An intact male beagle, approximately 2 years of age, was presented for evaluation of diarrhea.
History. The dog was first presented 2 months previously after being picked up by the owner from a roadside. At that time, the dog was in moderate body condition and the owner reported intermittent diarrhea with tenesmus for several weeks. The feces were foul-smelling with excess mucus and occasional frank blood. A fecal flotation examination done at the time of the initial visit detected a small number of Ancylostoma caninum eggs. An ivermectin/pyrantel heartworm preventative was dispensed for monthly administration. At the current visit, the owner reported that the intermittent diarrhea had continued.
Physical Examination. The dog was alert and responsive. Conjunctival and oral mucous membranes were judged to be slightly pale.
Laboratory Work. Routine hematologic and blood chemistry values were analyzed. The abnormal findings are shown in the box.
A fecal sample provided by the owner was examined using a centrifugal flotation procedure. A small number of helminth eggs was detected (Figure 1).
Diagnosis. Chronic whipworm infection.
Whipworm, Trichuris vulpis, is a common parasitic infection of the canine large intestine in the United States. Although infection is subclinical in many dogs, heavy worm burdens or increased host susceptibility can lead to large bowel diarrhea, as reported in this patient. Chronic disease may also be accompanied by anemia, hypoproteinemia, and eosinophilia.