Serological relationship between a donkey alphaherpesvirus (isolate M7/91) and equid herpesvirus type 1 and 4.

Rabbit hyperimmune serum prepared against a donkey alphaherpesvirus isolate (M7/91), and against EHV-1 and EHV-4 was used to characterise the antigenic relationship between these 3 viruses. Serum from immunised rabbits was always more specific for homologous virus and showed different cross reactivity for heterologous virus. It was concluded that the immunologic relationship between the M7/91 isolate and EHV-1, was closer than that between this isolate and EHV-4. A serological survey of donkeys (n = 116) and horses (n = 57) revealed evidence of the presence of neutralising antibody to M7/91 in their sera. The titres of antibody to M7/91 in donkeys, ranged from 1:32-1 > or = 256 and was significantly higher than antibody titres to EHV-1 and EHV-4, while in horses, titres were lower but comparable to equine herpesvirus 1 and 4.