Heterobilharzia americana infection in a dog

A 7-year-old castrated male Golden Retriever cross was evaluated because of chronic diarrhea and weight loss (from 40.9 kg [90 lb] to 27.7 kg [61 lb]).The diarrhea had begun approximately 1 month previously and was characterized as voluminous, mucoid, and bloody and was associated with tenesmus, urgency, and flatulence.A 2-week treatment regimen of enrofloxacin a and sucralfate dihydrochloride b did not result in resolution of clinical signs, and the dog was referred.The diet consisted of a commercially available dog food supplemented with raw meat.Historical dietary indiscretion and pica were reported.The dog had access to a large unfenced area typical of coastal plain topography that contained ponds and drainage ditches bordering a suburban residential development.The dog was found at 6 months of age and had a heavy intestinal worm burden; heartworm test results were positive.The dog received treatment for the intestinal parasites and melarsomine c for the heartworm infection.Treatment went well, and the dog was maintained on milbemycin d and fipronil e year-round.The referring veterinarian had performed fecal flotation and direct smear examinations for parasite ova; results were negative.When the dog was initially evaluated by the referring veterinarian, results of a serum biochemical profile revealed increased total (9.44 g/dl; reference range, 6.0 to 8.0 g/dl) and globulin (6.45 g/dl; reference range, 2.5 to 4.3 g/dl) protein concentra-tions, and results of a CBC revealed eosinophilia (1.9 X 10 3 cells/µl; reference range, 0.1 to 0.75 X 10 3 cells/µl).On initial examination at the referral hospital, the dog was quiet and thin with a poor coat and fecal staining of the perineum with a black tarry stool.The popliteal, submandibular, prescapular, and inguinal lymph nodes were large.On abdominal palpation, organomegaly and gas-filled bowels were detected.On transrectal examination, no obvious abnormalities were detected.A CBC, serum biochemical analysis, tick-borne disease serologic analysis, urinalysis, and coagulation profile were performed.Results of the CBC revealed mild normocytic normochromic nonregenerative anemia, with a PCV of 30% and a mild increase in band neutrophils (900 cells/µL; range, 0 to 300 cells/µL).Results of the biochemical analysis revealed hyperglobulinemia (7.2 g/dl; range, 2.5 to 4.3 g/dl) and increased alkaline phosphatase (269 U/L; range, 20 to 155 U/L), aspartate aminotransferase (55 U/L; range, 1 to 37 U/L), and alanine aminotransferase (85 U/L; range, 3 to 50 U/L) activities.Serologic results were negative for immunoglobulins against Ehrlichia canis and Borrelia burgdorferi but were positive for Rickettsia rickettsii, with a titer of 1:1,024.The urine was concentrated (specific gravity, 1.030), and 3+ proteinuria was the only abnormality detected.Prothrombin and partial thromboplastin times were within reference ranges.Thoracic radiography revealed a moderate interstitial pattern and mildly large sternal lymph nodes.Lymph node aspirates of the popliteal and the prescapular lymph nodes were performed and revealed reactive lymphocyte hyperplasia.During abdominal ultrasonography, the splenic capsule appeared moderately irregular, evidence of peritoneal effusion was seen, and the walls of the small intestinal loops were thickened (6 mm) and hypoechoic.Because of the peritoneal effusion, abdominal exploratory was performed.A standard ventral midline laparotomy inspection of the abdomen and its contents revealed multiple abnormalities including a diffusely thickened irregular firm to sclerotic pancreas, generalized hepatomegaly, generalized mesenteric lymph node enlargement, and multifocal to diffuse miliary transmural nodules in the duodenum, jejunum, ileum, and colon.Biopsy samples of the liver, pancreas, stomach, duodenum, jejunum, lymph node, and colon were obtained.Histologically, granulomas and numerous schistosome ova were scattered throughout the liver, pancreas, small intestine, colon, and a mesenteric lymph node.The stomach was least affected with only a focal microgranuloma in the submucosa and no ova seen.Ova were round to ovoid, approximately 100-µm thick with a yellowish to clear often collapsed hyalinized wall, and were either empty or contained a developing miracidium.The inflammatory cell infiltrate was similar in all