BackgroundExamination of bile could be useful to diagnose Platynosomum spp.‐induced cholangitis in cats. Obtaining bile via percutaneous ultrasound‐guided cholecystocentesis (PUC) is possible but raises safety concerns in cats with severe cholecystitis.ObjectivesThe objectives of this study were to investigate the use of PUC to collect bile samples from cats with known platynosomosis and to determine if bile analysis could be a diagnostic test.AnimalsTwenty‐seven free‐roaming cats positive for Platynosomum spp. eggs via fecal examination.MethodsIn this prospective study, fecal egg counts were performed by double centrifugation with Sheather's solution. Bile was collected using PUC from anesthetized cats. Egg counts in bile were performed with a stereoscope. Euthanasia and postmortem examination were performed immediately after PUC.ResultsAll cats had ultrasound (US) evidence of cholangitis or cholecystitis. Thirty‐nine PUCs were performed with 14 cats having 2 PUCs 12 or 24 days apart. Postmortem examinations showed no overt gallbladder damage or leakage but fresh blood was noted in the gallbladder lumen of 3 cats. Median Platynosomum spp. egg counts were higher in bile (1450 eggs/mL; IQR, 400; 5138 eggs/mL) as compared to feces (46 eggs/mL; IQR, 10; 107 eggs/mL) (P < .001).Conclusion and Clinical ImportanceBile egg count analysis is an alternative method with higher egg counts as compared to fecal egg count analysis for the diagnosis of platynosomosis. Obtaining bile via US guidance is technically feasible and safe in cats with cholangitis/cholecystitis. Cholecystocentesis and bile analysis are especially relevant for those cats with chronic cholangitis/cholecystitis and negative fecal egg counts for Platynosomum.

Treatments for Platynosomum fastosum—the liver fluke of cats—have been developed based on fecal egg counts. Post mortem fluke counts are required to understand true efficacy. In this study, two praziquantel treatment regimens were evaluated using post mortem fluke counts: a high-dose treatment (HT) of 20 mg/kg body weight (BW) administered intramuscularly (IM) once a day for three consecutive days and a low-dose treatment (LT) of 5 mg/kg BW administered once (IM) and repeated 14 days later. A continual enrolment study design was used with 16 naturally infected cats randomly allocated in blocks of four to the HT (eight cats) or LT (eight cats) group. Treatment success, defined as absence of live flukes post mortem, was determined 10 days after the last treatment. Pre- and post-treatment fecal egg counts (centrifugation with Sheather’s sugar flotation solution) and bile egg counts (obtained via percutaneous ultrasound guided cholecystocentesis) were evaluated as supportive efficacy data. Twelve cats completed the study with two cats withdrawn from each group. Neither treatment was 100% effective. In the HT group, three of six cats had live flukes, albeit low numbers, at post mortem, while all six LT group cats had live flukes. While fecal and bile egg counts were reduced in both group, they were not reflective of the true infection status of the cats post mortem.