Scottish fold osteodystrophy
The Scottish Fold is one of the rarest purebred cats in Australia. One of the features of this breed of cats is the forward-folding ears which develops from 2 - 4 weeks of age, which is a physical feature that made the breed so attractive, but which comes as an incomplete dominant disease associated with abnormal and sometimes crippling endochondral ossification. Kittens with radiologically evident bone lesions are only produced from fold-to-fold matings.
As a result of these findings, the breed was banned in England in the mid 1970s, but was eventually exported to the USA where they were outcrossed with other breeds to produce the Scottish shorthairs (Scottish Fold straight ears or Scottish Fold variant). The Scottish shorthair developed a number of skeletal abnormalities such as an abnormal, inflexible tail base, shortened feet, abnormal gait and consequent lameness.
Clinical symptoms may present from weaning onwards, with symptoms of arthritis worsening as the kitten grows to maturity. Affected homozygous cats (fold-to-fold matings) are lame, and affected bones are deformed and swollen. All Scottish Fold-related cats with folded-ear phenotype, even if heterozygotes, suffer from some degree of osteochondrodysplasia of the distal limbs.
A partial, left-sided conduction deafness has also been reported associated with this disease.
Radiographic changes mainly include exostosis and secondary arthritis around affected joint lesions, and defective conformation in the phalanges and caudal vertebrae. The oral chondroprotective agents such as glucosamine and chondroitin sulfate have improve clinical well-being of feline patients but surgical intervention is usually required to improve mobility in most affected cases. Radiation therapy has also been attempted in some cats, with clinical improvement reported.
Since the prognosis of clinically affected cats with bone abnormalities is guarded to poor in most cases, it is suggested that breeding of fold-eared cats should be severely limited, and if used at all, they should be mated only to normal-eared cats.
- Scottish Fold of Calgary
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