Causes of Mortality and Morbidity of Wild Koalas, Phascolarctos Cinereus (Goldfuss), in Victoria, Australia

Abstract

Between 1975 and 1980, necropsy investigations were conducted on 44 wild koalas (24 males, 20 females) from several localities in Victoria, Australia. An additional 11 (5 males, 6 females) were presented for clinical appraisal and treatment. Traumatic injuries resulting from motor vehicle accidents and intra-specific conflict were the commonest reason for submission (19 of 55; 35%). Keratoconjunctivitis (8 of 55; 15%), ascending urinary tract infections (6 of 20 females; 30%), ascending genital tract inflammation (10 of 20 females; 50%) and sarcoptic mange (2 of 55; 4%) were recognized as specific diseases or disease syndromes. A peracute syndrome characterized by lassitude, depression, anorexia and coma was identified in moribund koalas submitted from the wild and also in hospitalized animals. The condition, termed koala stress syndrome, was thought to be initiated by intercurrent disease or trauma, long term hospitalization and frequent manipulation and treatments. Hematological observations in 54 apparently healthy wild koalas from five different populations and on 17 sick or injured animals are also presented. Certain blood parameters are discussed in relation to the health status of the populations or individuals. Areas for further research into koala diseases are also discussed.

THE PREVALENCE AND CLINICAL SIGNIFICANCE OF CHLAMYDIA INFECTION IN ISLAND AND MAINLAND POPULATIONS OF VICTORIAN KOALAS (PHASCOLARCTOS CINEREUS)

“…This is consistent with a study in Queensland koalas that also used molecular detection techniques (Jackson et al 1999). Earlier studies that assessed clinical signs or postmortem pathologic changes consistent with Chlamydia-induced disease found a higher prevalence of disease in female koalas than males (Obendorf 1983). Although the prevalence of C. pecorum infection increased with age class, we found no statistically significant association between Chlamydia infection rate and age class.…”

The potential impact of native Australian trypanosome infections on the health of koalas (Phascolarctos cinereus)

“…As the PCV value reductions in koalas with trypanosome infection were not marked the effect may not be biologically significant. Reduced PCV levels in koalas have also been attributed to heavy tick infestations (Obendorf, 1983;Spencer and Canfield, 1995) and details of the tick burden of koalas in this study were infrequently recorded in admission examinations.…”

Association of Uterine and Salpingeal Fibrosis with Chlamydial Hsp60 and Hsp10 Antigen-Specific Antibodies inChlamydia-Infected Koalas

“…With a natural life span of approximately 15 to 18 years, it is highly adapted to a relatively low-nutrient, hightoxin diet of eucalypt leaves. It is widespread in eucalypt forests of eastern Australia but is subject to a range of potentially threatening processes, such as inbreeding from historical hunting and population management (11,29), effects of ongoing habitat fragmentation on social structure and food quality and availability (7,15), and increased mortality due to predation by domestic dogs, road trauma, and disease (5,30). Infection by Chlamydia pneumoniae or Chlamydia pecorum commonly causes proliferative conjunctivitis and chronic, fibrotic disease of the urogenital tracts of koalas, often resulting in infertility and death (3,32).…”