Familial Episodic Hypokalaemic Polymyopathy
Hypokalaemia is a debilitating and sometimes fatal disease characterised by periodic bouts of skeletal muscle weakness which can affect the whole body but is most noticeable in the neck muscles .The cat tends to adopt a “meerkat” posture and has difficulty walking and jumping. The severity of the symptoms can range from slight muscle weakness to complete collapse.
Symptoms have been known to appear as early as five weeks of age, most at a much later onset of four months, some at fifteen months.
A blood test can be used to confirm the clinical condition. The results will show low serum potassium and high CPK, an enzyme indicating muscle damage.
In some cases potassium supplements can be used to alleviate the symptoms but this is not a cure for the condition, being of genetic origin.
There is now a genetic test available. A mouth swab is all that is necessary, sent to the Langford Diagnostic Laboratory, Bristol. Details can be found at the Langford website:- http://www.langfordvets.co.uk/
Contact Mrs Carolyn Kempe, Hon Secretary email: firstname.lastname@example.org, for the code to claim the discount offered by Langford to BCC members.
Please note that any tests submitted other than those by a veterinary surgeon, having verified the cat’s microchip number, will not be eligible for inclusion on any genetic register e.g. the FAB or GCCF. A certificate will be sent to you noting your cat’s status as follows:-
Normal: does not have the mutated gene .
Carrier: has one copy of the mutated gene. Is unaffected but can pass the gene to it’s kittens.
Affected: has both copies of the gene and therefore has the condition.
HKL is classified as an autosomal recessive disease. This means that the cat has to have two copies of the mutated gene for the disease to manifest.
A cat tested as “affected” must not be bred from however slight the symptoms.
All kittens from such a cat will inherit one copy of the gene if mated to a “normal” and some will inherit two if mated to a “carrier”.
A cat tested as a “carrier”, having one copy of the gene , will appear normal and not have the disease, but will pass on the gene to some of it’s kittens.
“Carriers” can be used but must only be mated to cats tested free of the gene. Any resulting kittens kept for breeding must be tested for HKL.
It is recommended that breeding cats tested as “carriers” should not be neutered as many could still play an important part in preserving the health of the gene pool. For every 1% of the Burmese breed classed as “affected” there will be an estimated 18% “carrier” status. To remove so many individuals from the gene pool would not be wise.
The number of cats being tested is encouraging and it is hoped that if this continues, together with responsible breeding, the “carrier” frequency will gradually be reduced until the disease is eliminated from the Burmese breed.