Lymphocyte blastogenesis to concanavalin A in dogs with localized demodicosis according to duration of clinical disease.

ABSTRACT

The aim of the study was to determine the degree of Con A induced lymphocyte blastogenesis in dogs with localized demodicosis (LD) within 1-3 and 6-8 weeks from appearance of the clinical signs. Ethidium bromide fluorescence assay was used for evaluation. In observation 9 clinically normal dogs, 6 dogs with LD a 4 dogs with generalized demodicosis (GD) were used. The results showed a statistically significant depression (P < 0.01) of blastogenesis in the LD dogs in comparison with that in the healthy dogs (Fig. 1). Responses to Con A were normal in dogs with LD in 1-3 weeks. However, a significantly depressed response to Con A (P < 0.025-0.001) was demonstrated in the LD dogs in 6-8 weeks (average 6.7 weeks) and it was comparable with that in the GD dogs with the duration of clinical disease on average for 8.7 weeks (Fig. 2; Tab. II). Thus, immunosuppression is not a necessary condition for dogs to develop spontaneous clinical LD and immunosuppression develops with the clinical signs of disease.