Fleas and Ticks: Dangers, Signs, and Complete Prevention for Your Dog
Updated 16 October 2026
In short: fleas cause itching and allergies and can transmit tapeworm; ticks transmit serious diseases such as babesiosis, Lyme disease or ehrlichiosis. Prevention relies on a suitable parasite treatment, chosen with your vet and renewed without gaps, on checking the coat after every walk and on keeping the home clean. If your dog has a fever, seems dull or passes dark urine after a tick bite, see a vet quickly.
Why are fleas and ticks dangerous?
Flea allergy dermatitis
Flea saliva can trigger an allergy: intense itching, redness, scabs and hair loss, even with very few fleas.
Tapeworm (Dipylidium)
When grooming, a dog can swallow a flea carrying the larvae of this intestinal worm.
Anaemia
A heavy infestation can weaken a puppy or an older dog: pale gums, tiredness.
Tick-borne diseases
Babesiosis, Lyme disease, ehrlichiosis, anaplasmosis: some can be fatal without treatment.
A female flea can lay dozens of eggs a day. They fall off around the home: the few fleas you see on your dog often hide a much larger population in the environment.
| Disease | Agent | Signs to watch for |
|---|---|---|
| Babesiosis | Red blood cell parasite | High fever, lethargy, dark (coffee-coloured) urine, pale or yellow gums |
| Lyme disease (borreliosis) | Borrelia bacteria | Shifting lameness, fever, tiredness; kidney damage possible |
| Ehrlichiosis, anaplasmosis | Blood cell bacteria | Fever, loss of appetite, nosebleeds, joint pain |
What about people? Ticks also transmit Lyme disease to humans, and fleas can bite people. Protecting your dog also protects your family.
How can I tell if my dog has fleas or ticks?
- Intense scratching, especially at the base of the tail, belly and neck.
- Small black specks in the coat: on a damp tissue they turn reddish-brown (digested blood).
- Redness, scabs, bald patches from licking.
- Run your hand through the coat after walks: a small lump under your fingers.
- Areas to check: ears, neck under the collar or harness, armpits, groin, between the toes.
- Once engorged, a tick becomes round and greyish.
Fever, lethargy, loss of appetite, lameness, dark urine, pale gums: see a vet quickly, especially after a tick bite.
What prevention should you use?
| Form | Protection period | Good to know |
|---|---|---|
| Tablet | 1 to 3 months depending on the product | Not affected by bathing; works after the bite |
| Spot-on | About 1 month | Avoid bathing 48 h before and after applying |
| Parasite collar | Up to several months | Must fit well; remove if it irritates |
| Spray | Short | As an occasional extra |
- Protect all year roundFleas survive winter in heated homes, and ticks are active whenever temperatures are mild.
- Check after every walkEspecially after tall grass, woods and meadows. Remove any tick quickly: the risk of transmission rises the longer it stays attached.
- Keep the home cleanVacuum resting areas often, wash bedding at 60 °C.
- Ask your vet about vaccinesVaccines against Lyme disease exist and can be useful in high-risk areas.
Remember to check under the harness and collar: ticks like to hide there. A Y harness comes off in seconds for a post-walk check.
No need for parasite treatment in winter.
FALSEFleas breed all year in heated homes, and ticks come out on mild days.
Brewer's yeast or garlic repel fleas.
FALSEThere's no solid evidence. Garlic is actually toxic to dogs.
An indoor dog can get fleas.
TRUEYes: they come in on shoes, other animals, shared hallways.
Already dealing with fleas or a tick? See how to treat an infestation.
Frequently asked questions
How do I protect my dog from ticks?
With a tick-active parasite treatment renewed without gaps, and by checking the coat after every walk in nature.
What are the symptoms of babesiosis?
High fever, lethargy, loss of appetite and dark urine. It's a veterinary emergency.
When are ticks most active?
Mainly in spring and autumn, but they can be active all year when it's mild.
Do dog fleas bite people?
Yes, they can bite people, especially around the ankles, but they don't live on humans.