How Do I Find The Right Dewormer For My Dog?

Deworming sounds like a pretty gross concept, but it’s a necessary part of keeping your dog happy and healthy.

But if you have a new pup, you might be wondering how you set about doing it — and also what even are those worms you’re fighting?

The Dodo spoke to Dr. Bernadine Cruz, a veterinarian at Laguna Hills Animal Hospital in California, to find out everything you need to know about deworming dogs, and to get information on how to choose the right dewormer for your dog.

Worms are a type of parasite that are common in dogs.

Dogs are popular hosts for worms and other parasites because they spend a lot of time sniffing, rolling in dirt and eating things they shouldn’t (including poop — ew), which means it’s easy to pick them up.

There are five main types of worms that dogs can contract. The first four are intestinal worms, while heartworms live in dogs’ hearts, lungs and blood vessels:

Most puppies who have worms get them from their moms. If a dog has ever had roundworms, dormant worms can stay in her body and be activated by hormones when she becomes pregnant. These can be passed to her puppies before they are born or through nursing.

Adult dogs can contract worms by eating soil or feces that contains worms. Which means there actually is a good reason why you should stop your dog from eating poop (besides the gross factor).

“Do not allow a pet to eat another pet’s feces. The most common means of parasite transmission is oral-fecal route,” Dr. Cruz told The Dodo.

Dogs can also contract worms by eating fleas, which can contain tapeworm larvae, while grooming.

Mosquito bites can also lead to heartworms if your pup is bitten by an infected bug.

So basically, there are lots of opportunities in the average dog’s life where he may pick up a worm infestation — which is why it’s so important to keep him on a good-quality preventative medication.

So once your dog actually gets worms, what will happen to him?

“Depending on the worm, the age of the pet [and] the degree of the parasitic load (or how many worms are present), a pet may vomit them up [or] may pass them in their stool,” Dr. Cruz said.

But that doesn’t mean all the worms come out on their own — a lot of them will stay inside your dog and cause health issues (yuck). Symptoms of worms in dogs can include things like:

“The most accurate way of determining if internal parasites are present is to bring a fresh stool sample to your veterinarian for testing,” Dr. Cruz said. (If you think your pup has worms, ask your vet how to collect a sample.)

First of all — what exactly is deworming? Dewormer medicines are given as preventative medication to stop worms from growing, and as a treatment to kill worms in your dog’s body.

So if your pup does run into a situation where he’d normally contract worms, the medications make it so your dog’s body is an inhospitable host, which stops an infection from happening.

If you’re getting a puppy, you should start deworming him as soon as you get him.

Puppies should be dewormed every two weeks until they reach 12 weeks of age, then monthly until they are 6 months old because they’re more susceptible to worms than adult dogs are.

This is because a puppy can contract worms through their mom’s milk and is often in close contact with other puppies in his litter, which can cause infection to spread.

Puppies also don’t have strong immune systems yet, so they aren’t able to fight infections as easily as adult dogs.

With adult dogs, you should give preventative deworming medicine at least every three months — follow your vet’s advice and the instructions on the packaging of your dewormer.

While there are several OTC (over-the-counter) medications available, Dr. Cruz said it’s important to consult with your vet before choosing a dewormer, as many of the readily available options aren’t actually that effective.

“The safest and most effective medications are available by prescription only,” Dr. Cruz said. “The forms that are available at feed stores and pet stores are often given for the wrong type of parasite and [are] not effective in eradicating the parasite.”

There are different types of dewormers for different types of worms, and your vet will help you decide on the best treatment for the type of worm your dog has (or is likely to pick up based on his lifestyle).

“The determination of which medication is best for your dog should be based on a dialogue between you and your veterinarian,” Dr. Cruz said. “Does your pet readily accept tablets [or] prefer chews [or] topicals, [as well as] your price sensitivity, your lifestyle and that of your pets.”

So avoid self-treating your dog, and double-check with your vet about the type of worm and type of medicine they advise before buying.

We independently pick all the products we recommend because we love them and think you will too. If you buy a product from a link on our site, we may earn a commission.