Update on Canine and Feline Blood Donor Screening for Blood-Borne Pathogens

Wardrop, K.J.; Birkenheuer, A.; Blais, M.C.; Callan, M.B.; Kohn, B.; Lappin, M.R.; Sykes, J.

Positive serum antibody assay results suggest previous infection with the pathogen in question but do not prove current infection. Negative results of antibody testing generally suggest lack of infection, but serum antibodies can be undetectable even in the presence of an active infection. This situation is likely most common when the antibody test is performed during the acute stage of infection, which is well documented with several vector-borne pathogens (see Ehrlichia and Anaplasma sections). Other agents, such as Bartonella, are stealth organisms that evade the immune system and may not induce detectable serum antibodies. Severely immunocompromised animals also may fail to mount a specific antibody response (eg, cats with advanced FIV infection). These dogs and cats generally are ill, and hopefully would be excluded from the donor pool based on other findings.