Hookworm, roundworm, whipworm and tapeworm are the 4 most common intestinal worms that can infect your pets. See Figure 1 for a visual representation. This family of parasites are usually missed as they don’t pose as great of a risk compared to ticks and heartworm. However, it is important nonetheless to be aware of their existence, and what you can do to keep them at bay in your household.

Figure 1: Common types of intestinal worms in adult stage form (Cornell University, 2018)

Life Cycle

Most intestinal worms follow a very similar life cycle – that is, a pet licks/ingests contaminated material containing eggs, adult worms grow within the body, and lay eggs which are expelled in their faeces. See Figure 2 for a visual representation. Contaminated material can be anything from faeces and dirt, to plant matter, offal/raw food or milk from a bitch.

Figure 2: General life cycle of intestinal worms(Dupont Vet Clinic, 2022)

Am I at risk of being infected?

There is a level of caution pet owners should also exercise for themselves, as they can be transferred from an infected pet. This happens usually when an infected pet licks their bottom, and then licks a human family member – but it can be as easy as giving your pet a good cuddle or pat in order to pick them up.

Intestinal worm infestation symptoms

Intestinal worms can pose a threat to the overall health of our pets in the smallest of ways. Even a small worm burden can pose a risk to ongoing general health. This includes:

  • The inability to gain weight
  • General poor condition e.g. poor coat
  • Mild GIT-related issues such as diarrhoea (with trace amounts of blood/mucus)

In a pet with a greater worm burden, it can become a serious threat, with more severe symptoms such as:

  • Lethargy/lifelessness
  • Anaemia
  • Stunted growth
  • Severe GIT-related issues such as diarrhoea (with significant amounts of blood/mucus).
  • Distended abdomen
  • Adult worms visualised in faeces

Intestinal worm infestation diagnosis

Generally speaking, it is impossible to physically see worm eggs in faeces, as they are so tiny they can only be picked up on a microscope. There is, however, the potential to see adult worms, if a big enough worm burden exists that the pet begins to expel them in the faeces.

Investigation usually only starts once clinical signs (as mentioned above) develop. During consultation, Vets will sometimes take a faecal sample and perform a microscopy/faecal float study. This is a diagnostic tool that can sometimes assist with providing a more accurate regime for your pet, but not a necessity in order to provide treatment.

What can I expect if my pet undergoes intestinal worm treatment?

Treatment for intestinal worms is fairly straightforward – if the pet isn’t too severely compromised from a giant worm burden, the typical approach is to simply worm them using a basic intestinal wormer. A booster of the tablet is also recommended in 2 weeks from the initial dose.

Pets with an intestinal worm infestation usually prevent based on symptoms – and so symptomatic relief is usually paired with the intestinal worming tablet on a case-by-case basis.

An example would be if the pet has ongoing diarrhoea, an intestinal wormer is given to treat the worms, along with a stool binder and electrolyte solution to treat the diarrhoea.

Another (extreme) example would be if the pet has ongoing anaemia, an intestinal wormer is given to treat the worms, along with a blood transfusion to treat the anaemia.



Prevention is key to keeping intestinal worms at bay. Prophylaxis can start in pets from as little as 6weeks old. The regime as demonstrated in Figure below should be followed. Keep in mind, the worming schedule after the 6 month mark depends on which product is being used. There are a few different types of intestinal wormers available – all of which are in tablet form, except Bravecto Plus (an all in one flea, tick, intestinal worm and heart worm prevention) for cats – and some that require boosters every month (such as NexGard Spectra), or every 3 months (such as Drontal/ Cazitel).