Macarthur Veterinary Group
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Flea Control

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Fleas are a serious health problem to both dogs and cats. Apart from the obvious pain and irritation of flea bites, fleas suck blood, carry other parasites and can also lead to a serious skin problem known as Flea Allergy Dermatitis. Commonly know as “eczema”, this is the most common skin complaint we see in dogs and cats and one of the most distressing. In fact, fleas cause more skin problems in dogs and cats than all other causes put together. And your pet may be suffering from flea-related dermatitis even if you think they have no fleas!

The Flea’s Life Story:

Flea control is possible. It just takes an understanding of the life cycle of the flea, and how you can stop it.

When an adult flea first jumps onto your pet, it must take a feed of blood before breeding and laying eggs. Having done this, it continues to bite and feed regularly, and can lay up to 50 eggs per day. Whilst an adult flea will normally have only a short life, it can easily lay several hundred eggs. These eggs fall into the bedding, carpet or grass, concentrated into the areas where your pet spends the most time.

You generally can’t see the tiny white eggs. The small black specks that you may see in your pet’s coat are actually faeces (flea poo).

Within just a few days, a small hairy larva will hatch from the egg. The larvae live deep in the base of the carpet/grass/bedding, feeding on organic material like crumbs and flea faeces. They later form a pupa (cocoon) in which the new adult flea develops. The pupa provides great protection for the flea, hidden deep in the carpet or grass and resistant to insecticides. Under the right conditions a new adult flea will emerge from the pupa. This requires warmth, humidity and vibration - created by the movement of animals or people. The new adult flea detects a passing animal and jumps on. The whole life cycle then starts over.

Fleas are usually a much bigger problem in summer. They don’t live longer or bite any more often, but they do breed much faster, so there’s lots more of them! In the heat and humidity of summer (or heated indoors in winter), the whole life cycle can take as little as 3 weeks, and just a few fleas can breed into thousands. Outdoors in winter, the pupa may lie dormant for several months, but they are growing in number all the time, ready to hatch when the conditions are right.

Adult fleas only make up 5% of the fleas’ population that exists in your home. So, you’ll see that the adult fleas on your pet are actually just the tip of the iceberg.

So, how do you stop them?

For effective flea control, you need to do two things:

  1. Kill the adult fleas on your pet(s).
  2. Control the immature stages in the environment. It’s vital to treat all dogs and cats in the household (even if they don’t appear to have any fleas).

We’ll first discuss the various types of products that can be used to achieve these two goals. Then we help you to gauge the severity of your flea problem and recommend which product(s) to use in your situation.

Immature stages in the environment can be very difficult to kill. It is important that you wash your pet’s bedding regularly. Environmental sprays and flea bombs may be required in severe cases. But usually it is preferable to use a product on your pets (all of your pets) that can stop the fleas from breeding and/or kill flea eggs and larvae in the environment.

Insect growth regulators are birth control for fleas - effectively sterilising the female flea & ensuring that the eggs will never hatch. But they don’t kill adult fleas, or prevent an untreated (hitch-hiker) flea from feeding and laying fertile eggs on your pet. Some of the better insecticides will be shed with your pet’s hair into their bedding, and can then kill eggs and larvae in the environment – as well as the adult fleas on your pet.

To kill the adult fleas on your pet, you need to apply an insecticide. The most effective products are safe, kill fleas quickly and have a long residual action (which means they continue to kill fleas long after they are applied).

We recommend

  • Bravecto (3 monthly chew) for dogs or
  • Activyl (monthly spot-on) and
  • Advocate (monthly spot-on) for cats.

Benefits of these products:

  • Bravecto only requires administration every 3 months and also protects against ticks.
  • All kill 90-100% of fleas within 8-12 hours
  • Spot-on’s are easy to apply – a small amount of liquid is applied on the back of the neck
  • All help to break the flea life-cycle by controlling the environmental stages: 
    • Dead fleas don’t lay eggs!
    • Small amounts of spot-on products are shed with the hair to kill larval stages in the environment. 

How severe is your flea problem?

Mild: You can't see any fleas on your pet or they have only the occasional flea or flea dirt. Scratching is rare.
Moderate: You can see some fleas and flea dirt (and there’s sure to be a lot more that you haven’t seen).
Severe: You can see a lot of fleas on your pet. In very severe cases, fleas may also bite humans in the home.
Flea Allergy Dermatitis: Scratching/biting is severe because your pet has an allergic reaction to flea bites. You may not see any fleas on your pet. But just one flea bite every 1-2 weeks can keep them scratching all the time. Dogs may develop hair loss and dermatitis especially on the rump and the backs of the hind legs. Cats may develop small scabs over most of the body.

Note: The level of scratching and biting is not a good indicator of the number of fleas on your pet. Some animals may have lots of fleas and show few clinical signs, whilst others develop an allergy to flea bites, and scratch continuously from very few fleas.

Recommended Flea Control Programs:

For the majority of pets, our standard product recommendations: (Advantage, Advocate Revolution) will be all you’ll ever need! But in some cases we may tailor a flea control program using the best product(s) to suit your pet’s needs and your budget.


Most dogs receive an annual heartworm injection so the most effective and affordable way to control fleas is with Activyl or Bravecto.

Activyl is a monthly spot-on applied to the back of the neck, for dogs and cats. It’s new to Australia so fleas have not developed any resistance.

Bravecto offers 3 months protection with a single tasty chew which also kills paralysis ticks – great for travelling with their owners to the beach, Hawkesbury or Blue Mountains on weekends where deadly paralysis ticks are prevalent. Bravecto cannot wash off so is ideal for dogs that swim or are washed regularly or are being treated with medicated shampoos. It is ideal to time dosing to the same day as 3 monthly worming.  Download a reminder app to your phone today!

For those owners preferring a monthly all in one product for their dog treating heartworm, fleas and intestinal worms (except tapeworm) monthly Advocate or Panoramis can be used instead.


Advocate is applied monthly to the skin on the back of your cat’s neck.  It kills adult fleas and larvae, prevents heartworm, lungworm and controls most intestinal worms – not tapeworm. It is more cost-effective than using both a flea-only preparation and a separate oral tablet every 3 months to control intestinal worms. For owners preferring a tablet for cats – monthly Comfortis can be used instead.

Severe Flea Problems

For heavy infestations, rapid relief can be obtained using oral Capstar tablets. This kills adult fleas rapidly within half an hour but fails to prevent reinfestation.
For indoor pets, you should vacuum the house thoroughly including all carpets, crevices and furniture fabrics to reduce the larvae and egg burden in the environment. Then treat the house with several flea “bombs”. Be sure to treat under the furniture.
For outdoor pets prevent access to underneath your house which may be a perfect breeding ground for fleas and regularly mow your lawn. In severe flea infestations, outdoor fumigation may be required. If this is the case be sure that an insect growth regulator is included in the preparation used, or flea eggs and larvae will soon repopulate your yard.

Flea Allergy Dermatitis

Seek veterinary attention as your pet is in a lot of discomfort and needs diagnosis and medical treatment. In these cases it is not sufficient to simply control the fleas.

Alternative Flea Products

  • Capstar tablets provide the fastest way to kill fleas on your pet. A single dose will kill fleas on your pet within 30 minutes, but it has no residual action so we recommend it only if used in conjunction with a residual monthly or quarterly product.
  • Comfortis is a monthly chewable tablet that rapidly kills fleas in dogs and cats.
  • Advantage is a monthly spot-on. Kills adult fleas and larvae on dogs and cats.
  • Panoramis is a monthly chewable tablet for dogs that kills fleas, prevents heartworm and controls most intestinal worms – not tapeworm. 
  • Frontline Plus is another monthly spot-on. It kills adult fleas and contains an insect growth regulator..
  • Frontline Spray is safe to use in puppies and kittens from 2 days of age. It requires diligent application all over your pets’ coat.
  • Sentinel Spectrum is a monthly flavoured tablet for dogs – it stops fleas from breeding, prevents heartworm and kills intestinal worms.  Sentinel does not kill adult fleas.
  • Revolution is a monthly spot-on for both dogs and cats. It kills adult fleas, larvae and eggs, also prevents heartworm, and controls intestinal worms in cats but not dogs
  • Permoxin concentrate (for dogs only) can be used as a rinse, or diluted to make up a flea spray.  . 

Products we do NOT recommend

Flea collars, flea powders, wool-wash, any shampoo or rinse containing organophosphates, eucalyptus or tea-tree oils; supermarket spot-ons and tablets containing cythioate or garlic are not recommended.

Important things to remember:

  • Prevention is better than cure!
  • Treat all dogs and cats in the household.
  • Use a product that treats the environment too, but don’t expect a “quick-fix” to severe infestations.
  • You may see occasional fleas even after treatment. None of these products are flea repellents – a flea needs to jump on your pet before being affected by the insecticide. But they will not survive for very long!
  • Maintain flea treatment all year round.
  • With central heating in many houses, it might as well be summer all the time!
  • Carefully read and follow all product directions.
  • If in doubt, ask us for advice.