Health Testing Guide

A guide to health screening and the interpretation of common DNA test results for Rough and Smooth Collies.

Why health testing matters

When buying a puppy, you will naturally want to do everything possible to ensure that the puppy is healthy when it leaves its breeder and throughout its life.

Health screening and DNA testing help breeders make informed decisions about the dogs they breed from. Some breeds have an increased risk of particular inherited conditions, and suitable testing can reduce the likelihood of producing affected puppies.

“Vet checked” does not mean “health tested” A routine veterinary examination checks a dog’s apparent health at that time. It is not the same as DNA testing, hip scoring, clinical eye examination or another recognised health-screening scheme.

Health testing cannot guarantee that a puppy will never develop a medical condition. DNA tests normally examine a particular gene variant, while health can also be affected by other genes, age, diet, exercise, injury and the environment.

A breeder should be willing to explain the tests carried out on the sire and dam and provide copies of the results or links to officially recorded results.

Health screening for Collies

The Royal Kennel Club Health Standard lists the following tests and screening schemes for Rough and Smooth Collies:

BVA/RKC/ISDS Eye Scheme examination
BVA/RKC Hip Dysplasia Scheme
DNA test for CEA/CH
DNA test for PRA-rcd2
DNA test for Degenerative Myelopathy
DNA test for MDR1

The schemes recommended for a breed can change as new evidence and tests become available. Always check the current Royal Kennel Club Health Standard and seek advice from the relevant breed club or breed health co-ordinator.

Clinical screening and DNA testing

CLINICAL SCREENING

Examines the dog

Clinical schemes assess the dog for physical evidence of a condition. Examples include hip scoring and examination under the BVA/RKC/ISDS Eye Scheme.

DNA TESTING

Examines a gene variant

A DNA test identifies whether a dog carries a particular tested genetic variant. It does not provide a complete assessment of the dog’s overall health.

Clinical eye examination remains important even when DNA tests have been completed because a DNA test only covers the specific condition and gene variant for which it was designed.

Further information about hip scoring is available on the Hip Dysplasia and Hip Scoring page.

Understanding a recessive DNA test

CEA/CH, PRA-rcd2 and Cyclic Neutropenia are examples of conditions generally described as autosomal recessive. Results may be presented using different letters by different laboratories, but the basic meanings are:

Result	Example	General meaning
Clear	N/N	The dog has no copies of the particular variant tested and cannot pass that variant to its offspring.
Carrier	N/Variant	The dog has one normal copy and one copy of the tested variant. For a recessive condition, the dog is not normally clinically affected but can pass the variant to its offspring.
Affected	Variant/Variant	The dog has two copies of the tested variant. The clinical significance depends on the particular condition, and the dog will pass one copy to every puppy.

Carriers should not automatically be excluded For a simple recessive condition, a carrier can be mated to a DNA-tested clear dog without producing affected puppies. Used responsibly, carriers can help preserve valuable qualities and genetic diversity within a breed.

Collie Eye Anomaly — CEA/CH

Result	Common notation	Meaning
Clear	N/N	The dog does not carry the CEA/CH variant tested and cannot pass that variant to its offspring.
Carrier	N/CEA	The dog carries one copy of the CEA/CH variant and has a 50% chance of passing it to each puppy.
Genetically affected	CEA/CEA	The dog has two copies of the CEA/CH variant and will pass one copy to every puppy. The degree of clinical eye change can vary between dogs.

A clinical puppy eye examination remains valuable because it records the physical changes present in the individual dog.

Cyclic Neutropenia — CN

Result	Common notation	Meaning
Clear	N/N	The dog does not carry the tested Cyclic Neutropenia variant.
Carrier	N/CN	The dog carries one copy and may pass it to its offspring, but is not expected to develop this recessive condition.
Affected	CN/CN	The dog has two copies of the tested variant and is genetically affected.

Degenerative Myelopathy — DM

The commonly available DM test is a risk test. Having two copies of the associated variant does not mean that every dog will develop clinical Degenerative Myelopathy.

Result	Common notation	Meaning
Clear	N/N	No copies of the tested DM-associated variant were detected.
Carrier	N/DM	One copy of the tested variant was detected. The dog can pass it to its offspring.
At risk	DM/DM	Two copies were detected. The dog has an increased genetic risk but may never develop clinical disease.

Further information is available on the Canine Degenerative Myelopathy page .

Dermatomyositis — DMS

DMS testing is different from a simple clear, carrier or affected recessive test. It assesses a combination of genetic risk factors and reports the dog as having a lower, moderate or higher relative risk.

The notation and risk calculations can depend on the test model and laboratory used. Results should therefore be interpreted using the risk category and breeding guidance supplied on the individual laboratory report, rather than by comparing the letters with an old results table.

DMS is a risk assessment, not a diagnosis A lower-risk result does not guarantee that a dog will never be affected, and a higher-risk result does not mean that the dog will definitely develop Dermatomyositis. Seek advice from the testing laboratory, breed health co-ordinator or a veterinary geneticist when planning a mating.

Multi-Drug Resistance — MDR1

The MDR1 variant can affect the way a dog transports certain medicines out of the brain. Dogs with one or two copies may be at increased risk of adverse effects from some drugs.

Result	Common notation	Meaning
Clear	N/N	No copies of the tested MDR1 variant were detected.
One copy	N/MDR1	The dog carries one copy and may have increased sensitivity to certain medicines. It may pass the variant to its offspring.
Two copies	MDR1/MDR1	The dog carries two copies and has a greater risk of serious adverse effects from certain medicines. It will pass one copy to every puppy.

Always tell your veterinary surgeon about an MDR1 result Show the laboratory certificate to your veterinary practice. Drug safety depends on the particular medicine, dose and route of administration. Never alter or refuse necessary treatment without discussing the options with a veterinary surgeon.

Checking a dog’s results

Ask to see the original certificates for the sire and dam. Results for many registered dogs can also be checked through the Royal Kennel Club Health Test Results Finder.

Check that the name, registration number and microchip number on the certificate relate to the correct dog. Remember that a panel may include tests that are not relevant to the breed, while important clinical schemes such as eye testing and hip scoring cannot be replaced by a DNA panel.

Further information

This guide provides general information only. Test notation, risk calculations and breeding recommendations can change. Always use the interpretation supplied by the testing laboratory and seek current veterinary or specialist genetic advice when necessary.

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