What are whipworms in dogs?

If you've noticed your dog having digestive issues or bloody diarrhea, whipworms might be the culprit. These intestinal parasites are one of the most common worms affecting dogs, yet many pet parents don't know much about them. Understanding what whipworms are and how they affect your pup can help you protect them from this persistent parasite.

What exactly are whipworms?

Whipworms get their name from their distinctive shape — they look like tiny whips with a thick handle and thin, thread-like front end. These parasites, scientifically known as Trichuris vulpis, live in your dog's large intestine, specifically in the cecum and colon. Adult whipworms measure about 2 to 3 inches long, making them visible to the naked eye, though you're unlikely to see them unless your vet performs specific testing.

How do dogs get whipworms?

Dogs pick up whipworms by accidentally swallowing microscopic eggs from their environment. These eggs come from the feces of infected dogs and need about 2 to 4 weeks in the soil to mature before they can cause infection. Your dog might ingest these mature eggs while sniffing around contaminated soil, drinking from puddles, grooming their paws after a walk or eating grass in areas where infected dogs have been. The eggs are incredibly hardy and can survive in soil for years, which makes whipworm infections particularly challenging to prevent and control. Once your dog swallows the eggs, they hatch in the intestine and the larvae develop into adult worms over the next 8 to 12 weeks.

What symptoms should pet parents watch for?

Many dogs with whipworms show no symptoms at all, especially with light infections. When symptoms do appear, bloody diarrhea is the most common sign. Other symptoms include weight loss despite a normal appetite, dehydration, anemia in severe cases and general lethargy or weakness. "Whipworms burrow into the intestinal wall where they feed on blood and tissue," Dr. Aliya McCullough, Fetch's Chief Veterinary Officer, explains. "This damage to the intestinal lining causes inflammation leads to bloody diarrhea."

How are whipworms diagnosed and treated?

Diagnosing whipworms can be tricky because adult females don't lay eggs consistently. Your vet will examine a stool sample under a microscope to look for the distinctive barrel-shaped eggs with plugs on both ends. Sometimes multiple stool samples are needed since the worms might not be shedding eggs when the first sample is taken. Treatment involves prescription deworming medications that kill the adult worms in your dog's intestines. Your vet will typically recommend repeating the treatment after a few weeks to catch any worms that were still developing during the first round. Most dogs recover completely with proper treatment, though severe infections might require additional supportive care for dehydration or anemia.

Can whipworms spread to humans or other pets?

The good news is that dog whipworms rarely infect humans. Whipworms also can't spread directly from dog to dog. Remember, those eggs need time in the environment to mature before they become infective. However, if you have multiple dogs and one has whipworms, your other dogs are at risk if they share the same outdoor spaces where infected feces might be present.

How can you prevent whipworm infections?

Prevention starts with good hygiene and regular veterinary care. Pick up your dog's poop immediately, both in your yard and on walks, to prevent eggs from contaminating the soil. Many monthly heartworm preventives also protect against whipworms, so talk to your vet about the best option for your pup. Regular fecal testing during your dog's annual check-ups can catch infections early, before symptoms develop. Since whipworm eggs are so resilient, completely eliminating them from contaminated soil is nearly impossible, but keeping your yard clean and maintaining your dog on preventive medication provides excellent protection.