Fleas are an annoying part of outdoor life. Fleas are commonly found in grasses (fields and your yard) and anywhere wildlife (including squirrels and rabbits) have passed. Fleas become a much more annoying part of your life when they move indoors.
Fleas can cause irritation to your pet as they live and feed on the pet. This feeding then causes itching. Of more serious concern, fleas can cause allergies to animals when they inject their saliva into the blood stream of the animal being bitten. This causes intense itching and self-mutilation. Fleas also carry diseases. They can carry tapeworms, an intestinal worm, which infect animals when the dog or cat ingests the fleas. In certain parts of the country, fleas can also carry blubonic plague. If puppies or kittens have a large infestation of fleas, the puppy or kitten can become anemic or even die.
Dealing with fleas can be a very frustrating ordeal. It is important to understand how fleas live to effectively kill and control them. Adult fleas are frequently seen feeding on animals. Also easily found on animals is the evidence of flea infestation – “flea dirt”. Flea dirt is actually digested blood, which is flea feces. It can be combed off the pet with a flea comb and, in some cases, petting causes the dirt to fall of the pet. After a female flea has taken a blood meal, she can lay up to 50,000 eggs per day. Eggs are laid in the environment of the pet, not on the pet. Flea eggs will hatch about every two to three weeks. Once the egg hatches, the flea goes through two larval stages (caterpillar like stages). The flea then encases itself in a pupa case before emerging as an adult. The adult flea feeds on blood. The larval stages feed on flea feces and shed skin cells in the environment. Fleas need temperatures between 55 and 90 degrees Farhenheit and 50% to 92% relative humidity in order to survive and reproduce. The pupal stage is the only life stage that cannot be killed or controlled.
In the past, pyrethrins (also called organophosphates) were the only tool available to fight fleas. These chemicals were first developed in the 1940’s. When first formulated, they worked well. Pyrethrins can be toxic to dogs and cats, especially cats. Pyrethrin toxicity causes neurologic and respiratory disease; even death. When pyrethrins were the only products available for flea control, the toxicity seemed an acceptable risk in order to have good flea control. Over time, fleas have developed resistance to these chemicals so that they no longer kill fleas. If used in stronger concentrations, these chemicals can be a bit more effective; however, the higher concentration of pyrethrins cause a greater risk of toxicity for your pet. Most of the over-the-counter flea products today are formulated with pyrethrins. Due to the pyrethrin resistance of fleas, for these products to be effective an insect growth regulator should be added. Due to the toxicity risk to your pet, pyrethrin chemicals should be used with great caution and never used in animals less than 12 weeks of age.
There are many types of flea prevention out there for your pet and finding the right one can be a bit of a challenge. Not everyone has the same circumstance or the same pet! Advantage Multi (for cats) is also topical done once monthly and protects against fleas, heartworms, ear mites, hookworms and roundworms. Revolution is a topical product applied once monthly that is available in both canine and feline options. Revolution Feline protects against fleas, ear mites, hookworms and roundworms. Frontline Plus is a topical monthly product that protects against fleas, ticks and chewing lice.
In the recent past, newer types of chemicals have been developed to help control fleas. Fipronil, selamectin and lufenuron work in different manners from pyrethrins to kill fleas. These new types of flea control are known as Frontline, Revolution and Sentinel; are monthly methods of flea control. Frontline has also added an insect growth regulator (IGR) to the Frontline Plus to help achieve some environmental control. Frontline and Revolution have fewer side effects and health risks due to their affects only on fleas’ nervous systems; not on pets or humans. Sentinel works as a “birth control for fleas”, it does not kill adult fleas, but keeps them from reproducing, thus preventing a population explosion. Over time, fleas may develop resistance to these products as they have with pyrethins. It should take years for this resistance to occur.
Controlling fleas involves not only killing the adult flea stage but also controlling the environment (where the larval and egg stages are vulnerable). The main component of flea control is the adult flea-killing product. Scientists have developed different chemicals to act as insect growth regulators (IGR); these chemicals can either affect the egg’s protective layer or the larval life cycle. The IGRs stop the flea life cycle by either destroying the egg or killing the larva. The IGRs can be added to either flea-killing products for on your pet or for in the environment. The insect growth regulators should not be relied upon as a sole flea control program. Environmental control involves frequent vacuuming. After every vacuuming, the bag should be discarded. Loose bedding or area carpets should be washed in the hottest water setting for these items. Control of fleas should be focused on areas where the animals habitually rest, as that is where the highest concentration of eggs and flea feces will be found. However, the entire living area does also need to be treated. Since fleas do not like the vibrations from foot traffic, fleas, eggs, larva and pupa are usually found along the periphery of rooms, under furniture and in cracks and crevices of flooring. These are the areas that should receive the heaviest application of flea control products. When choosing a product to apply in the environment, micro-encapsulated formulations will allow the product to remain effective in its killing ability for longer periods.