experience it since they have high calcium requirements for producing milk.

It is common practice to make a diagnosis of vitamin A insufficiency in dogs based on symptoms that emerge in the later stages of the illness, when some animals may still not make a full recovery even after the deficit is treated. The eye ailment xerophthalmia, which is characterized by this symptom, is likely the most readily identifiable one. A lack of vitamin A is linked to a number of other less specific and frequently harder-to-diagnose dietary origin illnesses. Loss of weight, a rough coat and scaly skin, uncoordinated movements, likely diminished susceptibility to infections, and, in growing puppies, stunted growth are a few of these symptoms.

2.8 Dermatological disorder

The skin, the largest organ in the body, serves as a barrier between an animal and its surroundings and regulates body temperature, protects the immune system, enhances sensory awareness, and produces vitamin D. In addition to performing all of these crucial tasks and being directly impacted by illnesses, the skin may also share or reflect pathologic processes from other tissues. These traits make dermatological issues among the most prevalent illnesses in dogs and cats.

The most common dermatological disorders are pyoderma, dermatophytosis, malassezia dermatitis, sporotrichosis, cryptococcosis, demodicosis, canine scabies, flea allergy dermatitis, atopic dermatitis, etc.

The best way to diagnose skin problems is to take a thorough medical history and do a comprehensive physical and dermatological examination. The evaluation provides invaluable data and directs the course of the investigation. There should be specific examinations and occasionally, treatment trials.

Important dermatology diagnosis procedures include skin scrapings, trichograms, fungal and bacterial cultures, cytological analysis, and skin biopsies. To detect mites, skin scrapings are used; depending on the suspected mite, they may be shallow or deep. The obtained sample is examined using optical microscopy.

For patients with suspected fungal illnesses, fungus culture is advised. The lesion margin should be used to gather hair samples and skin scales. Bacterial culture is not frequently carried out, but it is advised in cases with pyoderma that is resistant to a first therapy or when rods are seen in cytology.

The hairs from the affected area are pulled out for the direct study of the hairs, or trichogram, which is then microscopically analyzed. This method can be used to identify irregularities in the hair growth phase as well as the presence of dermatophytes and follicle parasites.

The examination known as cytology, which examines tissue cells, is very effective and beneficial in evaluating a lesion and determining the next stage in the diagnostic process. The sample can be collected via a lesion impression, swab, skin scrape, or fine-needle aspiration.

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Red mange caused by Demodex canis.

Usually, histopathology combined with clinical findings results in a conclusive diagnosis. A skin biopsy is advised in cases of atypical lesions, potentially cancerous nodules, dermatoses requiring expensive treatments, when the patient’s health is at risk, when there has been a poor response to prior treatment, and to rule out other possible diagnosis.

2.9 Endocrine disorder in dogs and cats

The most common endocrine diseases in dogs are Cushing disease, hypothyroidism, and diabetes mellitus. The most common endocrine diseases in cats are hyperthyroidism and diabetes mellitus.

Diabetes mellitus is a group of metabolic diseases characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both. Diabetes is characterized by a rise in blood glucose levels (hyperglycemia), passing of glucose (glucosuria) and ketone bodies (ketonuria) in urine, and deficiency or inability to utilize insulin for the normal metabolism of carbohydrates, proteins, and fats. Clinical signs of diabetes are related to these biochemical alterations hyperglycemia, ketonuria, and glucosuria, in addition to damage to other systems and general signs include anorexia, depression, lethargy, weight loss, polydipsia, and polyuria.

Diagnosis is usually based on clinical and pathological findings. Diabetes can be diagnosed by the presence of four classic signs that include polyuria, polyphagia, polydipsia, and, foremost, hyperglycemia. In blood, hemoglobin A1c (HbA1c) may be considered as a biomarker for the presence and severity of hyperglycemia, implying diabetes or prediabetes, or, over time, as a biomarker for a risk factor. These are the glycosylated products involving a glycation reaction between a sugar (glucose or fructose) and a protein (Hb for glycalated Hb and albumin for fructosamine) or amine (fructosamine). These are produced by nonenzymatic reactions. They are used for measuring blood sugar in diabetes.

The thyroid gland produces fewer T4 and T3 hormones when someone has hypothyroidism, an endocrine condition. Yet, the most prevalent endocrinopathy in dogs rarely affects cats. Around 95% of adult dogs with hypothyroidism have the primary loss of the thyroid gland. Dermatological disorders are observed in 60%–80% of hypothyroidism cases, and thyroid hormones are crucial for maintaining healthy skin function. Alopecia (usually bilaterally symmetric and sparing the head and limbs), superficial pyoderma, dry and desquamated skin, dry or oily seborrhea, brittle and easily pulled hair, hyperkeratosis, hyperpigmentation, otitis, inadequate wound healing, pruritus, myxedema, and obesity are common findings. Clinical symptoms, serum TSH totals, and free T4 levels are used to make the diagnosis.

Cushing syndrome, also known as hyperadrenocorticism, is brought on by the adrenal glands’ chronically high cortisol release. It happens iatrogenically, following the administration of synthetic glucocorticoids, or spontaneously, as a result of inherent hyperfunction of the pituitary or adrenal glands. Eighty to eighty-five percent of spontaneous hyperadrenocorticism in dogs and cats is hypophysis dependent. The diagnosis is made based on clinical symptoms connected to laboratory analysis and diagnostic imaging results. Hyperadrenocorticism is confirmed by plasma ACTH, low dexamethasone dose suppression test, ACTH stimulation test, and urine cortisol/creatinine ratio. To rule out iatrogenic causes, it is also critical to learn the history of glucocorticoid usage.

Hyperthyroidism is a common disease in cats and mostly afflicts cats middle-aged and older. Thyrotoxicosis or hyperthyroidism is caused by an increase in the production of thyroid hormones (known as T3 and T4) from an enlarged thyroid gland. In most cases, the enlargement of thyroid glands is caused by a noncancerous tumor called an adenoma. Some rare cases of hyperthyroid disease are caused by malignant tumors known as thyroid adenocarcinomas. Most cats with hyperthyroidism have elevated levels of the thyroid hormone T4 in their bloodstream.

2.10 Neonatal diseases

Due to the high rates of morbidity and mortality that are linked with the newborn period in dogs and cats ranging from 7% to 35% in dogs and from 14% to 16% in cats, it continues to be a significant issue for veterinarians and breeders. The health of a litter can be affected by a wide range of events during pregnancy, delivery, and the first few weeks of life, all of which need to be adequately addressed by the breeder and the veterinarian. Litter viability can be directly impacted by maternal, neonatal, environmental, and birth-related variables. Neonatal mortality is also influenced by ignorance, poor management, a lack of neonatal care, and neglect.

Selecting the best parents for mating begins with the optimal management for the birth of healthy puppies and kittens, and genetics is a decisive element for successful reproduction. Prior to mating, the vaccination of females is a crucial consideration. Females who are not immunized are more likely to experience miscarriage, premature birth, stillbirth, and neonatal mortality due to infectious illnesses. Also, the puppy’s and kitten’s immunity will be affected by the puppy’s and kitten’s inadequate immunization status, leaving neonates exposed to diseases during the neonatal period. With the possibility of parasitic transmission via placental, lactogenic, and ambient contamination, maternal deworming before and during pregnancy is also crucial for the health of the litter.

Puppies and kittens are frequently more susceptible to getting numerous infectious infections during the perinatal period since their immune systems are still developing. In general, bacterial, viral, and parasite diseases cause higher rates of morbidity and mortality in children than in adults. Because passive immunity is not transferred when colostrum is not consumed soon after birth, newborns will be more susceptible to illnesses. Moreover, unclean environments are more likely to support a number of diseases that can endanger the lives of puppies and kittens.

Dogs and cats experience significant rates of mortality during the perinatal period, and the causes of death and risk factors are frequently not looked into. The veterinarian must have a fundamental understanding of physiology, pregnancy and neonatal care, and preventive measures in addition to being aware of the key elements involved in managing puppies and kittens. Greater neonatal survival and reproductive success are impacted by breeders receiving instruction on proper handling and by training their staff annually.

2.11 Bacterial diseases

Bacterial diseases are a group of diseases that are caused by bacteria either gram positive or gram negative. Bacteria are single-cell prokaryotes, they do not have a true nucleus but all bacteria contain both DNA and RNA. The virulence or pathogenicity of various bacteria and mechanisms by which they cause disease is of a different kind. Bacteria multiply rapidly and spread all over tissue and cause septicemia (e.g., anthrax) and toxemia (e.g., tetanus). Bacteria are ubiquitous and affect almost all species of animal and some bacteria play a major role in zoonosis also.

Grams-positive bacteria:

1.Streptococcal infections—Streptococcus canis, Streptococcus equi subsp. zooepidemicus, Streptococcus pyogenes

2.Enterococcus spp. Infections—Enterococcus faecalis and Enterococcus faecium

3.Staphylococcal Infections—Staphylococcus pseudintermedius, Staphylococcus aureus, and Staphylococcus schleiferi

4.Rhodococcus equi infection—Rhodococcus equi

5.Corynebacterium Infection—Corynebacterium auriscanis, Corynebacterium urealyticum

6.Listeriosis—Listeria monocytogenes

7.Erysipelothrix Infections—Erysipelothrix rhusiopathiae and Erysipelothrix tonsillarum

8.Anthrax—Bacillus anthracis

9.Canine nocardiosis—Nocardia asteroides

10.Canine actinomycosis—Actinomyces viscosus

11.Feline leprosy—Mycobacterium lepraemurium

Grams-negative bacteria:

1.Escherichia coli infection—Escherichia coli

2.Proteus infection—Proteus mirabilis

3.Klebsiella infection—Klebsiella pneumonia

4.Serratia marcescens infection—Serratia marcescens

5.Enterobacter infection—Enterobacter spp.

6.Citrobacter infection—Citrobacter freundii, Citrobacter koseri

7.Pasteurella infection—Pasteurella multocida, Pasteurella canis, Pasteurella dagmatis, and Pasteurella stomatis

8.Pseudomonas infection—Pseudomonas aeruginosa

9.Canine brucellosis—Brucella canis, Brucella abortus

10.Chlamydial infection (feline pneumonitis)—Chlamydia felis

11.Feline infectious anemia—Mycoplasma haemofelis

12.Leptospirosis—Leptospira icterohemorrhagica, Leptospira pomona, Leptospira canicola

Diagnosis is a very important key to cure the disease. For diagnosis, sample collection and its transportation is very important. The sample may be tissue, swabs, discharge, skin lesion sample, blood, feces, urine, abscesses, eye, milk, etc. As soon as the sample is processed, the results are better. Clinical findings, e.g., pustules, are found on the skin in streptococcus infection, jaundice and nephritis in leptospirosis, etc. Laboratory tests like complete blood count, biochemical, urine examination, and fecal examination can also be useful for diagnosis.

Identification of infective agents can be done with the help of different staining procedures like gram staining for grams positive, e.g., Streptococcus and grams negative, e.g., E. coli, Diluted carbol fuchsine stain, Ziehl-Neelsen or acid-fast staining for mycobacterium, modified Ziehl-Neelsen staining, e.g., Brucella, Giemsa staining, e.g., Mycoplasma haemofelis, Polychrome methylene blue staining (M’ Fadyeans reaction) for anthrax, etc.

Bacteriological media are also helpful for the isolation and identification of various bacteriological agents. Some very commonly used bacteria media are chemically defined media, nutritive media, e.g., nutrient agar for fastidious organism, enriched media, e.g., selenite broth for salmonella isolation, chocolate agar for haemophilus, selective media, e.g., MacConkey agar for enterobacteriaceae and other grams-negative bacteria, brilliant green agar for salmonella isolation, Edwards media for streptococci, indicator media, e.g., MacConkey agar for enterobacteriaceae and other grams-negative bacteria, Edwards media for streptococci, blood agar, XLD agar for salmonella isolation, etc.

Biochemical tests for bacterial identification like catalase test, oxidase, urease test, Voges-Proskauer test, hydrogen sulfate, and indole test are also used as a diagnostic tool.

Molecular and immunological methods include bacteria-specific antibodies that are available for the identification of specific bacteria and molecular diagnosis may be performed with the help of PCR and ELISA.

Management includes the use of antimicrobial agents on the basis of antibiotic sensitivity tests, serological examination must be continued in a regular routine. strict sanitary measures should be adopted.

2.12 Viral disease

Viruses are considered as an obligate intracellular organism, which is dead particle out of the living cell, they synthesize their proteins by the host cell machinery. Viruses contain only a single type of nucleic acid either DNA or RNA. Viruses are responsible for many fatal infections in canine and feline, e.g., Rabies, parvovirus infection, canine distemper, etc. Some viruses play an important role in zoonosis, e.g., Influenza.

Some most commonly found viral diseases of dogs and cats with their causative agent are as follows:

1.Rabies—genus Lyssavirus (single-stranded RNA virus). Rabies is a viral infection possible in all mammals, including men. It is transmitted by the bite or scratch of an infected cat or other animal. It may also be transmitted by saliva deposited into an open wound

2.Canine distemper—genus Morbillivirus (family Paramyxoviridae) (negative-stranded RNA virus)

3.Infectious canine hepatitis (ICH)—Canine Adenovirus 1 (CAdV-1) (double-stranded DNA virus) genus Mastadenovirus

4.Feline Adenovirus Infection—feline adenovirus 1 (FAdV-1) (double-stranded DNA virus) genus Mastadenovirus

5.Canine Herpesvirus Infection—Canid alphaherpesvirus 1 (CHV-1) genus Varicellovirus

6.Influenza Virus Infections—influenza viruses (Orthomyxoviridae)

7.Canine Parainfluenza Virus Infection—canine parainfluenza viruses (family Paramyxoviridae, genus Rubulavirus). Simian virus 5 (SV5), parainfluenza virus 5, canine parainfluenza 2

8.Canine Respiratory Coronavirus Infection—Canine Respiratory Coronavirus genus Betacoronavirus of the Coronaviridae family

9.Kennel cough or canine infectious tracheobronchitis—CHV-1, CAdV-2, CDV, CPIV, CRCoV, and CIV

10.Other viruses that infect dogs and cats—Canine Parainfluenza Viruses, Novel Canine Respiratory Viruses, Canine Pneumovirus, Pantropic Canine Coronavirus, Canine Bocavirus, Canine Hepacivirus

11.Canine Parvovirus Infections—Canine Parvovirus-2 variants family Parvoviridae, subfamily Parvoviridae, genus Protoparvovirus

12.Feline Panleukopenia Virus Infection—Feline panleukopenia virus/feline parvovirus FPV

13.Feline Coronavirus Infections—Feline coronavirus family Coronaviridae, genus Coronavirus

14.Feline Infectious Peritonitis—Feline Infectious Peritonitis Virus (Feline coronavirus family)

15.Feline Leukemia Virus Infection and Fading kitten syndrome—Feline Leukemia Virus, gammaretrovirus, Oncornavirus subfamily of retroviruses. Feline leukemia is a contagious disease caused by a virus that is spread by saliva, urine, and other body fluids from an infected cat. There is no effective treatment. A vaccine is available that prevents leukemia.

16.Feline Immunodeficiency Virus Infection—Feline Immunodeficiency Virus, family Retroviridae, subfamily Orthoretrovirinae, genus Lentivirus

17.Feline Herpesvirus Infections—Feline Herpesvirus 1 (family Herpesviridae, an alphaherpesvirus), Felis catus gammaherpesvirus 1 (family Herpesviridae, genus Percavirus, a gammaherpesvirus)

18.Feline Calicivirus Infections—Feline Calicivirus, family Caliciviridae, genus Vesivirus

19.Feline Foamy (SyncytiumForming) Virus Infection—Feline Foamy virus, family Retroviridae, subfamily Spumaretrovirinae

20.Paramyxovirus Infections—family Paramyxoviridae; genera Morbillivirus (feline morbillivirus [FeMV], canine distemper virus [CDV])

21.Feline Poxvirus Infections—Poxviruses (family Poxviridae, genus Orthopoxvirus)

22.Papillomavirus Infections—Papillomaviruses (family Papillomaviridae)

2.12.1 Diagnosis of viral diseases

On the basis of history clinical signs like hyper salivation, nervous signs in case of Rabies, hemorrhagic gastroenteritis in parvovirus infection.

For laboratory, diagnosis collection of samples from live animals (feces, nasal discharge, blood, etc.) and from a dead animal (affected organs) is very important. Various laboratory tests can be performed to aid in the diagnosis of viral infection.

Virus demonstration can be done with the use of various modern laboratory procedures:

●Detection of virus—by electron microscopy

●Detection of antigen—by FAT, IPT

●Detection of antibody—by ELISA

●Detection of nucleic acid—by RTPCR

Virus Isolation is also a very important part of diagnosis. It can be done with the help of cell lines which will be used according to the virus like purified chicken embryo cell lines, human diploid cells for rabies.

Detection of inclusion body (negri bodies in case of rabies virus infection, Bollinger bodies in case of pox virus infection, etc.) can be detected in affected tissue of a particular organ or organ system.

Serological tests like virus neutralization test and ELISA (Enzyme Linked Immuno Sorbent Assay) are used as an advanced diagnostic tool for the isolation and identification of viruses.

Management of viral diseases can be done with proper vaccination, the use of antiviral agents based on the detection of viruses along with symptomatic treatment.

2.13 Fungal disease of dogs and cats

Fungi are microorganism that infects animals as well as humans and cause disease conditions known as mycoses. Mycoses may be deep or superficial. Deep mycosis includes life-threatening systemic infection of fungi, subcutaneous mycosis, and endemic mycosis. Superficial mycosis includes skin and mucosal surface infection, e.g., Malassezia dermatitis. Fungi grow mainly in worms and moist areas of the body. Many fungal infections are resistant to commonly used antifungal drugs and are zoonotic in nature.

Some fungal infections which infect dog and cats are as follows:

1.Dermatophytosis—dermatophytic fungi, i.e., genera Microsporum and Trichophyton, e.g., Microsporum canis, Nannizzia gypsea or Microsporum gypseum, Trichophyton mentagrophytes

2.Malassezia Dermatitis—Malassezia pachydermatis (lipophilic yeast). It is normal mycobiota of canine and feline skin

3.Blastomycosis—Blastomyces dermatitidis, Blastomyces gilchristii, Blastomyces helices (dimorphic fungi)

4.Histoplasmosis—Histoplasma capsulatum (dimorphic fungi). Cats appear to be as susceptible as or slightly more susceptible to Histoplasmosis than dogs

5.Cryptococcosis (most common systemic mycosis of cats)—Cryptococcus neoformans, Cryptococcus gattii

6.Coccidioidomycosis—Coccidioides immitis, Coccidioides posadasii (dimorphic fungi)

7.Paracoccidioidomycosis—Paracoccidioides brasiliensis and Paracoccidioides lutzii

8.Sporotrichosis—Sporothrix schenckii

9.Candidiasis—Candida albicans (yeasts)

10.Rhodotorulosis—Rhodotorula spp.

11.Aspergillosis–Aspergillus fumigatus, Aspergillus niger, Aspergillus flavus

12.Pneumocystosis—Pneumocystis carinii

13.Rhinosporidiosis—Rhinosporidium seeberi

Diagnosis can be done on the basis of history and clinical signs like mycotic stomatitis in kittens in case of Candida albicans infection.

Detection of fungus can be done by sample collection by a skin scraping, direct microscopy, staining by Lactophenol cotton blue staining, woods lamp test in case of dermatophytosis (Microsporum canis—apple green color), isolation of fungus by its culture in Sabouraud dextrose agar which gives colony characteristics like white to cream shiny high convex heaving a pleasant berry smell in Candida.

Ringworm is a contagious skin infection caused by a fungus. It may be airborne or found in the soil. Ringworm causes hair loss, usually in a somewhat circular pattern, leaving the skin dry, raised, and crusty. Ringworm lesions are usually found first on the face, ears, or paws, but without treatment, they can cover the entire body. A veterinarian should diagnose ringworm and can prescribe proper topical and/or systemic medication.

Serological tests like AGID, counter immunoelectrophoresis, and molecular tests targeting 18s RNA, 26s RNA, and PCR are advanced diagnostic tools for the isolation and identification of different causative agents of fungal diseases in dogs and cats.

Management of fungal diseases can be done with the help of antifungal drugs after isolation and detection of fungus, regular changing and washing of clothing of animals, stopping sniffing of waste materials, and proper sanitation of surroundings.

2.14 Parasitic diseases of canine and feline

The parasite is defined as an organism that depends on another organism (i.e., host) and takes nutrition directly from the host. They are metazoans like helminths, arthropods, or protozoans like unicellular organisms.

Parasites can be classified into two types that are as follows:

●Endoparasite [internal parasite]—e.g., Dipylidium caninum [double-pore tapeworm of dog], Dirofilaria immitis [heartworm of dog], etc.

●Ectoparasite [external parasite]—Ctenocephalides canis [dog flea], Ctenocephalides felis [cat flea], Dermacentor variabillis [American dog tick], Rhipicephalus sanguineus [brown dog tick], etc.

Parasitic diseases are diseases caused by parasites infection or infestation. Parasitic diseases are major threats to the health of animals like poor growth, reduced weight and increased susceptibility to other infectious disease. Higher mortality in pups due to ancylostomiasis is an example of a fatal parasitic disease in dogs. Another important thing in the veterinary parasitology of canine and feline is the transmission of canine and feline parasites to and from humans which cause the disease known as zoonosis which has great concern. Example—hydatidosis, where the human is accidentally infected with a larval tapeworm when ingests an egg of Echinococcus granulosus from dog feces, and toxoplasmosis due to Toxoplasma gondii which is generally a parasite of cat but in humans it causes abortion.

2.14.1 Trematodes [fluke] diseases in dogs and cats

The most important trematode diseases of dogs are as follows:

●Fasciolosis—Fasciola hepatica [liver fluke]

●Dicrocoelium infection—D. dendriticum [lancet fluke or small liver fluke]

●Schistosomiosis—S. incognitum [blood fluke]

●Opisthorchis infection—Opisthorchis tenuicollis

●Oriental or Chinese liver fluke infection—Clonorchis sinensis

●Lung fluke infection—Paragonimus westermani

●Intestinal fluke infection—Echinochasmus perfoliatus

Trematodes diseases of cats:

●Fasciolosis—Fasciola hepatica [live fluke]

●Platynosomum infection—P. fastosum [liver and bile duct]

●Opisthorchis infection—Opisthorchis tenuicollis [cat liver fluke]

●Lung fluke infection—Paragonimus westermani

2.14.2 Cestodal [flatworm] diseases in dog

●Taeniasis—T. hydatigena, T. ovis, T. pisiformis, T. krabbei, T. multiceps, T. serialis

●Echinococcosis—Echinococcus granulosus

●Dipylidium infection—Dipylidium caninum (double-pore tapeworm of dog)

●Diphyllobothrium infection—D. latum [absorb vitamin B12 and cause pernicious anemia]

●Spirometra infection—Spirometra mansoni [zoonotic parasite]

Flatworm infection in cat:

●Taenia infection—Taenia taeniaeformis

●Diphyllobothrium infection

●Spirometra infection

2.14.3 Nematodes [roundworm] infection in dog

●Toxocara infection—T. canis [arrow-headed worm] in human Toxocara canis larva cause visceral larva migrans [VLM]

●Strongyloides infection—S. stecoralis [thread worm]

●Ancylostomiasis [hookworm of dog]—Ancylostoma caninum [each parasite sucks 0.1 mL blood/day and causes microcytic hypochromic anemia]. Cutaneous larva migrans [CLM] in man caused by the larva of ancylostoma.

●Lungworm infection—Filariodes osleri [hemorrhagic wart-like lesion at the bifurcation of trachea]

●Eye worm infection—Thelazia callipaeda [conjunctival and lacrimal sac affected]

●Spirocercosis—Spirocerca lupi [oesophageal tumor worm]

●Stomach worm infection—Ganathostoma spinigerum

●Heartworm infection—Dirofilaria immitis [venacaval syndrome]

●Whipworm infection—Trichuris vulpis [large intestine affected]

●Kidney worm infection—Dictoyphyma renale [damage kidney parenchyma]

Nematodes [roundworm] in cat:

●Toxocara infection—T. felis

●Stomach worm infection—Physaloptera praeputialis, Gnathostoma spinigerum

●Eyeworm infection—Thelazia sp.

2.14.4 Arthopodes infestation [external parasite] in dogs and cats

Arthopodes [insecta + acarins] act as intermediate host or vector also. Example—Dirofilaria immitis [heartworm of dog] have an intermediate host, i.e., mosquitoes [anopheles, ades, and culex], in case of Spirocerca lupi infection beetle acts as intermediate host in case of Dipylidium caninum [double-pore tapeworm of dog] intermediate host is flea [Ctenocephalides canis in dog and in case of feline is Ctenocephalides felis] and also lice [Trichodectes canis].

They also can act as vector like tabanus, haematopata fly, haematobia and other flies act as vector for Trypanosoma evansi infection in the dog.

External parasites are bugs (insects) that live on the outside of a cat’s body and include fleas, ticks, lice, and mites. They cause irritation and may transmit some diseases to other cats. Careful skin examination by a veterinarian can detect these parasites.

Fleas are the most common external parasite of cats. Fleas and flea dirt are readily seen in a cat’s hair coat. Flea control should be implemented at the earliest sign of flea infestation because fleas multiply rapidly and a small problem becomes a major one in a short time.

Ticks are most prevalent in early spring and most commonly found on outdoor cats that get into the underbrush and wooded areas. Ticks can transmit several diseases (including Rocky Mountain Spotted Fever) and should be removed with care. Grasp the tick near its head with a pair of tweezers and pull it away from the skin with a firm tug.

Lice are small, light-colored parasites that are transmitted from cat to cat and can be seen at the base of the hair. Signs of lice infestation (pediculosis) are a rough and dry haircoat, matted hair, and scratching and biting of the skin. Lice are effectively controlled with a variety of chemicals available from a veterinarian.

Ear mites are easily transmitted from cat to cat and dog to cat. Signs of infestations are head shaking and scratching at the ears. If untreated, ear mites predispose the ear to secondary bacterial infection. Treatment requires having a veterinarian clean the ear and use miticidal drugs.

Some other important external parasites of dogs and cats are as follows:

●Blood-sucking parasite—like tick [Rhipicephalus sanguineus]

●Skin myiasis [maggoted wound]

●Demodicosis—Demodex canis [follicle mite] and in pure breed, cats have Demodex cati

●Pnemonyssus caninum [mite which is affect nasal passage and sinuses of dogs]

●Scabies—Sarcoptes canis [burrowing mite]

●Notoedres cati mite infestation in main cats

●Otodectes cynotis [ear mange] found in dog and cat

●Linguatula serrata [tongue worm]—dog definitive host

Diagnosis of parasite infection is based on anamnesis (age, sex, breed and duration of illness), clinical sign [example—dragging of the anus in Dipylidium caninum infection, spectacle eye in demodicosis], urine examination [e.g., finding eggs of Dioctophyma renale], sputum examination [for eggs of Paragonimus westermani], milk examination [migrating larvae of Toxocara canis, Ancylostoma caninum], fecal examination, etc.

A fecal examination is done to detect the various stages of parasites in the feces of affected animals. Fecal examination is of two types, i.e., Qualitative examination and quantitative examination.

The qualitative examination includes the direct smear method, floatation method [for nematodes egg mainly], and sedimentation method [for trematodes egg mainly]. The quantitative examination method includes the McMaster egg counting technique [to determine the severity of infection] and Stoll’s technique.

Other diagnostic methods are skin scrapping examination [for Demodex mange, sarcoptes mange], examination of blood (thin or thick blood smear for blood protozoa), Knott’s technique for detection of microfilariae [example—microfilaria of Dirofilaria immitis], biopsy [example—for detection of visceral leishmaniosis], and immunologic and molecular parasite diagnosis.

Management of parasite

●Chemical control:

●Chemotherapy—example in babesiosis diminazene aceturate use, pyrantel pamoate in ancylostomosis, etc.

●Chemoprophylaxis—follow deworming schedule in dogs and cats

●Chemo-immunoprophylaxis

●Immunological control—vaccines

Example—Ancylostoma caninum immunize with third larvae that have been attenuated with ionizing radiation.

●Intermediate host or vector control:

●Chemical control—use insecticide and acaricide like malathion, deltamethrin, lindane, etc.

●Biological control—use Gumbusia fishes for mosquitoes control, hymenopterans fly for ticks control, and bacteria Bacillus thuriengiensis for mosquitoes control.

●Mechanical control—intermediate host/vector like ticks, lice, etc., are collected manually and killed by using the hard objects.

2.15 Protozoal diseases of dogs and cats

Protozoa are unicellular eukaryotes microscopic organisms. They have well-defined nuclei as well as other cell organelles. They may be free-living or parasitic. Many protozoa are transmitted by vector. With the help of advanced techniques, we find many new species and strains of pathogenic protozoa. Parasitic protozoa are the cause of important zoonotic diseases of dogs and cats worldwide, such as toxoplasmosis, leishmaniosis, giardiasis, and cryptosporidiosis.

Some protozoal diseases of dogs and cats are as follows:

●Toxoplasmosis—Toxoplasma gondii (Cats are the definitive host and are the only species known to complete the sexual phase of T. gondii)

●Neosporosis—Neospora caninum (Dogs are the definitive hosts)

●Sarcocystosis—Sarcocystis felis, Sarcocystis canis, Sarcocystis caninum, and Sarcocystis neurona

●Leishmaniosis (cutaneous and visceral leishmaniosis)—Leishmania chagasi, Leishmania infantum

●Giardiasis—Giardia lambia, Giardia canis, Giardia cati, Giardia duodenalis

●Trichomonosis—Tritrichomonas foetus or Tritrichomonas blagburni

●Cryptosporidiosis—Cryptosporidium canis, Cryptosporidium felis, Cryptosporidium parvum

●Cyclosporiasis—Cyclospora cayetanensis

●Cystoisosporiasis—Cats are the definitive hosts for Cystoisospora felis and Cystoisospora rivolta, Cystoisospora canis, Cystoisospora ohioensis, Cystoisospora neorivolta, and Cystoisospora burrowsi are described in dogs

●Rangeliosis—Rangelia vitalii (dogs)

●Amebiasis:

Nonenteric (Free-Living)—Acanthamoeba, Balamuthia, and Naegleria

Gastrointestinal Amebiasis and Balantidiasis—Entamoeba and Balantidium

Diagnosis is mainly based on clinical signs like severe diarrhea with blood and mucous along with abdominal pain and tenesmus in case of invasive amoebiosis. Chronic diarrhea and steatorrhea in puppies and kittens in case of giardiasis. On microscopic examination of meat sample in trichinella (trichinoscopy), fecal examination—trophozoites and cysts are found ex. Monkey face-like trophozoites with falling leaf motility in saline mount and cyst in iodine mount in case of giardia infection.

The staining technique is also helpful in the diagnosis of protozoa ex. In Iodine, wet-mount cysts of Acanthamoeba appear yellowish brown. Modified Ziehl-Neelsen staining of oocytes of cryptosporidium looks pinkish red color.

Isolation or culture ex. NNN (novy-mac Neak Nicolle) media is biphasic media for Leishmania, Diamond media in case of giardiasis, etc.

Serological diagnostic tests like antigen detection ex. Copro antigen by ELISA in giardia, Sabin-Feldman dye test in case of toxoplasma. Indirect fluorescent antibody test, direct agglutination test for neospora caninum. Delayed hypersensitivity test, Montenegro test for leismaniosis. Molecular diagnosis is done with the help of specific DNA sequence and PCR.

2.15.1 Haemoprotozoal diseases of dogs and cats

There are a wide range of protozoal parasites present in the blood of cats and dogs which are transmitted with the help of vectors ex. tabenus fly and ticks (riphicephalus, dermacentaer). These protozoa may be extracellular ex. Trypanosoma or intracellular ex. Babesia. Haemoprotozoa shows severe systemic illness in acute or chronic forms.

●Ehrlichiosis—Ehrlichia canis (canine monocytic ehrlichiosis), Ehrlichia ewingii (canine granulocytic ehrlichiosis)

●Anaplasmosis—Anaplasma phagocytophilum (granulocytic anaplasmosis), Anaplasma platys (thrombocytotropic anaplasmosis)

●Haemobartonella infection—Haemobartonella canis, Haemobartonella felis

●Babesiosis—Babesia canis (large protozoa), Babesia gibsoni (small protozoa)

●Trypanosomosis—Trypanosoma evansi

Diagnosis on the basis of clinical signs and history makes on owners complaints as ticks are present on the body of the patient and the patient shows clinical signs like hemoglobinuria in babesia, generalized lymph adenopathy in ehrlichiosis. Laboratory diagnosis based on complete blood count shows anemia and thrombocytopenia in ehrlichiosis. The blood smear shows an extracellular parasite in case of trypanosoma infection, an intracellular parasite found in RBC ex. Babesia and Haemobartonella, in neutrophils ex. Ehrlichia ewingii, in monocyte ex. Ehrlichia canis, in platelates ex. Anaplasma platys, buffy coat smear examination ex. trypsanosoma.

Serological diagnosis includes complement fixation test, ELISA, countercurrent immunoelectrophoresis in babesia, and IFAT in case of Ehrlichia infection. Various commercial kits are available (4Dx test) for the diagnosis of Lyme disease, ehrlichiosis, anaplasmosis, and heartworm diseases. Molecular diagnosis is based on the identification of specific DNA sequence of the pathogen ex. BcMSA1 and BcSA1 in case of babsia infection, and sequence analysis of 16SrRNA in Ehrlichia.

For the therapeutic management of haemoprotozoal diseases in dogs and cats, specific drugs are available for particular haemoprotozoal infections like doxycyclin for ehrlichiosis, diminazine aceturate for babesiosis, etc. Repell tick by use of a tick collar, use of acaricidal agents like amitraz, deltamethrin, and removal of ectoparasite with the help of drugs like Avermectins (Ivermectin or doramectin) or Sarolaner, flunalaner, or Afoxolaner can also help.

2.16 Hereditary diseases in dogs and cats

The most common hereditary diseases in dogs are hip dysplasia, hypothyroidism, diabetes mellitus, progressive retinal atrophy, entropion, ectropion, cataract, cryptorchid male, overshot, undershot jaw, wry mouth, missing teeth, allergic skin disease, and night blindness. Dogs affected by genetic disorders should not be selected for breeding. In dogs with hip dysplasia, the ball and socket do not fit or develop properly, and they rub and grind instead of sliding smoothly. It is hereditary and is especially common in larger dogs, like the Great Dane,