Key Questions in Clinical Farm Animal Medicine, Volume 3: Therapy, Prevention and Control of Disease

By Manoj Kumar Ahirwar, D Sai Bhavani, P Rama Devi and 14 more

Providing well over 1,500 questions to test your knowledge of clinical farm animal medicine, the book has been produced in a convenient format so that it can be used at any time in any place. Each chapter starts with a brief introduction to the topic before providing relevant multiple-choice questions.
Covering clinical veterinary medicine for common livestock species, this book includes questions about:
- diseases of the haemolymphatic and immune system;
- metabolic, genetic, neonatal and deficiency diseases;
- poisoning.
Including a full chapter covering emergency and critical care, this self-test resource for students provides a convenient and useful current source of information to anyone interested in learning, revising and assessing their knowledge.

• Language: English
• Publisher: CAB International
• Release date: Dec 27, 2023
• ISBN: 9781800624849

Book preview

1Diseases of the Hemolymphatic and Immune System

G.S. Haritha and P. Ramesh

Introduction

The haemolymphatic system includes diseases of the haematologic, immunologic and lymphatic systems of cattle, sheep, goats, camels and horses. It consists of the blood (i.e. plasma and formed elements) and the bone marrow. Other organs such as the liver and kidneys also perform specific functions in relation to haemopoiesis. The lymphatic system consists of the lymphatic vessels and lymphatic tissues/organs (spleen and thymus). Abnormalities in plasma proteins, disorders of the haemopoietic system – abnormalities of RBCs, WBCs, diseases causing haemorrhage, purpura haemorrhagica and lymphadenopathy, diseases of the spleen and thymus, and immune deficiency disorders – are considered as the basis for questions in this chapter.

The haematologic system has three general functions: transportation, regulation and defence. These functions involve removal of haematologic waste products, delivery of nutrients and oxygen to cells, blood volume regulation, blood cell and antibody production, and blood coagulation. Haematopoiesis is the formation of blood cells, originating in stem cells in red bone marrow. Blood is composed of plasma and formed elements, including RBCs, WBCs and platelets. Plasma is made up of 90% water. The remaining 10% is composed of proteins, salts, nutrients, wastes, gases, hormones and enzymes. Erythrocytes, or RBCs, are the most numerous of the blood cells. Each RBC contains haemoglobin, which is responsible for carrying oxygen. Extravascular and intravascular haemolysis accounts for most blood loss (apart from immune mediated blood loss) leading to anaemia.

WBCs fight infection and are the first line of defence. Granulocytes (neutrophils, basophils and eosinophils) and agranulocytes (lymphocytes and monocytes) have different mechanisms to combat invaders. Neutrophilia is the most common finding in acute infections and in bacterial or fungal infections, whereas eosinophilia is evident in allergic or parasitic infections. Lymphocytes regulate the immune system. T lymphocytes (T cells) are responsible for cell-mediated immunity and B lymphocytes (B cells) are responsible for antibody production. Monocytosis can be seen in any inflammatory condition. Platelets and numerous clotting factors must react in sequence before clotting of blood can occur. Any variation will result in disorders of the haemopoietic system.

The lymphatic system is essential for providing specific and non-specific immune response mechanisms through the production of lymphocytes (agranulocytes) and antibodies. It also returns any excess proteins that may escape from the blood vessels to the systemic circulation, and filters the blood. The lymphatic organs include the spleen, thymus, peyers patches and lymph nodes. The primary lymphoid organs (thymus and peyers patches) activate the T and B cells to produce antibodies, whereas the secondary lymphoid organs trap and process antigens and mature lymphocytes that mediate immune response. These organs enlarge in size in response to antigenic stimulation. The lymph nodes are small bean-shaped structures located along the lymphatic vessels and are found throughout the body. They provide clues regarding the health of the animal. For example, the mandibular, prescapular, prefemoral and supramammary lymph nodes are normally palpable. The parotid, pharyngeal, cervical and inguinal lymph nodes are palpable when enlarged. Mesenteric lymph nodes are palpable when enlarged by rectal examination.

Multiple Choice Questions

Which vitamin is anti-haemorrhagic?

Vitamin K

Vitamin A

Vitamin E

Vitamin C

In erythropoiesis, the rate of production is controlled by which hormone?

Insulin

Parathormone

Erythropoietin

Prostaglandins

The largest lymphoid organ is the:

Thymus

Spleen

Lymph node

Peyers patches

Which ligament is responsible for colic in horses?

Gastrophrenic

Falciform

Hepatogastric

Nephrosplenic

The largest lymph node in the head is the:

Retropharyngeal

Mandibular

Parotid

Hyoid

The control organ of the immune and lymphatic systems in juvenile farm animals is the:

Thymus

Spleen

Tonsils

GLT

Anaemia may be regenerative, indicating the bone marrow is responding and attempting to replace red blood cells (RBCs), or nonregenerative, in which the bone marrow response is not able to meet the increased need for RBCs. Which of the following CBC findings is consistent with nonregenerative anaemia?

Macrocytosis

Normochromic

Nucleated RBCs

Polychromasia

Haemolytic anaemia is typically regenerative and results from loss of RBCs not due to bleeding. It is due to factors that accelerate RBC destruction. Which of the following is the most common primary mechanism of haemolytic anaemia in cattle?

Immune-mediated

Infection

Neoplasia

Toxins

Nonregenerative anaemias tend to be secondary to a chronic disease process that reduces RBC production or renders RBC production ineffective in meeting the need for RBC replacement. Which of the following chronic diseases is not associated with nonregenerative anaemia?

Chronic blood loss

Chronic liver disease

Chronic renal disease

Nutritional deficiencies

Sheep and goats affected by caseous lymphadenitis exhibit abscesses near the peripheral lymph nodes (external form). Abscesses can also form in the internal lymph nodes or organs (internal form). Which of the following is the causative agent of caseous lymphadenitis in sheep and goats?

Brucella melitensis

Corynebacterium pseudotuberculosis

Fusobacterium necrophorum

Pasteurella multocida

Which of the following RBC conditions does not cause anaemia?

Decreased production of RBCs

Loss of RBCs through bleeding

Phagocytosis of ageing RBCs in the spleen

Shortened lifespan of RBCs

Antibody molecules, called immunoglobulins, fall into several classes and serve different functions in the humoral immune system. Which of the following statements about immunoglobulins and their roles is correct?

IgA is the principal antibody type secreted by the intestines

IgE is the principal antibody in circulation

IgG is the first antibody formed in response to a new antigen

IgM is the principal antibody type found in respiratory secretions

Erythropoiesis (red blood cell production) is regulated by erythropoietin. Which of the following chronic diseases is most likely to lead to anaemia caused by decreased erythropoietin production?

Chronic bronchitis

Chronic hepatitis

Chronic pancreatitis

Chronic renal failure

In all animals, congenital heart defects can cause abnormal shunting of blood. Left-to-right shunts cause blood to be recirculated through the pulmonary vessels and can result in chamber dilatation. Right-to-left shunts cause blood to bypass the pulmonary vessels and can cause cyanosis. Which of the following conditions is most likely to result in a right-to-left heart shunt?

Patent ductus arteriosus (PDA)

Ventricular septal defect (VSD)

Patent foramen ovale

Tetralogy of Fallot

Without intervention, susceptible cattle raised in regions at high altitudes can develop right ventricular cardiac failure secondary to pulmonary hypertension. Which of the following clinical signs is least likely to occur in cattle with bovine high-mountain disease?

Oedema of the brisket region (ventral parasternal muscles)

Ventral abdominal distension due to ascites

Coughing

Exophthalmos

Heart sounds are associated with valve closure. They occur because of the rapid changes in the speed of blood flow and vibrations throughout the heart, valves and cardiac blood. There are four heart sounds that can potentially be auscultated, but they are not normally heard in all species. All four heart sounds are most likely to be heard in healthy animals of which of the following species?

Cats

Dogs

Horses

All of these

Complete blood counts typically report the percentage of each type of blood cell, the absolute numbers of each type of blood cell, morphologic abnormalities and unusual cells. Which of these parameters is most important for a meaningful interpretation of the leukogram?

Absolute numbers of cell types

Morphologic abnormalities

Percentage of cell types

Unusual cells

There are five types of white blood cell found in varying numbers in circulation. These cells can be divided into two groups, granulocytes and agranulocytes. Which of the following is the rarest type of granulocyte?

Basophil

Eosinophil

Lymphocyte

Monocyte

Complete blood counts typically report several parameters for erythrocytes. Which one of the following CBC components is calculated instead of directly measured?

Haemoglobin concentration

Mean corpuscular volume (MCV)

Number of RBCs per a specific volume

Packed cell volume (PCV)

The mean corpuscular haemoglobin concentration (MCHC) is a value calculated by dividing the haemoglobin concentration by the packed cell volume (PCV). Some abnormal MCHC values are due to artefacts caused by which of the following conditions?

Autoagglutination

Collection tube overfilled

Fresh blood analysed

Haemolysis

A characteristic feature of anaemia due to cobalt deficiency in cattle is:

Microcytic hypochromic anaemia

Macrocytic hypochromic anaemia

Normocytic hypochromic anaemia

Normocytic normochromic anaemia

A characteristic feature of anaemia due to iron deficiency in pigs is:

Microcytic hypochromic anaemia

Macrocytic hypochromic anaemia

Normocytic hypochromic anaemia

Normocytic normochromic anaemia

Deficiency of iron causes what in calves?

Microcytic hypochromic anaemia

Macrocytic hypochromic anaemia

Microcytic normochromic anaemia

Macrocytic normochromic anaemia

A characteristic feature of anaemia due to copper deficiency in cattle is:

Microcytic hypochromic anaemia

Macrocytic hypochromic anaemia

Normocytic hypochromic anaemia

Normocytic normochromic anaemia

A haemolytic crisis is associated with which type of poisoning?

Arsenic

Mercury

Copper

Lead

Epinephrine controls haemorrhage by which action?

Vasodilation

Vasoconstriction

a and b

None of these

Induration of the udder with enlargement of the supramammary lymph node occur in:

Tubercular mastitis

Staphylococcal mastitis

Mycoplasmal mastitis

Leptospiral mastitis

‘Koch blue bodies’ are:

Piroplasms of the Theileria annulata in RBC

Schizonts of the Theileria annulata in RBC

Piroplasms of the Theileria annulata in lymphocytes

Schizonts of the Theileria annulata in lymphocytes

An onion skin appearance to a cross section of caseated mass in a lymph node is noticed in:

Caseous lymphadenitis of sheep

Ulcerative lymphangitis

a and b

None of these

Stress or exogenous ACTH administration leads to:

Eosinopenia

Eosinophilia

Lymphocytosis

Monocytosis

The state of shift to the left upon haematology denotes all of these except:

Bacterial infections

Inflammation

Increase in immature neutrophils

Increase in immature lymphocytes

Which drug prevents platelet aggregation?

Epinephrine

Aspirin

Diazepam

Phenyl butazone

Which is the most abundant leukocyte type in bovines?

Lymphocytes

Neutrophils

Eoisnophils

Monocytes

Which blood cells contain granules toxic to parasites?

Lymphocytes

Neutrophils

Eoisnophils

Monocytes

T-cell maturation occurs in the:

Spleen

Lymph node

Thymus

GLT

The RBCs are smaller in which species?

Cattle

Goats

Horses

Camels

Which of these statements is true about camel RBCs?

Oval, can expand up to 240% of volume, non-nucleated

Round, can expand up to 150% of volume, non-nucleated

Oval, can expand up to 240% of volume, nucleated

Round and nucleated

Which type of anaemia lacks functional bone marrow?

Myelophthisic

Aplastic

Iron deficiency

Vitamin B12 deficiency

A Rouleaux formation is seen in:

Cattle

Sheep

Horses

Pigs

What is essential for maturation of RBC?

Copper and cobalt

Vitamin B12 and cobalt

Folic acid and copper

Vitamin B12 and folic acid

In blood smear examinations, shift to left is an increase in the number of immature neutrophils, and characteristic of:

Bacterial infections

Allergic reactions

Parasitic infestation

All of these

Which type of immunity is provided by T-lymphocytes and B-lymphocytes, respectively?

Humoral and cellular

Cellular and humoral

Both cellular

Both humoral

The ideal anticoagulant for the estimation of blood glucose levels is:

EDTA

Heparin

Sodium fluoride

All of these

Number of blood groups present in horses are:

7 groups

8 groups

11 groups

13 groups

The greatest percentage of blood volume is found in the:

Heart

Capillaries

Distributing arteries and arterioles

Venules and veins

Which of the following would not contribute to local haemostasis?

Exposure of platelets to collagen

Conversion of prothrombin to thrombin

Conversion of plasminogen to plasmin

Release of thromboxane A2

Following loss of blood, the least likely event is an increase in:

Heart rate

Sympathetic activity

Stroke volume

Total peripheral resistance

Thrombocytopenia is a reduction in the number of circulating blood platelets. Which of the following would most likely occur in thrombocytopenia?

Decreased vascular permeability

Failure of initiation of blood clotting cascade

Failure of conversion of fibrinogen to fibrin

Absence of plasmin

Which of these is an extracellular parasite?

Babesia

Trypanosoma

Theileria

Anaplasma

Amyloid degeneration is most commonly seen in:

Cattle

Pigs

Sheep

Horses

Which is a feature of viral inflammation?

Suppuration

Presence of neutrophils

Presence of lymphocytes

All of these

Which of the following cells does not produce any endogenous pyrogen?

Lymphocytes and macrophages

Neutrophils

Monocytes

Lymphocyte and eosinophils

Thrombosis of the spleen is seen in:

Strangles

Glanders

Swine fever

Infectious bovine rhinotracheitis

Which of the following regarding piglet anaemia is correct?

It occurs in baby pigs which are reared on soil rich in Fe

It is macrocytic hypochromic type of anaemia

Piglets reared on cement floors easily fulfil their Fe requirement

It is a microcytic hypochromic type of anaemia

Poikilocytosis means:

Variation in the shape of RBCs

Variation in size of RBCs

Variation in number of RBCs

None of these

Porphyria is most commonly seen in:

Cattle and swine

Sheep and goats

Laboratory animals

Horses and dogs

Erythrocytes that have a narrow rim of haemoglobin surrounding a large pale area are known as:

Cabot rings

Anisocytosis

Annulocytes

Leptocytes

Lymphadenitis is inflammation of:

The lymph node

The lymph vessel

a and b

None of these

Abnormal notching of the erythrocytes is known as:

Crenation

Pessary cells

Cabot rings

Basophilic stippling

Refractile inclusions found in the RBCs of horses that undergo phenothiazine therapy are called:

Howell-Jolly bodies

Annulocytes

Drepanocytes

Heinz bodies

Anaemia due to failure of erythrocyte maturation is called:

Dyshaemopoietic anaemia

Macrocytic hypochromic anaemia

Aplastic anaemia

Haemolytic anaemia

Anaemia due to replacement of bone marrow by other tissues is called:

Dyshaemopoietic anaemia

Macrocytic hypochromic anaemia

Aplastic anaemia

Myelophthisic anaemia

Acute haemorrhagic anaemia is caused by:

Anaplasmosis

Snake venom

Deficiency of folic acid

Sweet clover toxicity

Which of the following pair is correctly matched?

Excess onion – haemorrhagic anaemia

Aplastic anaemia – ionising radiation

Deficiency of folic acid – microcytic anaemia

Deficiency of iron – macrocytic anaemia

The active toxic principle in onions which causes anaemia is:

N propyl disulphide

Ricin

a and b

None of these

In haemorrhagic anaemia, the type of anaemia will be:

Macrocytic normochromic

Microcytic hypochromic

Normocytic normochromic

Microcytic normochromic

Granulomatous lymphadenitis with caseation and calcification occurs in all of the following except:

Tuberculosis

Glanders

Johne’s disease

Strangles

Excessive phagocytic activity