Fleas are common external parasites in Indiana. Fleas tend to become a problem by mid-summer and persist until hard freezing weather in the fall.

Quick Facts:

  • Fleas can jump 8" high and 12" laterally.
  • A flea consumes 15 times its own weight in blood each day.
  • 85% of fleas take their first blood meal within 15 minutes of jumping onto an animal, and they continue feeding every 30 minutes for the rest of their lives.
  • The flea life cycle can be completed in as fast as 3 weeks; in less-ideal conditions, unhatched flea pupae (cocoons) may remain unhatched for up to 1 year.
  • Did you know? Fleas feed (i.e., suck blood) far in excess of what they require to stay alive themselves. Flea droppings (digested blood from the animal) serve as a food source to feed the next generation of fleas. Once flea eggs hatch into larvae, the larvae feed on droppings from the adult fleas.
    It's an ingenious — albeit disgusting — life cycle!

fleaWhile fleas can be found anywhere on your pet, they tend to prefer the back, groin, and tailhead areas. Fleas can be difficult to spot, especially if your pet just has a few; however, even only 1 or 2 fleas can make your pet miserable. Animals with fleas tend to bite or scratch at their rear end and belly. Pets may often jump or act startled when they feel a flea bite.

To check your pet for fleas, start looking at the back just in front of the tail. Rest your palms on your pet's hips and carefully roll through your pet's fur with your thumbs. Try to examine all the way down to the skin. Fleas are about 2 mm in length and are brown in color. Look carefully since fleas will try to run away from your fingers. Also examine for the presence of flea feces, which is actually digested blood from your pet. Flea feces is visible as small black specks — about the size of crushed black pepper. If you are unsure if what you are seeing is flea feces, try combing some of the specks onto a sheet of white paper. Place a drop of water onto the paper and run one of the specks through the water drop with your index finger. If the speck leaves a red trail behind, this confirms that the speck represents digested blood. Even if you do not see live fleas, the presence of flea feces proves that your pet has had fleas in the recent past.

Keep in mind that fleas can be extremely difficult to find on some pets. Because some pets lick or groom themselves excessively, they may swallow many or all of their fleas — giving owners the false impression that fleas are not the cause of their scratching. For those pets who are allergic to flea saliva, just a few flea bites per week can keep them scratching continuously. We commonly recommend flea adulticide treatment for pets who are primarily scratching at the back, tail, or belly — even if no fleas are visible. Remember: for every adult flea you see, there are likely hundreds of eggs in the environment that you do not see.

flea life cycleSeveral good flea products are available. It is important to understand the differences between products. Adulticides kill adult fleas. Insect Growth Regulators (IGRs), on the other hand, prevent flea eggs from hatching but do not kill adult fleas. In general, IGRs are best suited for prevention of a flea problem or when used in combination with an adulticide. Start them early in the flea season before a flea infestation occurs. Adulticides are good to use to bring an existing infestation under control. They are also well-suited for use with pets who are highly flea allergic; this should prevent flea bites from occurring and will help prevent allergic skin disease.

Insect Growth Regulator:

Sentinel: An IGR in combination with heartworm preventative. Will not kill adult fleas but will prevent fleas' eggs from hatching. Very useful at breaking the flea life cycle and preventing an infestation. For use in dogs only. Give with a meal.


Vectra 3D: Liquid applied once monthly to the back of the neck. Kills fleas, ticks, and mosquitoes for 30 days. Also contains an IGR. Bathing with a 'soapless' shampoo is acceptable, but should be kept to a minimum. FOR USE ON DOGS ONLY.

Revolution: Liquid applied once monthly to the back of the neck. Kills fleas and ticks (tick control on dogs only) and prevents heartworm disease. Also prevents the development of flea eggs. For use on both dogs and cats.

Advantage Multi: Liquid applied once monthly to the back of the neck. Kills adult fleas and intestinal parasites and prevents heartworm disease. For use on both dogs and cats.

Capstar: Oral tablet; kills fleas quickly — usually within a few hours. Since Capstar is only effective for about 1 day, we recommend starting a once-monthly product if your pet is likely to be exposed to fleas on an ongoing basis. For use in both dogs and cats.

NexGard: Oral tablet; kills adult fleas quickly (usually within a few hours) and lasts for 30 days. Give with a meal. FOR USE IN DOGS ONLY.

Trifexis: Oral tablet; kills adult fleas quickly (usually within a few hours) and lasts for 30 days. Also prevents heartworm and intestinal worms. Give with a meal. FOR USE IN DOGS ONLY.

Traditional pyrethrin-based flea sprays are also effective adulticides, but they must be used at least twice per week. The newer-generation adulticides listed above are highly effective and much easier to use. DO NOT USE PERMETHRIN-BASED (A STRONGER FORM OF PYRETHRIN) SPRAYS OR TOPICALS ON CATS! They can cause severe neurological side effects!

Besides flea treatment for your pet, your pet's environment should be treated as well. Your house may be contaminated with fleas and their eggs — especially if your pet has had fleas for some time. We recommend vacuuming all areas of your home; this should remove a large percentage of the problem. Be sure to dispose of the bag from the vacuum after this first thorough vacuuming. Anything washable should be washed; this includes rugs and pet bedding. Finally, treat your house with a flea adulticide containing an IGR. This will kill the existing adult flea population and provide ongoing control of eggs and larva. Do not apply household sprays to pets. Outdoors, we recommend keeping grass and bushes trimmed since fleas like damp, dark conditions. We do not recommend spraying your lawn. Lawn spraying probably does very little good against fleas and may be toxic to you and your pets.

Your pet may require an examination by the veterinarian — especially if the skin appears red, crusty, or infected. Medication may be indicated to control the secondary skin problems caused by a flea infestation.