Autumn is upon us again, and that means winter is around the corner.  As New Englanders, we know the weather is predictably unpredictable.

Ticks, fleas, and other parasites that seek our pets as dinner hosts thrive during temperature fluctuations.  You may have noticed that ticks have been especially ferocious this fall.

Every pet parent knows that parasites are bad.  A common mistake, though, is to use parasite prevention “seasonally.”  That has big ramifications for Fido and Fluffy, because ticks and other nasty critters do not check the calendar before going on a hunt.  Alas, if the temperature is warm enough, they hunger for blood meals and are on the prowl.

If you choose to use tick prevention only seasonally, then your pet is at risk right now.  Deer ticks have a two-year life cycle, and are not killed by typical periods of frost, cold weather, or snow.

Tick diseases can be terrifying because they strike suddenly, severely, and unexpectedly.  We live in the center of the bull’s eye for Lyme disease, which can infect both Fido and his fellow humans.  The list of other local tick diseases is long, but common ones include anaplasmosis and ehrlichiosis.

Adult deer ticks are smaller than a sesame seed.  In fact, they are so tiny that we often miss them on our own bodies, despite our relative lack of hair.  Pets have dense, furry coats.  Although tick checks are a good idea, it is unrealistic to depend on tick searches alone to protect your pet from infectious diseases.

Fleas are another common, year-round companion for Fido and Fluffy.  They thrive in warm, humid climates.  Remember, though, even though it is winter outside, it’s never winter inside your home.  Indoor temperatures are always flea-friendly, although the drier air during winter months slows flea reproduction.

Fleas go through several stages before emerging as adults and seeking blood meals.  Flea eggs, larvae, and pupae live in the environment.  In your home, favorite locations would be where your pet likes to sleep.  Couches, beds, and pillows are common environments for immature fleas.

Once the adult flea emerges, it quickly seeks a host and prefers to spend its entire adult life on that warm, blood-rich host.  Fleas feed constantly and love the taste of cat and dog blood.  They are so adept at making themselves at home on your pet that they are rarely noticed until the infestation becomes severe.

Adult fleas live for several weeks on their host, laying hundreds or thousands of eggs during that time.  These microscopic eggs shake off into Fido’s and Fluffy’s environment, gradually emerging into adults weeks or months later and starting the cycle all over again.  During humid weather, this cycle speeds up.  That explains why many flea infestations are identified in late summer.

Some pets develop flea allergies.  They itch and chew and develop rashes.  Other pets with fleas are virtually symptom-free.

Besides the annoyance of fleas, these pesky bugs also spread diseases such as bartonellosis (cat scratch disease) and tapeworms.

If you use flea prevention seasonally or not at all, then your pets are at risk right now.

Even totally indoor cats are at risk for fleas all year.  Other people may accidently bring hitchhiking immature fleas on their clothes and into your home when they come by.  Visiting pets may introduce fleas to your home as well.  It may be months before you become aware of your flea infestation, and you may wonder how this could possibly happen to your indoor-only Fluffy.

Fortunately for Fido and Fluffy, there are now multiple excellent options for flea and tick prevention.  In most cases, topical pesticides such as flea collars and drops can be avoided.  The newer and safer preventatives are FDA-approved medicines.  Like other medications, they work from the inside and do not expose pet and family to pesticide residue.

Heartworms also have a tale to tell.  It can be tempting to ignore heartworm disease in Massachusetts.  The prevalence of this disease is much greater in the South, but it definitely exists here, too.  Heartworm disease is serious because it kills pets.  Heartworms are spaghetti-like worms that live in and around the heart of dogs.  If left untreated, it causes heart failure and death in dogs.  In cats, their development is often arrested prematurely in the lungs.  These cats may cough with asthma-like symptoms, or may suddenly die.

Heartworm disease is virtually 100 percent preventable.  The disease, though, is challenging to treat and not without risks.  In dogs, treatment is costly, painful, and lengthy.  There is no established treatment for feline heartworm disease.  Instead, symptoms are managed with hopes that the cat recovers.

If your pet is not on regular heartworm prevention, talk to your veterinarian.  Multiple options exist, including the tried-and-true monthly chewables, topical prescription applications, and newer long-acting injections.