Genetic and Health Testing

Below is a brief explanation of the genetic and health testing all our Aussies receive prior to breeding. This may not be a complete list. For more information please visit: www.pawprintgenetics.com and www.ofa.org

OFA Hips and Elbows

Hips and elbows are x-rayed after a dog reaches 2 years of age. This helps screen for hip and elbow dysplasia which has a genetic component. The passing ratings are Excellent, Good, and Fair. In our program, we only use dogs with a rating of Excellent or Good.

CERF/CAER

A CAER exam (formerly known as a CERF) is an annual eye exam done by a board certified veterinary ophthalmologist. During this exam they dilate the pupils and check the eye health and look for defects in the eye. A normal/clear rating indicates nothing of significance was found. As there are some eye diseases that do not show until later in life, it if important to repeat this test yearly on all breeding dogs. This exam is also done on all puppies before they leave to their new homes. Some genetic defects, such as CEA, cannot be detected on exam after 7 weeks of age.

MDR1

Also known as "Multi-Drug Resistance" or "Ivermectin Sensitivity." The MDR1 gene is responsible for interrupting the production of a protein that protects the blood-brain barrier from certain drugs. While the most common drug associated with MDR1 is Ivermectin, dogs affected by MDR1 are also sensitive to other common drugs such as Acperomazine, Butorphanol, Loperamide (imodium), Digoxin, and several more. While it is easy to avoid problems with MDR1 by avoiding problem drugs, it can impede normal veterinary treatment. It is estimated around 50% of Aussies carry at least one copy of the MDR1 gene.

  • Dogs carrying two copies of the MDR1 gene (M/M) will be extremely sensitive to these drugs and can experience severe neurological disturbances such as ataxia, seizures, and death.

  • Dogs carrying only none copy of the gene (M/n) will still be sensitive but react at higher doses.

  • Dogs not carrying any copies (n/n) can safely receive the listed problem drugs.

 

A full list of drugs to avoid from Washington State University: http://vcpl.vetmed.wsu.edu/problem-drugs

HSF4/HC

Also known as "Hereditary Cataracts." This gene is responsible for 70% of cataracts in Aussies. It is estimated 25% of Aussies carry at least one copy of the gene. In Aussies, this gene is dominant but not completely penetrant. This means that only one copy of the gene is necessary to predispose a dog to hereditary cataracts, but not all that carry the gene will get the disease. It is thought that those affected who do not develop cataracts have secondary genes that have interacted with the HSF4 gene, however these are not known yet. Cataracts can also be caused by injury and old age.

  • Dogs carrying two copies of the HSF4 gene (M/M) will be up to 12 times more likely to develop cataracts.

  • Dogs carrying only one copy of the gene (M/n) will be at increased risk for developing hereditary cataracts.

  • Dogs not carrying any copies (n/n) will not develop hereditary cataracts.

CEA

Also known as "Collie Eye Anomaly." CEA causes a defect in tissue layers under the retina in both eyes. This may cause blindness, but a majority still are visual. It is estimated between 5-10% of Aussies are carriers. 

  • Dogs carrying two copies of the CEA gene (M/M) are affected.

  • Dogs carrying only one copy of the gene (M/n) are not affected but can pass the defect onto offspring.

  • Dogs not carrying any copies (n/n) are not affected and will not pass the gene onto offspring.

PRA/PRCD

Also known as "Progressive Retina Atrophy" or "Progressive Rod Cone Degeneration." PRCD is unique to Aussies and causes the rods and cones in the eyes to degenerate in mature adults, causing eventual blindness. It is estimated 5-10% of Aussies carry at least one copy, with 1% or less being affected.

  • Dogs carrying two copies of the PRCD gene (M/M) are affected and will eventually go blind.

  • Dogs carrying only one copy of the gene (M/n) are not affected but can pass the defect onto offspring.

  • Dogs not carrying any copies (n/n) are not affected and will not pass the gene onto offspring.

DM

Also known as "Degenerative Myelopathy." DM is a painless neurological disorder which causes the cells in the spinal cord that as responsible for transmitting signals to the brain to breakdown. These dogs will progressively become weaker in the hind-end, leading to eventual paralysis. The paralysis will slowly move forward, and the dog will eventually be completely incontinent and immobile. Dogs are usually mature adults to geriatric when they begin to experience symptoms and the progression of symptoms takes years. Testing for DM in Aussies is fairly new and there is thought to be several components to the disease. Diagnosis of DM can only be done through necropsy. Many times a diagnosis of living dogs is only done as a "most likely culprit" after many other conditions have been ruled out.

  • Dogs carrying two copies of the DM gene (M/M) are affected and have an increased likelihood of developing the disease.

  • Dogs carrying only one copy of the gene (M/n) are not affected but can pass the defect onto offspring.

  • Dogs not carrying any copies (n/n) are not affected and will not pass the gene onto offspring.

 

Epilepsy

There is no current test for epilepsy in any breed but it should be mentioned. Epilepsy is estimated to affect 4% of Aussies and cannot be cured. Primary epilepsy usually presents in young adults, 1-4 years of age, and a diagnosis is made after other causes have been ruled out. Dogs affected may require lifelong treatment, though medication is not always effective in controlling seizures. Epilepsy can be fatal.