Feral animals are a fact of life on the land and many producers understand the threat of livestock predation, destruction of crops or damage to farm infrastructure. Compared to these risks, the human and animal health impacts of feral animals are often overlooked, though the threat is just as pressing.
Research indicates that wild dogs, for example, can live comfortably within a kilometre of urban and suburban centres, sparking concerns for livestock in ‘peri-urban’ regions (i.e. production areas on the fringes of urbanised land) and by extension domestic pets, with further implications for human health.
“Dogs can act as carriers for a wide range of diseases, spreading parasites or diseases from property to property,” says Dr Simon Humphrys, Executive Manager Biosecurity and Product Integrity at Animal Health Australia.
“One nasty parasite is hydatids – which incubate in dogs and dingoes, foxes, sheep and goats, even wildlife,” Dr Humphrys explained.
Humans are most often exposed to hydatid eggs through the coats and manure of domestic dogs, which get them from eating infected carcasses.
“The only way to control these parasites is to break the life cycle. This means ensuring both wild and domestic dogs cannot feed on potential hosts, or enter areas where the infection is present.”
Another major biosecurity threat is from feral pigs, which roam across vast tracts of land, often causing damage to fences, irrigation infrastructure, uprooting crops, or killing lambs, while also fouling every water point on their travels.
Pigs can be a significant reservoir of disease, parasites, and weed pathogens/seeds that they can readily transmit to livestock and plants or translocate. They’re often the first to make holes in fences that also allow for easier movements by other wildlife and livestock, increasing the number of uncontrolled interactions between animals that lead to increased biosecurity risks.
“Modelling suggests that, in the event of a major outbreak such as foot and mouth disease, just one pig could rapidly increase the size of the infected area,” Dr Humphrys explained.
“It’s clear that managing feral animals in a coordinated way and at relevant landscape scales is the most cost-effective way to manage biosecurity risks, but sometimes it needs to come right down to the individual, given that something as simple as allowing a wild dog to take a bite out of a carcass could allow a threat to establish or spread.”
The National Wild Dog Action Plan is an excellent example of a cross jurisdictional initiative including a range of stakeholders that are tackling wild dog impacts at a regional scale using the whole range of control tools according to a stakeholder agreed regional control plan. For more information or to take part in a coordinated control program, contact the National Wild Dog Facilitator , your state authorities, or PestSmart Connect.
At the farm level, ensuring that fencing is secure, that farm buildings are in good repair and that carcasses and waste are disposed of promptly and in an appropriate manner – depriving feral visitors of food – will help to prevent feral animals being attracted to or gaining a foothold on the property.
For more information, visit the Farm Biosecurity website.