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CA in the Kelpie

CA, Cerebellar Abiotrophy or Ataxia

CA or Cerebellar Abiotrophy is a significant issue that affects our breed.

What is cerebellar abiotrophy?

The cerebellum is the part of the brain that regulates the control and coordination of movement. In this condition, cells in the cerebellum mature normally before birth, but then deteriorate prematurely causing clinical signs associated with poor coordination and lack of balance. The Purkinje cells in the cerebellum are primarily involved; cells in other areas of the brain may also be affected.

What does cerebellar abiotrophy mean to your dog & you?

The cerebellum is the part of the brain that regulates the control and coordination of voluntary movement. The clinical signs of cerebellar dysfunction in affected dogs may include poor balance, a wide-based stance (feet planted far apart), stiff or high-stepping gait, apparent lack of awareness of where the feet are (standing or walking with a foot knuckled over), and head or body tremors. These signs worsen either quickly or slowly (see breed list above). Affected dogs may become unable to climb stairs or stand without support. They have normal mental alertness.

Where other regions of the brain are also affected, you may see signs such as behaviour change (loss of house training, aggression), confusion, blindness, and seizures.

How is cerebellar abiotrophy diagnosed?

This is a rare disorder. The clinical signs are suggestive of cerebellar disease, particularly if they are seen in a breed in which abiotrophy is known to occur. Your veterinarian will do tests to rule out other conditions that can cause similar signs.

For the veterinarian: Routine diagnostic tests are normal with this condition and a definitive diagnosis can only be made by brain biopsy or on post-mortem. MRI may be helpful in dogs in which there is gross cerebellar malformation; however generally with this condition, the cerebellum appears grossly normal. Histopathologic abnormalities are often minimal and do not seem to correlate with the severity of cerebellar signs.

How is cerebellar abiotrophy treated?

There is no treatment for this condition. Dogs do not recover from this disorder and usually at some point (depending on the rate of the progressive deterioration that occurs), euthanasia becomes the best option.

Cerebellar Abiotrophy (CA/ataxia) in the Australian Kelpie by Kathy Gooch

The most prevalent genetic disease to affect the Australian Kelpie is CA (cerebellar abiotrophy). Because the ramifications of this condition are universally widespread it is the most significant genetic disorder in the breed. It is also one which is not openly discussed by breeders. Affected dogs are usually destroyed, with no necropsy being done and the carrier parents are bred to other dogs, only to perpetuate the carrier status. Hopefully this article will answer questions regarding this condition and illustrate the need for a DNA test and co-operation amongst breeders with regards to submitting samples.

What is cerebellar abiotrophy?

The cerebellum is the part of the brain that regulates the control and coordination of movement. In this condition, cells in the cerebellum mature normally before birth, but then deteriorate prematurely causing clinical signs associated with poor coordination and lack of balance. The Purkinje cells in the cerebellum are primarily involved; cells in other areas of the brain may also be affected.

How is cerebellar abiotrophy inherited?

CA is an autosomal recessive mode of inheritance. This means BOTH parents must be carriers or affected. Carriers exhibit no clinical symptoms of the disease, while affected dogs can exhibit a range of symptoms from mild to severe. Clinical signs are first seen at 6 to 12 weeks, and the condition worsens quickly (over a few weeks).

This form of CA is known as Postnatal cerebellar abiotrophy – Cells in the cerebellum are normal at birth and begin to degenerate at variable times thereafter. The most common breeds affected are Australian Kelpie, Border Collie, Labrador Retriever –

What does cerebellar abiotrophy mean to your dog & you?

The cerebellum is the part of the brain that regulates the control and coordination of voluntary movement. The clinical signs of cerebellar dysfunction in affected dogs may include poor balance, a wide-based stance (feet planted far apart), stiff or high-stepping gait, apparent lack of awareness of where the feet are (standing or walking with a foot knuckled over), and head or body tremors. These signs worsen either quickly or slowly (see breed list above).

Affected dogs may become unable to climb stairs or stand without support. They have normal mental alertness. Clinical signs can come in varying degrees of severity from mildly affected egg; slight head tremor, slight propping in the rear end; to severe, falling over and total loss of control. Symptoms usually appear at 6 to 12 weeks. Some dogs adapt to the dysfunction and show little disability.

Where other regions of the brain are also affected, you may see signs such as behaviour change (loss of house training, aggression), confusion, blindness, and seizures.

How is cerebellar abiotrophy diagnosed?

The clinical signs are suggestive of cerebellar disease, particularly if they are seen in a breed in which abiotrophy is known to occur. Your veterinarian will do tests to rule out other conditions that can cause similar signs. Unfortunately 100% diagnoses can only be determined upon necropsy of the brains of suspect animals. This re-enforces the need for a DNA test to determine carrier/affected status.

How is cerebellar abiotrophy treated?

There is no treatment for this condition. Dogs do not recover from this disorder and usually at some point (depending on the rate of the progressive deterioration that occurs), euthanasia becomes the best option.

Breeding advice:

Affected dogs, should NOT be bred. The options for their parents (carriers of the trait), and their siblings (suspect carriers) are such;

  1. Wait until a DNA test is established, breed to a tested clear dog or bitch and test the puppies for carrier status. None will be clinically affected.
  2. Desex carriers and use them strictly as working dogs.
  3. Euthanize carriers; which is illogical and radical as this narrows the genetic pool of the Kelpie drastically and only sets the parameters for other genetic problems to crop up.

CA has become a widespread problem in the breed. It is apparent that it is not just an Australian, American, or European problem. Because of the relative ease of importing a dog from Australia a Rabies free country it is now a global issue. CA is also in both the Working Kelpie and the Show Kelpie.

More than one Working Kelpie line is affected. Dr. Don Robertson, a West Australian geneticist who studied the problem wrote in an article on CA in Kelpies for the Australian Veterinary Journal in 1989 “In the Kelpies studied here, the putative gene appears to have been inherited from several dogs which have been prominent in sheep dog trials and have been widely used for breeding. Consequently, an increase in the incidence of cerebellar abiotrophy in working sheepdog strains can be expected. “. Unfortunately at present there are very few Working Kelpie pedigrees in which these lines do not appear. This once again exemplifies the need for a DNA test.

It seems that the reason it does not appear that CA is a problem in Australia is the “shoot, shovel and shut-up attitude” No one talks about affected litters. They just disappear in a hole. Then the parents which are obviously carriers are bred to other dogs and if nothing shows up the pups are sold as “normal”. The unsuspecting buyer is than buying a possible carrier. Then the buyer purchases another dog from the same lines in the hopes of doing a line breeding. Than as bad luck would have it that dog is a carrier. These dogs are bred and unfortunately you have a litter of affected pups. The ones showing symptoms are shot and the non affected ones sold and bred. Odds are they are carriers as well so the problem continues on. Some of these carriers have been exported out of the country only spreading the problem. The issue with CA as well is that it can appear at six weeks as tremors or at two or three years as seizures. This is a terrible loss to many people of a beloved pet, not to mention the time and money put into training a dog. If a DNA test was developed, affected individuals could be euthanized and carriers could be desexed and still used as working dogs. Also the non carriers of a litter could be bred and the positive traits of those lines still passed on with out the worry of genetic problems. If breeders think that they would lose money as a result of this DNA test, exactly the opposite would occur. If a pup was sold with a CA clear certificate the value of that pup would be greater than those without. Also because of the cost of export, breeders and buyers would be put in a position to have testing done before dogs left the country.

Because the Kelpie has a relatively small gene pool to eliminate excellent carriers from the gene pool would be madness. The KEY is to KNOW THE STATUS of the dogs you are breeding.

Recent advances in technology have provided the scientific means to locate the genome responsible for CA. This is an expensive procedure and funding is still needed. But thanks to monies contributed by the Working Kelpie Council and a generous individual that owns one pet Show Kelpie; Mr. Terry Snow research has now been started. It is the hope to have the gene identified in a few short months. In addition a DVD is in the process of being made which outlines all aspects of CA and includes footage of affected dogs will be available to all veterinarians and Kelpies owners through Dr. Wilton and the Working Kelpie Council.

Because the symptoms of CA are not always definitive and varying degrees occur, this may not be a simple gene. This is what Dr. Wilton will determine. What is needed now is co-operation from all breeders who may have suspect dogs or litters to submit blood to Dr. Wilton. This can be done from overseas as well as Australia. These samples must be submitted directly to Dr. Wilton. They must be accompanied by a pedigree. All information will be retained by Dr. Wilton in confidence.

His contact info is;

Alan Wilton
School of Biotechnology and Biomolecular Sciences
University of New South Wales
NSW 2052
Phone +61 2 9385 2019
Fax + 61 2 9385 1483
Mobile 0422 736 425

Email- a.wilton@unsw.edu.au

More CA Resources

Click HERE to Access the Working Kelpie Council of Australia’s website on CA

Downloadable Resources

Report: How CA is inherited in the Australian Kelpie

Just Because of Jane

Hereditary Cerebellar Abiotrophy in Australian Kelpie Dogs