Pet Health


Fleas are the most common external parasite of dogs and cats. Flea allergy dermatitis is the most common skin disease of dogs and cats! The ideal flea control program utilizes products that target the various stages of the flea life cycle, not only the adult fleas on the pet. In order to help you select the most appropriate products to achieve a flea-free existence for an allergic pet, we will start by telling you about the life cycle of the flea.

Life Cycle of a Flea

Eggs: are laid in the hair coat and are designed to fall off your pet. They are resistant to insecticides, but susceptible to various Insect Growth Regulators.

Larvae: develop in the pet’s environment. They like areas with low light and high moisture. Larvae are susceptible to traditional insecticides and insect growth regulators. Larvae eventually spin cocoons and become pupa.

Pupae: are resistant to freezing, desiccation (drying), and insecticides. Pupae can lie dormant for up to 9 months; they are stimulated to hatch as young adults by vibration (walking on the carpet), warm temperatures and increased CO2 (carbon dioxide) from your pet’s breath. Normally, hatching occurs when a dog or cat is near and the new flea finds the pet within seconds.

Adults: only account for 3-5 % of the flea population. Completion of the life cycle from egg to adult often varies from 2-4 weeks. Adult cat fleas cannot survive or lay eggs without a blood meal, but once it is feeding on a DOG or CAT, the female can lay 40-50 eggs per day and up to 3,000 in their 3-week lifetime. Newly hatched fleas need to start feeding within 2 days. They start to lay eggs 2 days after their first blood meal. The optimum temperature for flea survival is 70F to 85F and at an optimum humidity of 80%.

Flea Control Recommendations:

For the flea allergic patient 100% flea control is required to remain itch free. Even very minimal exposure may be sufficient to perpetuate itching in an allergic patient (one or 2 bites per week is enough!).
The most important rule for flea control is:
If fleas are present, ALL pets in the household must be treated for at least 3 consecutive months for effective control.

Common Questions:

Question 1: Should I treat my pet for fleas if it is indoor-only?
For the most effective flea control, all pets in the household should be treated year round with a good quality flea product. It is true that indoor-only pets are less likely to have fleas; however, it is not unheard of for indoor-only pets to have fleas. First, if there are other pets in the household that DO go outside, they can carry fleas into the house. Second, even if there are no other pets in the house, fleas can come indoors on your shoes and clothing, then find their way to the nearest dog or cat. Generally, fleas do not prefer to take their blood meals from humans- they much prefer dogs and cats. But if there is a bad infestation in your house, fleas will bite and feed from the humans in the house. If you never want to see a flea on your pet, treat them with a good quality flea preventative even if they are indoors 100% of the time.

Question 2: Should I treat my pet for fleas in the winter?
When it comes to flea control, one of the most common mistakes pet owners make is to stop giving their pets flea preventative at the end of summer when the weather starts to cool down. Perhaps for that reason, at EEVMC we see most of our flea allergy dermatitis cases in October and November. It really takes a period of sustained temperatures below freezing to make the flea population dwindle. To complicate matters, the last several winters in Pittsburgh have been very mild, with wide fluctuations in temperature even in January and February. The result has been that we have continued to see the occasional flea allergy dermatitis case even in the dead of winter. If you never want to see a flea on your pet, treat them year round.
Following is a list of flea products for dogs and cats. This is not a complete list, just one that contains some of the products that we consider to be acceptable and effective. There are dozens of products available today, with a wide range of costs. In general, it has been our experience that flea control is one of those situations in which “you get what you pay for”. Most of the products listed below are in the pricier range of available products. If your pet has a flea problem, don’t skimp on good quality flea control. The less expensive products are not as effective, and more importantly, not as safe.

Not all of these can be used in both dogs and cats, so be sure to check each product’s specifications carefully. Products that contain pyrethrins or permethrins should NOT be used on cats. In addition, some of the products provide coverage for issues other than fleas, such as ticks, heartworm, and gastro-intestinal parasites. Some of them are available over-the-counter, others by prescription only through a veterinary facility. This list changes often, as new products are developed and come to market. We will do our best to keep this list up-to-date.

  • Nexgard Oral Chewtabs (Merial)
  • Seresto Collar (canine and feline) (Bayer)
  • Advantage II (canine and feline), Advantage Multi, K9 Advantix (Bayer)
  • Revolution (canine and feline) (Zoetis)
  • Comfortis (Elanco)
  • Trifexis (Elanco)
  • Bravecto (Merck)
  • Vectra 3D (Ceva)
  • Simparica (Zoetis)
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