How Often Should a Dog Be Dewormed?

Deworming is one of the routines we need to keep on top of as dog caregivers. It can be internal or external, depending on whether the parasites live outside or inside the dog's body.

Deworming should also start from fifteen days of age and continue throughout the dog's entire life. Let's look at when a dog should be dewormed and how often we should repeat it.

Internal Deworming

Internally, dogs can be affected by different parasites. The most common are those that live in the digestive system. But there are also parasites that settle in the lungs or heart.

It's very important to use anti-parasite products against these worms. First, because some are capable of causing serious, even fatal, diseases. One example is heartworm, which causes heartworm disease (dirofilariasis).

But we also need to protect our dog because several of these parasites can be transmitted to humans. Children are especially at risk, since they may eat soil containing worm eggs or eat with unwashed hands.

• Types of worms in dogs and their treatment

External Deworming

There are several parasites we can find on our dog's body. Fleas and ticks are by far the most common. Depending on where we live and the dog's own predisposition, we'll find more fleas, more ticks, or both.

External parasites aren't just a cosmetic nuisance. Ticks, by sucking blood to feed, can transmit serious diseases such as babesiosis or ehrlichiosis. Fleas, meanwhile, also cause hemobartonellosis or transmit intestinal parasites such as tapeworm.

Since both are blood-feeding parasites, severe infestations can also cause anemia. In addition, fleas bite other animals and humans. They're hard to get rid of once established in the environment.

• Diseases spread by fleas
• Diseases spread by ticks

How Often to Deworm a Puppy?

Puppies can pick up parasites from their mother or from the environment from the moment they're born. Given the characteristics and development of the intestinal worms that can affect them, the first internal deworming has been set at fifteen days of age.

But a single deworming won't be enough to eliminate all the worms the puppy will be exposed to. That's why another internal deworming is scheduled fifteen days later, and this is then repeated every 2-4 weeks. It's usually timed a few days before each vaccine, since for the vaccine to work effectively, the dog needs to be properly dewormed.

Once the vaccination schedule is complete, at 12 weeks at the earliest, the internal deworming schedule will follow the recommendations for adult dogs. As for external deworming, it's a good idea to start it even before the puppy goes outdoors. Our vet should recommend the right product for puppies.

How Often to Deworm an Adult Dog?

Dogs can pick up both internal and external parasites from the environment or from contact with other dogs or animals. Intestinal parasites can easily go unnoticed, since a healthy dog often shows no symptoms. But they can still transmit them, even to humans. The same goes for external parasites. Fleas, in addition, infest the environment.

Their larval stages develop there. If we don't prevent our dog from catching fleas, we can end up with an infested home, which is hard to eliminate. Internal and external deworming for adult dogs should be adapted to their living conditions. As a general rule, external deworming is monthly and internal deworming every 3-4 months.

But this will depend heavily on the product chosen, since some maintain their preventive effect for more than four weeks. On the other hand, in situations like periods of heavy flea presence, it may be necessary to deworm before four weeks are up. That's why it's important to work out the most suitable deworming schedule together with the vet.

What Products Are Used for Deworming?

For puppies, the most commonly used option for internal deworming is a syrup, which we can easily give with a syringe. As they grow, and in adult dogs, pills are usually used. There are pleasant-tasting ones, which encourage the dog to eat them on its own, like a treat.

For external deworming, spot-on treatments and collars are widely used. For smaller dogs, whether by age or size, a spray can be used. New advances in deworming products come out periodically.

So, products keep being launched that are active against more and more parasites and their different growth stages, or that, with a single spot-on or pill, eliminate both internal and external parasites. Depending on where we live, these products should also work against the mosquitoes that transmit heartworm or leishmania.

My Dog Has Parasites Even Though I Deworm It

No deworming product will be 100% effective. Also, although we've mentioned a monthly or quarterly frequency for deworming, there will be circumstances where more frequent deworming is needed.

On the other hand, there are parasites that may not be covered by the product we've chosen. One example is giardia, which usually isn't eliminated by regular deworming products.

That's why, if our dog has diarrhea, we should see a vet. It could be parasites even if we've dewormed the dog. The vet will need to give us a specific treatment.

Bibliography Carlson and Giffin. 2002. Manual práctico de veterinaria canina. Madrid. Editorial el Drac.