How often to deworm a dog or a cat

Why deworm even if it looks healthy

Many parasites cause no symptoms at first. Some, like certain roundworms, can pass to people, especially children who play on the floor or at the park.

There are internal parasites (intestinal worms) and external ones (fleas and ticks). Each type is treated with different products: ask your vet which ones your pet needs.

Puppies and kittens

• Puppies: from 2 weeks of age, every 2 weeks until 2 weeks after weaning.
• Kittens: from 3 weeks of age, every 2 weeks until 2 weeks after weaning.
• After that, once a month until 6 months.

If you adopted it, ask the shelter when it was last dewormed and bring that date to its first vet visit.

Adult dogs and cats

• As a general reference, at least 4 times a year (every 3 months).
• More often if it goes to parks, lives with many animals, eats raw meat or hunts.
• Indoor cats get dewormed too: your vet will tell you how often.
• Fleas and ticks: the product and frequency depend on which one you use; some are monthly and others last several months.

Write each deworming in its vaccine record (cartilla), with the date and the product.

Signs it may have parasites

• Worms or «grains of rice» in its poop or around its tail.
• Diarrhea, vomiting or a swollen belly, especially in puppies.
• Weight loss even though it eats well.
• Scooting on its bottom or licking under its tail a lot.
• Constant scratching, or fleas or ticks you can see.

If you see any, take it to the vet: don't give it a dewormer on your own without knowing its weight and what it has.

Frequently asked questions

How often should an adult dog be dewormed?

As a reference, at least 4 times a year, and more often if it goes to parks a lot or lives with many dogs. Your vet adjusts the frequency to its lifestyle.

How often should a puppy be dewormed?

From 2 weeks of age, every 2 weeks until 2 weeks after weaning, and then monthly until 6 months.

How often should a cat be dewormed?

Kittens from 3 weeks, every 2 weeks until 2 weeks after weaning, then monthly until 6 months. Adults at least 4 times a year; indoor cats as your vet recommends.

Can I deworm it at home?

Yes, if your vet tells you the product and the dose for its weight. Don't use dog products on cats: some are toxic to them.

Related guides

• Dog and cat vaccines in Mexico: schedule and vaccine recordWhich vaccines dogs and cats need in Mexico, the rabies rule and how the vaccine record (cartilla) works.
• Free rabies vaccine and spay or neuter in Mexico City (2026)2026 rabies vaccination dates, free rabies shots year-round and requirements for free spay and neuter in Mexico City.

Wagori: everything for your pet, in one app

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Sources

Information from:

• ESCCAP: worm control in dogs and cats (guideline 1)
• El Universal: how often to deworm a dog or cat (in Spanish)