Fleas by Dr. Dana Cini

A creepy crawly nightmare for pet owners! Don’t despair if your pet has fleas, there are safe and effective treatment options available from your veterinarian, but first you should understand the lifecycle and behaviour of this tiny insect.

The flea species that is found on dogs and cats is Ctenocephalides also known as the cat flea, this flea will feed on many mammals but prefers dogs and cats. Fleas are not only a nuisance but can have serious health consequences for your pet. A heavy flea infestation can cause life threatening anemia in very young or old debilitated animals. Some animals suffer from flea allergy dermatitis which is an allergy to the saliva of the flea causing severe itching, scratching and fur loss often from just one bite. Fleas are also why many pets get tapeworm infestation.

The life span of an adult flea is 4-6 weeks. A female will typically lay 20-30 eggs a day, over a life time she will lay several hundred eggs. The eggs will incubate in temperatures of 18-27 degrees making our homes a perfect place for fleas to thrive. The flea will lay eggs on the host but they fall off into the environment along with “flea dirt” which is another name for flea feces. It is this flea dirt that pet owners should look for to see if their pet has fleas. Eggs are too small to see and fleas often move quickly making them hard to spot. Using a fine comb, comb your pet several times down their back, if you see a black pepper-like substance in the comb this is flea dirt and your pet has fleas.

Flea eggs hatch into larva (like tiny caterpillars) these larvae will then feed on the flea dirt shed into the environment. Once they have matured they can spin a cocoon around themselves to become a pupa. The pupae are the most resistant life stage the hard shell protects the developing flea from insecticides. The adult flea will hatch from its cocoon when conditions are ideal. They can detect vibrations and increasing carbon dioxide levels as a host becomes available. The first priority of the newly hatched flea is to take a blood meal ideally from a dog or cat but they will also feed on humans if nothing else is available. The number of hatching fleas has to be quite high for fleas to bite people. Within 24-48 hours of feeding the female flea will begin producing eggs and will not stop until death. The entire life cycle of the flea typically takes 4-6 weeks.

Prescription flea prevention products such as Advantage and Advantage multi should be started in the spring prior to the beginning of flea season. These products are very effective and once applied to the skin of your pet will kill adult fleas within 24 hours and last for 1 month. Other products such as Advantix contain insect growth regulators (IGR) that can kill the developing eggs and larvae as well.  Pet store products are not as effective because they will only kill fleas for a short time after application and therefore will not kill newly hatched fleas after their effectiveness has worn off allowing the cycle to continue.

The good news is if fleas are caught early all the pets in the house can be treated for at least 3 months with a prescription spot-on product and the environment does not need to be treated with insecticide sprays. It is a good idea to wash your pet’s bedding and thoroughly vacuum the house focusing on areas where your pet likes to hang out. This will decrease the number of eggs and larvae in the environment.   Discard the vacuum bag outside of the house. It is always best to avoid a flea problem by applying prescription flea prevention on all your pets from early June to November.