|The Australian Cattle Dog is affected by certain health problems. At present we are gradually eliminating these hereditary disorders thanks to different forms of screening. These tests are indispensable tools for breeders as they allow them to offer a real guarantee when it comes to the quality of their production.
PROGRESSIVE RETINAL ATROPHY PRCD & RCD-4
PRA PRCD is a hereditary disease that displays clinical signs when an ACD is around 4 years old. The dog starts to have problems seeing at night and later on during the day due to progressive cone rod degeneration. The disease is incurable and there are no known effective treatments to slow down the symptoms. PRA is a disease affecting many breeds of dogs, but the forms are diverse and varied (there are currently 17 mutations of the disease) and it is often breed specific. When it comes to the ACD, the most common form is PRCD.
At the turn of the century, around 25% of Australian Cattle Dogs were free from PRA PRCD, 50% were carriers of the disease, while 25% were likely to develop it, thereby gradually becoming blind.
At present, a DNA test offers the possibility of determining, as of the age of 5 weeks thanks to a blood sample or cheek swab, whether an Australian Cattle Dog is CLEAR, CARRIER or AFFECTED. Knowing which category your dog falls into is of use for several reasons. First of all, the test indicates whether a dog will develop this disease before he starts to show any symptoms (4 years of age at the earliest). It also allows breeders to make the right choices in view of no longer producing blind dogs.
As a result, the following pairings are possible:
- CLEAR x CLEAR - automatically producing CLEARS
- CLEAR x CARRIER - producing CLEARS or CARRIERS
- CLEAR x AFFECTED - systematically producing CARRIERS
However the following combinations should be strictly avoided:
- CARRIER x CARRIER - producing NORMAL, CARRIERS, but also AFFECTED dogs
- CARRIER x CARRIER - producing CARRIERS and AFFECTED dogs
- AFFECTED x AFFECTED - producing entirely AFFECTED dogs
It goes without saying that untested dogs should only be mated to CLEAR ones.
Thanks to the DNA test, the above mentioned figures have evolved. At present most Australian Cattle Dogs are either CLEAR or CARRIERS.
Some ACDs are also carriers of PRA RCD-4, a late offset version of the disease. For this reason it is highly recommended to test brood stock for these two forms.
An ACD Pack screening 5 diseases at the same time
For a reasonable price, breeders can send the DNA of their dogs to the German laboratory LABOKLIN in view of having their DNA tested for the following health problems: Primary Lens Luxation, Degenerative Myelopathy, Progressive Retinal Atrophy PRCD, Progressive Retinal Atrophy RCD4, and Neuronal Ceroid Lipofuscinoses (early and late offset).
According to official statistics, around 12% of Australian Cattle Dogs become partially deaf as they gain their colour, while 2% become fully deaf. Only one of the parents needs to be a carrier of the problem for it to be passed on to some of the offspring, but the results are worst if one of the parents is actually half deaf.
If it's easy to spot a deaf dog, such isn't the case for individuals with partial hearing loss. In light of the number of half deaf ACDs, it's important for dogs to undergo a Brainstem Auditory Response "Baer" test before being used for breeding. Pups, that can be checked as of 6 weeks of age, should also be tested before being sold to their future owners. This test helps determine whether a dog hears perfectly well or not by detecting electrical activity in the cochlea and auditory pathways in the brain, the way an antenna detects TV signals. The response waveform consists of a series of peaks, with an ear that is deaf forming an essentially flat line. In France it is possible to have one's dogs tested at various Veterinary Hospitals or by a handful of private clinics.
DISH - A HEREDITY SPINE DISEASE
This article is intended to raise awareness in breeders of Australian Cattle Dogs for a grave health problem of the spine with high heredity. The disease's name is DISH (diffuse idiopathic skeletal hyperostosis) which roughly translates to increase in bone substance without known cause. DISH is common in ACDs and until now very often underestimated or unrecognised. A research project is underway at the Swiss University of Bern aiming to develop a gene test for DISH. Prof. Tosso Leeb is collecting blood samples of affected dogs and their relatives. X-rays of the spine are analysed and categorised by PD Dr. med. vet. F. Steffen, ECVN.
Age of onset:
It was shown that at 15 months of age there are no signs of DISH on dogs, who were later to be diagnosed as DISH affected. The earliest signs of DISH on x-rays are probably visible from 2 years of age on or even older.
Mode of inheritance:
In various unrelated lines of descent, there are as many as 4 uninterrupted generations of affected dogs recorded. For every affected dog there was at least one affected parent to be found. This means DISH is most likely a dominant mode of inheritance. Dominant means: Dogs who have either one (heterozygous) or two (homozygous) defective alleles on the DISH gene locus are affected of DISH. Only dogs with two healthy alleles are free of DISH. A recessive or polygenetic mode of inheritance DISH has not yet disproved, but we hope the dominant-mode-of-inheritance hypothesis will stand true as our current data strongly supports it. Until now, there are no DISH affected dogs out of two DISH free dogs recorded.
From the current scientific and veterinarian views, it is strongly recommended to take x-rays of the spine before breeding a dog. Until there is a genetic test developed, the safest choice is to breed only two dogs older than 2 years old that are both free of DISH.
What is DISH?
DISH (diffuse idiopathic skeletal hyperostosis) is a non-inflammatory process, also known as bamboo spine. In a DISH affected dog the spines tendons and ligaments (especially the anterior longitudinal ligament) calcify already in a young dog (even before the age of 2 years). The intervertebral spaces and the intervertebral discs are affected only very rarely. X-rays show those calcifications have the same bone density as the vertebrae. Calcification begins in the middle of a vertebra. Sometimes a fine line is visible at the original border of the vertebra.
Most frequently DISH affects the lumbar spine although any other part of the spine can be affected as well. It is most infrequent in the cervical region. Interestingly DISH is extremely rare for the lumbosacral region (L7 to S1). The cause for DISH is yet unknown although a huge genetic component is assumed. There is no reason to believe that overly exercise in young puppies would have any cause in calcification of the anterior longitudinal ligament ventral.
Clinical signs are rare in young dogs affected with DISH. A change in tail carriage, a bent or stiff spine, loss of movability, change of gait (pacing) or refusal to work in otherwise cooperative dogs can be strong indications of problems in the spine. The amount of clinical signs is dependent of the degree of DISH (number of affected vertebrae) and the age of the dog (in aging muscle power and movability decrease, pain increases).
Dogs with clinical signs may even suffer from both diseases, DISH and SD (spondylosis deformans).
DISH rarely affects intervertebral spaces and discs.
DISH rarely affects L7-S1 (lumbosacral region)
SD often comes with disc problems and commonly shows clinical signs.
Source - http://www.australiancattledog-info.info/
HIP AND ELBOW DYSPLASIA
Bad hip dysplasia isn't a frequent problem for Australian Cattle Dogs but it could become a concern if too many untested dogs or those with the disease are used for breeding.
As a result, dogs with a score of "E" or "D" (advanced stages of the problem) should only be kept as pets, while those with a score of "C" should only be mated with "A" dogs.
The same rule applies to elbow dysplasia. ACDs with a mild degree of elbow dyplasia (0/1 or 1/0) can still be bred from, as long as they are mated with dogs that have been formally identified as clear.