WayOut ACDs | HEALTH

Health concerns in ACDs

Australian cattle dogs are a generally healthy breed, however, there are genetic diseases that are more prevalent in ACDs. These include congenital deafness, progressive retinal atrophy and hip and elbow dysplasia.

Deafness

Progressive Retinal Atrophy

Hip Dysplasia

Elbow Dysplasia

Deafness

Deafness in ACDs can occur in one or both ears. A dog that is deaf in one ear is often called a 'uni" - short for unilaterally deaf. These dogs can function normally and most owners do not notice any issues with their dogs. Sometimes these dogs may have to look around to locate the direction a sound is coming from or they may sleep more soundly when the hearing side is down but they have usually adjusted to how they hear the world and have minimal to no noticeable differences from fully hearing dogs. In terms of breeding, a unilaterally deaf dog is affected with deafness. The genetics of deafness in ACDs is not yet determined and, while breeding unilaterally deaf dogs is a personal decision, doing so is believed to lead to increased risk of producing deafness in litters descended from that dog either directly or in future generations.

Dogs that are deaf in both ears have long challenged breeders. Some breeders choose to euthanize these puppies as they can be difficult to find competent homes for. Other breeders will place them in carefully screened homes. Even a full hearing cattle dog puppy is a challenge. A deaf cattle dog puppy requires a home that is committed to training and protecting their puppy in ways that are unique to deaf puppies as well as in all the ways a hearing puppy must be taken care of. A deaf dog will not hear a car coming. A deaf puppy, like a hearing puppy, won't automatically come when called but must be taught to come - with the difference that the deaf puppy learns to respond to hand signals or signals from a vibrating collar.

Puppies are screened for deafness via a Brainstem Auditory Evoked Response Test aka BAER test. This screening is done by the breeder - generally when the puppies are 6-9 weeks old. The parents of the litter, therefore, should also have been screened for deafness when they were puppies.

Click here for more information about deafness in cattle dogs: http://www.lsu.edu/deafness/deaf.htm

http://www.offa.org/deafgeninfo.html

Click here for resources on living with a deaf dog: http://www.deafdogs.org/faq

Progressive Retinal Atrophy

Progressive Retinal Atrophy, or PRA, causes late-onset progressive degeneration of the retina which means the dogs gradually go blind starting with night blindness and progressing over time to complete blindness. The age of onset is extremely variable with some dogs completely blind by 8 and some dogs just starting to show signs of night blindness at 14. Australian cattle dogs have been found to have the prcd form (progressive rod-cone deterioration) and the responsible gene has been found.

PRA or prcd is a simple recessive genetic disease. Two copies of the gene must be present for a dog to be genetically affected - which means that the dog will eventually go blind though, again, the age when signs will begin to be noticeable varies. Dogs are screened for the onset of clinical signs and other eye abnormalities via a CERF exam done by an ophthalmologist.

Genetically, dogs can be clear, carrier or affected. These are often referred to as Pattern A (clear), Pattern B (carrier), or Pattern C (affected). A clear dog has no copies of the affected gene and will not pass on or develop PRA. The carrier dog has one copy of the gene and can pass on the affected gene but will not develop PRA. An affected dog has two copies and can pass on the affected gene and will eventually develop PRA. Breeding choices can be made to avoid producing affected puppies but, because of the widespread occurrence of the disease in the gene pool and the relative newness of the genetic test, sometimes breeders will do breedings that can produce affected puppies in order to preserve other worthy attributes and genetic qualities in the parents. The ultimate goal is to remove the disease from the breed but to do so without losing any positive traits in the breed or bottlenecking the breed around the few clear males available to breed to.

For more information on PRA and genetic testing, visit: http://www.optigen.com/opt9_test_prcd_pra.html
For more information on CERF exams: http://www.vmdb.org/cerf.html

Hip Dysplasia

Hip Dysplasia is a disease of abnormal joint development characterized by joint laxity and the resulting development of degenerative changes (arthritis) secondary to that laxity. The rapidity of the development of arthritis is influenced by rate of growth, nutritional status of the growing puppy and adult, amount and type of exercise and, most importantly, by the amount of joint laxity present in the individual. Mildly loose joints will be slower to develop arthritic changes than severely loose joints. Fat dogs show wear and tear sooner than thin dogs. Joint laxity is a heritable condition. Obesity is an environmental condition.

The Australian cattle dog is generally a stoic breed with a high pain tolerance and well muscled rear legs. These factors, along with amount of joint laxity, influence what outward signs of hip dysplasia are shown by the individual. Not seeing any outward signs of a problem is absolutely NOT an indication that there is no problem.

Dogs are screened for hip dysplasia via PennHIP and OFA. The PennHIP method uses an objective measurement of joint laxity and thus can quantify the risk factor for the development of joint issues as the dog ages as well as provide an indication of the relative strength of selection pressure being applied in breeding decisions.

OFA subjectively assesses the status of the hips at the time of submission of the x-rays. OFA looks for signs of arthritic changes and the conformation of the hip joint itself to diagnose hip dysplasia. Because arthritic changes build up as the animal ages and because the evaluation is subjective, dogs that pass OFA at two years of age may be considered unaffected and bred but still may go on to develop hip problems as they age.

No method is perfect and both methods are utilized at WayOut but I prefer the PennHIP method because of its greater objectivity and usefulness in making breeding decisions to improve hips. In studying the occurrence of hip problems in dogs, knowing the status of hips in the horizontal pedigree (brothers and sisters, uncles and aunts) is just as important as knowing the hip status of direct relatives (mother, father, grandparents). The more testing in the family as a whole, the greater the confidence one can have that a litter or puppy will not be affected with this disease.

For more information on Hip Dysplasia and PennHIP: http://research.vet.upenn.edu/Default.aspx?alias=research.vet.upenn.edu/pennhip

For more information on OFA: http://www.offa.org/hipinfo.html

Elbow Dysplasia

Elbow dysplasia is a genetically influenced disease of abnormal elbow joint development. There are several different conditions that are lumped together under the name Elbow Dysplasia including: Ununited Anconeal Process; Fragmented Medial Coronoid Process; and Osteochronditis.

Screening for Elbow dysplasia is done at two years of age via radiographs submitted to OFA for review by board-certified radiologists. Elbow dysplasia leads to the formation of arthritis in the joint. Severity of the disease determines whether any outward signs are noticed as the puppy grows. Some puppies show lameness while others have no observable problems. Some forms of elbow dysplasia respond well to surgical intervention. All dogs considered for breeding should be screened for elbow dysplasia. It is relatively new for breeders of ACDs to screen elbows but again, not seeing a problem is absolutely NOT a reason to not screen.

Breeding decisions are a personal choice and using affected dogs is sometimes necessary but doing the basic screening in order to know what may be produced and attempt to minimize problems should be done in all cases before breeding.

For more information on Elbow Dysplasia and OFA: http://www.offa.org/elbowinfo.html