Generalized cutaneous urticaria associated with Giardia infection in a five-month old puppy

Giardia cysts are commonly encountered in fecal examinations of dogs; intestinal infections can be asymptomatic or cause diarrhea but have not been previously associated with urticaria. A five-month old dalmatian puppy presented with a one-week history of cutaneous urticaria and pruritis. Wheals were most prominent on the head, abdomen, and inguinal region. A fecal flotation was performed to rule out internal parasites as a cause of hypersensitivity. Fecal float yielded many Giardia cysts, and treatment for giardiasis with fenbendazole was initiated. Urticaria improved drastically within a day after treatment initiation and completely resolved by the completion of the treatment regimen. No Giardia cysts were detected on the follow up fecal flotation three days later, and fecal Giardia antigen testing was negative at this time. No additional changes in management, housing, food, or environment were noted and the puppy has remained without additional clinical signs for three months following initial presentation.