Tick on leaf

Fleas and ticks are fighting back. It used to be that they would pester our pets between May and September — but now experts recommend that pet owners give parasite prevention products year-round to fight off the biting little buggers. What’s up with that?

Warming Up to Ticks

In the case of ticks, we are seeing more of them in more places. Ticks are on the march, spreading to areas where historically they hadn’t been a problem. You might say they are investing in change. They hitch rides on migrating wildlife such as deer and they infiltrate the edges of urban sprawl when real estate developments clear away woodlands, leaving rodents, popular hosts for ticks,  without predators. 

Climate change may be a factor, too, although the patterns are different for different types of ticks. According to veterinary parasitologist Susan E. Little at Oklahoma State University, drought has driven the lone star tick population in Texas, Oklahoma and Kansas down, but the same conditions gave a dramatic boost to the brown dog tick population in those areas. “Same climate change,” she says, but a “different effect on different species of ticks.”

In some places, warming trends bringing milder winters have allowed ticks to move into new areas, including those at higher altitudes and latitudes. Even in Alaska, which historically didn’t have a tick problem, the bloodthirsty arachnids are making their presence known, thanks to the presence of dogs from the lower 48 and longer periods of greening in warmer months of the year.

And ticks are tough. They don’t die off in harsh winters but shelter cozily beneath snow cover or leaf litter. They might not be as active, but they are out in wintertime. “About 30 percent of human cases of Lyme disease are transmitted by ticks that are out between October and March,” says Dr. Little.

The tick’s super reproductive capacity is a factor, too. When conditions are just right for ticks — humid and mild — their reproductive abilities go into overdrive, increasing their populations dramatically. Depending on the species, says Dr. Little, “an adult female tick will produce between 4,000 and 15,000 eggs” at one time. Skipping preventive, she adds, can be catastrophic. “If you have an adult brown dog tick that’s attached to a dog and the dog brings that into the house [and] the dog is not on tick control and [the tick] feeds and it’s been fertilized and it drops off in the environment, she is going to lay several thousand eggs in the home.

“And then the eggs are going to hatch out several thousand larvae and you’ve got a home tick infestation just from the introduction of a single fertilized female tick.”

Indoor-Outdoor Pests

What about fleas? While cases of flea allergy dermatitis are less dramatic and less severe than they were back when I first began practicing, thanks to better products for prevention, they do still occur.

The climactic conditions that can lead to a higher flea population vary from year to year, but in many places fleas are out to get our pets seven to 12 months a year. And as with brown dog ticks, fleas enjoy a cushy indoor existence. They can lurk in your home year-round.

Even if your pet — a cat, for instance — lives indoors, fleas and ticks can find their way inside via other pets, people and wildlife. You or your dog can bring them home from a hike, and critters such as opossums, squirrels and raccoons can spread them if they are living beneath your home or have found their way into a crawl space.

Some of those parasites even prefer to live indoors. Take brown dog ticks — please! They can survive for more than a year indoors, even with nothing to feed on. Depending on their life stage, fleas can survive for many weeks indoors.

When you stop administering flea-prevention products, under the assumption that “flea season” is over, you run the risk of having to fight them all over again. Today’s flea-control products are fast-acting and effective, but depending on which product you use, there can still be a three- to four-month lag between the time you begin treatment and the time you can expect the fleas to, er, flee. Even if new fleas make their way into your home or onto your pet, the important goals are to kill them quickly and make sure they can’t reproduce, as well as to provide your pet with ongoing protection.

Fleas and ticks aren’t just disgusting to us and uncomfortable for our pets. They can transmit diseases to animals. When we come into contact with parasites that have latched onto our pets, we run the risk of disease as well. That makes preventing parasite infestation a public health issue.

Dr. Little and other parasite experts have a mantra: every pet, every month, all year long. The best way to successfully control parasites, especially in a multi-pet household, is to make sure that every animal is treated on a regular basis.

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