Recognising and Treating Worms in Dogs: What You Should Know

Does your dog snap at every blade of grass and sniff at other dogs’ faeces? The risk of worms increases with every walk. Worms are among the most common parasites in dogs – and most owners only notice the infestation late.

Where does my dog get worms?

Worm eggs survive for months in the environment. A quick sniff at dog faeces is enough for an infection. The eggs stick to grass tips, park benches and even your shoe soles.

The classic route of infection: your dog picks up worm eggs while walking – from the faeces of other dogs that were there weeks ago. Raw meat when BARFing also carries risks, especially offal such as lungs and liver.

Puppies often become infected already in the womb or during nursing. A bitch with a worm infestation passes the parasites directly on to her puppies.

Fleas act as intermediate hosts for tapeworms. If your dog swallows an infested flea while grooming, it ingests tapeworm eggs in the process.

Which types of worms most commonly affect dogs in Germany?

Roundworms top the statistics. Almost every second puppy carries them. The whitish, spaghetti-like worms grow up to 18 cm long and are usually clearly visible in the faeces.

Hookworms are smaller but more aggressive. They burrow into the intestinal wall and suck blood – an infestation can lead to anaemia. Furthermore, the larvae also penetrate through the skin.

Tapeworms appear as rice-grain-like segments in the faeces or around the dog’s anus. The fox tapeworm is particularly dangerous for humans, as it can cause liver cysts.

Heartworms are also present in Germany due to climate change. Mosquitoes transmit the larvae when feeding on blood. Left untreated, they lead to heart failure.

How can I tell if my dog has worms?

Many dogs show no symptoms initially. A heavy infestation becomes noticeable through weight loss despite normal food intake.

Diarrhoea and vomiting occur with advanced infestation. The faeces can become bloody or slimy. Some dogs develop a distended belly while simultaneously losing weight.

“Scooting” – when the dog drags its anus along the ground – indicates itching caused by worms. Dull, scruffy fur can also be a sign.

In puppies, the symptoms are more pronounced: growth disorders, frequent vomiting and a round belly with thin legs are typical.

Visible worms in the faeces or vomit confirm the suspicion immediately. Tapeworm segments look like moving grains of rice and stick to the anus.

Can my dog pass worms on to me?

Yes – and this happens more often than many assume. Roundworm eggs remain infectious on your hands for weeks if you do not wash them thoroughly.

Children are particularly at risk. They put their fingers in their mouths more often and play in sand, where worm eggs may be lurking.

An infection with the fox tapeworm can become life-threatening for humans. The larvae form cysts in the liver and lungs, which only show symptoms after years.

Pregnant women and immunocompromised individuals should minimise contact with the dog if worms are suspected, until treatment has been carried out.

How dangerous are worms for my dog?

A light infestation often remains asymptomatic. It becomes problematic with heavy infestation or in certain life stages.

Puppies can die from worm infestation. Their immune system is immature and the parasites deprive them of vital nutrients. A distended belly combined with weakness is an emergency.

Old or sick dogs tolerate worms less well. Hookworms can lead to life-threatening anaemia due to blood loss.

Heartworms attack the heart directly. Without treatment, they lead to death from heart failure within months.

How does treatment at the vet work?

The vet needs a fresh faecal sample – ideally pooled faeces from three consecutive days. Single samples can be misleading, as worm eggs are not shed daily.

Deworming is usually carried out with tablets or pastes. The dosage depends on body weight and type of worm. A broad-spectrum product works against several types of worms simultaneously.

After 24 hours, the worms begin to die. You may then find dead worms in the faeces – this is normal and shows that the treatment is working.

In cases of heavy infestation, several treatment cycles are necessary. A follow-up examination after four weeks confirms the success of the treatment.

How often should I deworm my dog?

The standard recommendation is: four times a year, i.e. every three months.

Dogs at higher risk require more frequent treatments. This includes hunting dogs that regularly eat wild animals, or dogs that ingest the faeces of other animals.

Puppies receive their first deworming treatment at three weeks of age, then every two weeks until they are three months old. Thereafter, the normal schedule applies.

As an alternative to prophylactic deworming, you can have the faeces examined every three months. Treatment is then only carried out if the result is positive.

Can I treat worms in dogs myself?

No. Deworming agents are prescription-only and must be dosed precisely. Underdosing leads to resistance, while overdosing can harm your dog.

How long does it take for the worms to disappear?

Most worms die within 24 to 48 hours. You will then see them dead in the faeces. Complete elimination can take up to a week.

Are home remedies effective against worms?

No. Neither coconut oil nor carrots or other home remedies kill worms. They may at best have a supportive effect, but never replace medical treatment.

Can my dog get worms again despite deworming?

Yes, immediately after treatment. Deworming agents only work against existing worms but offer no protection against new infections. That is why regular repetition is necessary.

Do all dogs in the household need to be dewormed at the same time?

This makes sense, as dogs can infect each other. Treat all animals on the same day with the same product.