Intestinal Parasites in Central Oregon

Central Oregon’s outdoor lifestyle is one of the best things about living here — and one of the reasons intestinal parasites are such a consistent challenge for local pets. The same trails, rivers, and open spaces that make Bend such a great place to have a dog also create year-round exposure to parasites that dogs and cats pick up from contaminated water, soil, and prey animals. Both dogs and cats are at risk throughout the year, with exposure peaking in spring, summer, and fall when pets spend the most time outdoors.

The most important thing to know is that many pets show no outward symptoms even when infected. Regular fecal testing is the only reliable way to know your pet’s parasite status — and it’s something we recommend for all dogs and cats regardless of whether they’re showing signs.

Most Common Intestinal Parasites in Dogs in Central Oregon

Giardia

For dogs in Central Oregon, Giardia is the number one intestinal parasite — and the Deschutes River, Tumalo Creek, and the many lakes and irrigation canals throughout the region are prime sources. Giardia is a microscopic protozoan found in slow-moving and standing water, and in soil and grass where infected animals have defecated. Your dog can become infected by drinking contaminated water, eating contaminated grass, or simply licking their paws after walking through an area where an infected dog has been.

Young dogs and immunocompromised dogs are most susceptible, but any dog can get Giardia — including dogs who only drink from seemingly clean sources on trail. The most common symptom is diarrhea or intermittent soft stool. Some dogs also experience weight loss, vomiting, or decreased appetite. Others show no symptoms at all, which is exactly why testing matters. There is no reliable prevention for Giardia other than limiting exposure to contaminated water sources. We recommend an annual fecal test for all dogs and a spot-check fecal test for any dog showing GI symptoms. Dogs that test positive should be treated with medication.

Roundworms

Roundworms are the second most common intestinal parasite in local dogs. They live in the digestive tract and shed eggs in the stool. Dogs pick them up the same way they do Giardia — from contaminated grass or soil — by eating it directly or licking their paws after contact. Roundworm eggs can survive in soil for months, which means high-traffic outdoor areas like off-leash parks and popular trailheads can be persistent sources of reinfection even after treatment.

The good news is that roundworms are preventable. Monthly dewormers like Interceptor provide reliable protection and are a standard part of preventive care for most dogs in our area. A fecal test can confirm infection, and positive dogs respond well to treatment.

Whipworms

Whipworms are less common than roundworms but show up regularly in local fecal screenings. Like roundworms, they live in the digestive tract and spread through contaminated soil and feces. Symptoms can look similar to Giardia — intermittent diarrhea, weight loss, and lethargy. Whipworms are also covered by most monthly dewormers, so dogs on preventive medication are typically protected.

Tapeworms

Dogs can get tapeworms too — typically from fleas or from hunting and eating small rodents. Dogs that spend time on trails where they may encounter rodents, or that have had flea infestations, are at higher risk. Tapeworm segments are sometimes visible in the fur around the dog’s anus and look a bit like a flattened grain of rice. Not all monthly dewormers cover tapeworms, so it’s worth confirming that your dog’s preventive medication includes tapeworm protection.

Most Common Intestinal Parasites in Cats in Central Oregon

Tapeworms

Tapeworms are the most common intestinal parasite in cats, and Central Oregon’s abundant rodent population makes outdoor and semi-outdoor cats particularly vulnerable. Cats get tapeworms from eating infected fleas — which can happen during grooming — or from hunting and consuming mice, voles, and other small prey animals. Cats that go outdoors and hunt are at consistent risk.

Tapeworm segments look like grains of rice and may be visible in the fur around the cat’s rear end. Monthly dewormers like Profender provide both prevention and treatment. If your cat goes outdoors at all, tapeworm prevention should be part of their routine care.

Roundworms

Cats can also pick up roundworms — either through contaminated soil or, more commonly in Central Oregon, through hunting infected rodents. Kittens are especially susceptible and can be infected before or shortly after birth. Regular fecal testing is the most reliable way to catch roundworm infections in cats, particularly those with outdoor access.

Why Central Oregon Pets Are at Particular Risk

A few things about our region make intestinal parasites an especially consistent concern. The Deschutes River corridor, the trail systems at Smith Rock and Tumalo State Park, and the many irrigation canals throughout Bend and Redmond are all frequented by large numbers of dogs — which means higher concentrations of parasite eggs and organisms in the surrounding soil and water. Dog parks like NorthWest Crossing Dog Park see heavy use year-round, and shared surfaces in those environments are reliable exposure points.

The region’s relatively mild winters also mean that some parasites remain viable in soil longer than they would in colder climates. While exposure peaks in spring through fall, year-round preventive care is the appropriate standard for most Central Oregon pets.

Prevention: What Actually Works

For most dogs in Central Oregon, a monthly broad-spectrum dewormer is the backbone of intestinal parasite prevention. Products like Interceptor cover roundworms, whipworms, and hookworms. Combined with flea prevention — which also addresses tapeworm risk — monthly preventives cover the majority of common parasites. Ask our team whether your dog’s current preventive covers tapeworms specifically, since not all products do.

For cats, monthly dewormers like Profender address tapeworms and roundworms. Cats with regular outdoor access benefit most from consistent preventive care. Indoor-only cats are at lower risk but should still receive annual fecal screenings, since exposure can still happen through tracked-in soil or occasional contact with the outdoors.

For Giardia specifically, there is no reliable preventive medication. Limiting your dog’s access to standing or slow-moving water — particularly in heavily used trail areas — is the most practical risk reduction strategy, though this isn’t always feasible for active trail dogs. Regular fecal testing catches infections early so treatment can begin before the parasite becomes entrenched.

Preventive medications are available through our online pharmacy for convenient home delivery. If you’re not sure which products are right for your pet’s lifestyle and exposure level, or if it’s time for a fecal screening, request an appointment and we’ll help you build a prevention plan tailored specifically to your pet.