Medical, Genetic and Behavioral Risk Factors of the Toy Breeds

By Ross D. Clark DVM

This book (Toy Group) provides you with the thorough descriptions and positive attributes of these breeds, including origin, purpose, history, normal heights and weights, acceptable colors, and behavioral traits. Our books differ from most books on dog breeds because this book also provides you with a comprehensive and authoritative source of all the known, predisposed hereditary health syndromes for these breeds. You will find extensive references for each problem described. We also provide the breed club address for these breeds and a list of laboratories and organizations that can provide professional help and information.

As a small-animal veterinarian, I have always been intrigued by the way dogs have been bred to fill a purpose in life, and I am further impressed that they also tend to love performing that service. Greyhounds and other sight hounds are built for speed, with aerodynamic bodies consisting of a small head, deep chest, narrow waist, and large leg muscles. On the other hand, dachshunds take their name from German words meaning badger dog, and they use their long nose, long body, and short legs to both track, enter, and dig into badger dens.

After developing a practice that catered to clients with show dogs, my interest in each breed continued to grow as I studied and observed more and more about the unique predisposition and incidence of health problems in each breed. Breeders of purebred dogs for show were a challenge and inspiration for me to research and help them with their unique health problems. Historically, references to hereditary problems are scattered throughout various veterinary medical texts and journals, such as ophthalmology, neurology, gastroenterology, cardiovascular, and dermatology. This book, as well as the other books and articles I have written, has been researched and compiled with the intention to provide both veterinarians and dog owners with comprehensive and authoritative predisposed information under the breed name.

At the date of this publication, the American Kennel Club, Canine Health Foundation, and the Kennel Club of England report over four hundred known hereditary health syndromes throughout the dog kingdom. During the writing of my first book in 1983, less than fifty hereditary issues were able to be predicted or diagnosed. Sequencing of the canine genome; DNA tests; metabolic testing, including blood tests and urine testing; and phenotypic examinations, such as radiographs, ultrasound, and CERF or OFA eye registry exams by a board-certified veterinary ophthalmologist have advanced the science of breed-related health and behavioral problems.

This book will provide veterinarians, researchers, pet owners, and breeders with a comprehensive guide to all the known problems veterinarians and dog owners should consider during pet selection and throughout each life stage of our canine friends.

• Language: English
• Publisher: Xlibris US
• Release date: Jul 28, 2017
• ISBN: 9781524585044

Ross D. Clark DVM

Ross D. Clark, DVM is the founder of Woodland PetCare Centers and a cofounder of National PetCare Centers. He received his doctor of veterinary medicine degree in 1963 from Kansas State University. He is practice management editor for Veterinary Economics Magazine and served as president of the Tulsa County Veterinary Medical Association, the Oklahoma Veterinary Medical Association, and also as president of the Western Veterinary Conference—the world’s largest continuing education conference for veterinarians. American Animal Hospital Association named him Outstanding Practitioner for the Western Region in 1987 and National Merit Award Winner in Toronto, Ontario, Canada, in 1991. Veterinary Partners Incorporated, an organization of veterinarians, lawyers, and accountants that do practice management consulting, recognized Dr. Clark with their prestigious Pioneer Award at the Western Veterinary Conference in 2004. He served two terms as president of Kansas State University Veterinary Medical Alumni Association from 1990 to 1992, and Kansas State University named him an alumni fellow in February of 2003. Over the past forty-five years, Dr. Clark and his partners have cared for show dogs from most states in the United States of America, plus show dogs from Canada, Mexico, and Spain. He is the author of eight books, including Medical, Genetic, and Behavioral Aspects of Purebred Cats and the coauthor of the first and second edition of Medical and Genetic Aspects of Purebred Dogs. He is also author of four management books: first, a practice management manual; second, The Best of Ross Clark; third, Mastering the Marketplace—Taking Your Practice to the Top; and his latest book, Open Book Management for Veterinary Hospital Teams. He has toured throughout the world as a practice management lecturer and consultant. In addition, Dr. Clark has been a Veterinary Economics “Hospital of the Year” judge for over twenty-eight years. Dr. Clark is currently owner and managing partner of four small animal practices and three pet resorts in Oklahoma. Dr. Clark and his team have been doing veterinary practice management consultation, seminars, and appraisals since 1981. Ross is married to Linda Clark, and they have two children, twins Kent and Kimberly Clark.

Book preview

MEDICAL, GENETIC

& BEHAVIORAL RISK

FACTORS OF THE

TOY BREEDS

BY: ROSS D. CLARK, DVM

H. DAVID HAYNES, DVM – LEAD RESEARCH

AND EDITORIAL ASSISTANT

ART J. QUINN, DVM, DACVO – PROFESSOR EMERITUS,

OKLAHOMA STATE UNIVERSITY CENTER

FOR VETERINARY HEALTH SCIENCES

BRAD HOWARD, DVM – RESEARCH ASSISTANT

PAUL SCHMITZ, DVM – TECHNICAL ASSISTANT

JAN COODY, MBA – TECHNICAL ASSISTANT

NITA RITSCHEL – EXECUTIVE ASSISTANT

GERI HIBBLEN JACKSON – PHOTO ACQUISITIONS

LINDA A. CLARK, RVT, AKC JUDGE – PHOTO ACQUISITIONS

Copyright © 2017 by ROSS D. CLARK, DVM. 743866

Library of Congress Control Number: 2017902569

All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the copyright owner.

This is a work of fiction. Names, characters, places and incidents either are the product of the author’s imagination or are used fictitiously, and any resemblance to any actual persons, living or dead, events, or locales is entirely coincidental.

Rev. date: 07/28/2017

Xlibris

1-888-795-4274

www.Xlibris.com

TABLE OF CONTENTS

AFFENPINSCHER

BRUSSELS GRIFFON

CAVALIER KING CHARLES SPANIEL

CHIHUAHUAS

CHINESE CRESTED

ENGLISH TOY SPANIEL

HAVANESE

ITALIAN GREYHOUND

JAPANESE CHIN

MALTESE

MANCHESTER TERRIER

MINIATURE PINSCHER

PAPILLONS

PEKINGESE

POMERANIAN

POODLES – MINIATURE & TOY

PUGS

SHIH TZU

SILKY TERRIER

TOY FOX TERRIER

YORKSHIRE TERRIER

MEDICAL, GENETIC & BEHAVIORAL

RISK FACTORS OF THE TOY BREEDS

CHAPTER CONTENTS:

I. ORIGIN AND HISTORY

II. DESCRIPTION

III. SHOW RING REQUIREMENTS

IV. RECOGNIZED RISK FACTORS IN TOY DOGS

CARDIOVASCULAR-HEMATOLOGICAL-RESPIRATORY

DERMATOLOGICAL

ENDOCRINE-EXOCRINE-ENZYMATIC

DENTITION

MUSCULOSKELETAL

NEUROLOGIC

OPHTHALMIC

UROGENITAL

BEHAVIOR

OLD AGE

V. MISCELLANEOUS FACTS AND RESOURCES

GENETIC TESTS AVAILABLE

CHIC REQUIREMENTS

NATIONAL BREED CLUB AND WEBSITE

BY: ROSS D. CLARK, DVM

PREFACE

This book provides you with a through description and positive attributes of these breeds including origin, purpose, history, normal heights and weights, acceptable colors and behavioral traits. Our books differ from most books on dog breeds because this book also provides you with a comprehensive and authoritative source of all the known predisposed hereditary health syndromes for the breed. You will find extensive references for each problem described. We also provide the breed club address for this breed and a list of laboratories and organizations that can provide professional help and information.

As a small animal veterinarian, I have always been intrigued by the way dogs have been bred to fill a purpose in life and further impressed that they also tend to love performing that service. Greyhounds and other sight hounds are built for speed with aerodynamic bodies consisting of small head, deep chest, narrow waist and large leg muscles. On the other hand Dachshunds take their name from German words meaning badger dog and they use their long nose, long body and short legs to both track, enter and dig into badger dens.

After developing a practice that catered to clients with show dogs, my interest in each breed continued to grow as I studied and observed more and more about the unique predisposition and incidence of health problems in each breed. Breeders of purebred dogs for show were a challenge and inspirational for me to research and help them with their unique health problems. Historically references to hereditary problems are scattered throughout various Veterinary medical texts and journals such as ophthalmology, neurology, gastroenterology, cardiovascular and dermatology. This book, as well as the other books and articles I have written, is researched and compiled with the intention to provide both veterinarians and dog owners with comprehensive and authoritative predisposition information under the breed name.

At the date of this publication, The American Kennel Club Canine Health Foundation and the The Kennel Club of England reports over 400 known hereditary health syndromes throughout the dog kingdom. At the writing of my first book in 1983, less than 50 hereditary issues are able to be predicted and or diagnosed. Sequencing of the canine genome, DNA tests, metabolic testing including blood tests and urine testing; plus, phenotypic examinations such as radiographs, ultrasound, and CERF or OFA eye registry exams by a Board Certified Veterinary Ophthalmologist have advanced the science of breed related health and behavioral problems.

This book will provide veterinarians, researchers, pet owners and breeders with a comprehensive guide to all the known problems veterinarians and dog owners should consider during pet selection and throughout each life stage of our canine friends.

NOTE

The fact that a breed shows many disorders may be more an indication of the extensive research done on that breed than on its comparative soundness of the breed.

Many genetic disorders are common to several breeds. We do not intend to convey severity of incidence by the length of text within a particular breed chapter. One breed may have forty percent incidence and another breed only four percent. If a thorough study has been done to indicate the percentage of incidence, we make note of it; however, please keep in mind the incidence is only an indicator of the dogs tested. A breed for instance may show eighteen percent incidence of hip dysplasia as indicated by OFA, although breeders and veterinarians may not elect to submit radiographs of hips so severely dysplastic that the owners and their veterinarians know that there is zero chance to be rated as OFA normal.

Please be aware that we have included and identified anecdotal information, defined by Merriam Webster’s dictionary as unscientific observation; however, the observations of breeders and veterinarians with a special interest in the breed will hopefully be converted to scientific research, often underwritten by breed clubs, to confirm or rule out predisposition to breed problems.

You will note that each chapter is thoroughly referenced to help with the reader’s research as well as to credit and appreciate the researchers, writers, and breeders that have helped the animal world and mankind by their work with these genetic disorders.

Ross D. Clark, D.V.M.

AFFENPINSCHER

007_a_reigun.tif

Ch La Bama

Owner/Photographer: Vickie Ehrlekrona

ORIGIN AND HISTORY

The Affenpinscher, also known as the Monkey Pinscher or Monkey Terrier, appeared in Europe as early as the 17th century AD.² This sturdy little terrier provided the genetic foundation for some of the more common small breeds such as the Brussels Griffon.’ The exact date and circumstances of its arrival in North America are not known; however, the breed was well established by the early 1900s. Affenpinschers were admitted to the AKC Stud Book and to show classification in 1936. Today the Affenpinscher is the rarest toy breed ranking 143rd out of 177 recognized breeds in 2013.

008_a_reigun.tif

Ch Minsmere Magnolia

Breeder/Co-owner: Azalea Alvarez

Owner/Photographer: Vickie Ehrlekrona

DESCRIPTION

Originally bred as a varmint hunter, the Affenpinscher is an inquisitive, alert, and intelligent breed. Normally possessing a quiet disposition, it carries itself with a comical seriousness; when attacked, it can become extremely excited and will battle fearlessly with an aggressor.¹

009_a_reigun.tif

Crisanda Sonic Boom

Breeder/Owner/Photographer: Vickie Ehrlekrona

THE SHOW RING

The ideal Affenpinscher should be no more than 11 ½ inches high at the shoulder and should weigh no more than 7 to 8 pounds.² The smaller animals are preferred.

Black, gray, silver or black and tan with symmetrical markings, or red, varying from a brownish red to an orangey tan, are seen as coat colors. Color is not a major consideration.²

The character of the coat is an important factor; it should be entirely stiff and wiry in texture. On the body, the coat should be short and dense; on the legs and around the eyes, nose and chin, it should be long, loose and shaggy.²

An Affenpinscher should reflect the sturdiness of its breed. Any tendency to frailty is discouraged. Its head should be round and not too heavy, with a well-domed forehead. Eyes should be round, of good size, black and very brilliant.¹ Ears are cropped to a point, rather small, but set high and erect. Uncropped are allowed and may be erect, semi-erect or dropped as long as they are symmetrical and maintain the monkey-like expression. The muzzle must be short and rather pointed, with a black nose and prominent chin. The neck should be short and straight. The back should also be straight, with its length about equal to height at the shoulder.²

Front legs should be as straight as possible, and the hind legs should not have much bend at the hock. Feet should be small, round, compact, and turned neither in nor is out.² The tail may be docked short and carried high or left natural. The docked tail in the adult should be 1 to 2 inches long.

The total overall appearance of the Affenpinscher is more important than any individual characteristic.² There are no disqualifications in this breed.

010_a_reigun.tif

Affenpinsher litter bred and photographed by Vickie Ehrlekrona

BREEDING AND WHELPING

Affenpinscher litters average between two and four puppies, with a maximum of seven. Whelps range from 2 to 8 ounces each, the average weighing 3 to 5 ounces.

If the tails are to be docked, it should be done at 3 to 5 days, close to the body leaving about 1/3 inch. Male puppies should have descended testicles by 4 months, but some can pull up a testicle until 7 months.

First estrus is expected between 8 and 14 months.

RECOGNIZED RISK FACTORS IN AFFENPINSCHERS

CARDIOVASCULAR-HEMATOLOGICAL-RESPIRATORY

The breed is at risk for anasarca. ⁶, ⁷ Anasarca is a generalized edematous condition seen at birth. Fluid accumulation may be in the body cavities, the subcutaneous tissue or both. The condition is usually lethal with affected pups being stillborn or dying shortly after birth.

The Affenpinscher is one of the breeds at increased risk for patent ductus arteriosus (PDA). ⁴, ⁶, ⁷ The ductus arteriosus fails to close at birth shunting blood from the aorta to the pulmonary artery; over perfusing the lungs and under perfusing the rest of the body. Puppies with PDA may have difficulty breathing, a cough and acute heart failure. PDA in dogs with signs of heart failure must be corrected surgically before five months of age to avoid permanent damage.

The shape of the Affenpinscher’s skull puts it at greater risk for elongated soft palate. ⁶, ⁷ A caudally displaced maxilla causes the soft palate to extend into the laryngeal area obstructing upper air flow.

The breed has also been reported to be predisposed for collapsed trachea. ⁶, ⁷ The lumen of the cervical or intrathoracic trachea is reduced, usually on inspiration resulting partial airway obstruction. The affected dog often has a characteristic honking cough.

DERMATOLOGICAL

Schistosomus reflexus has been listed as occurring in Affenpinschers. ⁷ In this condition, the skin and subcutaneous muscles fail to close over the abdomen leaving the viscera exposed.

Seasonal flank alopecia is a localized form of follicular dysplasia in which hair is lost during one season of the year only to regrow in another. A well demarcated symmetrical alopecia is usually confined to the thoracolumbar area. In the Affenpinscher, the condition only occurred in the winter in dogs housed without heat or artificial light. ⁶, ⁷, ⁹, ¹²

Affenpinschers are considered at increased risk for allergic inhalant dermatitis (Atopy). ⁶, ⁷

ENDOCRINE-EXOCRINE-ENZYMATIC

Hypothyroidism has been reported in the Affenpinscher. ⁶, ⁷ There is destruction of the thyroid gland due to an attack from the animal’s own immune system. Clinical signs include, weight gain, lethargy and dermatological signs (bilateral, symmetric alopecia, brittle hair coat, thickened skin and hyperpigmentation).

Primary Hyperadrenocorticism (Cushing’s syndrome) has been reported in the breed. ³ The disease is the result of increased serum cortisol usually caused by a tumor of the adrenal or pituitary gland. Affected dogs exhibit polydipsia and polyphagia, muscle atrophy and hair loss.

DENTITION

Affenpinschers are seen with Oligodontia (missing teeth) ⁶(620), ⁷ and must be checked for retention of puppy teeth. ⁶(278), ⁷ An undershot bite (prognathism) is the rule rather than an exception. The Standard calls for a level or slightly undershot bite with the teeth not showing.

MUSCULOSKELETAL

Cleft lip/palate has been reported in the Affenpinscher. ⁶, ⁷

The Affenpinscher is one of the breeds considered at increased risk for Legg-Calve’-Perthes disease (LCP). ⁶(802), ⁷, ¹⁰ In LCP, an interruption in circulation results in ischemic necrosis of the femoral head and neck. The disease usually occurs between 4 and 12 months of age and only one leg is usually affected. Affected dogs present with lameness and pain. If diagnosed early enough, the affected leg may be placed in a non-weight-bearing sling; otherwise the damaged femoral head must be removed or replaced surgically. The condition is suspected to be inherited as an autosomal recessive trait with incomplete penetrance. ⁶(885)

Hip dysplasia occurs in the Affenpinscher. ⁶, ⁷ The Orthopedic Foundation for Animals (OFA) ranks the breed 55th in its Hip Dysplasia registry with 16.8% of the evaluations being abnormal. ¹⁰

Like many toy breeds, the Affenpinscher is at risk for patellar luxation. ⁶(924), ⁷ The OFA indicates that 3.8% of the patellar evaluations submitted for the breed were abnormal. ¹⁰

Elbow dysplasia is a developmental abnormality characterized by fragmented coronoid process, ununited anconeal process, osteochondrosis of the Medial humeral condyle and incomplete ossification of the humeral condyle. 5.1% of the 59 sets of elbow radiographs submitted to the OFA for evaluation were considered abnormal. ¹⁰

An X-linked muscular dystrophy, similar to that found in Irish Terriers has been reported in the Affenpinscher. ⁶, ⁷ T he condition is believed to be caused by the inability to produce dystrophin, a muscle fiber protein. Male puppies less than 10 weeks of age usually present with difficulty swallowing followed with a stiff neck and abnormal stilted gait. There is muscle atrophy but the tongue and hamstring muscles become more developed.

NEUROLIGIC

Chiari-like malformations/syringomyelia (CM/SM) has been documented in the Affenpinscher. CM/SM is a malformation of the caudal region of the skull which alters the volume of the caudal fossa resulting in herniation of the cerebellum and brain stem through the foramen magnum. This blockage causes cerebrospinal fluid to build up in the spinal canal causing fluid filled cavities in the cord (syringomyelia). Clinical signs include: thoracic limb weakness or paresis, paroxysmal shoulder scratching and neck and forelimb pain. Medical treatment consists of Gabapentin to relieve scratching activity, tramadol for cervical pain, corticosteroids for inflammation and to reduce CSF production and additional medications to reduce CSF production. Surgical treatment consists of surgery to increase the size of the foramen magnum by removing part of the occipital bone and the first vertebrae.¹⁴

OPHTHALMIC

013_b_reigun.tif

Distichiasis; Note the presence of eyelashes directed toward the cornea

Distichiasis is the abnormal location of eyelashes along the lid margin. This condition has been listed as occurring in Affenpinschers. ¹¹ Distichiasis can occur anytime during the dog’s life and has an undetermined mode of inheritance so breeding an affected dog is optional.

013_a_reigun.tif

Keratoconjunctivitis Sicca (KCS), Dry Eye

Keratoconjunctivitis sicca (KCS, Dry eye) ⁵, ⁶, ⁷ and corneal erosion syndrome ⁷ have been reported in Affenpinschers. KCS is a defect in the aqueous portion of the tear film and is usually caused by immune-mediated destruction of the lacrimal glands. The corneal erosions reported in the breed are similar to those seen in boxers. They typically appear in older dogs and are difficult to manage. They may represent inadequate function of the basement membrane necessary for epithelial adhesion.

Dermoids have been listed as occurring in Affenpinschers. ⁷ A dermoid is a congenital patch of skin growing in an abnormal location, usually the cornea or conjunctiva.

Corneal dystrophy (epithelial/stromal) is a non-inflammatory greyish white opacity in one or more layers of the cornea. The opacities are usually bilateral and composed of lipids. They are believed to be inherited and have been listed in the ACVO Ocular Disorders Report for the breed.¹¹

014_b_reigun.tif

Persistent Pupillary Membranes-PPM

Persistent pupillary membranes (PPM) are vascular remnants that persist in the anterior chamber of the eye. These remnants may bridge from the iris to the iris, the iris to the cornea or lens or form sheets of tissue that hang in the anterior chamber. Iris to iris and iris to lens PPM has been reported in the breed. ¹¹

014_a_reigun.tif

Cataract

Cataracts have been reported in the Affenpinscher. ⁶(903), ⁷, ⁸, ¹¹ A cataract is defined as a complete or partial opacity of the lens and/or its capsule that when complete will cause blindness in the affected eye. The mode of inheritance has not been defined.

Progressive retinal atrophy (PRA) has been reported anecdotally in the breed. ⁶, ⁷ PRA refers to the degeneration of the visual cells (rods and cones) in the retina leading to blindness. Age of onset and mode of inheritance have not been determined.

UROGENITAL

The Affenpinscher, like many toy breeds, is considered at risk for cryptorchidism.⁶, ⁷ Cryptorchidism occurs when one or both testicles are not permanently located in their normal position in the scrotum.

BEHAVIOR

The compatible nature and deep devotion of the Affenpinscher make it an admirable companion. It is exuberant, extremely curious, a barker and an outstanding watch dog.

OLD AGE

Cornea ulcers ¹ do occur in the breed with some individuals being prone to recurrence. Urinary calculi occur occasionally in older dogs. Mitral valve insufficiency may be seen in some individuals after 8 years of age.

MISCELLANEOUS FACTS AND RESOURCES

Additional health screening tests recommended for the Affenpinscher by the Canine Health Information Center (CHIC)

Here is how CHIC works to help dog fanciers improve their breeds

CHIC works with national breed clubs, the AKC Canine Health Foundation and the Orthopedic Foundation for Animals (OFA) to create a list of health screening procedures designed to eliminate inherited health problems from dogs used for breeding. The procedures vary from breed to breed and may change if new problems are identified or new tests become available. A dog must have completed all the required health screening procedures in order to receive a CHIC number. For more information contact: www.caninehealthinfo.org/

CHIC REQUIREMENTS FOR THE AFFENPINSCHER

Eye Exam by a boarded ACVO Ophthalmologist, minimum age 1 year: CERF evaluation, minimum age 1 year

Patellar Luxation: OFA evaluation, minimum age 1 year

Hip Dysplasia/Legg-Calve-Perthes (optional): OFA evaluation

Legg-Calve-Perthes (Optional): OFA evaluation ¹³

NATIONAL BREED CLUB

The National Breed Club is a good place to discover all the things you can do with your Affenpinscher and to contact other Affenpinscher owners.

AFFENPINSCHER CLUB OF AMERICA

www.affenpinscher.org

REFERENCES

1. Jones, A.F. and Hamilton F., Eds. The World Encyclopedia of Dogs. (Galahad Books: New York, 1971) 185, 495, 516.

2. American Kennel Club, The Complete Dog Book. 18th ed. (Howell Book House: New York, 1992) 422-423.

3. Affenpinscher column, American Kennel Club Gazette; August 1990.

4. Kirk, R.W., Ed. Current Veterinary Therapy VI. (W.B. Saunders: Philadelphia, 1977) 400-403.

5. Affenpinscher column, American Kennel Club Gazette; June 1990.

6. Ackerman, Lowell, The Genetic Connection: A Guide to Health Problems in Purebred Dogs. Lakewood, AAHA Press. 1999

7. Padgett, George A. Control of Canine Genetic Diseases. New York, Howell Book House 1998

8. Gough, Alex, Thomas, Alison. Breed Predisposition to Disease in Dogs and Cats. Ames, Blackwell Publishing. 2004

9. Scott, Danny W., Miller, William H. Jr., Griffin, Craig E. Muller and Kirk’s Small animal Dermatology-6th ed. Philadelphia, W.B. Saunders Co. 2001

10. Orthopedic Foundation for Animals website: www.offa.org

11. Genetics committee of the American College of Veterinary Ophthalmologists, Ocular Disorders Presumed to be Inherited