Older dogs normally have a higher infection of these worms than younger dogs. Though rare, there are some cases of human infection. The eggs of T. vulpis are prevalent in shady moist soil areas that have been contaminated by canine feces. Pathology/symptoms Because the eggs of T. vulpis eggs are very resistant from desiccation, they can live in soil for up to seven years. Once ingested by the canine, the eggs hatch and the resulted larvae live in the small intestine. At this point, though infected, the canine is still asymptomatic. When adult form, T. vulpis live primarily in the cecum with its anterior end attached to the superficial mucosa and its posterior end extended to the cecal lumen where it consumes the canine's blood, tissue fluid, and mucosal epithelium. Results of eosinophilia and hypoproteinemia may be found in clinical hematology. Severe infections include symptoms such as bloody diarrhea, weight loss, dehydration, and anemia, and in extreme cases, death. In the rare cases that T. vulpis infects humans, it can cause visceral larva migrans (VLM) which presents as eosinophilia, hepatomegaly, and pulmonary symptoms. More cases of VLM have been documented in children with the diagnosis based on the larger size of the eggs found in stool samples. However, cases have been documented in adults as well. Diagnosis Infection of this parasite can be confirmed with detection of eggs in the canine's feces. Adult T. vulpis females can produce more than 2,000 eggs per day. These eggs can be detected in the canine's feces by the fecal flotation method. This method utilizes the differences of specific gravity of eggs, fecal debris, and the flotation solution. Although these eggs are dense, the use of proper fecal flotation technique using a sugar solution and centrifugation can increase the chances of identifying these eggs in a fecal sample. Multiple fecal samples may need to be tested as the eggs may be shed periodically. Treatment Infection of this parasite can be treated with several drugs including febantel, fenbendazole, milbemycin, moxidectin (topical), and oxantel. Dogs require re-treatment monthly for 3 treatments due to the long prepatent period of this parasite. There are also monthly preventive treatments that can be used. These are usually one of the above drugs combined with a heartworm prevention drug. Removing fecal material that contains the Trichuris eggs is very important in preventing recurrence. Merck Veterinary Manual Prevention and control Keeping canines