First record of feline urinary bladder worm (Capillaria syn. Pearsonema) in Sri Lanka: Clinical, histopathological and molecular characterization

Nematode infections in the urinary tract of domestic cats and dogs are rare, although common in wild predatory animals. Here we report a case of a urinary bladder capillariosis in a cat from Sri Lanka. A three-year-old domestic male cat from the Kalutara District was brought to a private veterinary hospital due to frequent urination, vomiting, and loss of appetite. The physical examinations reported severe emaciation, gasping and abdominal breathing and retarded growth. Successive to urinary sedimentation, Capillaria-type eggs were detected. Blood Urea Nitrogen level of 28.02 Mmol/L and serum creatinine level of 0.42 mmol/L were higher than the normal ranges. Necropsy revealed an enlarged left kidney with oedematous renal parenchyma. Following the histopathological examination, multifocal areas of tubular degeneration and necrosis with multifocal fibroblast proliferation were observed in the renal cortex. The lungs showed diffuse pulmonary oedema and chronic interstitial pneumonia. Molecular analysis with PCR and DNA sequencing of the Capillaria-type eggs in sedimented urine, using an amplicon (18S rRNA) for Capillaria (563 bp) followed by phylogenetic analysis revealed a 100 % identity to Pearsonema collected from the urinary bladder of a raccoon from Japan. Cases of Capillaria in cats are rarely reported because most infected animals do not show clinical signs. This is the first case report of Capillaria syn. Pearsonema sp. identifies and characterizes the species using molecular tools and describes the infection's clinical symptoms.