VetVits July 04, 2016

As a dog owner there is little more upsetting than finding a parasite in, or on, your dog. And those that you may be most concerned about are worms. Parasitic worms are crafty little critters, and have evolved to take advantage of just about every organ system in a dog. From lungworms, to heart worms, to eye worms, to intestinal worms, to liver worms, to giant kidney worms — parasites are a real threat to your dog’s health.

Many of these intestinal parasites can also infest humans, and children in particular are at increased risk. But with knowledge and understanding, they need not be anything that you should worry about, and can be easily eradicated at home with the correct procedure.

What are worms, and how do I know if my dog has them?

The most common parasitic worms your dog will encounter are intestinal worms: worms that live within and replicate your dog’s stomach and intestines. The common symptoms of intestinal worms depend on the type of worm present. Hookworms can cause vomiting, diarrhoea, weight loss, a general unthrifty appearance, and in severe cases, enough blood loss to cause anaemia. Hookworms are contracted by a faecal-oral route, or via the skin: they have piercing mouthparts that can penetrate skin and migrate to the intestines.

Roundworms, tapeworms, and whipworms can cause vomiting, diarrhoea, and weight loss. Of course, if you see a worm in your dog’s stool, or rice grain-like organisms around your dog’s anus, then this is a sure sign that your dog is infested. Often, a dog can be infested with worms and show no signs at all! Intestinal parasites are more than just an unpleasant nuisance: many worms that infest dogs can infest humans as well, and soil that has been infested with parasitic worm eggs can be contaminated for years. Fortunately, even though intestinal worms are prevalent, intestinal worms are easy to treat, and even easier to prevent.

If your dog is suffering from symptoms such as vomiting, diarrhoea, loss of appetite, abnormally coloured stool, or weight loss, schedule a visit to your veterinarian, and bring a fresh faecal sample from your dog for analysis. If your dog has passed a worm, place it in a bag for the veterinary team to identify.

So your dog has worms, what’s next?

Your veterinary team will test the faecal sample for parasites. If they find parasite eggs, or have a high index of suspicion for parasites, then your veterinarian will prescribe a de-wormer. De-wormers vary, but most de-wormers are what is considered ‘broad spectrum’, which indicates that the de-wormer will kill a broad array of intestinal parasites.


Fenbendazole is a common broad spectrum de-wormer that is prescribed by veterinarians for hookworm, roundworm, whipworm, and tapeworm infestations in dogs. Fenbendazole kills parasites by inhibiting the parasite’s metabolism. It cannot be used in pregnant or lactating dogs.

Pyrantel pamoate

Pyrantel pamoate is a de-wormer that is used to treat hookworms and roundworms. It can be found over the counter at pet stores and feed stores, and is generally very well tolerated by dogs. It is also inexpensive, but is not as broad spectrum as some of the other medications. Pyrantel pamoate works by paralyzing the worm’s mouth parts so it cannot attach to the intestinal wall. It’s also safe for pregnant and lactating animals.


Praziquantel is another common de-wormer that is used to treat tapeworms. Praziquantel works by removing the parasite’s ability to protect itself against digestion. If your dog is suffering from tapeworms, then you also need to address a flea problem, as tapeworms require fleas1 as part of their life cycle. Talk with your veterinarian about the right flea control for your dog.

Most dogs tolerate de-worming medication very well, with a low incidence of side effects. If your dog has a large number of worms, the dog may have diarrhoea, vomit or defecate dead worms, which while unpleasant for both you and your dog.

Prevention is key

The best practice for both you and your dog, is to prevent intestinal parasites in the first place. To prevent the spread of intestinal parasites, bag and dispose of your dog’s faeces frequently, and if possible, prevent wild animals from access to your garden, as they carry infectious worms too! If your dog likes to hunt small mammals, ensure that your dog is dewormed several times a year, as your dog can contract worms from prey that they have munched upon.

Most heartworm prevention also contain an intestinal parasite de-wormer, and is a convenient way to deworm your dog. If you give your dog a heartworm tablet once a month, then you will greatly reduce the chance of your dog contracting a nasty intestinal worm infestation. It is also a good idea to have your dog’s faeces checked once a year or more by your veterinarian, to catch any signs of intestinal worms before they become a serious problem. Many pet owners are surprised when they find out that their dog has been secretly harbouring intestinal worms, but by always being aware of them you can prevent any further upset to you or your dog. Accessed: 28th June 2016

Author info:

Sarah Wooten is a small animal veterinarian and certified veterinary journalist. She is a 2002 graduate of the prestigious School of Veterinary at UC Davis. She practices in Greeley, Colorado part time at Sheep Draw Veterinary Hospital, and writes for multiple online and print publications.

Was this article helpful?

* * * * *

Thank you for your feedback.

Nothing beats a healthy, balanced diet to provide all the nutrients we need. But when this isn't possible, supplements can help. This article isn't intended to replace medical advice. Please consult your healthcare professional before trying supplements or herbal medicines.



Missed Promotion: {{missedPromo.DisplayText}}






(Basket total above includes promotional prices. You have SAVED £{{cart.TotalPriceListDiscount| number : 2}} today.)

Review basket and check out

Your basket is currently empty