Study of hereditary cerebellar degeneration in cats.

OBJECTIVE

To elucidate the nature of ataxia observed in 3 cats spanning 2 generations.

DESIGN

Experimental breeding was attempted to confirm heritability of the disease and establish the mode of inheritance; the original 3 cats and their offspring were studied.

ANIMALS

Seven diseased cats spanning 3 generations and 11 neurologically normal cats.

PROCEDURE

Cats were examined by use of the following methods: clinical observation, hematologic and serum biochemical examinations, neurologic examination, electrodiagnostics, magnetic resonance imaging, lysosomal enzyme activity assay, horizontal transmission test, and virologic and pathologic examinations.

RESULTS

All kittens (1 male and 3 females) obtained by backcrosses developed pure cerebellar dysfunction from the age of 7 to 8 weeks onward. It became progressively worse, but not fatal, between 1 and 2.5 months. Prenatal or perinatal infection with feline panleukopenia virus, inherited lysosomal storage diseases, including gangliosidosis and mannosidosis, and feline hereditary neuroaxonal dystrophy were excluded. Magnetic resonance imaging indicated that size of the cerebellum of diseased cats was markedly reduced. Cerebellar cortical degeneration, especially with extensive destruction of Purkinje cells, was observed microscopically.

CONCLUSION

The disease was concluded to be cerebellar degeneration of a new clinical form in cats having an autosomal recessive mode of inheritance.

CLINICAL RELEVANCE

When cerebellar dysfunction is diagnosed in a cat, hereditary cerebellar degeneration of this type should be considered in the differential diagnosis.