Parasite Prevention: Protecting Pets and Livestock Year-Round

By Blake Miller For The Mountain Times

Parasites aren’t just a nuisance. They can seriously affect the health and comfort of your animals. In Oregon’s mild, wet climate, we see year-round parasite activity in both pets and livestock. Dogs, cats, goats, sheep, pigs, chickens, and cattle are all at risk. A proactive, species-specific approach is essential for keeping your animals healthy and comfortable.

Understanding the Risks

External parasites like fleas, lice, mites, and ticks cause itching, hair loss, skin infections, and can even lead to anemia. Fleas are a major issue in our region, especially in the fall and winter. Flea infestations in dogs and cats often cause irritation, hair loss at the tail base, and scabbing. Fleas can also transmit tapeworms and cause anemia, particularly in smaller or younger animals.

Indoor pets are not exempt. Fleas can hitch a ride on clothing or other pets, and once inside, they spread quickly. If one animal in the home has fleas, all pets should be treated consistently to break the life cycle. Skipping even one pet can lead to reinfestation.

Internal parasites such as roundworms, coccidia, and barber pole worms (Haemonchus contortus) are common in livestock. They can cause diarrhea, weight loss, poor coat condition, bottle jaw, and even death. Young and immunocompromised animals are especially vulnerable. External parasites like lice and mites are also common in sheep, goats, pigs, and poultry, particularly in cooler months or when animals are housed in close quarters.

Five Key Strategies for Parasite Control

1. Fecal Testing and Targeted Deworming

A “one-size-fits-all” deworming strategy doesn’t work. Many parasites are resistant to common medications, and not all dewormers treat every type of parasite. Routine fecal testing helps us identify what’s present so we can choose the most effective treatment.

For livestock, we recommend fecal egg counts several times a year, especially in spring and early summer. Testing 10–20% of the herd every 3 – 6 months, or testing any animal showing signs of parasitism, is a practical approach. For dogs and cats, annual fecal testing is best, more often for pets with high exposure risk.

2. Flea and Mite Control in Pets

Over-the-counter flea products often contain older medications that fleas have developed resistance to. Many also wear off after just 2–3 weeks. Prescription flea medications from your veterinarian are more reliable and effective. They last a full month and target all life stages of fleas.

It’s important to treat every dog and cat in the household, even indoor pets, and continue treatment through winter, as fleas can survive indoors year-round.

3. Environmental and Pasture Management

Parasite control isn’t just about medication. Keeping living spaces clean plays a major role. Clean and replace bedding regularly, remove manure, and avoid overcrowding. For grazing animals, rotate pastures and avoid overgrazing. Feed should be kept off the ground. Chickens and pigs benefit from dry, well-ventilated housing and frequent bedding changes to limit mites and lice.

4. Monitor for Subtle Signs

Not all parasitic infections are obvious. Watch for pale gums, weight loss, poor coat condition, reduced appetite, or lethargy. In livestock, diarrhea or messy hindquarters, especially in young animals can signal internal parasites. If something seems off, don’t wait to investigate.

5. Routine Lice Treatment in Livestock

Lice thrive in cool weather and close quarters. They cause intense itching, hair loss, and poor coat condition — and can even reduce weight gain. If you see animals rubbing on fences or biting at their flanks, lice is most likely the cause. 

Lice are species-specific and do not spread to humans, but they spread quickly between animals. We recommend starting preventative treatment September 1st and continuing through May 1st using topical insecticides like Synergized DeLice or UltraBoss for sheep, goats, and cattle.

At Northwest Mobile Vet, we work with families and farms to create custom parasite prevention programs tailored to your animals, your property, and the season. With the right combination of testing, treatment, and management, we can dramatically reduce parasite loads and improve animal health and comfort.

Parasites are a part of life, but with the right tools, they don’t have to control it.