| dc.description.abstract | Compared to aquatic ecosystems, limited information exists on associated health parameters
influencing terrestrial vertebrates, specifically large carnivores, and discussions around wildlife
health measures are currently still quite rare. The African leopard Panthera pardus pardus
(Linnaeus, 1758), a popular species for research by ethologists and ecologists, has a noticeable
gap in knowledge regarding health status and assessment. Therefore, the main aim of this
study was to use a multi-disciplinary approach that combines relatively diverse parameters to
establish an integrated approach to the health assessment of ex-situ (captive) and in-situ (wild)
South African leopards. Peripheral blood is an informative, non-lethally sampled tissue that can
reflect the functioning of a whole organism. Thus, three overarching whole blood-related
aspects, namely haematology, haemoparasitology and organochlorine pesticide (OCP)
concentrations, were integrated with a newly designed body condition (BC) scoring system,
specific to big cats, to evaluate the interaction of these internal and environmental variables
from a health parameter perspective.
This study detailed haematological characteristics, confirming great variation in differential
blood cell counts and morphologies in leopards, as had been reported for other felids.
Differential leukocyte counts of leopards were in the same range as that of other big cats and
wild leopards had higher leukocyte counts than captive leopards. Overall, neutrophils were the
most numerous circulating leukocyte, followed by lymphocytes and eosinophils. Apicomplexan
haemoparasites from the genus Hepatozoon Miller, 1908 (Apicomplexa: Adeleorina:
Hepatozoidae) have been widely reported from wild carnivores in Africa, including non-specific
reports from leopards, but descriptions of potential developmental stages in naturally infected
leopards and associated haematophagous vectors are rare. This study presented detailed
morphological and molecular descriptions of two, concurring new haemogregarine species,
Hepatozoon luiperdjie Van As et al. 2020 and Hepatozoon ingwe Van As et al. 2020, along with
their associated host cell effects. It also described the first morphological traits of potential
hepatozoan life cycle stages within an Ixodes tick (Arthropoda: Ixodida: Ixodidae), collected
from a naturally infected animal. No clinical symptoms that could be ascribed to
hepatozoonosis were observed, confirming the asymptomatic nature of these infections in
large carnivores. The first report on baseline OCP concentrations in the blood of African
leopards, and relationships between OCP levels, was presented in this study. Captive leopards
had a slightly higher mean ΣOCP concentration (901 pg/ml) than wild leopards (768 pg/ml) and
OCPs accumulated in the following order DDTs (27%) > HCHs (21%) > Heptachlors (15%) > CHLs
(15%) > Drins (14%) > HCB (8%).
Finally, this study put forth a noteworthy interplay in the importance of body condition,
haematological characteristics, haemogregarine infections and OCP burdens in captive and wild
leopards. The most influential health factor for all leopards was neutrophil-to-lymphocyte
ratios (NLRs), followed by other leukocyte counts (lymphocyte, neutrophil, and eosinophil
counts in decreasing order of influence) and BC.
Body condition, NLR and OCP factors were the most influential variables for captive leopards,
while differential leukocyte counts and haemoparasite infections were the most influential for
wild leopards. The results from this study suggested the importance of focusing environmental
parasitology studies on terrestrial environments. Ultimately, this thesis has shown that an
integrated philosophy of leopard health, merging the variables identified in this study, is
valuable as a future tool of health assessment. | en_US |
