Flea Control & Treatment for Pets

Did You Know?

  • Fleas have been around for over 100 million years.
  • Some fleas can jump more than 150 times their own body  length – a distance of about 33cm – the same as you jumping  over a sky-scraper.
  • The female flea can lay 2000 eggs in her lifetime – that’s about 30-40 eggs every day.
  • The female flea consumes 15 times her own body weight in blood daily – the same as you eating the equivalent of a whole cow every day.
  • Adult fleas can bite your pet up to 400 times a day.
  • A flea can hatch from its cocoon, jump onto your passing pet (or you) and start feeding in as little as 7 seconds.


If you see a single flea on your pet – your pet has a flea problem! The flea population is typically made up of 50% eggs, 30% larvae, 15% pupae and only 5% biting adult fleas. So even one flea can represent a small infestation.

Fleas are laid loosely in the fur of your pet and drop out where the animal rests, sleeps or nests (such as in carpets, rugs, furniture, beds, kennels). The eggs hatch in 2-14 days into larvae. The larvae feed on dried adult flea faeces (which consist of dried blood sucked from your pet or yourself!), dead skin, hair feathers and other organic debris. The larvae pass through three stages before pupating within a cocoon.

The adult flea is able to hatch after about 5-14 days, or can stay resting in the cocoon until it detects vibration (pet and/or people movement), pressure (pet or person sitting/lying on them), heat, noise or carbon dioxide (from your breath) which stimulates the flea to hatch. This is why sometimes if you go away on holiday and come back into the house there is a plague of fleas as they all hatch as you re-enter the house! (in just 30 days, 10 female fleas under ideal conditions can multiply to over a ¼ million in different stages of the life cycle).

Adult fleas cannot survive or lay eggs without a meal of blood, but may hibernate from two months to one year without feeding, before they emerge from their cocoons. Once they have hatched, they must feed within a week.  An adult flea’s primary goal is a blood meal and to reproduce.

Fleas are a nuisance, causing skin itching and irritation which can lead to your pet scratching and biting to try resolve the itch. Some pets are also allergic to flea saliva resulting  in severe skin irritation and rashes on your pet.

Dogs and cats can also get tapeworms by swallowing a flea infected with a tapeworm larvae. A dog or cat may swallow a flea while self-grooming. Once the flea is digested inside the dog or cat, the larval tapeworm is free to develop into an adult tapeworm. By controlling the flea population you can help prevent your pet from getting tapeworm. 

Flea control is better than flea treatment. The most common skin disease our pet vets see is flea allergy dermatitis, but if we all work together it doesn’t need to get that far. Flea control is a challenge for both pet vets and owners. While adult fleas cause the clinical signs, the majority of the flea population (eggs, larvae and pupae) is actually to be found off the pet and in/around the home environment. Therefore, it is best to use a flea control programme that targets all stages of the flea life cycle rather than a flea treatment just for the adult fleas on your dog or cat. Please also note that flea infestations and tapeworms very often go hand-in-hand. Therefore, it is likely you'll also need a worm treatment.

Understanding flea control: life cycle of the flea.

  • Eggs are laid in your pet’s coat and fall into their environment. 
  • Larvae, which feed off of ‘flea dirt’ from adult flea faecal material, develop and spin cocoons.
  • Pupae develop. They can lay dormant for many months until they emerge as adult fleas.
  • Adult fleas are free to infect their host. Once they have a blood meal they will only last a limited time. However, during that short period they produce many more eggs to start the infectious process again.

Understanding flea control: flea facts.

In favourable conditions the entire life cycle can be completed in as little as 2 weeks.

  • 95% of fleas are in the environment.
  • Fleas lay 200 eggs in a short life period/their body weight in eggs per day.
  • Fleas consume 15 times their body weight in blood daily.

Why flea treatment is so important: flea effects on your pet.

  • Flea allergy dermatitis (FAD)
  • Discomfort & restlessness
  • Obsessive cleaning which can become a behavioural problem
  • Tapeworms
  • Anaemia in debilitated and young pets
  • Death in severe cases

Determining whether your pet needs a treatment for fleas: what to look for.

Determining whether it’s time for a flea treatment is simple because fleas are easy to find. Your cat/dog may show obvious signs of discomfort (i.e. scratching, restlessness and excessive grooming). Flea allergy dermatitis (FAD) often appears at the base of the tail but can be a more generalised skin abnormality which can lead to infection. It can take as little as one flea bite to set up an allergic skin reaction. If your pet does suffer from FAD it is essential they live in a flea-free environment. Allowing fleas to bite causes great discomfort and can be expensive for you.

In smaller numbers fleas are more difficult to spot as they’re particularly quick and agile. Cats in particular are very thorough at removing fleas which doesn’t solve the FAD problem for them though. What you can see is often the ‘flea dirt’ (faecal matter from adult fleas containing digested blood). It looks like a fleck of dirt. But when you lay these flecks onto a sheet of white paper and wet the paper, the flecks dissolve, leaving a red/brown residue.

Flea Control.

Flea control is a matter of year-round treatment as they are a problem any time of the year, particularly in our carpeted and heated homes where conditions are optimal for flea development. However, our pet vets always see a higher demand for flea treatments from early spring through to autumn, peaking in the summer months. Preventing flea infestation with flea control is always better than flea treatment alone. As only 5% of the flea population are adults on your pet, there are actually another 19 fleas somewhere else for every flea you see!

An effective flea control treatment involves 3 steps:

  • Flea treatment for the affected pet with a reputable product
  • Flea treatment for all other pets even if they don't show signs of infestation
  • Flea treatment for your house and environment

Flea control: are spot-on flea treatments effective?

Insecticide flea treatments applied to pets are designed to kill adult fleas. Be aware though that many products have limited effectiveness because they only work for a few hours after application. This is a particular problem with flea powders, washes and supermarket spot-on sets. They kill the adult fleas present on your cat or dog at the time of application but have little or no residual effect on eggs which are already in the environment and about to hatch. These flea treatments may be of use for pets which have a massive infestation but should not be used as the only solution. While they are attractive in price, they are not effective and therefore a waste of money. Furthermore, most of these flea treatments are based on organ-phosphate which isn’t good for the environment or your pet and can be harmful to humans.