Scratching the surface: the life of the flea
The average lifespan of an adult flea is four to six weeks. During this time, a female flea can lay countless numbers of eggs – up to 40 eggs daily! These eggs are laid on your pet and then drop off, hiding in your carpet, furniture and in the cracks of your hardwood floors. After two to 12 days, the eggs will hatch into larvae and feed on the feces of adult fleas (which is also hiding in the same places, incidentally).
The larvae then go through two molting processes. After the second, the larvae spin a cocoon, where they live as pupae waiting for the chance to emerge to feed on an appropriate host. The pupa develops into a flea in the cocoon, but can lay dormant for many months while it waits for the perfect opportunity to come out.
When conditions are right (meaning that a flea detects the presence of your pet), it will emerge from its cocoon, find a host, and take its first blood meal. Once a female takes her first blood meal, she will begin to produce eggs within 24 to 48 hours and continue until she dies. Forty eggs per day for four to six weeks – that’s a lot of fleas, folks!
While the length of the flea’s life cycle varies depending on conditions, the average time it takes for the flea to grow from egg to adult is about three weeks.
So, why are fleas so bad? Well, to start, their saliva has histamine-like substances and antigens that can be extremely irritating to your pet’s skin, especially if they have a flea allergy. In dogs and cats who are flea allergic, just one flea bite can set off a cascade of events that leads to generalized itchiness and skin infection.
As I mentioned earlier, fleas also carry disease. From cat scratch fever and infectious anemia to tapeworms, fleas have the ability to make your pets very sick. In addition, fleas can also transmit disease to humans. Ever heard of the Black Death? Yep, bubonic plague was spread by fleas. And though uncommon, cases still occur in the United States every year.
Finally, fleas are blood suckers. This may not be important to a 150-lb. dog, but for a flea-infested kitten who weighs only 2 lb., the presence of fleas can be a death sentence. Fleas can consume enough blood to cause anemia and death in cases like this.
Fortunately, veterinarians have lots of tools at our disposal for combating them. Monthly oral and topical medications are quite useful for controlling the flea population at many different life stages. Some concentrate on killing adults, some on sterilizing them and some do both! Ideally, products that kill adults while also preventing them from reproducing are best. If you think back to the life cycle above, you know that even if an adult flea is killed, she could have already laid hundreds of eggs in your house that are just waiting to hatch!
There are so many products available to combat fleas that sometimes it is hard to know which one to pick. Rest assured – your veterinarian probably has a favorite. Stop by the clinic or give them a call to discuss your pet’s needs. If you’ve found a product somewhere other than your vet’s office, please be sure to call your vet to ask about it before applying it to your pet. Some over-the-counter products are potentially toxic for cats or ineffective at controlling fleas, so make sure what you apply is safe and effective.