Sensitization to dust mites in cats with Otodectes cynotis infestation

Abstract

Sensitization to the dust mites was demonstrated by an intradermal (ID) skin test in 33 of 55 cats with Otodectes cynotis infestation. Positive ID test reactions to Dermatophagoides farinae were noticed in 32 (58.2%), to Dermatophagoides pteronyssinus in 29 (52.7%) and to Acarus siro in seven (12.7%) cats. The presence (P = 0.03) and duration (P = 0.04) of pruritus were positively associated with the ID test results. All the cats had a complete response to systemic ivermectin therapy, although three of them became reinfested as soon as they were in contact with other cats. The ID test was negative in 25 cats that had reacted positive previously, when the test was repeated 3-6 months after the acaricidal treatment. During that time there was no evidence of concurrent ectoparasitic infestation. The remaining eight cats were re-infested by O. cynotis or lost to follow-up.