It's in the genes

Please read the New development at the end. Extremely important for all Breeders.

 In the Genes. Compiled by Lynette Trollip

 I have had a number of calls from distressed border collie owners whose dogs have been diagnosed with Hip Dysplasia (HD). Having had some of our own dogs diagnosed with HD, this compelled me into doing a lot of research. The bottom line always remains the same, HD is a genetic disorder. It also made me aware of other genetic diseases in Border Collies (bc) I want to share with you.

The ultimate responsibility for maintaining the integrity of the bc breed lies with breeders. In order to ensure a healthy gene pool for future generations of bc’s, breeding prospects should be evaluated with reasonable concern for potential problems. We need to acknowledge the primary genetic disorders/diseases thought to be a problem in our breed.

 Hip Dysplasia (HD): HD literally means improper growth of the canine hip. Puppies as young as five months will begin to show signs of the disease, however in the majority, symptoms will begin to show during the middle or later years in the dog’s life. Symptoms include walking with a limp, a swaying gait, bunny hopping when running, difficulty in the back legs when getting up, pain in the hip, decreased activity, reluctance to use stairs, reluctance to jump or stand on hind legs and pain and soreness after heavy exercise. Interestingly a dog that has HD in one socket is prone to having a problem with the ligaments of the knee in the other leg. Complicating matters is that genes for HD are believed to be “masked” or hidden in some generations, especially when you have a dog with high pain tolerance. A diagnosis is based on the combination of a physical exam and x-rays. BC’s with HD that are fortunate enough to show few if any symptoms may have progeny that are not so fortunate.

There is no complete cure for HD; however, there are methods to alleviate the clinical signs. There are several surgical procedures available depending on dog’s age, body size, and the severity of the hip joint’s degeneration. The Triple Pelvic Osteotomy (TPO), Total hip replacement and femoral head and neck excision. Medical management, is many times, the only realistic option for dog owners because of the high costs involved with corrective surgeries. These include: weight management, daily exercise that provides good range of motion and muscle building as well as limiting wear and tear on joints like swimming, warmth and good sleeping areas, massage and physical therapy and making daily activities less painful like placing ramps on stairs.

Oral supplements like glucosamine, chondroiton, green-lipped mussel, omega 3 fatty acids, Methyl-sulfonyl-methane (msm) and hyaluronic-acid could be used to help manage inflammation in conjunction with anti-inflammatory drugs like Rimadyl or Previcox. A treatment plan should always be discussed with your veterinarian.

HD is by far the most prevalent known disease that affects bc’s. Despite what some claim, data from numerous scientific studies provide overwhelming evidence that HD is an inherited disease. To confuse matters more, the expression of the disease is affected by environmental conditions as the type and amount of food a dogs gets at the critical growth stages, as well as the type and amount of exercise and activity it gets. It must be remembered, however, that these environmental factors can not cause HD. They merely affect whether the HD genes present in the individual will be expressed to the fullest. Even if the expression of HD in a certain individual is suppressed by careful control of the environment, you can not change the dog’s genetic makeup. The dog will still pass on the genetic tendency for HD just as if it actually has the disease. Conversely, if a dog does not have the genes for HD it won’t develop the disease no matter how it’s raised.

How do we prevent HD? There is only one thing that researchers agree on; selective breeding is crucial. We can significantly reduce the incidence by breeding with animals with certified hips. Breeding two animals with excellent hips does not guarantee that all offspring will be free of HD, but there will be a much lower incidence than if we breed two animals with poor hips. If we only bred animals with excellent hips it would not take long to make HD a rare occurrence. If owners insisted on only purchasing an animal that had parents and grand parents (three to four generations) with certified good or excellent hips, or if breeders only bred excellent animals, then the majority of the problems caused by HD would be eliminated. Following solid recommendation for exercise and nutrition may help, but will never come close to controlling or eliminating the disease if stricter requirements for certified hips are not instituted or demanded.

I have contacted the ISDS office in the UK and their response is that HD is not a big problem in the working ISDS population; therefore the ISDS is not controlling for HD, but will record owner’s results of certificates to help breeders inform purchasers. The ISDS office in Germany does however control HD because they believe they have a problem that can be solved by breeding control. In 1992 a study of dogs in Germany showed 52% were normal, 31% borderline, 11% mild, 4.5%moderate and 1.2% severe. In a study done in America 14.6% of dogs studied were dysplastic or borderline.

Collie Eye Anomaly (CEA): CEA is a congenital disorder where parts of the eye, particularly the retinal area, do not develop normally. The severity of the disease ranges from no visual impairment to blindness. The disease is much more straightforward than HD in both it’s inheritance patterns and our ability to control it. The ISDS is controlling for CEA because it is present at 25-27% in the UK population. Puppies should be examined before they are 10/12 weeks of age by a qualified veterinary ophthalmologist. With ISDS, before pups can be registered, all breeding dogs have to pass the eye examination. There is also a reliable DNA test for the CEA gene, which determines whether a dog is affected, a carrier or clear. Visit www.optigen.com. It is believed that the carrier rate in the US may be as high as 25%.

Progressive Retinal Atrophy (PRA): PRA is a progressive disease where tissue in the retina of the eye is destroyed. PRA generally shows up in dogs around two years of age. At first it shows up as night blindness, and slowly progresses over about 8 years to total blindness.

Focal/Multifocal Acquired Retinopathy (FMAR): This inflammatory eye disease is common in many working breeds and is probably the most frequently seen retinal lesion in Border Collies. Sometimes called "distemper scars" or "worm scars", it is characterized by lesions in the retina that can accumulate over the years, often leading to impaired vision and sometimes leading to blindness. The lesions have a typical "bull's eye" pattern, and tend to be asymmetrical (affect one eye more than the other). The age of onset and rate of progression varies greatly from individual to individual. Males are more frequently affected than females. The characteristics of this disease strongly suggest environmental cause; no heritable pattern has ever been established for its occurrence. Its pathology clearly distinguishes it from PRA, although it is sometimes mistaken for PRA, especially in the later stages of the disease.

Osteochondritis Dissecans (OCD): OCD is a condition that occurs primarily in puppies between the ages of 4-9 months, but can also be found in older puppies. It is considered to be a common disease in rapidly growing dogs of large breeds. However, medium breeds such as the Border Collie can also have a high incidence of this disease. It is seen twice as often in males as in females. The shoulder joint is the most commonly affected site but it can be seen in stifles, elbows, hocks or other joints. The diagnosis is usually confirmed by x-ray of the involved joints. In approximately one third of the cases of OCD, the disease is bilateral (in both joints). Occasionally, it is present in several different joints in the same individual. OCD is thought to be caused by a problem in the growth rate of the joint cartilage relative to the underlying subchondral bone. Although the factors that cause OCD are not completely understood, direct factors considered to be involved in the development of OCD are rapid growth and trauma to the joint. Indirect factors affecting rapid growth include nutrition, hormones, and genetic predisposition to rapid growth and large size. Indirect influences that may lead to increased trauma to the joint include conformation and behavior, which are also influenced by heredity. Certain sites for OCD lesions, such as the elbow, appear to have a greater direct genetic contribution and a higher heritability than other sites, such as the shoulder. The most important contributing factor in OCD of the shoulder, the most common site, is thought to be trauma. OCD can best be prevented in growing puppies by controlling the main precipitating factors, over nutrition and activities that could result in injury to the joints.

Deafness : The bc breed has a relatively high incidence of deafness. Its prevalence and inheritance are unknown. Inherited deafness in one or both ears is due to the degeneration of sensory inner ear structures within a few weeks of birth. Deafness occurs in many breeds and is especially common in the Dalmatian. Other breeds with a relatively high incidence include the English Setter, Australian Shepherd, and Shetland Sheepdog. There is a strong association of deafness with increased amounts of white in the coat and blue eyes in breeds with merle and piebald coat colouring. Dr. Mark Neff at the university of California-Davis is currently studying non-congenital deafness in bc’s. His research has proven that this is inherited, but more information is needed to develop a DNA test. For further info go to www.vgl.ucdavis.edu/chhg/index.php.More breeders are starting to have breeding stock and litters hearing (BEAR) tested.

Ceroid Lipofuscinosis (CL): Also known as Storage Disease, a rare, inherited disease which affects the nerve cells of the body. This disease has been diagnosed in dogs, humans, cats, sheep, goats, cattle, horses and lovebirds. In dogs, CL has been reported in many breeds, including the Border Collie. Affected dogs appear normal at birth but begin to exhibit symptoms around one to two years of age. Symptoms include: unreasonable fear of familiar objects and surroundings, abnormal gait, unsteady on feet, difficulty jumping, demented behaviour, mania, hyperactivity or rage. The age of onset and severity of the disease varies among individuals but symptoms can include a decline in progressive motor control with seizures and a loss of coordination; cognitive and abnormal behaviour; and visual impairment. Affected Border Collies rarely survive beyond 26 to 28 months of age and there is no treatment or cure at this time.

 Epilepsy: BC’s are prone to epilepsy, a neurological seizure disorder, which can be extremely serious. Although epileptic seizures can usually be controlled by drugs that is not always the case. Unfortunately there is no test for this at the moment. Ethical breeders need to disclose known cases.

 Malignant Hyperthermia: This is a very serious, although fairly unusual condition that affects bc’s. Typical symptoms include staggering after a brief period (5 or 10 minutes) of exercise. If left to run they would collapse. Body temperatures shoot up extremely high and take a long time to return to normal, even in cold weather. Any exercise or stress can trigger an attack. If the temperatures goes high enough it can trigger seizures, strokes or even death. Dogs with this condition must have their exercise carefully controlled and monitored.

 TNS: TNS stands or Trapped Neutrophil Syndrome, a hereditary disease where the bone marrow produces neutrophils (white cells) but is unable to effectively release them into the bloodstream. Affected puppies have an impaired immune system and will eventually die from infections they cannot fight.
Once thought to be rare, it is now believed that the disease goes undiagnosed for several reasons. First, not very many veterinarians know about the disease to look for it. Second, even when looking, blood counts do not always show lower than normal neutrophil (white blood cell) counts. Finally, because it is an autoimmune-deficiency disease, young puppies present a variety of symptoms depending upon what infections they fall prone to. Thus many cases are not properly diagnosed and have just been thought to be "fading puppies".
Making the diagnosis even more difficult is the fact that age of onset varies depending on which infection is involved at the time. Most puppies become ill before leaving the breeder but some do not have symptoms until later. The oldest known survivor was 2 years 8 months. Most affected puppies die or are euthanized by about 4 months of age.
The research now suggests that the gene is widespread throughout the Border Collie breed. TNS cases have been positively diagnosed in Australia, Great Britain, Hungary, the Netherlands, New Zealand, and the United States.
TNS carriers have been identified in lines not related to the Australian and New Zealand lines where the disease was first identified - including 100% ISDS lines.
It is autosomal recessive, which means that both parents have to be carriers to produce an affected puppy.

 Anesthetics: A reminder, because of their low body fat, some bc’s may be sensitive to barbiturate-based anesthetics. This is something that you should discuss with your veterinarian before any kind of surgery or procedure for which your dog will be anesthetized.

 Finally: The “ultimate breeder” will use as many tools as possible to increase the odds that the young working dogs he/she sells will live long and useful lives, and serve their owner with pleasure not pain. Info on Genetic tests for CEA, PRA and CL visit www.inqababiotec.co.za or contact Henriette van der Zwan on 012 343 5829 or your local vet. This test is available in SA. See bottom of article.

 The question is what can or should SASDA do to encourage responsible breeding?

 Not commonly known is that SASDA does have a disease data base whereby people can report health conditions. It is then noted on the dog’s registration but not printed on the actual pedigree certificate.

 Should we not perhaps start printing on the pedigree e.g? “CEA clear”.

 If a breeder does test against certain diseases, surely they should be rewarded with recognition and monetary gain? I know of a show line breeder who asks approx R7000 per puppy, as they can prove they have done these tests on their breeding line for a couple generations now.

 Never had a problem with any disease? Surely the “Lucky ones” should be keen to do testing and prove their freedom from a problem?

 Another idea is to distribute an information leaflet with the registration papers which also encourage dog owners to list health problems with the office.

 Again what are we going to do with the info?

 I do realize it won’t be possible to demand testing, but we should encourage the ones who can.

 We will be discussing issues around this: your input would be gladly received via the office, the president or me directly.

Lynette Trollip (trollip@iburst.co.za or fax 086 5099 416)

References;

  1. www.isds.org.uk
  2. www.gocco.co.za/hd_gradings.html
  3. www.bordercolliekennel.nl/hips_&_eyes.html
  4. www.bcdb.info/links.htm#genetics
  5. www.offa.org/hipguide.html
  6. www.workingdogs.com
  7. www.peteducation.com
  8. www.bordercollie.org
  9. www.buzzle.com
  10. www.bordercolliehealth.com
  11. www.bordercolliehealthsite.org
  12. www.canadasguidetodogs.com
  13. www.americanbordercollie.org

******GOOD NEWS FOR ALL SOUTH AFRICAN BORDER COLLIE OWNERS. THE Collie Eye Anomaly (CEA) AS WELL AS OTHER TESTS CAN NOW BE DONE IN PRETORIA AT AN EXTREMELY REASONABLE TARIFF. CONTACT E-MAIL animalgenetics@inqababiotec.co.za or Tel 012 343 5829 Mobile 0828592229 Henriëtte van der Zwan

IMPORTANT MESSAGE FROM THE REGISTRATION OFFICER

To All Breeders / Prospective Breeders / Members September 2010
GENETIC TESTING FOR EYE DISEASES AND OTHER DISORDERS
Testing for various eye diseases and other disorders had previously not been required by SASDA for breeding or registration purposes, mainly because our breeders had not had reasonable access to facilities capable of doing these tests in South Africa.
We are, however, currently in a position to have such tests done, since a lab in Pretoria is now able to do DNA testing for various disorders, upon receipt of a blood sample from your local veterinarian. (Information for all relevant details available from the office 017 735 1844 / sasda@telkomsa.net.)
Although SASDA will not make testing compulsory at this stage, we would like to start moving in that direction in order to ensure the general health and well being of our dogs and thus prevent future problems.
With this in mind we appeal to all breeders to have, where possible, at least your breeding stock eye tested and send the results in to the Office to be recorded on the Registration Database. This information will be kept confidential and will only be used, with your consent, for research purposes.
I thank you for your co-operation in helping maintain a healthy and strong breeding base for future dogs.
Hendrik Johan Ferreira
REGISTRATION OFFICER
PS. Costs may have changed, so please contact the lab directly to get the latest testing fees.

Feedback Comments

Feedback