A number of tests are available for the English Shepherd. Two or more of these tests purchased as part of this bundle will be discounted.
- Collie Eye Anomaly associated with the NHEJ1 gene
- Degenerative Myelopathy associated with the SOD1 gene
- Multi-Drug Resistance associated with the ABCB1 gene
- Progressive Retinal Atrophy associated with the PRCD gene
Collie Eye Anomaly
*Optigen Officially Licensed*
Collie Eye Anomaly/Choroidal Hypoplasia (CEA/CH) is a developmental defect of the eye. Specifically, the abnormal development of the choroid – an important layer of tissue under the retina of the eye – in which there is a decrease in the development of the blood vessels. Puppies can be diagnosed by an ophthalmologist as early as 6-8 weeks of age. As the puppies get older the tapetum (the reflective layer at the back of the eye) develops and this can hide the signs of CEA. This phenomenon is called “go normal”, but it does not mean that CEA goes away or gets better. Affected dogs can also develop optic disc coloboma and retinal detachment.
Important: Degenerative Myelopathy is a rare disease that presents most commonly in German Shepherd Dogs and Boxers, sporadically in Pembroke Welsh Corgis, Cardigan Welsh Corgis, Bernese Mountain Dogs, Rhodesian Ridgebacks, Borzoi and Chesapeake Bay Retrievers. It is rarely diagnosed in other breeds or mixed-breed dogs. DM is considered genetically complex and will have more than one contributing genetic variant. The variant targeted by this test is widespread and found in more than 120 breeds. However, association of the variant with the disease has only been shown in very few breeds and should never be used to inform breeding decisions, except where close relatives have been clinically diagnosed.
Canine degenerative myelopathy (previously also known as chronic degenerative radiculomyelopathy) is a progressive disease of the spinal cord in older dogs. Most dogs are at least 8 years old before clinical become apparent. DM usually starts with a muscle weakness, loss of muscle and loss of coordination (ataxia) in the hind limbs. Progression is generally quote slow, but dogs will eventually be crippled within approximately 3 years of the onset of disease.
In certain breeds a mutation on the ABCB1 gene, which encodes the MDR1 protein (which stands for Multi Drug Resistance 1) can cause animals that carry the mutation to be particularly sensitive to certain drugs. The variant was first detected in a subpopulation of dogs that were highly sensitive to Ivermectin-induced neurotoxicity. The variant on the ABCB1 gene results in the brain being unable to efficiently pump some drugs out, causing a toxic build-up of these drugs in the brain. Dogs subsequently experience and range of symptoms from vomiting and diarrhea to lethargy, seizures, or coma.
A whole range of drugs are pumped out of the brain by the MDR1 protein pump, including antiparasitics, immunosuppressants, antidiarrheals, chemotherapy, antibiotics, antihistamines and more. More details on the drugs that can be dangerous for dogs can be found here. Your vet should be aware if your dog has one or two copies of the defective ABCB1 gene, as it may affect future treatment options.
Progressive Retinal Atrophy (PRCD type)
*Optigen Officially Licensed*
Progressive retinal atrophy (PRA) is the most common form of inherited disease affecting the retina in dogs. Genetically different forms of PRA, caused by mutations in different genes, affect many breeds of dog with each form usually affecting one or a small number of breeds. PRA is characterised by progressive degeneration of the retina at the back of the eye and leads to vision loss and blindness.
Progressive Rod Cone Degeneration (PRCD) is a form of PRA and was one of the first PRAs for which a genetic variant was identified. PRCD is different than most forms of PRA in that the variant has been found in a large number and diverse range of breeds.