Understanding the epidemiology of Chlamydia psittaci infections in mares

University of the Sunshine Coast

  • Project code: PRJ-011402

  • Project stage: Closed

  • Project start date: Wednesday, June 20, 2018

  • Project completion date: Wednesday, June 29, 2022

  • Journal Articles From Project: Epidemiology of Chlamydia psittaci infections in pregnant Thoroughbred mares and foals The Veterinary Journal (Issue: volume 273; 105683 on 1/7/2021), Developing an on-farm protocol for a suspected Chlamydia psittaci foal loss Australian Veterinary Journal (Issue: future on 17/8/2022), Chlamydia psittaci and Australian Thoroughbreds: a two-year study on C. psittaci infection in pregnant mares and their foals BEVA Equine Veterinary Journal (Issue: future on 18/7/2022)

  • National Priority: HOR-Thoroughbred diseases and parasites


Equine reproductive loss due to infectious agents impacts significantly on Australian Thoroughbred breeders. While a range of bacterial agents are a recognized cause of equine abortion, Chlamydia psittaci has emerged as a cause of reproductive loss as well as zoonotic disease of veterinarians and stud workers. Recent work has confirmed that prevalence rates of C. psittaci-infected equine pregnancy losses were higher than were originally considered and not limited to New South Wales, suggesting that this problem may be widespread and not just a recent phenomenon. While molecular methods have pointed to contact with birds as a key part of this issue little else is known about equine chlamydiosis, challenging any efforts to reduce the risk to animal and human health.
In this project, we aim to reduce pregnancy losses in Australia’s thoroughbred industry by revealing basic information on the epidemiology of this disease, focussing on two key aspects of this disease, the C. psittaci-infected mare and the potential avian reservoirs of C. psittaci infection.


Thoroughbred Horses

Research Organisation

University of the Sunshine Coast

Objective Summary

The overarching objective of this project is to reduce pregnancy losses in Australia’s thoroughbred industry as well as to reduce the risk of future spill-over events to humans, thereby improving health and wellbeing of the horses and protecting Australian public from this zoonotic infection.
To support this objective, this project will address key questions about the epidemiology of equine chlamydiosis by aiming to improve our understanding of:
(i) the incidence of C. psittaci infection in mares, the duration of infection and the risk of associated equine pregnancy loss; and
(ii) the avian reservoirs of equine C. psittaci infection and the potential routes of transmission to horses.