Deworming pets: why it’s important

Deworming pets is generally not done often enough, probably because no pet owner likes to think of their dog or cat having worms. However, the reality is that no matter how much you pamper your pet their chances of carrying worms is highly likely.

Deworming your pets regularly is as important as vaccinations

Pets can harbour several kinds of worms, some of them deadly, and deworming regularly is as important as annual vaccinations and good nutrition.

Worms, their eggs or larvae are present in soil, in fleas and in raw food. Freezing doesn’t kill worm larvae; only cooking does. Unfortunately only two kinds of worms are commonly seen with the unaided eye and some infestations cause few or no symptoms. This is why veterinarians recommend routine deworming every three months.

Worms that can infect your pet

These worms or parasites include the parasitic tapeworm, the roundworm, the hookworm, the whipworm, and the heart worm. The only two commonly seen in the stool with the unaided eye are roundworms and tapeworms. Some worm eggs or larvae can be dormant in the pet’s body and activated only in times of stress, or in the case of roundworms and hookworms, until the later stages of pregnancy when they activate and infest the soon-to-be-born puppies and kittens.


This parasitic flatworm lives in the intestines, the liver and even the brain. It can be passed on to humans.  It has a long ribbon-like body with many segments that can become independent, and a small head bearing hooks and suckers. You may notice dried, white, grain-like segments in faeces or under your pet’s tail.

Tapeworm must be first pass through an intermediate host (a flea) before they can infect your dog and cat and you which is why we also recommend protecting your pet against fleas all year round.

Symptoms of tapeworm infestation

– biting

– licking

– dragging of the hindquarters


This round-bodied, unsegmented worm hatches in the intestines and lives there. The eggs of the roundworm usually enter the pet’s body through contaminated water or food or contaminated soil.

Your dog may be infected with roundworms by its mother during pregnancy. Roundworms can also develop in a puppy after it is born when the puppy eats larvated eggs from the environment or drinks worm larvae (young worms) in the mother’s milk. Another way roundworms are passed is when roundworm larvae are present in the tissues of a mouse or other small mammal which the puppy eats.

Roundworms pose a significant risk to humans. Contact with contaminated soil or dog faeces can result in human ingestion and infection. Once infected, the worms can cause eye, lung, heart and neurological symptoms in people.

Symptoms of roundworm infestation

– general weakness

– a swollen belly

– a dull coat

– vomiting

You may notice the adult roundworms in your dog’s faeces or vomit. They will appear white or light brown in colour and may be several centimetres long.


This parasitic worm attaches to the wall of the gut of a dog or cat, puncturing the blood vessels and feeding on the animal’s blood. A severe hookworm infestation can kill puppies, often making them severely anaemic from the loss of blood.

A hookworm lays up to 30 000 eggs per day. These are ejected into the digestive tract and pass into the environment through your pet’s faeces. The eggs can stay dormant in the soil for up to 10 years.

Their larvae can infect your pet – and you – simply through contact and penetration of the skin, and through the dog eating the larvae when they ingest soil or during their routine licking (cleaning).

Symptoms of hookworm infestation

– diarrhoea

– bloody diarrhoea

– weight loss

– anaemia


These look like whips with wider ‘handles’ at the end.  They are generally transmitted through ingestion of contaminated matter. Although they seldom cause a dog’s death, whipworms are a real nuisance for the dog and can be a problem for the veterinarian to diagnose as there may be easily identifiable symptoms.

Symptoms of whipworm infestation

– bloody diarrhoea

– faecal incontinence

– weight loss

– malnutrition


Heartworm disease is a serious, often fatal, disease. It is caused by worms living in the heart and the pulmonary arteries. Heartworm infection can affect many different organs of the dog—heart, lungs, kidneys, and liver, for example—so symptoms may be varied. Most commonly though, signs of heart or lung disease are present.

Heartworms are currently only a problem in North Eastern parts of our country but people taking their pets on holiday with them to this region including Mozambique must protect them. Heartworms are transmitted via mosquitoes.

Symptoms of heartworm infestation

– coughing

– reduced exercise tolerance

– heart failure

Isolated and rare cases of human infection have been reported, however, the heartworm is generally not considered a risk to human health.


Giardia is a single-celled parasite that resides in the small intestine. Before passing in stools, they become encased within hard shells called cysts which allows them to survive outside the intestines for months. Once inside the host, the cysts dissolve and the parasites are released.

Symptoms of giardia infestation

– dehydration

– upset stomach or nausea

– abdominal discomfort

– flatulence

Giardia is a common cause of diarrhoea in people, but dog Giardia is not generally considered to spread from animals to humans.

Spirocerca lupi 

A potentially lethal disease currently concentrated in provinces up north. Sudden death can occur. This parasite can cause cancer. It is carried by lizards and dung beetles so pets that ingest these may be at risk.

Pet owners moving from Johannesburg and other regions north of the Western Cape are advised to treat their pets for worms before travelling. If you travel with your pets outside of the Western Cape then it is advised that you give them preventative treatment.

Symptoms of spirocerca lupi

– oesophageal obstructions

– regurgitation

– coughing

– weight loss

– loss of appetite

– salivation

– anaemia

– fever

– cancer

– painful swallowing

How do I prevent worms?

Remove faeces from your lawn, yard, street, or kennel daily.

Exercise your pets in grassy areas not frequented by other animals.

Prevent your pet from eating rodents and other small mammals, and earthworms

Control fleas

Deworm pregnant pets before breeding, and again before whelping to help prevent infecting newborn pets.

Deworming medication

There are several anti-worm medications available.

DRONTAL for dogs and cats

REVOLUTION is a tick and flea drop but also a dewormer and is safe to use on puppies from 6 weeks of age and is safe for pregnant and lactating bitches

PROFENDER is a topical drop for cats. It covers roundworm, hookworm and adult tapeworm as well as ticks and fleas.

ANTEZOLE paste for cats and dogs covers ascarids, hookworm and tapeworm

ADVOCATE is a topical treatment for cats and dogs

MEDIWORM for dogs only for roundworms and tapeworms.

MILBEMAX is a chewable tablet for both dogs and cats that is also safe for pregnant and lactating bitches. Covers hookworm, roundworm and tapeworm in cats. It can also be used to treatment and prevention of Spiracerca lupi and Heartworm.

Deworming your pets: when should you do it?

Puppies and kittens every 2 weeks until the age of 3 months (they may contract worms through their mother’s milk) then once a month until the age of 6 months.

Pets that roam a lot or eat bugs and rodents are considered high risk as are pets that are exposed to many other animals or eat a raw diet. These pets should be dewormed monthly.

For pets 6 months and older, every 3 months.

Remember to treat for fleas at the same time that you deworm, otherwise the fleas will re-infect your dog or cat with tapeworm.