An epidemiological survey of therapy and diagnostic procedures used by Norwegian small animal practitioners in cases of nasal mite (Pneumonyssoides caninum) infection in dogs.

Forty per cent of the members of the Norwegian Small Animal Veterinary Association (NSAVA) returned a questionnaire regarding the treatment and diagnosis of canine nasal mite infection in their practices in 1996. A total of 2392 dogs were treated for this infection by 156 NSAVA members in clinical practice in that year, averaging 15.3 treated dogs per veterinarian. An estimated minimum of 6000 Norwegian dogs were treated for nasal mite infection in 1996, at an estimated cost of treatment exceeding 3.3 million NOK. Fifty-nine per cent of the practitioners included at least a case history and clinical examination as diagnostic criteria prior to initiating treatment for nasal mite infection. Fewer than 10% routinely performed more thorough diagnostic procedures, and only 1.8% of the diagnoses were verified prior to treatment. A total of 27 different treatment regimens, involving either subcutaneously injected ivermectin or orally administered milbemycin oxime, were routinely used by NSAVA veterinarians to treat these dogs. Seventy-two (53%) of the veterinarians used ivermectin exclusively, 14 (10%) used milbemycin oxime exclusively, while 50 (37%) used both ivermectin and milbemycin oxime. No other drugs were used. Evaluation of treatment was made by assessing resolution of the clinical signs following treatment, and 97% of the veterinarians were satisfied with the effect of the treatment regimen they used. Adverse side-effects following treatment for nasal mite infection in 1996 were seen on 9 occasions; 4 following ivermectin administration and 2 following milbemycin oxime treatment, while in 3 cases no information on the drug used was provided. The risk of adverse reactions to treatment of nasal mite infection in dogs was 0.4%.