Immunodiagnosis of autoimmune skin disease in the dog, cat and horse.

The research article investigates the use of immunofluorescence for diagnosing autoimmune skin diseases in dogs, cats, and horses, across a sample of animals sourced largely from Western Australia. The study found that this method, when used alongside histopathological examination, could confirm the clinical diagnosis of autoimmune diseases in a significant proportion of the tested animals.

Study Sample and Methods

• The study was conducted between 1978 and 1985 and involved skin biopsies from 47 dogs, 6 cats, and 5 horses suspected to have autoimmune skin diseases.
• The animal cases were predominantly from Western Australia, with some referrals from Queensland and Victoria.
• Immunofluorescence was used to demonstrate immunoglobulin binding to intercellular cement substance and/or basement membrane, which is an indication of autoimmune response in these animals.
• Antinuclear antibody, a common indicator of several autoimmune diseases, was also noted in numerous cases.

Use of Immunofluorescence for Diagnosis

• A combination of immunofluorescence and histopathological examination was used to confirm the clinical diagnosis.
• The method was found to be effective in confirming autoimmune diseases in 19 out of the 47 dogs, 4 out of the 6 cats, and 2 out of the 5 horses in the sample.

Findings on Predispositions and Other Indicators

• Among the 19 dogs with confirmed autoimmune disease, there was no observed predisposition related to age, breed, or sex.
• However, a higher incidence (54%) of antinuclear antibody was observed amongst these dogs compared to the normal canine population (10%).
• Other autoantibodies, such as the rheumatoid factor, were sometimes present in the diagnosed dogs, indicating potential overlap with other autoimmune conditions.
• Apart from the antibodies, abnormalities in serum protein electrophoresis and serum complement C4 levels were also recorded in the group with confirmed autoimmune diseases, hinting at potential additional indicators of these conditions.