Clinical Changes Caused by the Liver Fluke Metorchis conjunctus in

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 amino-
peptidase 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,
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