Summer Pest Surveillance
Dr. Darlene Konkle, Wisconsin State Veterinarian and DATCP Administrator of the Division of Animal Health
As summer intensifies across Wisconsin, so does the activity among ticks, mosquitoes, and other pests. Awareness and seasonal surveillance are essential in protecting companion animal, livestock, and public health. Resources such as those below can be used or shared with clients for information on some of the diseases transmitted by these pests.
Ticks: Expanding Ranges, Emerging Threats
Tick populations in Wisconsin increase significantly during the warm season, with several species posing health risks. Reportable tick-borne pathogens include Lyme disease (Borrelia burgdorferi), Anaplasmosis (Anaplasma phagocytophilum), Ehrlichiosis (Ehrlichia spp.), Babesiosis (Babesia microti), and Rocky Mountain spotted fever (Rickettsia rickettsii).
Ticks that pose a threat to human and animal health in Wisconsin include:
- Deer Tick/Blacklegged Tick (Ixodes scapularis)
- American Dog Tick/Wood Tick (Dermacentor variabilis)
- Lone Star Tick (Amblyomma americanum)
- Asian Longhorned Tick (Haemaphysalis longicornis) – not yet found in Wisconsin but detected in adjacent states
Ticks inhabit wooded areas, overgrown pastures, and dense underbrush. They don’t jump or fly, but exhibit “questing” behavior to locate vertebrate hosts. Seasonal activity peaks from spring through early fall, though overwintering species may remain active during mild winters.
Effective ways to protect against ticks:
- Conduct regular integumentary inspections, especially in areas with dense fur or limited visibility like paws, ears, tails, and underbellies
- Implement yard and pasture management: reduce tall vegetation and remove organic debris
- Bathe livestock and pets frequently
- Consider sprays, rubs, and pour-on tick prevention treatments
Encourage client participation in passive surveillance using diagnostic tools such as the Tick App
(bit.ly/WItickapp) which provides information on tick identification, the diseases they transmit, tick bite prevention, and Wisconsin specific risks.
Mosquitoes: Surveillance and Environmental Control
Like ticks, mosquitoes are a persistent nuisance every summer. Wisconsin is home to at least 56 species which are most active from May to September until temperatures drop below freezing. The most common veterinary diseases in Wisconsin transmitted by mosquitoes are:
- West Nile Virus
- Eastern Equine Encephalitis (EEE)
- Heartworm disease
For detailed disease and control information on many reportable diseases, including West Nile and EEE, see Animal Disease on the CFSPH website: bit.ly/CFSPHinfo. For more information on the latest heartworm prevention and treatment recommendations, go to the American Heartworm Society homepage: bit.ly/heartwormsoc.
To prevent mosquitoes, encourage clients to follow these best practices for mitigation:
- Elimination of larval habitats (e.g., stagnant water in troughs, birdbaths, discarded containers)
- Limit animal exposure during peak hours: dawn and dusk
- Use of barn fans; consider appropriate netting for outdoor runs
- Biological control by natural predators (e.g., birds, bats, and opossum) may contribute to tick and mosquito suppression in some environments
By staying vigilant and implementing effective prevention strategies, veterinarians can help their clients safeguard livestock and companion animals from the dangers posed by these seasonal pests.
Reporting and Coordination
Veterinarians are vital partners in the early detection and response to disease outbreaks. Find lists of reportable diseases, including reportable vector-borne diseases, and report suspected cases of reportable animal disease to the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) via the DATCP Reporting Portal: bit.ly/AnimalDisease.