Early findings from CA testing in Kelpies and working Border Collies
Summary
Cerebellar abiotrophy (CA) has been reported in working Kelpies and working and show Border Collies. Dogs affected by CA can show head or neck tremors, problems with their balance, exaggerated or erratic leg movement and problems eating or drinking from a bowl.
Research at the University of Sydney using a samples from working Kelpies identified genetic markers that can be used to identify some dogs that are at high risk of developing CA. Genetic "markers" do not actually cause the trait they are a marker for. This means that in a minority of cases an animal can test negative but still have the trait, or conversely test positive but still lack the trait. The extent to which this happens for each marker is covered below.
The research that identified these markers for CA in working dogs is being prepared for publication. We will update our website when the publication is available.
We have tested 286 dogs for CA: VMP1, 224 dogs for CA: LINGO3 and 205 dogs for CA: NUP153 between December 2019 and June 2020.
CA: VMP1
This CA marker was identified in working Kelpies that started showing signs of CA at 6 to 8 months of age.
We have tested 286 dogs for CA: VMP1. Five of these dogs tested as being affected, i.e. having an A A result. Owners reported that all five showed signs of CA, and in all cases the signs of CA had become worse over time. This is consistent with the initial research, which also found that all dogs with an A A result had signs of CA that became more severe over time.
An additional 56 dogs have been identified as carriers for this form of CA. This gives us a gene frequency of 11.5% amongst the dogs we have tested. The gene frequency in the general population is likely to be lower, because breeders who have produced affected dogs are more likely to use the test.
The CA: VMP1 has successfully identified working Border Collies with CA.
This marker is excellent at predicting CA. We strongly recommend avoiding mating two carriers for this marker.
CA: LINGO3
This CA marker was identified in working Kelpies that started showing signs of CA at 6 to 12 weeks of age.
We have tested 224 dogs for CA: LINGO3. Twelve of these dogs tested as being affected, i.e. having an T T result. Owners reported that nine of these twelve dogs showed signs of CA. Of the affected dogs, most showed mild signs or moderate such as a head tremor and reduced coordination. This is consistent with the initial research, which also found that not all dogs with an T T result had signs of CA. Dogs affected with this form of CA are also reported as not worsening with time.
An additional 71 dogs have been identified as carriers for this form of early-onset CA. This gives us a gene frequency of 21% amongst the dogs we have tested. The gene frequency in the general population is likely to be lower, because breeders who have produced affected dogs are more likely to use the test.
This marker is good but not excellent at predicting CA. We still recommend avoiding mating two carriers for this marker.
This marker has identified CA in a border collie with show lines.
CA: NUP153
This CA marker was identified from a single litter of affected pups. In this litter pups showed signs of CA while they were very young, at around 4 weeks of age.
We have tested 205 dogs for CA: NUP153. Seven of these dogs tested as being "affected", i.e. having a del del genotype. Amongst these seven dogs, three showed signs of CA. All three affected dogs also tested as being affected for early-onset CA (CA: LINGO3), and the age of onset of their signs of CA was consistent with CA: LINGO3 rather than CA: NUP153.
We have concluded that the CA: NUP153 test is not useful to predict CA, except possibly in the family where it was first identified. We have removed this test from the panel to reduce the price. It is still available as an addition to the panel for those people who would like to use it.
Should I test my dogs? I hear the tests aren't perfect...
That is a decision you need to make yourself.
In their current form the tests work well enough that they could be used to prevent most CA cases in working Kelpies and working Border Collies. A good working dog is a valuable animal, so getting one extra healthy pup should more than cover your testing expenses.
Are there more types of CA?
Yes, there are. The working dog CA panel has identified the large majority of the CA cases we have been asked to test so far, but some cases that remain a mystery.
If or when more CA markers or improved CA markers are identified, we will update our panel to include them. If you've already tested your dog with us you can simply ask us to add that test to your dog, and you won't be charged the sample processing fee again.
If we test your dog as negative for CA but you believe it shows signs of the disorder, let us know. Tell us how old the dog was when you started noticing signs, how severe their signs are, and whether they have been getting worse. We will feed this information back to the research group.
Do these tests work for my breed?
We don't know if these tests work outside of working Kelpies and working Border Collies. We suggest testing a CA-affected dog from your breed to see whether our tests identify it as having CA. If they do, these tests will probably be useful for your breed. Conversely if your affected dog tests negative these tests are unlikely to help.
Does CA run in the male line or female line?
Both parents must be carriers or affected for the same type of CA marker to produce affected pups. Male and female pups are equally likely to be affected. This is reflected in the test results so far: Male and female dogs have been almost equally represented amongst the dogs we have identified as affected CA: VMP1 and CA: LINGO3. Two of the five dogs found to be affected with CA: VMP1 were male, and six of the twelve found to be affected with CA: LINGO3.
More about the dogs we have tested
More female dogs have been tested than male dogs.
Samples have been submitted from a lot of different countries. Carriers for either CA: LINGO3, CA: VMP1 or both have been identified in all countries that have submitted more than five samples.
