While extraordinary living creatures, dog worms aren't considered that by most and can be harmful to both your pet and you. In this final piece of our 3-part series on all things worm-related, we explore the topic of diagnosis and how to control a worm infestation in your dog.

In our last article we shared with you the importance of being aware of dog worms and how they can harm both you and your dog. You're now probably wondering about what can be done to combat them.

The truth is, there is no way you can 100% get rid of worms. Your pet and you will, at some point or other, be exposed to some degree. However, there are plenty of ways to reduce the chances of infestation. The key is to take the right preventative measures and treatment options tailored to your situation.

Let’s explore these.

How do I know my dog has worms?

The general recommendation to regularly look for signs of worms in your dog.  The Companion Animal Parasite Council in the USA recommends performing a check four times per year. In reality, this is not often done.

The flotation technique

It sounds particularly unglamorous, but the key method for worm diagnosis is faecal centrifugation testing. The goal is to detect nematode eggs or flatworm segments in your animal's faeces.

Toxocara canis

Usually, your vet will take a sample of your dog’s faeces that you will likely be asked to collect and provide. This is mixed with a special solution and then placed in a centrifuge to encourage faecal matter to sink and any eggs to float to the top. A sample of this will then be viewed under a microscope to determine if any eggs or segments exist, and what type of worms they are.

While this test is designed to indicate whether or not your dog has worms, a negative result does not always mean your dog is worm-free. Why? Because worms do not release eggs all the time; the animal might be present but not detected through faecal matter examination.

In fact, nematodes lay tens of thousands of eggs daily, but only 15 days after they’ve reached the digestive tract. Flatworms shed segments episodically. Therefore, a test may take place at the wrong time.

The case of heartworm

As heartworms do not reach the digestive tract, you will not find eggs in your pet's faeces. Therefore, a different testing method, various microfilariae antigen detection tests, will be conducted, including via a blood sample.

If tests return positive, and your dog shows symptom suggesting the presence of adult worms, your vet will perform radiographic and/or echocardiographic examinations.

How should I control my dog’s worms?

Sometime, your vet may prescribe you a deworming treatment without having performed a faecal examination. Rather than going through expensive medical procedures, they will asses the risk to your dog based on a variety of factors.

There are some general principles that will help you to understand the treatment process and prepare you with information for any questions you want to ask your vet.

Dewormers only treat worms that are present

It is important to note that, unlike anti-flea or anti-tick products, deworming treatments only treat the worms present. They do not prevent further infestation, even once the treatment has been administered. Therefore, no complete prevention is possible.

No single dewormer works on all worms

There are many good deworming treatments available on the market. Unfortunately, none of them will control all worm types we have been discussing throughout this series.

For instance, Uncinaria worms do not respond to the active ingredient milbemycine oxime. Similarly, Ivermectin is not effective against whipworms, nor too does the widely used combination of febantel+pyrantel+praziquantel work against heartworm.

Focus on the most important worms

It's not uncommon for vets to focus on the worms that pose the greatest threat to your animal and to public health. Echinococcus and heartworms can be deadly for both animals and humans. Toxocara and Ancylostoma are other types of worms that may also lead to your pet's death.

Two-in-one worming and mite/flea treatments

Some products are effective against both certain types of worms and some external parasites. If your dog has mites or fleas, you might consider choosing a product that can combat both with the one treatment.

Adapt to the situation

If you’re sure that your dog doesn’t hunt prey or eat raw food, there is a much smaller chance that they will be affected by flatworm.

If your female dog is pregnant, or on heat, roundworm or hookworm larvae encysted in her tissue may be revived and resume their journey to the digestive tract. There they will lay eggs, infect her puppies and contaminate the environment.

For those running a kennel, think about whipworm and regularly ask your vet to diagnose for them. If your dog doesn’t have fleas, they should not have Dipylidium either. During cold winters, your dog is also much less likely to be bitten by mosquitoes.

Running in the grass yard@Affectionate Pet Care

Think local

The risk your dog runs is closely linked to the place where you live. The Companion Animal Parasite Council has published a series of maps that indicate the prevalence or parasites in any US county. Find them here.

Reduce environmental contamination

It's now probably clear that your dog may become an unintentional contaminating agent for worm eggs. These eggs can in turn contaminate humans and animals in your local neighbourhood. Therefore, it is your responsibility as a citizen to contribute to limiting the risk of contamination.

In addition to treating your dog against worms, you should take the following measures:

  • Pick up faecal matter (always!)
  • Always wash your hands after collecting faeces
  • Do not touch faecal matter with your bare hands
  • Do not let your dog hunt prey
  • Do not feed your dog uncooked meat
  • Protect your dog against mosquitoes and fleas


It's been a long road on the journey to understanding dog worms but we're sure you're much more informed than before. We've introduced you to a range of common dog worms that can affect both your pet and you, informed you about the health implications of the various types of worms, and provided information about diagnosis and treatment.

With all the said and done, there still is, unfortunately, no way to keep your pet 100% free of worms. Likewise, there is no treatment to prevent your dog from being infected with worms in the future.

This leaves us all to make a well-educated guess for treatment, based on the risk that your dog harbours or will harbour harmful worms. It will also depend on the cost involved in detection and treatment options.

As always, it's recommended to seek expert advice from your vet. They will take the time to inform you about the products and the treatment strategies tailored to your situation. And to hopefully avoid any of the more harmful worms in your dog's lifetime.

We wish you all success and happy pooches!

Source: Gilles Ventejol

Gilles Ventejol has more than 20 years' marketing experience in the animal health industry. He has launched new veterinary medicines, led prospective work on new drugs development, and organised international events in the animal health space. He has also written countless materials for vets and owners, including reports, articles, guides and brochures, and produced video content and website material.

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