STEROIDAL SAPONIN TOXICITY IN EASTERN GREY KANGAROOS ( MACROPUS GIGANTEUS): A NOVEL CLINICOPATHOLOGIC PRESENTATION OF HEPATOGENOUS PHOTOSENSITIZATION

Molecular survey for Chlamydia among southern greater gliders (Petauroides volans) from southeastern New South Wales, Australia

Southern greater gliders (Petauroides volans) are endangered Australian marsupials for which there is little health data currently available. Chlamydia pecorum is the only reported pathogen of greater gliders and infects a broad range of hosts, including other marsupials, ruminants, swine and birds. Conjunctival and cloacal swabs collected from thirty-two southern greater gliders across southeastern New South Wales, Australia were screened for Chlamydia spp. by 23S real-time PCR. None of the ninety-six swabs tested returned a positive result for Chlamydia DNA. We found no evidence of Chlamydia infection among the four geographically disparate populations sampled, suggesting that Chlamydia may not pose a widespread health risk to southern greater gliders in this region, based on the current data. However, various clinical signs of ophthalmic pathology were observed, warranting further investigation to determine their underlying aetiology.

Poor Survival Rate of Eastern Gray Kangaroos (Macropus giganteus) Affected by Chronic Phalaris Toxicity

Chronic phalaris toxicity (CPT) is a neurological disease caused by animals ingesting toxins produced by early growth stages of Phalaris aquatica, a pasture plant introduced to the southeastern regions of Australia post colonization. Little is known about the clinical progression of CPT in wildlife, as incidents are sporadic and predominantly reported when animals are in the end stages of disease and in a poor welfare state. We studied a cohort of 35 eastern gray kangaroos (Macropus giganteus) affected by CPT to clarify clinical prognosis and survival rates. Kangaroos were captured in May, June, and July of 2022 at Plenty Gorge Parklands, Victoria, Australia. Each animal was radiotracked for 180 d, clinical progression and disease outcomes monitored twice a week. By the conclusion of the study, 24 animals had died (19 by euthanasia due to deterioration, five found dead). Ten animals survived, with two demonstrating a reduction in clinical signs and eight showing full resolution of clinical signs. One animal was disqualified from the study. The overall survival rate was 29.4% (95% confidence interval 17.5-49.5%). The survival duration of animals that died ranged from 5 to 133 d. There was no difference in survival rate based on sex (P=0.2), age class (P=0.49) or the month of capture (P=0.49). These results suggest that CPT is an important health and welfare concern for at-risk macropod populations, with high case-fatality rates and prolonged clinical durations. Further research to manage the disease via methods such as reducing Phalaris aquatica plant coverage and preventative treatments for animals is warranted to reduce disease incidences and improve disease outcomes in wildlife populations.

A Solutions-Focused Translational Research Framework for Wildlife Health

Wildlife health is of emerging relevance for conservation, human health, and domestic animal health. Increased research on wildlife health problems has not been accompanied by a relative increase in effective solutions. Translational research was developed in human health to overcome blocks impeding the development of solutions out of basic research, and a translational research framework is proposed to overcome the same barriers in wildlife health. This framework has four translational phases: problem definition, potential solution development, efficacious solution development, and effective solution development. Implementation of translational research will require a restructuring of the wildlife health research enterprise with a shift, supported by funding sources and journals, to solutions-focused research including later translational phases, the creation of more deeply integrated multidisciplinary and interdisciplinary teams incorporating better representation from human social sciences, and the inclusion of end user and stakeholder participation in all phases of research.

The aetiology, prevalence and morbidity of outbreaks of photosensitisation in livestock: A review

BACKGROUND

Photosensitisation is a clinical condition occurring in both humans and animals that causes significant injury to affected individuals. In livestock, outbreaks of photosensitisation caused by ingestion of toxic plants are relatively common and can be associated with significant economic loss.

OBJECTIVES

The agents that are most commonly implicated in outbreaks of photosensitisation have not been formally investigated on a global scale. To address this question, a systematic review of the literature was undertaken to determine the most common causative agents implicated in outbreaks of photosensitisation in livestock in Australia and globally, as well as the prevalence and morbidity of such outbreaks.

METHODS

A systematic database search was conducted to identify peer-reviewed case reports of photosensitisation in livestock published worldwide between 1900 and April 2018. Only case reports with a full abstract in English were included. Non peer-reviewed reports from Australia were also investigated. Case reports were then sorted by plant and animal species, type of photosensitisation by diagnosis, location, morbidity and mortality rate and tabulated for further analysis.

RESULTS

One hundred and sixty-six reports qualified for inclusion in this study. Outbreaks were reported in 20 countries. Australia (20), Brazil (20) and the United States (11) showed the highest number of peer-reviewed photosensitisation case reports from this analysis. Hepatogenous (Type III) photosensitisation was the most frequently reported diagnosis (68.5%) and resulted in higher morbidity. Panicum spp., Brachiaria spp. and Tribulus terrestris were identified as the most common causes of hepatogenous photosensitisation globally.

CONCLUSIONS

Hepatogenous photosensitisation in livestock represents a significant risk to livestock production, particularly in Australia, Brazil, and the United States. Management of toxic pastures and common pasture weeds may reduce the economic impact of photosensitisation both at a national and global level.