Health issues/research

Mission Statement

To promote the health and well being of the purebred Shetland Sheepdog. We plan to accomplish this goal through research and public education. We encourage all breeders and owners of Shetland Sheepdogs to be aware of health problems in the breed and to use all resources available to them to ensure the lifelong health and well being of all Shelties in their care. We will function as a public resource and clearing house for information related to health concerns as they pertain to the purebred Shetland Sheepdog.
ASSA Research Committee Chair: Mary Mahaffey

CONTENTS

ASSA Health Activities
Notice on Genetic Diseases in Shelties

Canine Health Information Center (CHIC) Program for Shelties

Current Research Projects
Articles

Current Research Projects
Study on DNA Markers for Female Infertility
Dermatomyositis (DM)
Gallbladder Disease and Hypercholesterolemia Study

Articles
To Test or not to Test?
Considering breeding your Sheltie?

Notice on Genetic Diseases in Shelties

Concerned breeders of Shetland Sheepdogs are striving to breed healthy Shelties and decrease the incidence of heritable diseases in the breed. Hip Dysplasia, thyroid disease, eye diseases, Dermatomyositis (Sheltie Skin Syndrome), von Willebrand’s disease (vWD), and epilepsy are some of the known health problems of the breed. Although these problems are NOT COMMON in the breed, the Board of Directors of the American Shetland Sheepdog Association recommends that questions about the health of the dog and its relatives be asked when inquiring about the purchasing of a puppy or adult, use of a stud dog and/or the acceptance of a brood bitch.

Does the dog and its relatives have CERF and OFA or PennHip numbers or an exam form signed by a qualified veterinarian for these tests? Does the Sheltie (adult or puppy) or its relatives have any of the above mentioned problems? Questions should also be asked about abnormal tooth alignment or missing teeth and crypt-orchidism (retained testicle).

The American Shetland Sheepdog Association (ASSA) is NOT advising you not to buy a puppy or breed to a stud dog if these conditions exist, but wants puppy buyers and breeders to be aware of genetic problems in the breed so that informed decisions can be make when buying or planning a breeding.

CanineHealth Information Center (CHIC)
Program for Shetland Sheepdogs

              Health problems, in general, are not common in Shelties; however, testing of breeding stock is a recommended practice to keep the incidence of certain problems as low as possible.  It must be remembered that dogs are animals, not machines, and on average, every dog has 4 to 5 defective genes.1   Congenital and/or hereditary problems will occur no matter how conscientious a breeder is. Nonetheless, breeders should strive to breed Shelties that are a combination of beautiful breed type and good health. 

              The Canine Health Information Center (CHIC) www.caninehealthinfo.org/chicinfo.html  is a canine health database program jointly sponsored by the AKC/Canine Health Foundation (AKC/CHF) and the Orthopedic Foundation for Animals (OFA).  Its purpose is to assist breeders in breeding healthy dogs and being a central resource of health information for breeders, owners, and researchers.  Over 100 breed clubs participate in the program.  The national club for each participating breed recommends health tests to be performed in dogs used for breeding.  The number and types of tests are tailored to the needs of each breed.  Dogs that have had the required tests will receive a CHIC number, and the CHIC database can be searched for dogs having CHIC numbers.   Additional health tests may be recommended, but are considered optional for that breed.   Normalcy is not required for participation in the CHIC program; abnormal results of any test are only released to the public with owner permission.  As new tests become available, the list of required and optional tests may be altered.    Participation in the CHIC program is voluntary.

Breed requirements for Shetland Sheepdogs are as listed below and on the CHIC Shetland Sheepdog web page.  www.caninehealthinfo.org/brdreqs.html?breed=SS

Required tests:

• Hip dysplasia (OFA or PennHIP)
• Eye clearance (Canine Eye Registration Foundation, CERF)
• von Willebrand's Disease (VetGen, test results registered with the OFA)
• Multiple drug sensitivity (MDR1) DNA test (Washington State University, results registered with the OFA)

Optional tests:

• Autoimmune thyroiditis (OFA evaluation from an approved laboratory, test results registered with the OFA)
• Collie eye anomaly DNA test (Optigen, test results registered with the OFA)
• Elbow dysplasia (OFA)
• Congenital cardiac database (OFA evaluation by board certified cardiologist or internal medicine specialist)
• American Temperament Testing Society, TT title, (test results registered with the OFA)

Brief Explanation of the Tests

Required tests:

Hip Dysplasia Evaluation – As of March, 2008, Shetland Sheepdogs rank 129th of 150 breeds of dogs evaluated for hip dysplasia by the Orthopedic Foundation for Animals (OFA) www.offa.org.  Of 16,223 Shelties evaluated, 4.8% were dysplastic.   OFA certification or PennHIP evaluation of the hips (x-ray examination) is on the required list for the CHIC program because hip dysplasia can be a crippling disorder, and one affected influential dog used in breeding programs could increase the incidence in Shelties.  OFA hip evaluation results are automatically included in the OFA database with no extra charge.  More information can be obtained by clicking on the following link http://www.offa.org/hipgeninfo.html .

Eye Certification with the Canine Eye Registration Foundation (CERF) http://www.vmdb.org/cerf.html – Eye abnormalities can occur at any age.  Ophthalmic examination can detect a variety of congenital abnormalities, including Progressive Retinal Atrophy (PRA) and Collie eye anomaly (CEA), which also occurs in Shelties. The merling gene may make it difficult to detect mild cases of CEA by ophthalmic examination because merling is normally associated with less pigmentation of the eyegrounds (back of the eye). Also, the CEA lesions (chorioretinal hypoplasia) in some mildly affected dogs may be partially masked as the eye matures, so may be missed at 8-10 weeks of age or later.   Thus examination at an early age, about 5-8 weeks of age, is recommended.    Because the onset of other eye diseases (such as cataracts and retinal degeneration) can occur at any age, dogs should be reexamined periodically.   A more detailed discussion can be found at: http://www.vmdb.org/aug02.html#d xspot .  Ideally, each dog should be examined within the preceding 12 mos. of being bred.  According to the link above, the likelihood of a genetic problem showing up after age 9 years is low.  The test is an eye examination performed by a board certified veterinary ophthalmologist.  Results are automatically included in the OFA database with no extra charge. 

von Willebrand’s Disease (vWD) DNA Test – vWD is a potentially serious bleeding disorder and one that can be kept from being a major problem in the breed by having this one-time DNA test done.  According to the VetGen website (http://www.vetgen.com/canine-vwd3.html ), the incidence of vWD in Shelties as of January, 2005 is: Clear – 92%, Carrier - 7%, Affected – 1%.   Dogs “Clear By Parentage” (first generation - see OFA website for detailed policy) would be accepted into the CHIC program.   The test can be performed using DNA from cheek brush collection that can be mailed-in by the owner.  

Multiple Drug Sensitivity (MDR1 gene) DNA Test – This DNA test identifies dogs that are sensitive to several medications.  Shelties, Collies, Australian Shepherds, and Border Collies are a few of the breeds with this genetic mutation.  Several commonly used drugs, ex. antiparasitic drugs (some used in heartworm preventatives), tranquilizers (acepromazine), and anti-diarrheal drugs (Imodium®) are a few of the drugs that may affect dogs with this genetic mutation.   This test would provide useful, practical knowledge for every Sheltie owner, since knowing the status of each dog as clear, carrier, or affected would help a veterinarian determine which drugs to use or avoid in a particular dog.  As of March, 2008, 448 Shelties have been tested (Washington State University) with 11% being heterozygous (carriers) for the MDR1 mutation, and 1 % homozygous for the MDR1 mutation.   Heterozygous dogs (carriers) exhibit sensitivity to drugs that is similar to or less than that of homozygous (affected) dogs.  A complete list of drugs that may affect dogs with the MDR1 gene can be found at the following link: http://www.vetmed.wsu.edu/depts-VCPL/drugs.aspx.  More information on the topic can be found at: http://www.vetmed.wsu.edu/depts-VCPL/ and http://www.ashgi.org/articles/mdr1.htm .  Dogs “Clear By Parentage” (first generation - see OFA website for detailed policy) would be accepted into the CHIC program.  The test can be performed using DNA from cheek brush collection that can be mailed-in by the owner.

Optional tests:

Autoimmune Thyroiditis – Autoimmune thyroiditis may lead to hypothyroidism.  It is generally accepted that autoimmune thyroiditis is inherited; however, studies to determine mode of inheritance either have not been performed or are inconclusive. 2     According to the OFA website, where breed results for the Michigan State University Laboratory are listed, Shetland Sheepdogs are 24th of 140 breeds (in which 100 or more evaluations have been performed) with autoimmune thyroiditis.   Of 14,110 Sheltie evaluations, 12.7% were positive for autoimmune thyroiditis.   From the OFA website, “Since the majority of affected dogs will have autoantibodies by 4 years of age, annual testing for the first 4 years is recommended.   After that, testing every other year should suffice.   Unfortunately, a negative result at any one time will not guarantee that the dog will not develop thyroiditis.”  The ASSA Research Advisory Committee recommends that, at a minimum, dogs be tested at 2, 4, and 7 years of age.  A blood sample is needed for this test.  The Committee debated whether or not this test should be on the required list as it should be repeated multiple times over the life of a dog, and it is more expensive than other procedures that should be repeated such as eye certification.  More information on autoimmune thyroiditis can be found at the following links: http://www.offa.org/thygeninfo.html and. http://www.upei.ca/~cidd/intro.htm .

Collie Eye Anomaly (CEA or Choroidal Hypoplasia) DNA Test - CEA is a recessively inherited ocular anomaly that affects development of a portion of the eye.  Homozygous recessive dogs may have lesions ranging from mild to severe.  Heterozygous dogs will be phenotypically normal.  Choroidal hypoplasia, coloboma, and retinal detachment are features of the disease.  It occurs in Shetland Sheepdogs as well as other herding breeds.   The CEA DNA test can distinguish between normal, carrier, and affected dogs. Unlike CERF examination, it is indifferent to the age of the dog or the presence of the merle gene.  The ASSA Research Advisory Committee encourages breeders to consider this test for their breeding stock to keep the incidence of this problem as low as possible.   A blood sample is needed for this test.   This test is for CEA only, so CERF examinations must still be performed to rule out other types of hereditary eye disease such as progressive retinal atrophy.   For an excellent discussion on the topic, see the following link www.optigen.com/opt9_test_cea_ch.html .

Frequencies Based on CERF Eye Exams in the U.S. from 1991 to 1999

CERF numbers may underestimate the prevalence of the CEA mutation, because of the difficulty of detecting the defect in older dogs and the difficulty in diagnosing in a merled dog. Although the incidence of CEA in American Shelties is relatively low, it occurs in European Shetland Sheepdogs in a significantly greater frequency.  For this reason, it is recommended that, at the very least, imported Shelties be tested for the CEA gene.  Dogs “Clear By Parentage” (first generation - see OFA website for detailed policy) would be accepted into the CHIC program. 

Elbow dysplasia – Of breeds having 100 or more elbow evaluations, Shetland Sheepdogs rank 62nd of 92 breeds with elbow dysplasia. As of March, 2008 there have been 404 Shelties evaluated with 97.3% being normal.  More information about elbow dysplasia can be found at the following link: http://www.offa.org/elbowinfo.html .  Radiographs (x-rays) are required for this test.

Congenital Cardiac Database – Many congenital cardiac defects have a genetic component, and nearly all common ones produce audible murmurs that can be detected by a veterinarian using a stethoscope.   Although not common in Shelties, such defects have been found in the breed.  OFA certification for the cardiac database is primarily based on examination by a veterinarian using a stethoscope.  Because some veterinarians are more experienced at detecting subtle murmurs than other veterinarians, the ASSA Research Advisory Committee stipulated that the examination must be performed by a board certified veterinary cardiologist or internal medicine specialist.   Dogs must be 12 mos. of age to receive a certification number.  As of March, 2008 61 Sheltie evaluations have been entered into the OFA database.   More information can be obtained at the following link: http://www.offa.org/cardiacinfo.html

American Temperament Testing Society, TT title - The “TT” title isn’t exactly a health test; however, some breeds do include temperament testing in their CHIC test list, and since heredity does play a role in temperament, the ASSA Research Advisory Committee included it on the optional list.  Minimum age for a dog to take the test is 18 mos.   As of December, 2007, 472 Shelties have been tested.  The pass rate was 67.4%.   More information on the test can be obtained at the following link:  http://www.atts.org/about.html

1.  George A. Padgett, DVM, Michigan State University, Prioritizing Genetic Defects, www.lgd.org/library/PadgettDefects.htm

2.    Canine inherited disorders database -  http://www.upei.ca/~cidd/intro.htm

3.    From the OptiGen website: http://www.optigen.com/opt9_test_cea_ch.html

Current Research Projects

 Study on DNA Markers for Female Infertility
March 8, 2008

DOGenes, a company operated under the guidance of Mary Whiteley, Ph. D., is searching for DNA markers for female dog infertility. If you are interested in participating in the study, go to the following link and click on the link to join the study. https://www.dogenes.com/research.html

DM Research - A Search for Potential Genetic Cause
Updated, March, 2008

Blood samples from DM positive Shelties are needed for the current DNA research sponsored by ASSA. All you would provide is 6 cc of whole blood in a purple topped EDTA tube, a copy of a 3-5 generation pedigree and a copy of the dermatomyositis positive biopsy diagnosis. This should all be sent over night with a cold pack to:

Dr. Christine Rees
Texas A&M University
College of Veterinary Medicine
Department of Small Animal Medicine and Surgery
College Station , TX 77843-4474
979-845-2351

Prior to sending the samples, it is suggested you notify Sherry Lindsey, RN, BSN at shalainetx@aol.com or 830-620-6661 or one of her colleagues to be expecting the samples. If you explain the purpose of the blood draw, most veterinarians will draw blood at no charge or a reduced amount.

Thanks to all who support the DM research.
Sherry Lindsey RN BSN
DM information: www.shalaine.com/DM/DM.html
www.shalaine.com

DM Research - New Treatment Study
Updated, March, 2008

Three to 5 Shelties are needed for a study to evaluate a new drug, Dapsone, which is an oral medication found to be effective in the treatment of DM in humans. These dogs would be donated to the study and then altered, if needed, and placed in permanent adoptive homes following the drug study. Please see contact information below if you are interested in donating a DM affected Sheltie to the study. It may be altered or intact, with or without registration papers, as long as it is a purebred Sheltie.

Contact for Dr Christine Rees, DVM and Sherry Lindsey RN BSN:

Dr. Christine Rees, DVM, DACVD
Texas A&M University
Small Animal Clinic
College Station, TX
979-845-2351
CREES@cvm.tamu.edu
Sherry Lindsey, RN BSN
PO BOX 310233
New Braunfels, TX 78131-0233
830-620-6661
shalainetx@aol.com

Biopsy specimens: For both of the above studies, we suggest that DM biopsy specimens be submitted to Dr. Joanne Mansell who is collaborating in the DM research on Shelties. Her dermatohistopathology submission form, complete with mailing address and cost, is on the DM website, http://www.shalaine.com/DM/DM.html , at the "Biopsy Information for Vets" page.

NEW REPORT FROM DR MURPHY, MAY 30, 2007
April 2007

ASSA and the Collie folks received a proposal from Dr. Keith Murphy of Texas A&M regarding the identification of the gene for DM. I will quote a very small portion of the proposal we received from Texas A&M:
"Our laboratory carried out linkage studies in the Shetland Sheepdog and identified a region of canine chromosome 35 (CFA35) that may harbor a locus having an affect on the DM phenotype. We have also generated a gene expression of DM in the Shetland Sheepdog and identified more than 200 genes that are differentially regulated in diseased dogs. We propose to further investigate genes on CFA35, as well as genes of interest identified using the expression data. Our goal is to (1) identify candidate genes for DM and (2) develop a genetic test for early identification of affected dogs."

The Collie folks had already put in half the money to fund the study - roughly $40,000. The ASSA Board looked at pros and cons of this study, including the fact that Texas A&M might find the gene, might only find a likely marker or might not find anything. However, Dr. Murphy's staff has successfully found the genes for other breeds' diseases.

In the end, THE ASSA BOARD VOTED TO SPEND $40,000 TO FUND THE DM STUDY BY TEXAS A&M.
This was the ENTIRE SUM in the health portion of the ASSA Foundation's money. Donations to the ASSA foundation would be greatly appreciated. For more information on the ASSA foundation click here.

Investigation of Gallbladder Disease and Hypercholesterolemia in Shetland Sheepdogs
March 2008

Background:  Gallbladder disease has been recognized with increasing frequency in dogs within the past decade1-3.   Whether or not this is the result of a true increase in disease prevalence or simply the result of increased detection is not definitive.  However, some suggest that incorporation of abdominal ultrasonography in dogs as a routine diagnostic tool has resulted in increased detection of gallbladder disease2.  Several recent articles describing gallbladder mucoceles (severe distention of the gallbladder caused by a thick mass of sludge and mucus) in dogs suggest a breed predilection for the problem in Shetland Sheepdogs as well as Cocker Spaniels and Miniature Schnauzers.  Both Shetland Sheepdogs and Miniature Schnauzers are breeds predisposed to hyperlipidemia (too much lipid or fat in the blood),4,5 a factor that is known to contribute to gallbladder disease in people6,7.   A recent study confirms a link between hyperlipidemia and hypercholesterolemia (high blood cholesterol levels) and gallbladder mucocele formation in Shetland Sheepdogs2.   Collectively, this suggests the possibility of a genetic defect in a protein responsible for lipid homeostasis (regulation of blood lipid levels).  The Veterinary Clinical Pharmacology Laboratory at Washington State University is currently investigating a gene that plays an important role in lipid homeostasis.  A defect in this gene could be the cause of gallbladder disease in Shetland Sheepdogs.

Participation: The Veterinary Clinical Pharmacology Laboratory is seeking DNA (cheek swab samples) from Shetland Sheepdogs that have any of the following:
Hypercholesterolemia (fasting serum or plasma cholesterol > 400 mg/dL)
Hypertriglyceridemia (fasting serum or plasma triglycerides > 600 mg/dL)
Hyperbilirubinemia while not anemic (serum or plasma bilirubin > 2.0 mg/dL)
Surgical or ultrasonographic report of gallbladder disease (documentation must be made by DVM).

Participation is voluntary (i.e., you will not receive payment for the sample nor will you be charged for having your dog’s DNA tested).

DNA swabs can be obtained by emailing Dr. Katrina Mealey at the address listed below.
Instructions for correctly obtaining a sample can be found at the following website:

http://www.vetmed.wsu.edu/depts-VCPL/instructions.aspx

Questions about an individual animal’s inclusion in this project can be addressed to:
Katrina Mealey DVM PhD; Diplomate, ACVIM; Diplomate, ACVCP
Associate Professor and Director, Veterinary Clinical Pharmacology Laboratory
College of Veterinary Medicine
Washington State University
Pullman WA, 99164-6610

EMAIL: kmealey@vetmed.wsu.edu

References
Pike FS, Bert J, King NW, et al. Gallbladder mucoceles in dogs: 30 cases (2000-2002). J Am Vet Med Assoc 2004;224:1615-1622.

Aguirre AL, Center SA, Randolph JF, et al. Gallbladder disease in Shetland Sheepdogs: 38 cases (1995-2005). J Am Vet Med Assoc 2007;231:79-88.

Worley DR, Hottinger HA, Lawrency HJ. Surgical management of gallbladder mucoceles in dogs: 22 cases (1999-2003). J Am Vet Med Assoc 2004;225:1418-1422.

Whitney MS, Boon GD, Rebar AH, et al. Ultracentrifugal and electrophoretic characteristics of the plasma lipoproteins of miniature schnauzer dogs with idiopathic hyperlipoproteinemia. J Vet Intern Med 1993; 7:253-260.

Sato K, Agoh H, Kaneshige T, et al. Hypercholesterolemia in Shetland sheepdogs. J Vet Med Sci 2000; 62:1297-1301.

Loria P, Leonardo A, Lombardini S, et al. Gallstone disease in non-alcoholic fatty liver: prevalence and associated risk factors. J Gastroenterol Hepatol 2005; 20:1176-1184.

Andreotti G, Chen J, Gao YT, et al. Serum lipid levels and the risk of biliary tract cancers and biliary stones: A population-based study in China. Int J Cancer (2007 epub)

Articles

To Test or Not to Test…
Mary E. Galloway DVM

As ASSA Health chairperson, people who want to purchase a Sheltie frequently contact me asking what they should know about the breed’s health problems. A recent call highlighted some concerns expressed by both breeders and owners about the current focus on canine health and research and how it reflects on the perceived health of purebred dogs and Shelties in particular.

"I am interested in buying a Sheltie but when I hear about all the tests my puppy’s parents should have it worries me. I see your club is involved in various health research projects and is trying to raise money for further research. Should I look for a healthier breed? When I spoke with one breeder I was told about all the tests her dogs have had for a lot of diseases. I can get a Sheltie from another person who told me they don’t have to test for problems since they don’t have any in their lines. What do you think?"
Testing for diseases and monitoring the occurrence of diseases by breed clubs and breeders does not indicate that problems exist in that breed or line. In fact it is a positive indication that the people who breed these dogs are trying to produce the healthiest puppies they can. As researchers become more aware of the underlying causes for many diseases in our dogs, breeders try to use all the resources available to them to produce healthy dogs. This includes feeding a proper diet, providing proper exercise and housing and may include testing for abnormal conditions or diseases that exist in the breed. Testing for specific conditions will allow only unaffected animals to be used for breeding. The abnormal conditions currently recognized in Shelties are found in low numbers in the breed. Testing will allow these uncommon conditions to remain uncommon or even be eliminated from the breed.

A test may be one that screens for the presence of a condition or disease. This would include eye exams (CERF), radiographs of the hips for hip dysplasia (OFA, PennHip) or a blood test for thyroid disease. When a dog has one of these tests done it will tell the owner whether the condition is present in that dog at that time. Many of these tests need to be repeated throughout the dog’s lifetime since the condition can develop as the animal matures and ages. Some tests are done just once at a predetermined age since it is unlikely the condition will develop after that time. Checking for these conditions will allow breeders to breed only dogs that appear normal. What must be remembered is that although the dog may not show the condition him/herself these tests do not show if the dog is genetically free of the problem. The dog may appear normal but carry recessive genes. When this dog is bred to another dog also carrying recessive genes they may produce animals that will develop the disease. This is how affected animals can come from "normal" parents. The best safeguard we have to reduce or eliminate these problems in our dogs is to screen all breeding stock and breed only from those who are free of the condition. In the case of eye checks and thyroid testing, it must be repeated many times in a dog’s lifetime since these abnormalities may not appear until an animal is older. If all animals in the first 3-4 generations of your puppy’s pedigree have been tested and found normal it is unlikely that your puppy will develop the condition. It is important to point out that many of the disease conditions we recognize as having a genetic basis can also be influenced by the environment. The development of hip dysplasia is a good example. Research has shown diet and exercise as well as growth rates, can influence the development of hip dysplasia. Obesity can cause or aggravate a number of disease conditions in dogs. It is the owner’s responsibility to know how to correctly feed, house and exercise their growing puppy to ensure a healthy adult and to maintain good health in your adult dog.

The only absolute way to know your puppy will not develop a certain disease or condition is through genetic testing. A genetic test allows us to know what is actually coded in the genes of the animal being bred. It is not influenced by environment or outside stresses. It will tell you what genes the dog actually carries and not just which ones are expressed. Research is unlocking the key to many diseases in dogs and people. As these tests are developed and become available, breeders will test their breeding stock and know the genetic makeup of each animal. This will allow breedings to be planned to avoid producing affected offspring and to eventually eliminate the disease from the breed. The only genetic based test currently available for the Shetland Sheepdog is for von Willebrand’s Disease, a bleeding disorder.

That is why all this research is so important. Projects are underway to study many of the conditions that affect our Shelties today. Funding is needed for other projects that are of equal importance. As we eliminate one disease from our animals there will be others to demand our attention. That is why parent clubs like the ASSA monitor the breed through health surveys. Living creatures including dogs and man are constantly changing. Gene mutations are an ongoing process. Some mutations will produce disease conditions not recognized today. It is said all people carry 5-6 lethal genes as well as numerous genes that can cause the development of many disease conditions. The same is probably true for our dogs. The challenge for breeders is to use all the knowledge available today to avoid breeding animals together that carry the same deleterious genes. There is no dog or line of dogs that is free of all disease causing genes. If testing is not done, breeders may not be aware of problems that exist, but they are still there. It is true some diseases can’t be tested for at this time. They can be unpredictable and the best we can do is not use for breeding animals that develop the condition.

So don’t be afraid of a breed or breeder that is active in health research and testing of their breeding animals. This indicates the acceptance of responsibility and an ongoing effort to produce beautiful healthy Shelties.

Copyright © 1998-2008 American Shetland Sheepdog Association. All Rights Reserved.