Just one flea on your dog can signal a huge problem. A single flea can lay up to 50 eggs in one day1. These eggs then roll off your dog and infest the environment. Wherever your dog goes, fleas and their eggs go too. That's how just a few fleas can quickly become hundreds and infest and bite your pet.
Because adult fleas are the only life stage that is visible, it can be difficult to grasp the full scope of the infestation. Most pet owners focus treatment efforts on the adult fleas they see crawling around their pets and are unaware of the younger stages in the environment. Unfortunately, adult fleas make up only 5 percent of the total flea infestation problem. The other 95 percent are invisible to the naked eye.2
Understanding the four stages of the flea life cycle, how long fleas live and what fleas look like can help you stop the continual invasion.
Stage 1: Flea eggs
One flea can lay up to 50 eggs in one day, which fall off your dog anywhere he goes. As your dog moves around, flea eggs disperse into the surroundings including carpet, bedding and the backyard.
Stage 2: Flea larvae
Flea larvae hatch from the eggs in one to 10 days. They feed on organic debris, don't like sunlight, and live in moist, dark areas such as:
- In carpet
- Under furniture
- Under baseboards
- In bedding
- In shady areas in your yard
Stage 3: Flea pupae
Larvae turn into pupae by enclosing themselves in a sticky, silk‐like cocoon. They usually emerge as adult fleas one to two weeks later, but can stay in their cocoons for weeks or months waiting for a host, like your dog, to live on. This is why some people experience flea infestations and flea bites after returning from vacation or moving into a house. If a flea cannot find a dog or cat to jump on, it is not uncommon for them to jump on and bite people.
Stage 4: Flea adults
Full‐grown fleas are the ones you normally see, and they begin biting almost immediately after getting onto your dog. Contrary to popular belief, fleas do not jump from pet to pet or fly because they do not have wings. They stay on one pet biting, feeding and laying eggs for up to several months.
How to prevent and treat fleas
Killing fleas at multiple life stages helps break the flea life cycle and prevent flea bites on your dog. That's why it's important to use a product that treats and prevents fleas.
These products work in 2 ways:
- They kill the adult fleas on your dog.
- They break the flea life cycle by killing flea larvae, an immature stage of a flea.
When it comes to flea prevention for your dog, there are many products available at your veterinarian or local pet store. We recommend routine, year-round use of a flea preventive. Look for one that kills fleas through contact.
1. Dryden MW. Host association, on-host longevity and egg production of Ctenocephalides felis felis. Vet Parasitol. 1989;34:117-22
2. Grace SF. Fleas. In: Norsworthy GD, Crystal MA, Grace SF, et al, eds. (2006). The Feline Patient. 3rd ed. Ames, IA: Blackwell Publishing; 106-107.
Flea Diseases in Dogs
How to Help Get Rid of Fleas on Your Dog
How Do Flea Collars Work?
Compare Types of Flea Products