Clinical disease and treatment of Leptospira kirschneri sv Grippotyphosa in a Sumatran tiger (Panthera tigris sumatrae)

Abstract

CASE DESCRIPTION A 12-year-old sexually intact male zoo-managed Sumatran tiger (Panthera tigris sumatrae) was evaluated for a 3-day history of vomiting, hyporexia, and lethargy. Radiographs were supportive of gastrointestinal obstruction, and an exploratory laparotomy was performed. CLINICAL FINDINGS Diffuse tan foci were present on the liver parenchyma, and the tiger became icteric throughout the procedure. Hepatic histopathology and immunohistochemistry resulted in a diagnosis of leptospirosis. Serum microagglutination testing for Leptospira spp antibody titers were positive for L kirschneri serovar Grippotyphosa, rising from 1:400 to 1:3,200 in 2 days. TREATMENT AND OUTCOME The tiger was treated with antimicrobials, ursodiol, and mirtazapine, and increased biosecurity measures were instituted. Free-ranging wildlife on grounds were trapped, euthanized, and submitted for necropsy to screen for disease vectors. The tiger’s urine was intermittently opportunistically collected from the enclosure and remained PCR assay negative for Leptospira spp until being positive once again on day 595. Although the tiger was without clinical signs at that time, antimicrobial therapy and increased biosecurity protocols were instituted a second time until urinary Leptospira shedding was confirmed to have stopped. By 1,071 days after initial presentation, the tiger remained nonclinical, with no additional urinary shedding episodes. CLINICAL RELEVANCE While domestic and nondomestic free-ranging felids have been reported as subclinical Leptospira spp carriers, this report indicates the clinical importance of leptospirosis when a tiger presents with generalized gastrointestinal signs and icterus. Due to the zoonotic potential, biosecurity measures are necessary. This patient had a clinically successful outcome with antimicrobial therapy and supportive care.

Isolation of Leptospira kirschneri serovar Grippotyphosa from a red panda (Ailurus fulgens) after antimicrobial therapy: Case report

“…Bloodwork showed increased albumin 4.2 g/dL (expected range: 2.3–4.1) and MAT results showed a titer of 1:1,600 to Grippotyphosa. Since clinical resolution does not guarantee clearance of infection and cessation of urinary shedding of leptospires ( 7 , 9 ), urine samples were also collected by cystocentesis to perform fluorescent antibody testing (FAT) and culture. Two tubes each of HAN and T80/40/LH semi-solid media provided to the zoo ( 13 , 14 ) were inoculated with 2–4 drops of urine on site as soon as collected.…”

“…Employees are also at risk of infection from handling infected animals or cleaning enclosures. Several cases of leptospirosis have been documented in zoo animals ( 4 – 7 ).…”

“…In 2022, MAT and real-time polymerase chain reaction (RT-PCR) was used to diagnose a Sumatran tiger ( Panthera tigris sumatrae ) residing in a zoo with L. kirschneri serovar Grippotyphosa ( 7 ). Clinical signs of illness resolved after treatment, but a urine sample collected at 595 days after initial diagnosis was PCR positive.…”

A global one health perspective on leptospirosis in humans and animals

“…Isolated cases and outbreaks of leptospirosis have been uncommonly described in captive and free-ranging wildlife species. Reports of leptospirosis in captive wildlife species have included a tiger (Panthera tigris sumatrae), 39 southern tamanduas (Tamandua tetradactyla), 40 and nonhuman primates. [41][42][43] Affected free-ranging wildlife species have included nonhuman primates, 44 canids and felids, 45,46 Eurasian beavers (Castor fiber), 47 and marine mammals on the west coast of the US.…”