Southern Border Collie Club - Working For Collies
On the whole the Border Collie is a healthy breed – but as with any other breed there are some medical problems which may occur from time to time, some hereditary and some not. Experienced, responsible breeders will make every effort to breed only from well tested, healthy stock and to carry out all necessary tests to ensure that the pups are healthy. It should be pointed out that although the following section covering various diseases is comprehensive this is in order to explain what MAY occur in a minority of dogs – not to say that these diseases are common in the breed. It also explains the importance of not breeding from affected dogs and therefore the importance of breeders using every test available to ensure the health of their breeding stock and their puppies.
CEA – COLLIE EYE ANOMALY:
The more accurate name for it is Choroid Hypoplasia (CH) – the choroid is a layer of tissue under the retina, which in CEA can be seen to have underdeveloped, thin, almost transparent patches, in one or both eyes. Mildly affected dogs may have perfectly normal vision, but if bred from, can produce severely affected puppies. Severely affected dogs suffer a serious loss of vision and many have colobomas - holes or pits in the retina. At worst, severe CEA cases suffer intraocular haemorrhage, detachment of the retina, and blindness. CEA is inherited via an autosomal recessive gene, but thanks to the recent development of the gene test by OptiGen in the USA, producing affected puppies can be avoided in future by selective breeding.
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CL – CEROID LIPOFUSCINOSIS:
An hereditary, fatal disease, similar to Batten’s Disease in humans, CL is also called Storage Disease - an accumulation of toxins builds up in the brain, owing to an enzyme abnormality, which prevents the dog from disposing of them normally. Symptoms appear from around 15 months of age and gradually worsen, beginning with abnormal behaviour, such as fear of familiar people and objects, unsteadiness and abnormal gait, and progressing ultimately to dementia, disorientation, loss of bowel/bladder control, hyperactivity, rage and mania. As there is no cure, the only course is euthanasia. Confirmation of CL is post mortem. The recent development of the gene test to identify Carriers means selective breeding can eradicate this disease.
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TNS – TRAPPED NEUTROPHIL SYNDROME:
An hereditary disease where the bone marrow produces white cells (known as neutrophils) but is unable to release them into the bloodstream - as a result affected puppies have an impaired immune system and will eventually die from infections which they cannot fight.
Symptoms can be variable which has made it difficult to recognise as a genetic problem. A common symptom is recurrent infections in young pups, but some develop abnormal faces a few weeks after birth while others appear normal until vaccination when they have a bad reaction and never recover, while others live to several years of age with only occasional problems. Many cases of 'fading puppy syndrome' have turned out to be unrecognised cases of TNS. TNS is a genetic disease with recessive inheritance (like CL) which means that to have an affected puppy, both parents must be carriers (i.e. one defective and one normal copy of the gene but showing no adverse effects) and about one quarter of such litters will be affected.
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OptiGen 20/20 Clinics (CEA, CL & TNS testing at discounted rates) are held in the club's geographical area every February and September. A blood drawing session is arranged for 20 or more dogs and the samples flown next day to New York. Visit OptiGen's website for more information. A further discount is available to owners who register and pay OptiGen online by credit card. Results come back showing dogs to be either Normal, Carrier or Affected. Dogs with a Normal result receive a Certificate of status. For full details of the clinics contact the organiser Mrs Val Tiller directly. OptiGen prefer dogs to be permanently identifiable, and microchipping is available at Val's clinics.
In November 2007 and at the request of the Border Collie Breed Council, the General Committee of the Kennel Club approved DNA Testing Schemes For Border Collies for Collie Eye Anomaly/Choroidal Hypoplasia (CEA/CH) and Ceroid Lipofuscinosis (CL) and for Trapped Neutrophil Syndrome (TNS), whereby test results can be added to registration documents.
"Copies of all future test certificates issued by OptiGen will be sent directly to the Kennel Club, where the test result will be added to the dog’s details on the registration database. This will trigger the publication of the test result in the next available Breed Records Supplement, and the result will also appear on any new registration certificate issued for the dog and on the registration certificates of any future progeny of the dog.
Owners of dogs which are dual registered with both the Kennel Club and the ISDS should ensure that only the KC registration number is included on any OptiGen request or application form.
Owners who have already had their dog(s) DNA tested for these conditions can send the test certificate into the Kennel Club and the data will be added to the dog’s registration details. In addition, if the owner includes the original registration certificate for the dog (not a copy) then a new registration certificate will be issued, with the DNA result on it, free of charge. Please send the DNA test certificates to:
The Information Department
The Kennel Club
1 – 5 Clarges Street
For further information on this scheme please contact Dr Jeff Sampson, either by phone on 020 7518 1068 or by email email@example.com."
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PRA – PROGRESSIVE RETINAL ATROPHY:
PRA is a degenerative disease of the photoreceptors of the eye, inherited via an autosomal recessive gene. Usually the first symptom is night-blindness, especially noticeable when the dog is in unfamiliar surroundings, but eventually the dog goes totally blind. There is no cure.
SBCC runs Eye Testing Clinics for PRA annually at its Championship Show each spring, at Maidstone, Kent. Annual testing for PRA in adult BCs used for breeding is recommended.
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Figures from the Animal Health Trust indicate that 1 in 25 Border Collies tested suffers from congenital deafness. This still may not sound particularly important, but when you realise that the estimate for the incidence of deafness in the dog population as a whole is about 0.25 %, or 1 in 400 individuals, it begins to look a little more significant.
Even the most experienced Border Collie breeders sometimes do not recognise an affected puppy in the nest, especially one that is unilaterally deaf, and yet there are still people who are reluctant to hearing test, because “we haven’t got a problem”. However, the only way to know that for sure is to hearing test all breeding stock and progeny.
So how do we test for deafness? A skilled observer may sometimes identify bilaterally deaf dogs, as they often show very typical behaviour, such as the lack of response to loud noises, or remaining asleep when the other siblings are roused. But this subjective method of testing is open to misinterpretation as some normal animals may be unresponsive whilst others adapt quickly and stop reacting. A unilaterally deaf dog is very difficult to identify as it hears perfectly in the non-affected ear, and so usually behaves normally. It is almost impossible to confirm that a dog is unilaterally deaf without performing a more objective test, such as the Brainstem Auditory Evoked Response or BAER test.
The BAER is the electrical response of the brain to auditory stimuli. When sound enters the ear, the auditory pathway generates electrical impulses. These are picked up by recording electrodes, which are positioned on the head, and passed into a computer. A series of clicks are passed into the ear through a headphone, producing a repeatable sequence of peaks and troughs, which are displayed on a screen. The test is usually very quick and non-invasive, and gives an accurate and totally objective hearing assessment. Puppies are tested from 5 weeks of age, and adults can be tested too, although a light sedation may be required. With this kind of deafness, all the peaks in the BAER waveform are lost, so a straightforward yes-or-no assessment of hearing ability is possible. If the characteristic trace is acquired from both ears, the animal hears normally.
Now that the BAER test is available, no-one need ever find out that their much-beloved but somewhat wayward puppy behaves that way because he is in fact totally deaf, as it is no longer necessary to purchase a puppy whose hearing status is unknown. This is the aim of hearing testing – to ensure that breeders know the hearing status of the pups they are selling and to reduce (or in a perfect world, eliminate) the incidence of deafness in the Border Collie breed. Eventually it is hoped that a blood test will be available to identify carriers of the disorder, but until then, the only way to know with certainty the hearing status of each individual, and go some way towards reducing the percentage of affected dogs, is to evaluate every animal using the BAER test.