Clinical Changes Caused by the Liver Fluke Metorchis conjunctus in

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Vet. Pathol. 18: 778-785 (1981) Clinical Changes Caused by the Liver Fluke Metorchis conjunctus in Cats T. G. WATSON and N. A. CROLL Institute of Parasitology, Macdonald College of McGill University, Ste. Anne de Bellevue, Quebec, Canada Abstract. Cats infected with metacercariae of the fluke Metorchis conjunctus were followed clinically through their infection. Cats given 200 metacercariae showed few symptoms. All the cats passed ova on the 17th day. Three hundred metacercariae caused diarrhea, icterus, discolored urine, green feces and eosinophilia after 18 to 21 days. Eosinophilia, Ieucine aminopeptidase and alanine aminotransferase were elevated and remain the best indicators for metorchiasis. The hematological and serological abnormalities resolved rapidly and were absent from cats with chronic infection. Acute lesions (
Metorchis in Cats 119 Materials and Methods Male and female mixed-breed cats weighing 1.0 to 3.5 kg were treated with piperazine to expel Toxocara cati and then housed in cages with a mesh bottom and a plate to rest on. Water was provided ad libitum and each cat had about 100 g of Purina cat chow (Centre Agricole St. Clet, St. Clet, County Soulanges, P.Q.) daily; feces were examined for ova with the formalin-ether technique [ 171. Viable metacercariae were digested from the muscles of the common sucker (Catastomus commersoni) in artificial gastric medium. They were placed on the back of the cat’s tongue and were swallowed or flushed down the throat; cats were observed carefully to rule out vomiting of the inoculum. Blood collection was done between 0800 and 1000 hours. Cats were sedated with ketamine hydrochloride (0.05 mg/kg body weight); 4 ml of whole blood was removed by cardiac puncture with an 18 gauge needle and 5 ml syringe. Heparinked, microhematocrit capillary tubes were filled with whole blood for leukocyte and eosinophil counts in Unopette diluting chambers (Becton-Dickinson, Rutherford, N.J.). The hematocrit packed cell volume was measured from the remaining capillary. The remaining blood was clotted at 22°C for 30 to 40 minutes. The serum was frozen at - 17°C in 2- or 4-dram vials. The following tests were done: total serum protein, albumin, and globulin (Sigma, St. Louis, Mo.), with a Coleman Junior I1 Model 6/20 spectrophotometer (Canadian Coleman Co. Ltd., Toronto, Ont.); serum protein electrophoresis was done with a Corning 740 densitometer; serum bilirubin, leucine aminopeptidase and alanine aminotransferase activity were determined by Boehringer Ingelheim Mannheim GmbH Diagnostica (Waterford, Conn.); alkaline phosphatase was quantified by Sigma (St. Louis, Mo.) technical procedures. Three experimental infections were given as follows: Experiment I: Five cats, coded 1 to 5, were given 200 metacercariae apiece while two controls were given placebo. Blood samples were taken two days prior to infection, immediately prior to infection and on days 2, 4, 6, 8, 12,20 and 32 post-infection, when the cats were killed. Experiment 2: Cats 6 and 7 each were given 300 metacercariae. Blood was sampled before infection and at weekly intervals after infection until they were killed at day 59 (cat 6) and day 78 (cat 7). Experiment 3: Cats 8 to 12, three female and two male littermates weighing 1.5 to 3.0 kg, were used. Two cats received 200 metacercariae, two received 300 and one was given placebo. Blood was collected before infection and on days 7, 14, 17, 21, 24, and 28 and then weekly until day 77. On day 42 the two cats given 200 metacercariae were given 300 more metacercariae apiece; their blood was collected until day 9 1. Each cat was anesthetized by ketamine, a final blood sample was taken and the cat was killed with an intracardiac overdose of Somnotol (M.T.C. Pharmaceuticals, Hamilton, Ont.). After midline incision, the ductus choledochus was ligated at the duodenum and the duodenum was ligated above and below the ampulla of Vater. The gall bladder, cystic duct, common bile duct and ductus choledochus were separated, as were the lobes of the liver. Each lobe was sliced into 2- to 3-mm wedges and all tissues were examined for flukes. Representative tissues were fixed in 10% formaldehyde. The spleen, pancreas and viscera were examined for worms, lesions or enlarged nodes. Results The cats did not show identical or in some cases even similar clinical courses. Each experiment will be discussed briefly, typical case histories presented and finally the collected data will be given. Experiment 1. Clinical signs-rectal temperature, food intake, stool quality, color, Downloaded from vet.sagepub.com by guest on April 8, 2013
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