Severe Conjunctivitis Associated with Chlamydia felis Infection in a Free-ranging Eurasian Lynx ( Lynx lynx)

Detection of Sarcocystis albifronsi, Eimeria alpacae, and Cystoisospora felis in Eurasian lynx (Lynx lynx) in northwestern China

Eurasian lynx (Lynx lynx) is widely distributed in various habitats in Asia and Europe, and it may harbor multiple pathogens. Currently, the information on protozoan infection in Eurasian lynx is scarce. In this study, we performed nested polymerase chain reaction (nPCR) analysis to detect intestinal protozoan infection in three dead Eurasian lynxes, in northwestern China. Three dead Eurasian lynxes, an adult female (#1), an adult male (#2), and a cub male (#3), were sampled in West Junggar Mountain, the northwestern region of Xinjiang Uyghur Autonomous Region. The intestine samples were analyzed using nPCR. We used primers targeting the cytochrome C oxidase subunit I gene (COI) for detection of Sarcocystis and Eimeria species and targeting the small subunit 18 S ribosomal RNA gene (18S rRNA) for detection of Cystoisospora species. The nPCR-positive products were sequenced, aligned, and phylogenetically analyzed. Three intestinal protozoa, Sarcocystis albifronsi, Eimeria alpacae, and Cystoisospora felis, were found in three Eurasian lynxes. The intestine sample of Eurasian lynx #2 was detected with S. albifronsi and E. alpacae. In addition, C. felis was only found in the intestine sample of Eurasian lynx #3. To the best of our knowledge, S. albifronsi and E. alpacae were detected in Eurasian lynx for the first time. In addition, C. felis was firstly found in Eurasian lynx in China. These findings extend our knowledge of the geographical distribution and host range of intestinal protozoa.

CEFOVECIN PROTEIN BINDING AS A PREDICTOR FOR EXTENDED DURATION OF ACTION: A REVIEW OF CURRENT LITERATURE AND IN VITRO ANALYSIS IN MULTIPLE ZOOLOGICAL SPECIES

Cefovecin is a third-generation cephalosporin antibiotic with an efficacy of 2 wk following a single injection in domestic dogs and cats. A high degree of plasma protein binding to cefovecin has been proposed as one of the mechanisms responsible for the long elimination half-life, but protein binding has not been evaluated extensively in nondomestic species. In this study, a review of the current literature was conducted, and pharmacokinetic data were compiled for species in which cefovecin has been evaluated thus far. Additionally, in vitro cefovecin protein binding was evaluated in plasma from 22 nondomestic species representing a broad range of taxa. Animals of the order Carnivora demonstrated protein-binding levels of >98%, which is supportive of the long elimination half-life seen in related species. Protein binding was highly variable in Artiodactyl and Perissodactyl species, with dolphins (Tursiops truncatus) and barasingha (Rucervus duvaucelii) displaying high protein binding (99.12% to >99%), but not gazelles (Eudorcas thomsonii) or equids (91.76-92.70%). Cefovecin was not highly bound in any reptiles or birds, corresponding to short half-lives reported for these taxa. These results suggest that a high percentage of plasma protein binding in vitro may predict in which species cefovecin may exhibit a long half-life and duration of action in vivo. These findings may aid in selecting species for cefovecin pharmacokinetic research and for empirical treatment of infections caused by susceptible bacteria.

Management of Suspected Cases of Feline Immunodeficiency Virus Infection in Eurasian Lynx (Lynx lynx) During an International Translocation Program

The Eurasian lynx (Lynx lynx) population in Switzerland serves as a source for reintroductions in neighboring countries. In 2016–2017, three lynx from the same geographical area were found seropositive for feline immunodeficiency virus (FIV) in the framework of an international translocation program. This novel finding raised questions about the virus origin and pathogenicity to lynx, the emerging character of the infection, and the interpretation of serological results in other lynx caught for translocation. Archived serum samples from 84 lynx captured in 2001–2016 were retrospectively tested for FIV antibodies by Western blot. All archived samples were FIV-negative. The three seropositive lynx were monitored in quarantine enclosures prior to euthanasia and necropsy. They showed disease signs, pathological findings, and occurrence of co-infections reminding of those described in FIV-infected domestic cats. All attempts to isolate and characterize the virus failed but serological data and spatiotemporal proximity of the cases suggested emergence of a lentivirus with antigenic and pathogenic similarities to FIV in the Swiss lynx population. A decision scheme was developed to minimize potential health risks posed by FIV infection, both in the recipient and source lynx populations, considering conservation goals, animal welfare, and the limited action range resulting from local human conflicts. Development and implementation of a cautious decision scheme was particularly challenging because FIV pathogenic potential in lynx was unclear, negative FIV serological results obtained within the first weeks after infection are unpredictable, and neither euthanasia nor repatriation of multiple lynx was acceptable options. The proposed scheme distinguished between three scenarios: release at the capture site, translocation, or euthanasia. Until April 2021, none of the 40 lynx newly captured in Switzerland tested FIV-seropositive. Altogether, seropositivity to FIV was documented in none of 124 lynx tested at their first capture, but three of them seroconverted in 2016–2017. Diagnosis of FIV infection in the three seropositive lynx remains uncertain, but clinical observations and pathological findings confirmed that euthanasia was appropriate. Our experiences underline the necessity to include FIV in pathogen screenings of free-ranging European wild felids, the importance of lynx health monitoring, and the usefulness of health protocols in wildlife translocation.

Cefovecin pharmacokinetics after single-dose intramuscular administration in cheetahs (Acinonyx jubatus)

Cefovecin is a third-generation cephalosporin with potential value for use in exotic felids due to its long duration of action. A sparse sampling protocol was implemented with 18 zoo-housed cheetahs (Acinonyx jubatus) to evaluate the pharmacokinetics of cefovecin (Convenia^® ) after a single 8 mg/kg intramuscular injection. Blood was collected serially for 15 days following administration, and plasma cefovecin concentrations were determined using high-pressure liquid chromatography with ultraviolet detection. Pharmacokinetic parameters were estimated using population pharmacokinetic methods and non-linear mixed effects modeling (NLME). Cefovecin was well tolerated by all cats, with no adverse effects observed. Peak plasma cefovecin concentration was 84.75 µg/ml, with a mean residence time of 207.9 h and an elimination half-life of 144.1 h (6.00 days). Plasma concentrations of cefovecin were maintained >7 µg/ml in all individuals for the entire study duration (15 days). These concentrations are lower, and the half-life slightly shorter, than the values reported for domestic cats. Cefovecin was highly protein-bound (approximately 99.9%) in cheetah plasma, which is nearly identical to domestic cats. These results indicate that cefovecin is potentially useful as a long-acting antibiotic in cheetahs.