Preventing worms in a puppy

Author: VioVet
Published: Sunday 20th January 2013

Our customer asked:

I was looking for a wormer for my puppy and ordered the puppy suspension. After receiving the wormer I have been reading the leaflet that came with it and it seems to indicate that it is used for the treatment of worms. I was looking for a preventative wormer rather than a treatment for worms as my puppy does not have worms.

Please can you confirm if the suspension can be used as a preventative wormer or if it purely used for the treatment of worms?

Our response:

There are no products which prevent worms. Dogs do develop something of an immunity to worms themselves in time, but there is no vaccine or anything like that to help stimulate that immunity.

All available worm treatments kill off worms to a greater or lesser extent. They can only do that if the worms are present. If you are not seeing worms, that means that there are probably no tapeworms and there are not lots of other worms, but roundworms of various types can be present and you will never see them. If you send off a faecal sample to a lab they can look for worm eggs, which is the best way to check if worms are present. Otherwise you have no real way of knowing. If there are loads of worms present, they will tend to have an effect on the dog and are potentially a problem. If there are just a few, they do little harm, but the numbers can build up, especially in puppies. Worm eggs are also passed out in faeces, can remain viable in soil for years, and can occasionally cause serious health problems in children.

Virtually all puppies are born with worms. (Infected in the uterus and through the dam's milk.) They are present as microscopic larvae in their muscles and other places. These do no harm whatsoever. At some point later (days, weeks, years sometimes) these larvae will migrate to the gut and develop into adult worms. If just a few are present, they do no harm, but shed eggs into the environment. You will never know they are there. If lots of worms build up (which can often happen in puppies) then they can cause a lot of trouble.

The usual thing to do is to treat periodically for worms, especially in puppies, without knowing if worms are present or not. If laboratory tests are carried out, virtually all puppies have worms if they have not been treated for a while. That is just how things are. The canine roundworm (Toxocara canis) is regarded as a well adapted parasite. Basically it is remarkably good at getting into dogs. We just have to treat against it periodically and all is usually well.

Drontal will kill any adult worms extremely well, and cause no trouble for the puppy. A day afterwards, it has no effect and the puppy could develop worms again. They take a few weeks to develop at least, which is why you do not need to treat all the time. Dogs over 6 months of age have quite a good immunity to worms, rarely develop many, and are usually treated periodically as a public health matter (eggs getting into children) rather than as a health benefit for the dog itself. A few worms living in the gut of an adult dog are a common finding, but not a health problem for the dog.

There are some products which are prescription only which have a persistent worm killing effect (eg Stronghold and Advocate). However they work by remaining in the system for about a month, killing off any adult worms which start to develop. They are also pretty ineffective at killing the dormant worm larvae, only getting the maturing worms in the gut. In a way they are better than Drontal, but it is sometimes seen as a bit of an overkill, with the drug in the body for a whole month. Those products also kill fleas, and the persistent action is very helpful for that purpose.

I would recommend that you use the Drontal as recommended in the instructions which come with it. Very likely your puppy will benefit even though you never see any worms.