Vetrica Logo.

Worming Puppies and Dogs


Disgusting as it sounds, most puppies are born with worms, roundworms to be precise, usually Toxocara canis. This worm can do all sorts of damage to your new puppy's intestines, not to mention the fact that children can become infected with it.

Puppies become infected with the roundworm larvae while still in the womb. This particular worm migrates through an animal's body, finds a nice spot to settle down, and becomes dormant, a bit like a very deep sleep. There it stays, waiting for the right time to wake up, and complete its migration. When a bitch becomes pregnant, lots of these dormant worm larvae reactivate, migrate across the placenta and infect the puppies. During the final stage of their migration, the worms pass through the lungs of the pups and from there make their way to the intestines, where they finish their development, become adult worms and start laying eggs.

The worm eggs infest the environment that the pups are in (generally your house or garden), ready to infect a new dog. There's an important human health problem here as well. If the worm eggs are eaten by a person, they will infect that person. In healthy adults this is of little consequence, but in children the larvae may migrate through the child's body, causing trouble on the way. If the child is really unlucky, a larva might end up somewhere important like the retina, and cause vision defects. Moorfields Eye Hospital deals with about 20-30 cases each year of roundworm larvae in the human eye. Also, asthma is more common in children that have been exposed to Toxocara canis than those that have not.

Roundworms are very common. Samples taken in 1997 showed worm eggs in faecal samples taken from:

Streets in Leeds: 13.3%

Parks in London: 27%

Parks in Glasgow: 12%

A study conducted in 2004 found that 25% of dogs had roundworm eggs in their fur.

What can you do about it?

First, disregard what the pup's breeder said about worming. Too many still worm pups with old, inefficient wormers, or mix worming preparations into a large bowl of food and expect each pup to get the right dose as they fight round the bowl.

Worm your puppy regularly. The BSAVA (British Small Animal Veterinary Association) now recommends that dogs and cats are wormed against roundworms monthly, something we have advocated at Vetrica since we opened in 2001, for the reasons described below.

Best Practice Worming

The dog roundworm has a very complex lifecycle involving a migration through the body of the dog before the worm settles in the small intestine. The time from eating a worm egg until there are adult worms in the intestines laying more eggs is about a month. From this we can say that any dog wormed on a monthly basis should never produce worm eggs. This is what all responsible dog owners should be aiming for, and therefore at Vetrica we recommend monthly worming on this basis.

What Product to Use for Worming

The routine worming of puppies and adult dogs is easily and cost effectively achieved using a wormer called Milbemax®. These small tablets are easy to administer and also eliminate tapeworms, (though tapeworms are not usually a problem for young puppies).

However, for long term worm and flea control, we usually recommend Program Plus®. This is a combination of two drugs (milbemycin and lufenuron) in one tablet. Given once monthly with food it is a safe, very effective worm and flea prevention. Furthermore, if you use Program Plus®, we guarantee your puppy will not have fleas or worms. For more details see our Flea Free Guarantee.

Worming Treatments to Avoid.

Piperazine. This is available in a plethora of formulations, such as tablets, chocolate flavoured syrup or paste. It is often sold as "Easy Wormer," or "Puppy Wormer." The sad thing is, it is NOT suitable for puppies. It's only advantage over anything else is that it is cheap. We do not use piperazine at Vetrica.

Piperazine has practically no effect on worm larvae (which we are most concerned about with puppies), it has absolutely no effect on worm eggs, and only kills about 60-70% of adult roundworms. Practically this means that you have to worm puppy again and again and again with this to rid him of worms, and all the while he's passing those dangerous worm eggs into your garden, or the park, or where-ever he goes. In summary:-


Copyright ©Vetrica, all rights reserved.
Last updated 24 March 2005.