Fleas and Flea Control




Fleas are most often seen during the warmer months but as we keep our homes nice and warm throughout winter, we see fleas all year round. Only a small part of the adult flea population actually lives on your pet. The fleas’ eggs and larvae live in the environment and can survive for up to a year, so it is important to not only treat your animal directly for fleas but also decontaminate the environment as well.  Wash your pet’s bedding using the hottest cycle and regularly vacuum/clean carpets. We do not recommend flea collars or flea shampoos alone as they fail to address the environmental flea infestation.


Fleas are tiny wingless parasites that survive by sucking blood from dogs and cats and any other warm blooded mammals including humans although they much prefer hairy hosts.


There are two types of fleas most associated with house pets:


  1. the dog flea Ctenocephalides canis; and
  2. the cat flea Ctenocephalides felis - by far and away the most common flea seen on pets in Australia; the ability of the cat flea to adapt to a wide variety of warm blooded hosts has enabled it to become the main flea causing problems in our environment.


The Flea Life Cycle.


Adult fleas live out their entire life on their chosen hosts, extracting and consuming the blood of the host in order to survive. Neither the cat nor dog fleas voluntarily leave their hosts. If forcibly removed from a host the dog flea can and will re-attach to a new host if given the opportunity to do so. 


Ninety-five percent of the flea's life cycle is spent in the environment. Only 5% of its life cycle is spent as an adult on a host where it eats, mates, reproduces, lives and dies.



Flea populations are evenly distributed with about 50% eggs, 35% larvae, 10% pupae and 5% adults.


Adult fleas only have about one week to find a host, attach and feed. Once they score a blood meal they can mate and reproduce. Eggs are passed out into the fur of the host and fall out into the environment where they hatch out into flea larvae. Flea larvae move around in the environment eating organic material such as dead insects, vegetable matter and the blood rich faeces of adult fleas. They are blind and avoid sunlight and dryness, preferring dark, moist places like bedding, sand, cracks and crevices (see picture to the right, above).


Given an adequate supply of food the larvae should pupate and weave a cocoon within 1-2 weeks. After another 1-2 weeks the adult fleas are fully developed and ready to emerge from the cocoon however they may lie dormant until the right stimuli signal the nearness of a suitable host to attach to.


Vibrations (including sound), heat and carbon dioxide are all stimuli indicating the presence of a possible host. Without such stimuli, fleas have been known to overwinter in the larval or pupal stages. The pupal stage is the most resistant stage to the impact of adverse environmental effects.


Eventually the pupae hatch and a new adult flea emerges into the environment ready to attach to any suitable passing host - its primary goal being to find a blood meal and reproduce. The life cycle then starts all over again.






  1. The flea is one of the oldest inhabitants of planet Earth having been around for more than 350 million years.
  2. In just 30 days ten female fleas can multiply to more than 250,000.
  3. Just one female flea can produce 400 - 600 eggs in a lifetime.
  4. In six summer months if all the offspring of one female flea survived they would produce 6,400 billion fleas. These offspring would cover an area of 64 hectares or if laid end to end span the Earth 32 times.
  5. The main breading ground in the home for fleas is the carpet, not the pet. Flea eggs do not remain on the animal.
  6. The flea is activated into adulthood by many factors: vibration, climatic conditions and the presence of carbon dioxide emitted from animals (including people) nearby.
  7. Pre-adult fleas in the pupal phase can live as long as 2 years before emerging as biting adults.
  8. Adult female fleas need to have a blood meal before they can lay eggs.
  9. Historically fleas have been carriers of such diseases as Bubonic Plague and Typhus.
  10. Fleas are the essential host of the flea tapeworm and animals are infected by the flea tapeworm when they swallow fleas.
  11. Copulation between fleas lasts between 3 and 9 hours.
  12. The ratio of male to female fleas on dogs varies from between 1:1.8 to 1:2.2. The greater the number of females may be due to their longer life span, the disparity of survival rates between males and females during immature stages, or the ability of female fleas to better evade the host's grooming activity.
  13. Flea eggs are pearly white, oval with rounded ends and are 0.5mm long.
  14. Eggs are produced by females within the first 36-48 hours of the first blood meal. Average production is 27 eggs/day over 50 days or 1,350 eggs/female/50 days. This is also the equivalent of the female flea's body weight in eggs per day.
  15. During the first hour of feeding newly attached females will exhibit a 40% increase in body weight due to filling of the abdomen with blood. Males only increase by 3% during the same time.
  16. From a starting weight of 045mg after emergence, female fleas reach a maximum size of 1.08mg within 48 hours, a 140% increase in size. Males start at 0.36mg on emergence and reach a maximum of 0.43mg, a 19% increase in body weight.
  17. Female fleas consume an average of 13.6 micro litres of blood/day which equals 15.15 x their own body weight. Over one day, 72 females would consume 1ml of blood - it's no wonder dogs and cats can become anaemic.
  18. When a flea bites it spits 0.004 cu.ml of saliva into the wound to prevent its meal of blood from congealing.
  19. As a flea prepares to jump, it crouches like a runner in the starting block, lowering its head and contracting its body, compressing an elastic-like clump of protein called resilin found near the base of the large hind legs while at the same time engaging hook-like "catches" in the fleas exoskeleton that prevent this resilin from expanding prematurely. The flea effectively "cocks" itself for it leaps, then at the right moment it releases the catches and literally fires off into a leap as the resilin snaps back to its original size.
  20. Lift off for a flea occurs so rapidly that the flea reaches peak acceleration of 140Gs - more than 30 times that endured by astronauts during the launch of the Saturn 5 moon rocket!! 



What are the initial signs of flea infestation?


Some signs that your pet may have fleas include:


  • Vigorous scratching, biting and hair loss, especially at the base of the tail, over the rump and along the back.

  • Restlessness.

  • Nervous chewing of the tail.

  • Tiny red bumps (flea bites), particularly on the hairless or glabrous areas of skin on the under belly and in the groin area. 

  • You may see fleas (especially over the rump and in the groin region)

  • It can be difficult to find the fleas, but it is relatively easy to check for flea dirt (blood rich faeces).  Simply moisten a cotton ball, part your pet’s fur and place the cotton ball on the skin over the rump. If the cotton ball takes on black specs surrounded by a reddish halo, this may be flea dirt and can indicate that your pet has fleas.

  • You can also purchase flea combs with teeth that are specially designed to trap flea dirt, fleas and flea eggs as they are combed through your pet's coat. These are useful diagnostic tools.



What problems do fleas cause?


Dogs and cats can have a reaction to flea saliva resulting in a skin condition called Flea Allergy Dermatitis or FAD. Treatment for FAD is complicated and a veterinary consultation is recommended. FAD is the single most common cause of allergies, particularly in dogs, accounting for 70% of all skin allergies seen in veterinary clinics. Fleas also transmit the flea tapeworm, and they can cause anaemia from blood loss. Small kittens and puppies can die from blood loss caused by severe flea infestations.


What are the symptoms of FAD?


  • Hot spots - distinct areas of irritated, angry-red weeping skin (known as pyotraumatic dermatitis).
  • Hair loss (alopecia).
  • Skin infections (pyoderma).
  • Puritic (itchy), crusty skin lesions over the rump and along the back, inside the thighs, on the under belly and flanks and around the neck.
  • Thickening and darkening of skin in areas where infections and hair loss have occurred.


Cats may also show evidence of symmetrical hair loss with little or no dermatitis; ulcers on the lips and the front of the nose (rodent ulcers); crusty plaque-like skin lesions (eosinophilic granulomas) or a combination of any of these. They may also show symptoms of a condition called miliary dermatitis - numerous reddened or crusted skin lesions along the back.



In the Goulburn district, FAD is mostly a seasonal disease predominately occurring in summer and peaking in autumn. Pets that live indoors during winter can suffer from FAD thanks to fleas wintering over inside nicely heated houses allowing them to continue their life cycles without interruption.


How can fleas be eliminated?


The secret to flea control is to carry out a good flea control programme that is tailored to suit the needs of your household. Factors to consider are:


  • How many pets and what type of pets do you own?
  • Do your pets live indoors, outdoors or both?
  • What sort of outside environment is presented by your yard?
  • What is the inside environment like?


Since the majority of the flea's life cycle is spent off the animal it is essential to tailor your flea control programme to take this into account. There are many products on the market for treating both your pets and their environments. Talk to our staff and we'll advise you on how best to approach flea control. Remember to include regularly worm for flea tapeworm as part of your worming protocol as well.


Maintaining a preventative control programme against fleas for your pets is not going to be particulalrly cheap but it will be worth the cost in terms of disease prevention and hygiene.


Warning: Some non-veterinary brands of flea treatments for dogs are potentially lethal when applied to cats. Always seek veterinary advice about the best flea treatments for your pet.


Please call us to discuss an appropriate flea control program for your pet.