Fleas and ticks are not the only parasites that can cause problems for our dogs, cats and other pets. Mosquitoes are the number one vector of diseases and pathogens worldwide, but preventative medicine can make a big impact in reducing infection.
With summer swiftly approaching, and with it an increase in mosquitoes, Guilherme Verocai, a clinical assistant professor in the department of veterinary pathobiology and director of the Parasitology Diagnostic Laboratory at the Texas A&M College of Veterinary Medicine & Biomedical Sciences, has advice for combating the most common mosquito-borne diseases, including heartworms, the most significant parasite of dogs in the U.S.
Heartworms are most frequently found in dogs but can also infect cats, ferrets and wild animals such as coyotes.
“Adult worms live in the heart and pulmonary arteries,” Verocai said. “The larval worms, also known as microfilariae, are found in the bloodstream and are picked up by mosquitoes during a blood meal. The larvae will develop inside the mosquito and pass to another dog during a subsequent blood meal.”
The symptoms of heartworms include coughing and abnormal lung sounds, followed by heart, lung, liver or kidney damage.
Verocai said early treatment is vital for heartworms, but the best option is to use preventative medications to stop infection before it occurs.
The American Heartworm Society recommends testing annually for heartworm antigens and microfilariae in addition to keeping pets on preventative products all 12 months of the year. These products kill heartworm larvae once they enter the pet’s body and may also work against gastrointestinal worms, fleas, ticks and mites.
Verocai said topical products can be used as an additional measure to repel mosquitoes, but these products only reduce the animal’s chance of getting heartworms rather than eliminate the risk altogether.
“There are several topical products for dogs that contain repellents and insecticide drugs that have label claims against mosquitoes and are effective for up to a month,” he said. “There are no labeled products to control mosquitoes in cats that are effective for an entire month, but there are over-the-counter products that have repellency activity for shorter periods of time.”
Besides spreading heartworms to pets, mosquitoes can also transmit viruses including malaria, yellow fever, dengue and Zika to other animal species and people.
Various forms of encephalitis also can be spread to horses through mosquito bites, but vaccines usually are able to prevent infection. For horses, cows, and members of the deer family, mosquitoes can transmit roundworms that live in the host’s body but rarely cause disease.
Despite the many possibilities for harm, mosquito bites are usually no more than a nuisance to pets if preventative medicine is used year-round. For dogs and cats, these medications often help kill fleas and ticks as well, making it easy to prevent all three pests at once.