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| HEALTH NEWS AND SUTDIES |
| Link to information on current Research projects going on for the Australian shepherd and health issues http://www.ashgi.org/research.htm |
Genetic Mutation Associated With Hereditary Cataract In The Australian Shepherd –Launch of New DNA Test At Animal Health Trust Background During 2006 researchers at the Animal Health Trust, UK identified a genetic mutation in a small number of Australian Shepherds affected with Hereditary Cataract (HC). To further investigate the relationship between the mutation and HC in the breed the AHT recruited and analysed DNA samples from a large number of additional Australian Shepherd from the UK, Europe and USA. The results show that the mutation is a risk factor for the development of cataract in the Australian Shepherd. Our study indicates that the likelihood of developing bilateral posterior cataracts is approximately 12 times higher for Australian Shepherds that carry the mutation (either one or two copies) than it is for dogs that don’t carry the mutation. The mutation is dominant, which means that dogs only need to inherit a single copy of the mutation to be at increased risk of developing cataracts. This also means that dogs/bitches that have produced offspring with cataracts are not necessarily carriers of the mutation as the affected offspring may have inherited a single copy of the mutation from their other parent. DNA Test IS Available March 2008 The Animal Health Trust is very pleased to announce the launch of a DNA test based on the mutation we have identified. The test will be available from March 10th. For full details regarding how to submit a sample for testing will shortly be made available on our website (www.aht.org.uk). What The Results Mean If your dog carries one or two copies of the mutation it has an increased chance of developing bilateral posterior cataracts. We currently estimate it is about 12 times more likely to develop this type of cataract than a dog that doesn’t carry the mutation. If your dog does not carry the mutation it has a lower chance of developing cataracts, during its lifetime. It is possible that additional mutations exist in the Australian Shepherd population that are also risk factors for the development of cataracts; our DNA test does not currently detect these mutations. This test will detect those dogs that carry either one or two copies of the HC mutation, and those that are clear of the mutation. Breeders will be sent results identifying their dog as belonging to one of three categories: CLEAR: the dog does not carry any copies of the HC mutation and will neither develop the form of HC that is associated with this mutation, nor pass a copy of the HC mutation to any of its offspring. The dog has one copy of the HC mutation and is at increased risk of developing cataracts during its lifetime. The dog will pass the mutation to 50% (on average) of its offspring. The dog has two copies of the HC mutation and is at increased risk of developing cataracts during its lifetime. The dog will pass the mutation to all of its offspring. If a dog with one copy of the HC mutation is bred with a clear dog 50% (on average) of the puppies will inherited a single copy of the mutation and be at increased risk of developing cataracts. The remaining 50% of the puppies will be clear of the mutation. If a dog with one copy of the HC mutation is bred with another dog with one copy of the HC mutation approximately 75% of the puppies will inherit at least one copy of the mutation and be at increased risk of developing cataracts. If dog with two copies of the HC mutation is bred with either a clear dog or a dog with one copy of the HC mutation all the puppies will inherit at least one copy of the mutation and be at increased risk of developing cataracts. We are currently investigating the possibility more than one genetic form of HC exists in Australian Shepherds. If your dog has been clinically diagnosed with cataracts by a veterinary ophthalmologist we will test you dog free of charge upon receipt of a copy of the dog’s eye examination. Please email dnatesting@aht.org.uk for further details. Samples submitted should be cheek swabs (a non-invasive sampling method) obtainable from the Animal Health Trust. Samples should be sent together with a completed DNA Testing form and payment for each sample to Genetic Services, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU. |
| The Cataract Conundrum: Understanding and Applying the AHT's New Hereditary Cataract Test See article Here |