Cerebellar degeneration in Old English Sheepdogs.

OBJECTIVE

To evaluate related and unrelated Old English Sheepdogs (OESD) by clinical examination, histologic evaluation, and pedigree analysis to determine whether cerebellar degeneration develops in this breed and whether there are genetic implications.

DESIGN

Case study and pedigree analysis.

ANIMALS

24 clinically normal or affected OESD; brain tissue specimens from 25 unaffected or affected OESD.

PROCEDURE

Twenty-four OESD that were chosen because of a family history of gait abnormalities were given physical and neurologic examinations to determine whether they had clinical signs of cerebellar degeneration. Tissue specimens from 25 brains of OESD were examined histologically. Nine OESD that were determined to have cerebellar degeneration histologically as well as 2 clinically affected littermates of the histologically confirmed affected OESD were included in the pedigree analysis. Standard statistical evaluation of pedigrees for hereditary conclusions was used.

RESULTS

Twelve of the 24 OESD evaluated by neurologic examination had a progressive gait abnormality. Clinical signs of cerebellar degeneration typically started later in life in OESD, compared with description for other dog breeds, and progressed ore slowly. Results of pedigree analysis revealed that 11 of 49 dogs were affected in 9 litters, providing an affected-to-total ratio of 22.49%.

CONCLUSIONS AND CLINICAL RELEVANCE

Results of our study indicate that a slowly progressing late-onset form of cerebellar degeneration develops in OESD, and the mode of inheritance is by an autosomal recessive gene.