Dogs & fleas

To date more than 2500 flea species have been discovered worldwide, however the species you are most likely to find on your dog or in your home is the cat flea ( Ctenocephalides felis ).

Cat fleas unlike other fleas are not fussy feeders, they will feed off many animals, including us. The cat flea is reddish-brown in colour and approximately 3mm in size. They have tube-like mouth-parts adapted to feeding on the blood of their hosts. Their legs are long, the hind pair well adapted for jumping: a flea can jump vertically up to 7 inches (18 cm) and horizontally up to 13 inches (33 cm), making the flea one of the best jumpers of all known animals (relative to body size).

Fleas lay tiny white oval-shaped eggs. The larva is small, pale, has bristles covering its worm-like body, lacks eyes, and has mouthparts adapted for chewing. The larvae feed on various organic matter, especially the faeces of mature fleas. The adult fleas diet consists solely of fresh blood. In the pupa phase, the larva is enclosed in a silken, debris-covered cocoon.

Life cycle and habitat

Fleas go through a four stage life cycle, egg, larva, pupa, and adult flea. Adult fleas must feed on blood before they can become capable of reproduction.

The flea life cycle begins when the female lays eggs after feeding. Eggs are laid in batches of up to 20 or so, usually on the host itself, which means that the eggs can easily roll onto the ground.

Because of this, areas where the host rests and sleeps become one of the primary habitats for eggs and developing fleas. The eggs take around two days to two weeks to hatch, but they have been known to lie dormant for up to 2 years until conditions are right.

Flea larvae emerge from the eggs to feed on any available organic material such as dead insects, faeces, and vegetable matter. They are blind and avoid sunlight, keeping to dark places like cracks and crevices, also bedding. Given an adequate supply of food, larvae should pupate and weave a silken cocoon within 1–2 weeks after 3 larval stages. After another week or two, the adult flea is fully developed and ready to emerge from the cocoon. They may however remain resting during this period until they receive a signal that a host is near - vibrations (including sound), heat, and carbon dioxide from an animals breath are all stimuli indicating the probable presence of a host.
Fleas are known to overwinter in the larval or pupal stages.

Flea populations are evenly distributed, with about 50% eggs, 35% larvae, 10% pupae, and 5% adults. Their total life span can be as short as one year, but may be several years in ideal conditions. Female fleas can lay 5000 or more eggs over their life time, allowing for phenomenal growth rates.

Newly emerged adult fleas live only for about one week if a blood meal is not obtained. Optimum temperatures for the flea's life cycle are 70°F to 85°F (21°C to 30°C) and optimum humidity is 70%.

Dealing with a flea infestation

How to Apply Spot On Flea Treatments

Dog spot on flea treatments are extremely popular due to their high level of effectiveness and are often the easiest way to administer any form of flea treatment to your dog. Instructions for application may vary so you should always consult the instructions provided with the product.

  • Try to choose a time to apply your spot on flea treatment when your dog is comfortable and relaxed (before bedtime is often a good time), always avoid having to pin any animal down to get them still enough to treat as this will create a negative association and may make future treatments difficult to administer. Also avoid treating prior to a walk if it is likely to rain as the rain might wash the treating off before the dogs skin has sufficient time to absorb the treatment.
  • Also ensure any seal to treatment is broken before attempting to apply.
  • Part your dogs fur at the nap of the neck so you can see the skin underneath, it is the skin that you want to apply your spot on treatment too as this is how it is absorbed into the blood stream.
  • For larger dogs you will often find the dose of treatment needs to be applied on multiple areas, usually 2-3 spots further along the spine, if this is the case your spot on flea treatment instructions will direct you to do this.
  • Do not squeeze the treatment out too quickly. If it is not given a few seconds to be absorbed onto the skin and the fur surrounding it, the spot on flea treatment will roll off the animals coat and you will have only applied part of the full dose needed to fully treat/protect your dog.

Treating the home

Combatting a flea infestation in the home takes patience because for every flea found on an animal, there could be many more developing in the home. A spot-on insecticide will kill the fleas on your pet, and in turn your pet itself will be a roving flea trap and mop up newly hatched fleas. The environment ( entire carpet surface and all soft furnishings throughout your home, this means moving all of your furniture ) should be treated with a spray insecticide containing an insect growth regulator. Daily vacuuming whilst the problem persists is also necessary ( entire carpet surface and all soft furnishings throughout your home, this means moving all of your furniture ). Also make sure that you use a crevice tool at the carpet edge where it meets the wall. After every vacuum you must empty out your vacuum cleaner into a plastic bag of some sort, removing all of the dust from inside the cleaner, or remove the bag if using a bagged system. Tie the plastic bag up when finished and put into a rubbish bin outside of your home. Do not keep the bag in the home because although the vacuuming process will probably have killed the fleas, it will not have damaged the eggs. These eggs could still hatch and the larva could potentially escape the confines of the plastic bag and re-infest your home. Also ensure on a regular basis that your vacuum cleaner is sucking at maximum capacity by cleaning all filters. If your vacuum cleaner does not have a powerful suction it may have problems sucking up all of the eggs as their outer surface will stick quite well to carpet and soft furnishings. This entire process can take along time & become very tiresome. It's important not to give up and to stick to your flea destroying regime. Be sure to also vacuum & wash the dogs bedding on a regular basis and whilst your home is infested it's also a good idea to restrict your dogs movement around the home, as everywhere they go they could be distributing flea eggs. This will in turn reduce the amount of work that you have to do on a daily basis whilst the problem persists.