Frequency of delusional infestation by proxy and double delusional infestation in veterinary practice: observational study.

BACKGROUND Nothing is known about the prevalence of delusional infestation in veterinary practice and the consequences for psychiatrists. AIMS We attempted to examine the frequency of delusional infestation among pet owners presenting their animals to veterinary clinics. METHOD We conducted a survey among 32 663 veterinary clinicians who were members of the Veterinary Information Network. RESULTS The respondents had seen 724 suspected cases of delusional infestation by proxy in a pet. The clients were mainly White, female and 30-60 years old. They presented mainly dogs and cats, and the alleged infestation was mainly with arthropods or worms. Also, 252 clients claimed to be affected themselves; we termed this 'double delusional infestation'. CONCLUSIONS Delusional infestation is seen frequently in veterinary practice. Psychiatrists need to be aware that patients may have pets they believe are infested.