When Is Flea, Tick and Mosquito Season? How to Protect Your Pet Year-round

While it may seem like parasite activity spikes during the spring and summer, data shows that fleas, ticks and mosquitoes can cause health issues for your dog or cat year-round. Not only can these parasites impact your pet’s health by stealing their nutrients, but they can also pass on diseases like Lyme disease and heartworms. 

Certain areas of the U.S. face higher disease and infection risks than others, and at different times throughout the year. Protecting your pet from fleas, ticks and mosquitoes starts with prevention and education. Understanding the threat these pests pose can help you shield your pets from unnecessary exposure. 

Fleas Are Always in Season

It’s important for pet owners to stay alert for signs of infection and flea infestation no matter what the weather is like. Though fleas may be less prevalent during colder months, there is no season in which your pet is not at risk of contracting fleas. As long as they have a warm host to live on — like your dog or cat — fleas will make themselves at home.

When Is Flea Season?

As temperatures rise, owners should be especially vigilant. Fleas tend to be more active during warmer months. They favor humid weather and temperatures from 60 to 75 F — which can be as early as late February in some parts of the U.S. and during a second fall season throughout the country. 

Even if the outside temperature is inhospitable to fleas, your house’s indoor temperature will probably still be around or higher than 60 to 69 F, so your indoor pet is still at risk of hosting fleas. This means year-round risk, no matter where you live.

The Companion Animal Parasite Council (CAPC) offers a daily flea forecast that shows flea activity in the United States based on the weather and temperature.

Where Are Fleas Found?

The most likely place you’ll find fleas is on your pet. However, your environment may be infested with the other, microscopic life stages of the flea: eggs, larvae and pupae. These environmental stages of the flea life cycle tend to be invisible to the naked eye.  

When checking your pet for fleas, make sure to check your surroundings, too. Fleas may be found in places where you and your pets spend the most time, such as pet beds, furniture and carpets. Hitchhiking fleas can hop on people and pets as they move in and out of your home. Once they’re on a pet, fleas lay eggs, which can quickly develop into an environmental infestation.

What Can You Do to Protect against Fleas?

Although your pet may be the main host to fleas, these tiny pests can transfer to other surfaces, too. Wash bedding and vacuum floors and furniture regularly to help keep fleas from taking up residence in your home.

Another great way to help prevent an infestation on your pet or in your home is through a specially designed flea and tick collar. Seresto^® Flea and Tick Collar repels and kills fleas through contact, so they don’t have to bite your pet to die. Since the collar provides eight continuous months of protection, you don’t have to worry about administering a monthly preventive or dealing with greasy, messy topicals.  

Tick Season Has No Off-season

Like fleas, ticks don’t take time off. On their own, ticks live and breed in temperatures above 40 F. Some tick species can even be active all year long, regardless of temperature. Ticks transmit a variety of harmful diseases that affect pets and people alike, making year-round prevention essential.

When Is Tick Season?

It’s always important for owners to keep an eye out for ticks — on pets and humans. Peak tick season varies depending on where you live in the U.S. and the types of ticks most prevalent in your area.

Where Are Ticks Found?

Many pets and their owners live in or near ideal tick environments, so it’s difficult to avoid them entirely. Ticks hang out where they can easily feed on live animals, usually wooded areas and grassy spots like your backyard, a park, on hiking trails or in wooded areas or fields. Ticks cling to tall blades of grass or lower-hanging foliage until they can attach themselves to passing animals.

Avoiding exposure to ticks may not be possible for many pet owners, which is why preventive measures are crucial; exposure to a tick bite may mean exposure to disease.

Tick Disease Risks: Lyme Disease, Ehrlichiosis and Anaplasmosis

Common diseases spread by ticks vary based on season and location. Although the tick bite alone may not be dangerous, the potential infection or disease it can spread is cause for concern.

Ticks are known to spread dangerous diseases like Lyme disease, a fairly common disease in dogs. It is typically found in the Northeastern U.S. and Upper Midwestern U.S., where it is transmitted by the blacklegged tick (Ixodes scapularis), as well as along the Pacific coast, where it is transmitted by the western blacklegged tick (Ixodes pacificus).

This map from CAPC details the projected prevalence of Lyme disease in regions throughout the United States.*

Source: CAPC 2023 Annual Pet Parasite Forecasts 2023 (v1.0).*

Another dangerous infection spread by ticks is ehrlichiosis, a bacterial disease transmitted to dogs by the brown dog tick and American dog tick. Found throughout the U.S., the brown dog tick typically resides in warmer climates, but is also commonly found indoors.

Anaplasmosis is spread by ticks and requires a vet diagnosis and treatment with antibiotics. If you want to venture out with your pet, check the CAPC maps for tick-borne disease prevalence in cats and dogs before you leave to get a better understanding of what risks may pose a threat to your pet.* 

Keeping your pet safe from the dangers of ticks doesn’t have to start at the first signs of infection. Many owners choose preventive measures to decrease their pet’s chance of hosting ticks.

What Can You Do to Protect against Ticks?

Ticks are expected to be unusually prevalent throughout 2023. It may be difficult or even impossible for pet owners to avoid exposure to ticks entirely. Because ticks love long grass and low-hanging bushes, keep your yard mowed and your foliage trimmed. It may also help to treat your yard with products that kill ticks in and around your home, deck and patio.

Ticks can be found in urban areas as well, commonly in planters, trees and parks. Regardless of where you live, check your pet for ticks on a regular basis and get in the habit of doing daily self-checks, too — especially in seasons when tick activity or your pet’s outdoor access is higher.

Pet owners should also talk to their vet about tick prevention products like the Seresto^® Flea and Tick Collar. This convenient, odorless collar helps protect your dog or cat from ticks and their disease-carrying bites for eight continuous months. The collar steadily releases two active ingredients over your pet’s hair and skin, killing and repelling ticks. Plus, no worries if your dog is a swimmer or gets regular baths — the collar is water-resistant,** too. 

For an estimate of where multiple species of ticks and their numbers may be highest in your area, look for your state on the CAPC’s tick-borne disease alert map to get frequent updates on tick activity.*

Mosquitoes Are More Common During the Warmer Months

Unlike fleas and ticks, mosquitoes are temperature-sensitive and have more of a traditional season throughout most of the U.S. Other than the irritation their bites cause, the main concern with mosquitoes is their ability to transmit heartworms, leading to a potentially fatal disease for your dog or cat.

The CAPC provides a yearly forecast of the prevalence of heartworms across the U.S.*

Source: CAPC 2023 Annual Pet Parasite Forecasts 2023 (v1.0).*

When Is Mosquito Season?

Mosquitoes thrive in 75 to 80 F weather and aren’t as active when temperatures drop. Traditionally, that means most of the U.S. sees an increase in mosquito populations beginning in May, with heightened activity well into August.

However, just as with ticks and fleas, there is no set mosquito season, as these insects can survive throughout all 12 months of the year. Even in colder climates and seasons, the slightest increase in temperature can impact the mosquito life cycle, putting your pets at risk. It is extremely difficult to completely avoid exposure to mosquitoes, so many pet owners opt for preventive measures to decrease their dog or cat’s chance of contracting mosquito-borne illnesses.

Although not every mosquito bite will be dangerous, there is still a risk of disease — like the potential spread of heartworm. To keep your pet safe, it’s important to stay educated on which seasons carry higher risk and disease prevalence in your area. For a better idea of where mosquitoes are found, visit the CAPC parasite prevalence map to learn more about where parasites are commonly found and which disease threats have been reported in which areas.* 

Where Are Mosquitoes Found?

A lot of us are familiar with these annoying pests, especially during warmer seasons. Mosquitoes thrive in warmth and require stagnant water to breed. Areas with puddles, storm drains, water troughs, birdbaths or containers that can collect water are potential breeding grounds for mosquitoes.

When ready to feed, mosquitoes are attracted to people and animals, sensing a meal from as far away as 65 feet. Small and quick, they easily find their victims indoors and outdoors. Many pets and humans have a hard time avoiding mosquitoes entirely; that’s why it’s important to protect your pet with a preventive routine and stay educated on your area’s risk.

Multiple factors contribute to an area’s mosquito population and disease prevalence, so it’s not enough to only consider your location’s season or climate when determining risk. The CAPC identifies high-risk areas every year, which are widely spread throughout the United States, further illustrating the prevalence of heartworm-transmitting mosquitoes across the country. In 2023, the CAPC has reported an especially high risk for those located in the Mississippi River Valley and surrounding areas.

What Can You Do to Protect Your Pet from Mosquitoes?

Mosquitoes can transmit deadly diseases, so it is important to eliminate or avoid areas where they like to breed, when possible. Follow these tips to help prevent your dog or cat from being bitten by mosquitoes:

1. Stay indoors at dawn and dusk, when mosquitoes tend to be most active.
2. Avoid spending time near stagnant water, including improperly drained areas of your yard, kiddie pools, dog bowls or empty flower pots. Consider treating your yard with a mosquito-repelling spray.
3. Keep mosquitoes out of your home. Repair or replace tears in window or door screens, and look for openings where mosquitoes could buzz in.
4. Use a preventive treatment to help kill mosquitoes or repel them from your pet.

Protecting Your Pet from Heartworm

If you and your pet live somewhere with a large mosquito population, ask your veterinarian about prescribing a heartworm disease prevention product. When using preventive measures, consistency is key. It can take six months or more before a test can detect a heartworm infection, which means that missing just one monthly treatment can put your pet at risk. Speak with your veterinarian about finding the right one for your dog or cat. 

Flea, Tick and Mosquito Prevention Season Starts Now

As pet owners, we can’t always ensure our dogs and cats will avoid exposure to risks like mosquitoes, ticks and fleas. Especially if your pet spends a lot of time outside or in high-risk areas, it’s important to stay up to date on local statistics and keep your pet on a consistent preventive regimen to protect against infection.

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