• Characterization of progressive keratitis in Otariids: Otariid keratitis

      Colitz, Carmen M. H.; Renner, Michael S.; Manire, Charles A.; Doescher, Bethany; Schmitt, Todd L.; Osborn, Steven D.; Croft, Lara; Olds, June; Gehring, Erica; Mergl, June; et al. (2010)
      ... ‘Otariid Keratitis’ occurs in all populations of eared seals evaluated. A large‐scale epidemiological study is ongoing to identify the risk factors that contribute to this disease. Exposure to chronic sunlight appears to be an important risk factor as shade diminishes clinical signs; animals kept out of sunlight the majority of the time have less severe clinical signs....
    • Epidemiology of clinical feline herpesvirus infection in zoo-housed cheetahs (Acinonyx jubatus)

      Witte, Carmel L.; Lamberski, Nadine; Rideout, Bruce; Vaida, Florin; Citino, Scott B.; Barrie, Michael T.; Haefele, Holly J.; Junge, Randall E.; Murray, Suzan; Hungerford, Laura L. (2017)
      OBJECTIVE To determine the incidence of and risk factors for clinical feline herpesvirus (FHV) infection in zoo-housed cheetahs and determine whether dam infection was associated with offspring infection. DESIGN Retrospective cohort study....
    • Epidemiology of tuberculosis in multi-host wildlife systems: Implications for black (Diceros bicornis) and white (Ceratotherium simum) rhinoceros

      Dwyer, Rebecca A.; Witte, Carmel L.; Buss, Peter; Goosen, Wynand J.; Miller, Michele (2020)
      Cases of tuberculosis (TB) resulting from infection with Mycobacterium tuberculosis complex (MTBC) have been recorded in captive white (Ceratotherium simum) and black (Diceros bicornis) rhinoceros. More recently, cases have been documented in free-ranging populations of both species in bovine tuberculosis (bTB) endemic areas of South Africa. There is limited information on risk factors and transmission patterns for MTBC infections in African rhinoceros, however, extrapolation from literature on MTBC infections in other species and multi-host systems provides a foundation for understanding TB epidemiology in rhinoceros species. Current diagnostic tests include blood-based immunoassays but distinguishing between subclinical and active infections remains challenging due to the lack of diagnostic techniques. In other species, demographic risk factors for MTBC infection include sex and age, where males and adults are generally at higher risk than females and younger individuals. Limited available historical information reflects similar age- and sex-associated patterns for TB in captive black and white rhinoceros, with more reports of MTBC-associated disease in black rhinoceros than in white rhinoceros. The degree of MTBC exposure in susceptible wildlife depends on their level of interaction, either directly with other infected individuals or indirectly through MTBC contaminated environments, which is dependent on the presence and abundance of infected reservoir hosts and the amount of MTBC shed in their excreta. Captive African rhinoceros have shown evidence of MTBC shedding, and although infection levels are low in free-ranging rhinoceros, there is a risk for intraspecies transmission. Free-ranging rhinoceros in bTB endemic areas may be exposed to MTBC from other infected host species, such as the African buffalo (Syncerus caffer) and greater kudu (Tragelaphus strepsiceros), through shared environmental niches, and resource co-utilization. This review describes current knowledge and information gaps regarding the epidemiology of TB in African rhinoceros.
    • Genomic insights into a contagious cancer in Tasmanian devils

      Grueber, Catherine E.; Peel, Emma; Gooley, Rebecca; Belov, Katherine (2015)
      The Tasmanian devil faces extinction due to a contagious cancer…. From characterising immune genes and immune responses to studying tumour evolution, we have begun to uncover how a cancer can be ‘caught’ and are using genomic data to manage an insurance population of disease-free devils for the long-term survival of the species.
    • IOD in rhinos--epidemiology group report: report from the Epidemiology Working Group of the International Workshop on Iron Overload Disorder in Browsing Rhinoceros

      Dennis, Pam; Ellis, Susie; Mellen, Jill; Lee, Pauline; Olea-Popelka, Francisco; Petric, Ann; Ryder, Oliver A. (2012)
      The Epidemiology Working Group, a subgroup of the participants of the International Workshop on Iron Storage Disease (renamed iron overload disorder, IOD), identified several areas in which information is lacking regarding IOD in browser rhinoceros. One of the first steps necessary in understanding iron overload disorder (IOD) is to define the parameters by which to identify IOD....
    • Koala retrovirus diversity, transmissibility, and disease associations

      Zheng, HaoQiang; Pan, Yi; Tang, Shaohua; Pye, Geoffrey W.; Stadler, Cynthia K; Vogelnest, Larry; Herrin, Kimberly Vinette; Rideout, Bruce; Switzer, William M. (2020)
      Background Koalas are infected with the koala retrovirus (KoRV) that exists as exogenous or endogenous viruses. KoRV is genetically diverse with co-infection with up to ten envelope subtypes (A-J) possible; KoRV-A is the prototype endogenous form. KoRV-B, first found in a small number of koalas with an increased leukemia prevalence at one US zoo, has been associated with other cancers and increased chlamydial disease. To better understand the molecular epidemiology of KoRV variants and the effect of increased viral loads (VLs) on transmissibility and pathogenicity we developed subtype-specific quantitative PCR (qPCR) assays and tested blood and tissue samples from koalas at US zoos (n=78), two Australian zoos (n=27) and wild-caught (n=21) in Australia. We analyzed PCR results with available clinical, demographic, and pedigree data. Results All koalas were KoRV-A-infected. A small number of koalas (10.3%) at one US zoo were also infected with non-A subtypes, while a higher non-A subtype prevalence (59.3%) was found in koalas at Australian zoos. Wild koalas from one location were only infected with KoRV-A. We observed a significant association of infection and plasma VLs of non-A subtypes in koalas that died of leukemia/lymphoma and other neoplasias and report cancer diagnoses in KoRV-A-positive animals. Infection and VLs of non-A subtypes was not associated with age or sex. Transmission of non-A subtypes occurred from dam-to-offspring and likely following adult-to-adult contact, but associations with contact type were not evaluated. Brief antiretroviral treatment of one leukemic koala infected with high plasma levels of KoRV-A, -B, and -F did not affect VL or disease progression. Conclusions Our results show a significant association of non-A KoRV infection and plasma VLs with leukemia and other
    • The Elephant Welfare Initiative: a model for advancing evidence-based zoo animal welfare monitoring, assessment and enhancement

      Meehan, C.; Greco, B.; Lynn, B.; Morfeld, K.; Vicino, Greg A.; Orban, D.; Gorsuch, C.; Quick, M.; Ripple, L.; Fournier, K.; et al. (2019)
      The Elephant Welfare Initiative (EWI) is an effort supported by a community of member zoos with the common goal of advancing evidence-based elephant-care practices that enhance welfare. The idea for the EWI came about following the completion of a large-scale North American elephant welfare study, which demonstrated that daily practices, such as social management, enrichment and exercise, play a critical role in improving the welfare of elephants in zoos....