More than 40 percent of donkeys in Ethiopia were found in a recent study to be infected by the troublesome liver fluke that causes fasciolosis.
Fasciolosis is recognised as an important re-emerging zoonotic disease. It affects humans, but its main host is ruminants such as cattle and sheep.
Infection by the parasitic worm can cause fever, malaise, abdominal pain, gastrointestinal symptoms, anemia and jaundice, as well as respiratory symptoms. It can later progress to a latent phase with fewer symptoms and then to a chronic phase, in which it can inflame the bile ducts and gall bladder, and may cause gall stones, as well as fibrosis.
Mulugeta Getachew and his colleagues said fasciolosis was an important livestock disease worldwide, and the public health importance of human fasciolosis had increased in recent years.
The study team, in a research presentation to delegates at the recent British Equine Veterinary Association (BEVA) Congress, described their work to learn more about fasciolosis among Ethiopian donkeys and the possible role of the animals in the spread of the disease
For the study, the researchers collected 803 dung samples from randomly selected working donkeys from the central region of Ethiopia, which were tested for evidence of infection by the liver flukes. They also checked for the liver flukes and associated damage during post mortem examinations on 112 donkeys which had either died, and had been euthanised on welfare grounds.
They found that 44.4% of the donkeys whose dung samples were checked were infected, and 41.9% of those examined post mortem. Age had no bearing on the prevalence of the infection, they found.
Both of the flukes that cause fasciolosis – Fasciola hepatica and Fasciola gigantica – were identified, with an average infection intensity of 30 flukes.
Donkeys aged eight or older were found to harbour a significantly higher worm burden. They found enlargement and thickening of the bile ducts, fibrosis of large portal areas and irregular bile duct proliferation and enlargement due to an increase in the size of the cells.
The researchers said the high prevalence of the flukes and the associated liver-related issues in working donkeys showed not only the susceptibility of donkeys to the infection, but the impact it had on their health.
It also pointed to the potential role of donkeys in the cycle of the infection among livestocks and humans.
Donkeys needed to be considered in overall epidemiological studies of fasciolisis as part of the effort to control and prevent the disease, they said.
The study was funded by the British-based charity, The Donkey Sanctuary.
The researchers were from The Donkey Sanctuary, Biomathematics and Statistics Scotland, the Royal Veterinary College at the University of London, and the University of Glasgow.
A summary of the researchers’ work has been published in the Equine Veterinary Journal as part of the proceedings from the BEVA Congress.
Getachew, M.A., Innocent, G., Reid, S.W.J., Burden, F. and Love, S. (2015), A Neglected and Emerging Helminthosis: A Case of Equine Fasciolosis. Equine Veterinary Journal, 47: 21. doi: 10.1111/evj.12486_47
The abstract can be read here.