African swine fever: Dogs, a New Ally in the Search for Wild Boar Carcasses

The fight against African swine fever (ASF) doesn’t always take place at borders or in laboratories, but sometimes deep in the forest, where dead wild boars lie. This is because in Europe, the ASF virus circulates primarily among wild boars, and their carcasses serve as a major viral reservoir: as they decompose, they sustain the infection in the environment and fuel transmission among wildlife, with the constant threat of the virus being introduced into pig farms looming in the background. It is this reality that a Polish team explores in *Preventive Veterinary Medicine*, with the goal of comparing the effectiveness of several methods for locating carcasses (human ground searches, tracking dogs, hunting dogs, drones) to determine what truly works over large areas under real-world conditions. The study, conducted in the Opole Province in southern Poland between August 2022 and March 2025, has a very concrete objective: to locate carcasses as quickly as possible, remove them promptly, and cut off one of the virus’s main transmission routes.  

A control strategy that starts with carcasses

African swine fever in wild boars is unique in that it makes passive surveillance (the detection of animals found dead) particularly informative. Whereas monitoring other diseases relies primarily on systematic sampling, the presence of carcasses that test positive—along with their location and frequency—provides insight into the dynamics of an ASF outbreak. However, these carcasses must actually be found. And this is where human efforts reach their limits (reduced visibility, rugged terrain, dense vegetation, vast areas, team fatigue, and level of experience). In the forest ecosystem, dogs change the equation. The effectiveness of a dog’s sense of smell extends far beyond the limits of human vision. Dogs can thus speed up detection, shorten the time to removal, reduce the likelihood that carcasses will decompose or be moved by scavengers, and limit indirect exposure of other wild boars. This study shows that the most effective method involves trained dogs. Of a total of 400 carcasses located, 397 (99.2%) were found by search dogs, and the remaining 3 by hunting dogs. Neither drones, nor human search on foot, nor the combined methods tested could rival a dog’s sense of smell.  

Searching for carcasses over large areas

The researchers emphasize that the goal is not only to monitor the disease but also to reduce its transmission among wild boars, given the lack of a vaccine that can be used on a large scale in wildlife. In this context, carcasses scattered throughout the environment can infect other wild boars and, more insidiously, serve as a source of contamination for livestock farms (via boots, equipment, vehicles, and contaminated agricultural products). The study covered 810 km², with some areas surveyed multiple times. In total, 314 search operations were conducted: 86 of them (27.4%) resulted in the discovery of at least one carcass, for an average of 0.78 carcasses per search. Analysis of the samples revealed that 326 carcasses (81.5%) tested positive for the virus via RT-PCR.  

The Need for a Cooperative Effort

“Only through cooperation among various professionals can we successfully curb the spread of ASF , ” the authors state, describing a range of expertise that goes beyond the simple use of dogs. Hunters contribute their knowledge of wild boars’ movements, habits, and areas of presence; veterinarians handle sample collection, carcass disposal, and biosecurity; and farmers, through crop layout, influence how the landscape channels the animals. In this context, dogs are all the more effective when used in synergy within a well-oiled chain of cooperation. The authors go so far as to suggest that, combined with human searches and technologies such as drones, dogs can become a major tool. The other, more political issue concerns the resources mobilized. Training, deploying, coordinating, and funding canine teams requires a long-term strategy, integrated with other measures (movement management, zoning, fencing, enhanced surveillance, and hunting operations depending on the scenario).