The Dog Blog

From the Vet

How Much Do We Really Know About Fleas?

by Dr. Eileen Savier CVA, CVCH

Nov 7, 2023

If you have ever owned a dog you know something about fleas. But how much do you really know about them? I’m sure at some point your veterinarian has told you that your pet should be on monthly parasite prevention all year round and you probably do it because it what your veterinarian has said was best and you don’t give it another thought.

Well today we are going to go over the ick factor of fleas. If you’re not convinced that your veterinarian has your pets health and your health as a priority when making recommendations like parasite prevention, you will.

There are several species of fleas that can make a meal out of your dog. Six that are common and other flea species that may occasionally parasitize dogs. The six most common are the cat flea, the dog flea, the poultry stick tight flea, the human flea (two species), and the rat flea.

There are several stages to the flea life cycle, this is in part why an infestation can be difficult to control. No one product can effectively kill each stage of the life cycle. Typically I will prepare clients for ~3 months before we have good control after fleas have been found. We will start with the eggs. Eggs are deposited on the dog and then fall into the environment within a few hours. The duration they are eggs is dependent on the environment and that can hatch quickly. The next stage is the Larvae. This form looks like a maggot and are covered in small hairs. They feed on blood in adult flea feces, organic debris, flea eggshells, and other larvae. Outdoors larvae cannot survive in direct sunlight so they tend towards cool shades areas. Indoors they like carpets, under furniture, and along baseboards. Speed of larval development is also largely influenced by environmental factors. The pupae stage make cocoons and can be found in soil, vegetation, carpets, under furniture and on animal bedding. There is a large variation of development between species. Some fleas will emerge from the cocoon in eight days while other can remain in the cocoon for up to 30 weeks depending on the temperature. Carbon dioxide, increased temperature, and vibrations can all stimulate flea emergence. Once the adult emerge that begin feeding immediately when on a host and egg production begins within 20-24 hours of females taking their first blood meal. Females can produce 40-50 eggs per day and most adult fleas live 2-3 months.


In additional to being annoying and causing itching fleas can cause illness (iron deficiency anemia and death in young animals) and disease. The species of fleas determines the disease they transmit. The cat flea can transmit Typhus, Flea borne spotted fever, Cat scratch fever (Bartonella henselae), and Tapeworms.The rat flea can transmit Typhus, Salmonella, the Plague, and Tapeworms. There are also several species of fleas that can transmit mycoplasma and a few that transmit tularemia. Some of these disease are zoonotic meaning that both animals and people can become ill.

The cat flea is the most common external parasite in north america and the rat flea is more common in drier habitats.

Monthly flea preventions should eliminated fleas on pets, eliminating existing environmental infestation and prevent subsequent re-infestations. Severe infestations may take several months to bring it under control. Additionally, all pet in the home (including guinea pigs and bunnies) will need to be treated to gain control- talk to your veterinarian for treatment that is safe for small mammals. Over the counter products are not safe for small mammal or very young animals.
Fleas are gross and can carry organisms that can cause really terrible diseases. Please use parasite prevention on all your pets monthly year round.

About Dr. Eileen Savier

Barks & Recreation is proud to feature Dr. Eileen Savier CVA, CVCH as our Veterinary Blogger in our “From the Vet” Series — offering information related to the health and welfare of your furry family members! Currently part of the team of doctors at Keystone Veterinary Clinic, Dr. Savier is a 2012 Graduate of the Ross University School of Veterinary Medicine, She completed her clinical experience at The Ohio State University and after veterinary school she pursued further education and certification in Veterinary Acupuncture, Chinese Herbal Medicine, and Fear Free veterinary visits. Dr. Savier has a special interest in integrative medicine, animal behavior, and internal medicine and is committed to improving animal health care by integrating Eastern and Western philosophies. She enjoys working with fearful & aggressive dogs and cats and she has had additional training in low stress handling techniques and encourages positive reinforcement during exams and procedures. Her clinical interests include pain management, animal behavior, geriatric patient care, and internal medicine.

Dr. Savier is a member of the following associations:

Dr. Savier shares her home with two (soon to be three) dogs, two cats, and a toddler. She lovingly refers to her two dogs as Coconut Retrievers as they were rescue dogs she brought home from the island of St. Kitts. In her free time she enjoys spending time with her family, going to the beach, and planning her next Disney vacation.