Manx Syndrome Breed: Manx cat Condition: Manx Syndrome Related terms: spina bifida, myelodysplasia, spinal cord dysplasia, hydromyelia, spinal dysraphism, syringomyelia, spinal dysplasia Outline :The genetic mutation that causes Manx (tail-less) cats also frequently causes severe disease consequences because of its effects on the development of the spine and spinal cord. The various forms of spina bifida which commonly occur lead to complications which can cause partial paralysis, prevent normal behaviours, cause incontinence, and lead to painful infections. Cats evolved to have tails and they use them for communication and balance. As long as people buy or wish to keep Manx cats the serious disease and welfare problems caused by the genetic mutation carried by all these cats will be perpetuated. 1. Brief description The term ‘Manx syndrome’ is used to describe a range of conditions seen in the Manx cat, associated with it’s characteristic feature – a shortened or absent tail Unfortunately this very obvious vertebral mutation is often linked to some severe developmental abnormalities elsewhere in the spinal cord leading to significant neurological disease (disease of the nervous system). The commonest developmental problem seen in Manx cats is spina bifida. Spina bifida is a general term used to describe several conditions where the neural tube which forms the spinal cord fails to close and the arches of the vertebrae (bones of the spine) also fail to form completely. Signs shown by Manx cats with spina bifida vary according to the severity of the spinal cord abnormality, but can include an abnormal “hopping” gait, plantigrade stance (with more of the hind leg on the ground than normal), urinary and faecal incontinence, and lack of sensation in the hind legs and around the perineum (the skin round the anus and urethra openings). Some cats can be so severely affected that the deformity is fatal. 2. Intensity of welfare impact Some Manx cats have no signs of spinal cord problems, whilst others experience major welfare problems, such as lack of properly functioning hind limbs and urinary and faecal incontinence. Cats which are unable to control their bladder or bowels may be regularly soiled in urine and/or faeces which causes skin inflammation, irritation and infection. Those whose hind limbs do not function correctly are hindered in their ability to show a full range of normal behaviours. Severely affected individuals may die during foetal development in the uterus or are euthanased at an early age. 3. Duration of welfare impact Signs may be present at birth or appear in the weeks to months afterwards. Usually there is no effective treatment so the condition is life-long. Occasionally surgical treatment can be beneficial, although this can have its own welfare impacts. 4. Number of animals affected Manx cats with spina bifida are common. “Rumpy” cats (completely tailless Manx cats) are most often affected (Kroll and Constantinescu 1994). 5. Diagnosis Spina bifida is diagnosied using a combination of veterinary examination, x-rays, myelography and magnetic resonance imaging (MRI) scans. 6. Genetics Tail-lessness in Manx cats is due to a mutant gene, labelled M which causes abnormal development of the coccygeal (tail) and sacral vertebrae (the sacrum is the area of the spinal cord in front of the tail.) All Manx cats are heterozygous for the Manx gene (i.e. Mm), which means they have one mutant M gene and one normal m gene. The mutant M gene is dominant to the normal m gene (Long 2006). Homozygous MM cats with two mutant genes are so abnormal they die early during foetal development, thus the Manx gene is described as a lethal gene (Long 2006). 7. How do you know if an animal is a carrier or likely to become affected? Affected individuals are likely to be identified prior to leaving the breeders. All new Manx kittens should be fully examined by a vet prior to purchase. All Manx cats have the mutant gene, M, and could produce affected offspring. 8. Methods and prospects for elimination of the problem Currently there is no programme to decrease the unwanted affects of the mutant M gene. The gene is intimately linked to the phenotype that characterises the Manx cat i.e. tail-lessness, so breeding Manx cats results in persistence of these welfare issues. ufaw.org.uk/manxsyndrome.php
Posted on: Tue, 05 Nov 2013 16:45:16 +0000
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