Deworming

As the information below shows, it is very important for both humans and animals to take the right approach to worm control.

All puppies and kittens are born with roundworms (see below for an explanation of how this happens), and therefore need to be dewormed with a safe and effective treatment. It’s important to remember that deworming isn’t like a vaccination; it eliminates existing infections, not prevents new ones. This means that a dog that was dewormed a few weeks ago may already be reinfected. That’s why it’s important to repeat the deworming treatment regularly. You’ll find more information on how to handle deworming later in this guide.

Dogs and cats infected with roundworms usually shed large quantities of eggs in their feces. A single female roundworm lays about 200,000 eggs per day! The eggs in the feces are washed out by rain over a relatively large area, and the larvae wait until they are sniffed up or licked up by a new host. This could even be a child!

In the animal’s intestine, the larvae begin their journey through the body. They leave the intestine, and a large portion ends up in the lungs, where they are coughed up and swallowed. They then develop into adult worms in the intestines, where they begin laying eggs again. This completes the cycle. Some of the larvae do not return to the intestines via the lungs but instead encyst themselves in fatty tissue or muscles, where they remain dormant until the animal becomes pregnant. As soon as the animal becomes pregnant, these larvae become active and migrate to the mammary glands and the uterus. In this way, they infect the puppies or kittens both before and immediately after birth. It is this route of infection that makes it nearly impossible to permanently eradicate roundworms. The “dormant” larvae are not susceptible to deworming treatments! In humans (usually children) who become infected with roundworm larvae, you can also observe their migration through the body. Because humans are not the natural host, the life cycle is not completed via the lungs; the larvae become “dormant larvae.” Nevertheless, depending on where they encyst, they can still cause problems.

In puppies and kittens, roundworms consume a lot of food and cause poor growth and distended bellies.

Most tapeworm infections in our pets are caused by licking fleas that are infected with tapeworms. In most cases, this involves the tapeworm Dipylidium caninum, a relatively harmless worm that is not dangerous to humans either. We can identify an infection when small worms (“rice grains”) or segments of worms are present in the feces or visible around the anus. Thorough deworming with an appropriate medication is then necessary.

There are a number of tapeworms that are ingested through contaminated beef or mutton. These tapeworms are more harmful. One of them, Echinococcus granulosus, is even very dangerous to humans. Humans are intermediate hosts for this tapeworm, which is harmless to dogs on its own. People who become infected with the eggs of this tapeworm through contact with dogs (by not washing their hands properly after contact with infected dog feces) can develop massive cysts in their abdomen or brain, which cause serious problems. This is one of the reasons why dogs must always be treated for these types of worms before traveling to England or Scandinavia. They want to keep these kinds of risks at bay there.

Dogs that are regularly dewormed are at low risk.

Please note: There are many ineffective deworming products on the market. Your veterinarian is the best person to advise you on which product is best for your pet! 

As mentioned earlier, every puppy and kitten is born with a roundworm infection. That is why every puppy or kitten should be dewormed every two weeks starting at 3 weeks of age using an appropriate medication. This continues until two weeks after weaning. After that, the deworming treatment is repeated once a month until the animal is 6 months old. The frequency of deworming after that depends somewhat on the circumstances. A practical frequency is to deworm two to four times a year.

If you prefer to administer deworming treatments as infrequently as possible, we recommend bringing a stool sample from your pet to us a few times a year for testing for worm infestation. If no infestation is found, deworming is not necessary at that time!

For more information about the risks and the corresponding deworming frequency:
• Click HERE for dogs:
• Click HERE forcats.