A lot of pet parents assume intestinal worms are nothing to worry about—they think all their sick pet needs is some medication, and they’re good to go. Adult pets might recover from worms unscathed, but the same can’t be said about puppies and kittens. What might be a minor nuisance to adult pets can prove fatal to fur babies that are just weeks old.

If you’re planning to adopt a young pet, learn why protection against worms is paramount for puppies and kittens.

Negative health effects of intestinal worms

Worms in adult pets are relatively harmless. At worst, the pet will experience bloody diarrhea and “scooting” to relieve irritation around the anus. Worms in young pets are a lot more severe, causing symptoms that could be fatal. Tapeworms, hookworms and roundworms stunt growth in puppies and kittens at a critical point in their development. This may lead to permanent damage that affects the rest of the pet’s life.

Roundworms, in particular, stunt a young pet’s growth due to their feeding habits. These worms eat the partially digested food that moves into the small intestine. In doing so, roundworms steal key nutrients before they can get absorbed by the intestinal lining. This leads infected puppies and kittens to become malnourished, even if the pet’s appetite and food portions remain consistent.

Tapeworms and hookworms cause anemia because they feed off the pet’s blood supply. These parasites latch onto the small intestine’s lining, where they inject an anti-coagulant substance to prevent blood clotting. When worms detach from the lining, this substance allows blood to flow freely into the small intestine. In rare cases, the puppy or kitten may need a blood transfusion to replace what was lost.

Tapeworms, hookworms and roundworms in large numbers can lead to intestinal blockages. The parasites clump together to prevent the puppy or kitten from passing stool. An intestinal blockage is a serious condition that backs up the digestive system and cuts off access to vital nutrients. Blockages usually occur in the advanced stages of a worm infection, at which point the parasites are threatening the pet’s life.

Newly adopted pets need fecal testing

Fecal testing is the primary way vets diagnose an intestinal worm infection. For tapeworms specifically, the vet will collect a stool sample and observe it for worm segments. Adult tapeworms are visible to the naked eye, and they look like grains of white rice or cucumber seeds. It’s important to note that simply looking at a stool sample won’t detect tapeworm eggs or larvae. Plus, adult hookworms and roundworms don’t get excreted through a pet’s stool.

Vets can detect hookworm and roundworm eggs using fecal flotation. They place the stool sample in a solution that allows eggs to float to the surface. The eggs attach to a glass slide, which the vet examines beneath a microscope. Fecal flotation helps the vet diagnose an infection long before eggs have a chance to mature into adult worms.

All pets should get a fecal test upon adoption, even if they don’t show symptoms of a worm infection. Many dogs and cats come from shelters where they live in close quarters with other animals. Worms are easily transmitted from one pet to another, especially in overcrowded shelters. Take the extra precaution and schedule a fecal test for your new fur baby.

Treatment options for infected pets

There are treatments available for puppies and kittens diagnosed with intestinal worms. Tapeworms are treated with parasiticides, which are administered either through injection or a daily pill. Parasiticides kill tapeworms by allowing the pet to digest them in the small intestines.

Hookworms require medications called anthelmintics. The pet takes anthelmintics orally until the adult hookworms have completely died off. Anthelmintics only kill the adults, so infected pets will have to undergo intermittent treatment. The pet will finish a round of anthelmintics, then start another round two to four weeks later. This is because hookworm larvae need several weeks to mature into adults.

For roundworms, your vet will recommend placing the puppy or kitten on a monthly heartworm preventive. Many heartworm preventives double as protection and treatment for roundworms. Pets can and should continue monthly heartworm preventives long after the infection clears up.

Worms in puppies and kittens shouldn’t be taken lightly. Their immune systems aren’t fully developed yet, making them easy targets for parasites that need a host. When you bring home a new fur baby, testing for worms should be at the top of your to-do list. You’ll be able to catch infections early on and help your puppy or kitten grow into a healthy adult.