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 many veterinarians recommend pet owners use a product that both 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.
Bayer offers a variety of flea prevention and treatment products that kill fleas though contact. Fleas do not have to bite your dog to die.
Seresto® is an odorless collar that kills and repels fleas and ticks for 8 continuous months.
K9 Advantix® II is a monthly topical that kills fleas, ticks and mosquitoes through contact. No biting required. Do not use K9 Advantix® II on cats.
Advantage Multi® for Dogs (imidacloprid + moxidectin) is a monthly topical that protects your dog from fleas, hookworms, roundworms, whipworms and heartworms. Product Label.
Advantage® II kills fleas through contact so they don’t have to bite your dog to die. It works all month long to break the flea life cycle – so you can help protect your dog from biting fleas.
CAUTION: Federal (U.S.A.) law restricts Advantage Multi® for Dogs to use by or on the order of a licensed veterinarian. WARNING: DO NOT ADMINISTER THIS PRODUCT ORALLY. For the first 30 minutes after application ensure that dogs cannot lick the product from application sites on themselves or other treated animals. Children should not come in contact with the application sites for two (2) hours after application. (See Contraindications, Warnings, Human Warnings, and Adverse Reactions, for more information.)
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.
Related article: Tick disease and control