Fleas: Enemy Number One

It is that time of year again and due to our mild winter, we are expecting fleas to be quite problematic this year. To help you prepare adequately we wanted to give you some “ammunition” to prevent these pests from affecting your pets.

Fleas are the most common external parasite found on dogs and cats so knowing a bit about them will really help you to be successful in your prevention and treatment should you see or suspects they have invaded.

So why are we at Animal Care Hospital so concerned about finding these little bugs on pets? Well not only do we all hate the idea of bugs on our pets but disease transmission, skin irritation and skin infections are very real, making prevention a key goal in our practice. Also, should your pet have other allergies, flea bites can cause significant reactions even if only one or two fleas bite your pet.

Flea life cycle:

Understanding the life cycle will help you understand how to prevent an infestation as well as how to treat one should you be faced with that horrifying condition. So here is a brief overview:

Adult-take their blood meal from the host then begin to lay 40-50 eggs per day.

  • Eggs-fall off your pet and spread throughout your house and yard.
  • Larvae-move about the environment feeding on debris and last 2-3 weeks before forming a cocoon for their next stage of development.
  • Pupae- This cocoon stage of the cycle can survive for up to 7 months. This stage protects the flea from environmental conditions and most insecticides. Then once conditions are ideal for the adult stage they hatch and start the cycle all over again.
  • Adult who is waiting for its next host.

Adults are easily killed with many insecticides on the market today and may give you a false sense of success after even only one treatment. It is because of these other stages that success takes time and multiple treatments with a product containing an Insect Growth Regulator (IGR) are necessary.

First, what do fleas “like”?

Cozy and humid environments with organic matter. Outdoors you will find them in cool, dark, or shaded areas like under shrubs, in the wood piles, mulch and under piles of leaves. They are not out sunbathing in the middle of the yard so concentrating your environmental treatment in areas that are more to their liking will increase your success of control. The same goes for indoors. These stages will have the highest concentration of pests in areas where your pets like to be and in cool, dark areas with a lot of organic matter. Places like the upholstery, carpets, throw rugs, dog beds, under beds and furniture, cracks in the hard wood floors and along the baseboards, corners in the closets especially if your cat likes to nap in there and don’t forget the inside of your vacuum cleaner bag.

The immature stages of the life cycle can survive months waiting for the optimum environmental conditions to flourish so once you have treated the environment, be sure to keep your pets on prevention.

There are many effective treatments for the environment as well as for your pet. As a rule of thumb, treating your pet with an effective preventative and the environment with a product containing an Insect Growth Regulator (IGR-kill the eggs and larval stages) for three consecutive months will bring you the highest success rate.


Myths: I only need to keep my pets on flea prevention in the warm months.

Why should I continue to give my dog and cat prevention when its cold out? I only give my dog his Nexgard in the spring and summer months.

Fact: Adult fleas can survive for 10 days in 37.4 degrees F. They also survive on the warm bodies of our pets and other wildlife.

Fleas and ticks do not have a calendar, so they go by the temperature in their environment. Outdoors-must be consistently below 45 degrees for over 10 days before the threat is minimized so keep giving prevention if the temperatures exceed this by even 1 or 2 days.

Inside: well, as we like our homes nice and cozy, fleas will continue to thrive in our nice warm homes, so preventatives reduce the chance for an indoor infestation any time during the year.

Myth: My animal never goes outside so I do not need a preventative.

Fact: Fleas and various stages of their life cycle can enter the home environment on other pets in the house, on the people who enter the home and on things like wood for the fireplace. Remember once that flea takes its first meal, they will begin laying 40-50 eggs per day!

Myth: I do not need a preventative since I’ve never had a flea problem.

Fact: Due to our recent warmer winter months the risk of fleas is on the rise, so maintain that perfect record of no fleas EVER, prevention is necessary.

Dr. Nicky Polson is a veterinarian and owner of Animal Care Hospital in Morris, IL.