Rough Collie

The Rough Collie is the same as the Smooth Collie with the exception of coat length. The breed is thought to have evolved from dogs brought originally to Scotland by the Romans that then mated with native types. The breed is generally a long-lived one but there are health issues which interested parties need to be aware of.

Centralised PRA (RPED)

CPRA causes visual impairment and/or ‘night blindness’ due to the degeneration of the photo-receptor cells (Rods and Cones) of the retina of the eye. Clinical signs may be detected from between twelve and eighteen months of age hence the importance of the annual KC/BVA testing scheme. PRA is a progressive disease and the affected dog may or may not go completely blind.

The actual mode of inheritance of CPRA is not fully understood though it appears to be a non-congenital, multi-factorial, inherited disease. There is no DNA test available for CPRA.

British-bred Rough & Smooth Collies need only concern themselves with CPRA though the  Ophthalmologists admit it is many years since any cases have been diagnosed. Professor Peter Bedford suggests that improved feeding methods (the presence of Tocarphyll in the vitamin E content of ‘complete’ feeds) appears to have reduced its incidence. However, he also suggests that relatively few Collies are actually submitted for annual re-testing so accurate statistics are unavailable.

Generalised PRA (rcd2) affects some lines of American-bred Rough and Smooth Collies, and could become a problem if imported dogs and bitches are not tested for this form of PRA. Optigen offers a DNA test for GPRArcd2.

 

Collie Eye Anomaly (CEA)

CEA affects many of the pastoral breeds, including the Collie breeds and Shelties. It is a non-progressive congenital eye disease affecting the choroid layer of the eye hence it is referred to as choroidal hypoplasia (CH). It presents itself as a pale patch in the back of the eye due to localised lack of pigment in the choroidal and retinal layers of the eye. This pale patch is covered with abnormally large blood vessels, obvious to the ophthalmologist. Dogs can be clinically examined as young as six or seven weeks and badly affected puppies could either be blind or have impaired vision due to other CEA-linked problems such as detached retinas or holes in the retina (colobomas). Obviously such dogs should never be bred from.

Some clinically affected puppies, diagnosed with mild CEA at 6–7 weeks of age, often appear clinically ‘clear’ at the twelve-month check and are commonly referred to as ‘go-normals’. The breeder therefore receives a clear certificate at this stage. The CEA ‘go-normal’ label is very misleading as this dog is always genetically affected. However, many misguided breeders prefer to wait until their dog is 12 months old before having it screened in the hope that it will get a ‘clear’ certificate. No one will therefore ever know what its clinical status was at 6-7 weeks!

Over the years Rough Collie breeders have become disillusioned with CEA, especially in situations where two clinically clear dogs have been mated and the resulting litter has all been CEA-affected. As mildly affected dogs have no apparent visual difficulties and the disease does not progress, neither is it painful, many breeders have tended to disregard CEA. Hence Professor Bedford stating a few years ago that he believed there were no clear CEA genes in UK Rough Collies!

In 2010 one Rough Collie breeder decided she wanted to improve the eye status in her kennel, amongst other features, so introduced several genetically CEA-clear Canadian and American Collies into her breeding programme. Several other breeders have been making use of these outcrosses so, hopefully, the CEA situation will improve in time especially now that Optigen has introduced a genetic test for Choroidal Hypoplasia (CEA/CH). Clinically clear baby puppies can therefore be DNA tested before they leave the breeder so their ‘clear’ or ‘carrier’ status is known.

Whilst the DNA test only checks the Choroidal Hypoplasia (CH) aspect of CEA, it is believed   associated diseases such as detached retinas and/or colobomas are carried on a different gene and are unlikely to be present in genetically CEA/CH clear dogs.

Although several laboratories offer a DNA test for CEA, the KC currently only publishes CEA results from Optigen.

 

Hip Dysplasia (HD)

HD is a multi-factorial condition affecting numerous dog breeds. With both hereditary and environmental factors at force, there is currently no DNA test available. Hips are x-rayed from twelve months of age under the KC/BVA scheme.

The KC/BVA scoring system is unsatisfactory, being a subjective test, and because other countries  have  differing schemes, it is difficult to compare results.

 

Multi-Drug Resistancy (MDR1)

Some dogs among the Collie breeds and Shelties appear to by hypersensitive to certain toxins (either natural or drug-induced), at the same time appearing to be prone to more stress-related problems.

The problem was first publicised in 1983 after several Rough Collies died from Ivermectin poisoning (Ivermectin was never registered for canines but was occasionally prescribed for worming and/or fox mange treatment) and, since then, the veterinary profession has accepted this drug should never be given to the Collie breeds. In 2004, veterinary researchers in the USA discovered that a gene mutation in some dogs allowed drug toxins to leak across the blood-brain barrier into the central nervous system causing toxic reactions such as excessive salivation, ataxia, blindness, coma, respiratory problems and even death.

Dogs with the MDR1 mutation are found to be susceptible to a wide variety of drugs eg cancer treatments, certain antibiotics, anaesthetics and certain wormers etc. Most at risk are those Collies, of unknown MDR1 status, which are given drug ‘cocktails’ during and after routine surgery.

In 2004 a DNA test was introduced, and it took several years before some breeders acknowledged the problem. The number of breeders who regularly use this test is now increasing. They may have to continue using MDR1 ‘carriers’ for another generation or so, but there are currently sufficient clears and carriers in a variety of lines for us to eliminate known affected dogs from breeding programmes.

Several laboratories offer a DNA test for MDR1 and, although the KC automatically publishes results from Laboklin and Animal Genetics, they will also publish results from other labs providing the breeder submits the test certificate.

Kindly provided by:

Pat Hutchinson, July 2015
Health Coordinator, East Anglian Collie Association
www.e-a-c-a.co.uk