How Flea Treatment Works on Cats

Fleas are of course a complete nuisance for cats as well as us owners!

Unfortunately there’s more than a fair chance that your cat will at some point become infected by these infuriating little critters.

So what kind of flea treatments are available.

So what kinds of flea treatments are available?

Cat Flea Treatments

Mercifully, there are numerous treatment options available, including over-the-counter and prescription medications.

You’ve also got natural flea remedies although these tend be more for relief rather than prevention.

Here’s a run-down of the most effective products.

Topical Flea Treatment

Also known as spot-on treatments, topical flea treatments come in liquid form and are applied to the skin and hair of a cat.

They’re applied to the back of your cat’s neck or in other areas that are hard for the cat to reach, killing the fleas on contact.

Easy to use, but also toxic, they provide effective protection against fleas and ticks for up to three months.


  • Kills adult fleas on pet’s body
  • Prevents future infestations
  • Easy application
  • Affordable


  • Doesn’t kill eggs or larva
  • Poisonous when ingested
  • Can cause side effects such as allergic reactions or skin irritation

Buy at Amazon

Spray Treatments

Flea spray is a convenient way to control fleas on your cat. It’s a kind of topical solution that you apply directly on your cat’s skin.

They’re typically made from natural ingredients such as diatomaceous earth which is also known as DE.

DE has been found to be an effective way of killing not only adult insects but their eggs and larvae too.

There are two kinds: homeopathic flea spray and insect growth regulators. They are safe for pets and humans.

Homeopathic Flea Sprays contain ingredients such as garlic and thyme extracts that can be used to repel the fleas from your bedding or furniture.

IGRs (Insect Growth Regulators) prevent eggs from hatching into larvae. Their effects can last up to a month and can prevent further exposure.


  • Some versions can also be used on furniture, carpets and upholstery
  • Applied directly
  • Kills  adult fleas and larvae
  • Inexpensive


  • Can cause eye irritation in cats

Buy at Amazon

Cat Flea Collars

Cat flea collars are a popular way to combat fleas and ticks. The collar works by releasing insecticide over the cat’s fur and skin. This kills any insects that come into contact with the cat, preventing them from biting or laying eggs on the animal in order to reproduce.

There are generally two types of flea collars. Repellent flea collars and treatment flea collars.

Repellent flea collars work by releasing a toxic gas (usually pyrethrin or permethrin) that kills the flea when it bites.


  • Easy to  use
  • Affordable
  • Non toxic for pets and humans
  • Last up to 12 Months


  • May cause side effects such as skin irritation
  • Don’t provide protection against ticks and mosquitoes

Buy at Amazon

Oral Cat Flea Treatments

Oral flea treatments usually come as chew-ables, pills or liquids. Some of these treatments work by transmitting the insecticide/medication to the fleas when they bite, which ultimately kills them.

Others work by preventing eggs from developing into adults through a hormone growth regulator.

Chewable pills are popular variants that provide a quick and easy way to kill your cat’s fleas. The treatment tends to start working within 30 minutes of ingestion.

Liquid treatments are also widely used, especially with owners whose cats dislike ingesting pills.

Oral cat flea treatments can provide fast relief from flea infestations in cats. They’re less likely to cause side effects when compared to topical treatments.

They can however be expensive and are not always effective, so there’s a chance that the fleas will continue to inhabit the cat’s fur. In addition, some of these treatments can cause gastrointestinal issues such as vomiting and diarrhoea.


  • Fast relief
  • Easily administered (added to cat food)
  • Can be a safer option than topical  treatments


  • Expensive
  • Can cause side effects such as vomiting and diarrhoea

Buy at Amazon

Shampoo Cat Flea Treatments

A cat flea shampoo typically contains one or more insecticides and a surfactant. The insecticide kills the insects while the surfactant helps spread it over the cat’s fur.

Some owners use it as an alternative to applying a pest control product in their own home, which itself can be expensive and time-consuming.

When used alongside other cat flea treatments, shampoos can prove very effective. Cat flea shampoos are usually sold in the form of a liquid and are applied to the cat’s fur or skin.

However, it’s very important to use a shampoo made specifically for cats – feline versions are designed to be gentler on cats’ sensitive skin than those intended for humans or dogs.


  • Relatively inexpensive
  • Kills fleas on contact
  • Effective when used with other treatments
  • Can be repeated weekly


  • Can cause allergic reaction
  • Needs time to dry

Buy at Amazon

Useful Links

Common Fleas of the United States
Fleas – A Source of Torment for Your Cat
Flea Control in Cats

About the author