Intestinal Parasite Control: Protecting Your Family and Pets from Roundworms and Hookworms

Most pet owners are familiar with heartworm prevention and the serious threat that heartworm disease poses to dogs and cats. You've probably heard us say, "Please keep your pet on heartworm prevention year-round." But did you know that your heartworm prevention medication is doing double duty? Beyond protecting against heartworms, these medications also safeguard your pet from dangerous intestinal parasites, and this extra benefit is absolutely critical for keeping both your pets and your human family members healthy.

So what are these intestinal parasites, how do they affect our pets, and why should you care? Let's dive into the somewhat unsettling but important world of roundworms and hookworms.

What Heartworm Prevention Really Protects Against

All heartworm preventatives on the market today protect dogs and cats against roundworms and hookworms. These are among the most common intestinal parasites found in pets, and importantly, they are zoonotic, meaning people can contract them from infected animals. This makes parasite prevention not just a pet health issue, but a public health concern as well.

While heartworm prevention is the primary reason most pet owners give these medications, the intestinal parasite protection they provide is equally important and often underappreciated.

Understanding the Parasite Life Cycle

Roundworms and hookworms have complex life cycles, but understanding the basics helps explain why year-round prevention is so important.

Transmission: Dogs and cats become infected through the fecal-oral route. This sounds complicated, but it simply means they eat or lick something that has been contaminated with infected feces. This could be grass, soil, water, or even their own paws after walking through a contaminated area. Remember, dogs and cats frequently groom themselves and explore their environment with their mouths, making exposure quite common.

Development: Once ingested, the microscopic larval eggs enter the animal's body and begin migrating through tissues on their way to the gastrointestinal tract. There, they mature into adult worms that can grow several inches long.

Reproduction: Adult worms reproduce prolifically in the intestines, producing thousands of eggs daily. These eggs are passed in the pet's feces, contaminating the environment and starting the cycle all over again.

Environmental contamination: The eggs are incredibly resilient. Roundworm eggs, in particular, can survive in soil for months or even years, remaining infective through rain, snow, and freezing temperatures. This creates ongoing contamination in yards, parks, and anywhere infected animals defecate.

Why Humans Are at Risk

The same parasites that infect our pets can infect people, and the consequences can be serious.

Children are most vulnerable: Young children, like our pets, aren't always discriminating about what they put in their mouths. They play in dirt, touch contaminated surfaces, and sometimes forget to wash their hands before eating. This puts them at the highest risk for contracting roundworms and hookworms from contaminated environments.

Skin penetration: Hookworm larvae can actually penetrate intact skin. This means that walking barefoot in contaminated soil or grass, gardening without gloves, or even sitting on contaminated ground can lead to infection in both people and pets.

Visceral larval migrans: When these parasites infect humans, the larvae migrate through body tissues trying to reach the intestines. However, humans aren't the parasites' natural host, so the larvae often get "lost" and end up wandering through various organs and tissues. This condition is called visceral larval migrans, and it can affect the liver, lungs, heart, brain, muscles, and eyes.

Ocular larval migrans: When larvae migrate to the eyes, they can cause ocular larval migrans, which may result in vision problems, inflammation, or even permanent vision loss. This is particularly devastating when it occurs in children.

The images of what visceral and ocular larval migrans can do are truly disturbing. You can Google it if you're curious, but we'd rather you simply keep all of your pets on heartworm prevention year-round to avoid this risk entirely.

What These Parasites Do to Your Pet

Beyond the risk to humans, roundworms and hookworms cause significant health problems in pets.

Hookworms: These parasites are particularly nasty. They attach to the intestinal lining using their hook-like mouthparts and feed on your pet's blood. A heavy hookworm infection causes:

• Significant blood loss leading to anemia

• Weakness and lethargy

• Pale gums

• Dark, tarry stools

• Poor growth in young animals

• Life-threatening complications in puppies and kittens, who can become severely anemic very quickly

Hookworm infections are often life-threatening in young puppies and kittens because their small bodies can't afford to lose much blood.

Roundworms: While generally less immediately dangerous than hookworms, roundworms can still cause serious problems, especially when present in large numbers:

• Vomiting (sometimes with visible worms)

• Diarrhea

• Poor appetite and weight loss

• Pot-bellied appearance despite poor body condition

• Dull, rough coat

• Stunted growth in young animals

• Coughing (when larvae migrate through the lungs)

• Intestinal blockage in severe cases

Adult pets with healthy immune systems may show no symptoms despite being infected, which means they can be silently shedding eggs and contaminating the environment.

Maternal Transmission: Why All Puppies and Kittens Are at Risk

Here's something many pet owners don't know: breeding females pass both roundworms and hookworms to their offspring before they're even born.

Prenatal and nursing transmission: Most adult dogs and cats harbor encysted (dormant) larvae in their body tissues. These larvae become activated during pregnancy due to hormonal changes. The larvae then:

• Cross the placenta and infect puppies or kittens while still in the womb

• Migrate to the mammary glands and infect nursing babies through milk

Universal infection: Because of this maternal transmission, it's believed that virtually all puppies and kittens are born already infected with roundworms and hookworms, even if the mother appeared healthy and well-cared-for.

This is why veterinarians deworm puppies and kittens repeatedly, starting at just a few weeks of age and continuing every two weeks until they're old enough to start heartworm prevention. We're not being overly cautious, we're combating an infection that's almost certainly present.

Why Year-Round Prevention Is Essential

Some pet owners discontinue heartworm prevention during winter months, reasoning that there are few or no mosquitoes to transmit heartworms. While it's true that mosquitoes are less active in cold weather, this practice leaves pets vulnerable to intestinal parasites.

Environmental persistence: Unlike heartworms, which require mosquito transmission, roundworm and hookworm eggs persist in the environment. Roundworm eggs are particularly hardy; they can survive freezing temperatures for months. Even when snow covers the ground, these eggs remain viable and infective, waiting for warmer weather to continue their life cycle.

Continuous exposure: Your dog doesn't stop going outside in winter. Every walk, every bathroom break, and every romp in the yard is an opportunity for exposure to parasite eggs that have survived in the soil since fall or even from previous years.

Consistent protection: Monthly heartworm prevention works by eliminating parasites that your pet has been exposed to during the previous month. If you skip winter months, you're leaving a gap in protection during which your pet could develop an intestinal parasite infection. When spring arrives and you restart prevention, you may already be dealing with an established infection.

Travel considerations: Even if your local area seems safe, traveling to warmer climates during winter (or welcoming visiting pets from warmer areas) can expose your pet to both heartworms and intestinal parasites.

Additional Parasites Covered

Depending on which heartworm preventative you use, your pet may receive protection against additional intestinal parasites:

Whipworms: Some heartworm preventatives also protect dogs against whipworms. While whipworms are not zoonotic (they don't infect people), they can cause significant gastrointestinal problems in adult dogs, including chronic diarrhea, weight loss, and anemia. Whipworms are notoriously difficult to eliminate once established, so prevention is far preferable to treatment.

What's NOT covered: Tapeworms are the one common intestinal parasite that heartworm preventatives don't address. Tapeworms require a separate dewormer if they become a problem. Pets typically acquire tapeworms by ingesting fleas (which carry tapeworm larvae) or by eating infected prey animals. If you see rice-like segments in your pet's feces or around their rear end, contact us for appropriate treatment.

Protecting Your Community

When you keep your pet on year-round heartworm prevention, you're not just protecting your own family, you're being a responsible community member.

Reducing environmental contamination: Preventing intestinal parasites in your pet means fewer parasite eggs deposited in your neighborhood. This protects:

• Children playing in yards and parks

• Other people's pets

• Wildlife

• Anyone who walks barefoot in grassy areas

Public spaces: Dog parks, walking trails, playgrounds near grassy areas, and community green spaces can all become contaminated with parasite eggs from infected dogs. By preventing infection in your own pets, you help keep these shared spaces safer for everyone.

Responsibility to others: If you have visitors with children, service workers who enter your property, or neighbors whose yards adjoin yours, keeping your pets parasite-free is a courtesy and a health responsibility.

Our Product Recommendations

At Middle River Veterinary Hospital, we have extensive experience with various heartworm preventatives, and we have our preferred products based on effectiveness, safety, and comprehensive protection:

For dogs: We prefer Interceptor Plus. This monthly chewable tablet protects against:

• Heartworms

• Roundworms

• Hookworms

• Whipworms

• Tapeworms (Interceptor Plus specifically)

It's highly effective, well-tolerated by most dogs, and covers the broadest spectrum of intestinal parasites.

For cats: We prefer Revolution Plus. This monthly topical treatment protects against:

• Heartworms

• Roundworms

• Hookworms

• Fleas

• Ear mites

• Some ticks

Revolution Plus is convenient for cat owners and provides comprehensive parasite protection in a single application.

Of course, every pet is unique, and we're happy to discuss which preventative is best suited to your individual pet's needs, lifestyle, and any special considerations.

Beyond Prevention: Good Hygiene Practices

While year-round heartworm prevention is the cornerstone of intestinal parasite control, these additional practices provide extra protection:

For pet owners:

• Pick up pet feces immediately from your yard and dispose of it properly

• Don't allow pets to defecate in children's play areas

• Wash your hands thoroughly after handling pets, especially before eating

• Discourage pets from licking children's faces

• Keep sandboxes covered when not in use (cats may use them as litter boxes)

• Wear gloves when gardening in areas where pets defecate

For children:

• Teach children to wash hands after playing outside and before eating

• Discourage children from putting dirt, grass, or other outdoor items in their mouths

• Supervise young children around pets

• Keep children's play areas separate from pet bathroom areas when possible

For your pets:

• Bring fecal samples to your annual vet visits for parasite screening

• Start puppies and kittens on deworming protocols as recommended

• Begin heartworm prevention as early as your veterinarian advises

• Don't allow pets to eat feces (their own or other animals')

The Bottom Line

To protect your pets, your family, your friends, and your neighbors from the health risks posed by roundworms and hookworms, keep your pets on heartworm prevention year-round. It's simple, effective, and provides comprehensive protection that extends far beyond heartworm disease.

The monthly cost of prevention is minimal compared to the expense, discomfort, and potential health consequences of treating parasite infections in pets or, worse, dealing with human infections requiring medical intervention.

We're Here to Help

At Middle River Veterinary Hospital, we're committed to keeping your pets healthy and your family safe. If you have questions about heartworm prevention, intestinal parasites, or which product is right for your pet, please don't hesitate to contact us. We can help you choose the best prevention strategy and ensure your pet stays protected all year long.

Remember: an ounce of prevention is worth a pound of cure, especially when it comes to parasites that can affect the entire family!