HEALTH & THE BORDER COLLIE

© Sheila Gay

Wouldn't it be great if we didn't have to worry about any sort of canine disease? We'll probably always struggle to reach that ideal but we can be thankful that Border Collies are in general very healthy. Some years ago, the only widely available Border Collie litter test was for eyes. Dogs over 12 months old could be hip scored and adult eye tests could be done, but that was about it. To our greater advantage, times change, veterinary medicine moves on, often quite dramatically, and today there are many more tests we can do to safeguard the future health of our lovely breed.

Below you'll find information on BC health matters and testing. Please click to read my article 'DNA Testing – The Way Forward With Carriers (A Breeder's View)'.

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MEDICAL PROBLEMS THAT CAN AFFECT THE BORDER COLLIE

DEAFNESS:
Even the most experienced breeder may not detect an affected puppy in the nest, especially one that is unilaterally deaf. A skilled observer might identify bilaterally deaf dogs, as they often display a lack of response to loud noises, or remain sleeping when their siblings are woken up. This is a subjective method of testing though, and is open to misinterpretation as some normal dogs 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 virtually impossible to confirm that a dog is unilaterally deaf without a truly objective test, such as the Brainstem Auditory Evoked Response (BAER) test. In a BAER test, recording electrodes are positioned on the head, and pick up the electrical response of the brain to auditory stimuli. If the characteristic trace is acquired from both ears, the animal hears normally.

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.

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.

NCL - NEURONAL 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.

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.

IGS - IMERSLUND-GRASBECK SYNDROME:
Cobalamin Malabsorption, more commonly known as Vitamin B12 Deficiency. Affected puppies fail to thrive and the condition often goes undiagnosed. It is caused by an inherent inability to absorb vitamin B12 and is ameliorated by giving injections of B12.

SN - SENSORY NEUROPATHY
An hereditary neurological disease where sensory & to a lesser degree, motor nerve cells degenerate. Onset is in puppyhood with progressive loss of sensation in all limbs, giving rise to ataxia and often self-mutilation owing to the lack of feeling in the limbs. The disease is relatively rare, but the prognosis is very poor and affected dogs are usually euthanised on welfare grounds by the age of 2 years.

BCG - GONIODYSGENESIS & GLAUCOMA SUSCEPTIBILITY
Goniodysgenesis is a condition caused by the abnormal and incomplete development of the anterior chamber which can result in excessive pressure buildup in the eye. If the condition remains untreated the pressure will eventually cause permanent damage to the optic nerve, resulting in blindness preceded by extreme pain. The term primary glaucoma is used to describe those types of glaucoma caused by an inherited physical or physiological trait.

EPILEPSY - research is currently being undertaken by laboratories in various parts of the world. Please contact the Pastoral Breeds Health Foundation for more details. This foundation, supported by BC folk all over the UK, works tirelessly to promote research into health matters and regularly holds clinics for DNA testing.

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TESTING - WHEN CAN IT BE DONE?

A) Tests that can be performed on pups before they leave the litter:

1. Eye screening for CEA/CH (Collie Eye Anomaly/Choroidal Hypoplasia), Colobomas or other eye abnormalities

2. BAER Hearing Tests

The above 2 tests can be done from as early as 5 weeks old. A pup's hearing can be tested at any age, but the litter screening eye test should be done before pups go to their new homes. While having one or both DNA CEA/CH clear parents means a pup will not suffer that particular disease (and now that the DNA test is available, untested parents should not be bred from), it's still important to litter screen puppies, since the test should pick up any abnormalities and we can hopefully prevent other eye problems creeping into the breed.

Billy (Darian Dauntless) confidently demonstrates the BAER hearing test at 6 weeks old.

B) Tests that are performed in adulthood:

1. The adult eye test, which checks for any abnormality but particularly Progressive Retinal Atrophy and Primary Lens Luxation

2. Gonioscopy, a separate eye test which determines any predisposition to develop glaucoma (see DNA tests below)

3. Hip and elbow scoring, done after the age of 12 months. The British Veterinary Association will not score the plate of a dog under 12 months, therefore an x-ray taken prior to a 1st birthday would be purely for diagnostic purposes and not admissible into the BVA/KC scheme.

This x-ray is of Darian Sundown's hips, taken in December 1988 when she was just turned 12 months old. Her score was 0:0 - very pleasing for the first pup I'd ever bred! You can see quite clearly how well the ball fits into the socket on each side.

The following links may be useful:

Eye testing panellists in the UK
The British Veterinary Association canine health schemes
BAER hearing test centres


DNA TESTS:
There are 7 such tests currently available, as a result of many years of research supported by Border Collie breeders and owners around the world. We have much to thank this dedicated group of people for. These tests can be done in adulthood, or while pups are still 'in the nest'.

CEA/CH - Collie Eye Anomaly/Choroidal Hypoplasia

NCL - Neuronal Ceroid Lipofuscinosis

TNS - Trapped Neutrophil Syndrome

IGS - Imerslund-Grasbeck Syndrome

MDR1 - test identifies the genetic mutation which causes an adverse reaction to certain veterinary drugs

SN - Sensory Neuropathy

BCG - Glaucoma Susceptibility

How to use DNA test results
NCL, TNS and SN are invariably fatal and it's hoped that in time judicious use of the DNA tests will result in their total eradication. In the meantime however, having the DNA tests means we can identify clears, carriers and affecteds. Clears and carriers can both be bred from although obviously a carrier should only be mated to a clear. In this way no affected puppies can be produced and valuable bloodlines can be protected. The resulting puppies can then be tested to see if they have inherited the carrier parent's gene. Such knowledge is a vital tool for responsible breeders.

For a more in-depth look at breeding from carriers please refer to the top of this page & the link to my article on the subject.

Testing is done on either blood samples or buccal swab and the latter is especially useful if a breeder needs to test pups while they're still in the nest.

The following laboratories undertake DNA testing specific to Border Collies:

OptiGen
Animal Genetics UK
Laboklin

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© Darian Border Collies ~ Sheila Gay. All rights reserved.