Parasites are more than just a nuisance—they’re a year-round health risk that can compromise your pet’s comfort and well-being. Whether it’s fleas, ticks, intestinal worms, or heartworms, parasites can cause irritation, spread disease, and lead to serious medical issues if left untreated.
In this guide, we’ll walk you through the most common parasites, how they affect pets, and—most importantly—how to prevent them from being a problem at all.
Our Commitment to Prevention at Harbor Pines Veterinary Center
At Harbor Pines Veterinary Center, we believe proactive care is the best form of protection. Our team provides personalized parasite prevention plans to suit your pet’s lifestyle and risk level.
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The Most Common Pet Parasites—and Why They Matter
Fleas: Small Pests, Big Problems
Fleas cause itching, skin damage, and allergic reactions such as flea allergy dermatitis (FAD). They can also transmit tapeworms and other diseases.
Signs to watch for:
- Scratching, biting, or over-grooming
- Hair loss, scabbing, or redness
- Visible fleas or flea dirt
Flea Allergy Dermatitis in Dogs and Cats – Merck Vet Manual
Ticks: Small Vectors, Serious Illnesses
Ticks transmit dangerous diseases such as Lyme disease, Ehrlichiosis, and Anaplasmosis. These diseases can linger and cause chronic symptoms if not caught early.
Symptoms of tick-borne illness:
- Fever or lethargy
- Limping or joint pain
- Swollen lymph nodes
Preventing Ticks on Pets – CDC
Heartworms: Silent, but Deadly
Transmitted by mosquitoes, heartworms live in the heart and lungs, causing irreversible damage. Dogs are especially vulnerable, but cats can be affected too.
Early warning signs:
- Persistent cough
- Exercise intolerance
- Sudden collapse (in cats)
Heartworm Prevalence Map – CAPC
Intestinal Parasites: Hidden Harm
Parasites like roundworms, hookworms, and tapeworms live in your pet’s GI tract. These can lead to malnutrition and can even spread to humans.
What to look for:
- Diarrhea or vomiting
- Weight loss or poor coat condition
- Worms in stool or around the rectum
Intestinal Parasites in Cats and Dogs – AVMA
Other Common Parasites
- Ear mites: Cause head shaking, scratching, and dark discharge
- Mosquitoes: In addition to heartworms, they may carry other blood-borne diseases
Year-Round Parasite Prevention: Why It Matters
Parasites don’t take the winter off. Fleas and ticks can survive indoors, and heartworm-carrying mosquitoes thrive in warm climates—even in winter. That’s why prevention should never be seasonal.
The Importance of Year-Round Prevention – AAHA
What If My Pet Already Has Parasites? Treatment Options
Fleas & Ticks
- Topical or oral medications kill adult fleas and larvae
- Environmental treatments (sprays, laundering pet bedding) reduce reinfestation
- FAD (flea allergy dermatitis) may require anti-inflammatories and medicated shampoos
Heartworm Disease
Treatment is complex and varies by stage. In dogs, it may involve:
- Injections to kill adult worms
- Exercise restriction and supportive care
- Follow-up testing and long-term prevention
Cats cannot be treated in the same way, so prevention is critical.
Intestinal Worms
- Dewormers like pyrantel, praziquantel, or fenbendazole target specific parasites
- Follow-up fecal exams ensure the parasites are gone
- Zoonotic risk (transmission to humans) makes treatment essential
When to Call the Vet
You should contact your veterinarian if your pet shows any of the following:
- Scratching excessively or developing skin problems
- Vomiting, diarrhea, or weight loss
- Coughing, fatigue, or labored breathing
- Worms in stool or live ticks on skin
Prompt action helps avoid long-term health consequences and protects other pets (and humans) in your household.
How to Keep Your Pet Protected at Home
Checklist for Prevention
- Use monthly preventives year-round
- Schedule annual wellness and fecal exams
- Maintain a clean home and yard
- Check your pet for ticks after outdoor time
- Know the signs of parasite infections
Book Your Preventive Care Visit
Parasite prevention is not just about comfort—it’s a critical part of keeping your pet healthy and thriving. With a mix of veterinary support, year-round preventives, and education, you can shield your furry friend from these harmful pests.
Whether you’re starting a new prevention plan or need help managing an infestation, Harbor Pines Veterinary Center is here to help. Our team will tailor a program to suit your pet’s needs and lifestyle.