Every cat or dog will be visited by fleas during their lifetime. They jump onto a host to feed on their blood and will mate here with the eggs dropping off into the environment. Eggs hatch after 2 to 14 days producing larvae which will feed on skin debris, flea droppings and other organic matter. They will pupate after approximately 1 week and remain in this state for approximately 10 days although this can vary depending on environmental conditions. The flea will then wait for a sign that a host is nearby before emerging to feed. Only 5% of the flea lifecycle is represented by adults the remaining 95% is made up of larvae and pupae living in the environment.
There are many different types of flea with the most common being the cat flea Ctenocephalides felis. This does not just feed from cats as its name suggests but will parasitize dogs as well. It is not uncommon for people to be bitten by fleas and some experience a reaction to flea bites in the form of an itchy red spot often on the legs or ankles. Some pets develop flea allergy dermatitis where a single flea bite can set off an allergic reaction in the skin causing the animal to become intensely itchy and develop small lesions over their body. It is therefore very important in these individuals to keep up to date with an effective method of flea control.
Fleas don’t just cause irritation they can carry and transmit diseases harmful to humans such as Bartonella henselae a bacteria which causes mild flu like symptom and Rickettsia species which are bacteria that can cause a fever and skin rash. Fleas can also be responsible for the transmission of a particular species of tapeworm so it is advisable to treat for worms if evidence of fleas is found on your pet.
Finding evidence of fleas
Just because an adult flea has not been seen does not mean your pet does not have fleas. It is more common to see the evidence left behind than the adult flea itself. You are looking for small black specks in the coat which turn red brown colour when placed on white paper and dampened with water. The red brown colour suggests the presence of digested blood which is the main component of flea droppings. If the black speck turns grey then this is probably dirt picked up in the garden. The presence of flea dirt in the coat indicates a need to treat for fleas before the population in the environment increases to large numbers.
Treating for fleas
There are a large number of products available which either kill fleas or prevent them breeding.
Shampoos: Generally only effective whilst on the animal. Tend not to offer sufficient lasting protection and will not kill the life stages in the environment.
Collars: Often rely on the flea coming into close proximity to the collar to get a dose. Does not kill life stages in the environment.
Spot on treatments: A large range is available and their effectiveness is determined by what the treatment is made up of. Prescription treatments available from veterinary surgeons can be effective against the life stages in the environment and should always be used in cases of heavy flea infestations or animals with allergies.
Sprays: Effectiveness is determined by what they contain. The person applying the treatment is often at risk from inhaling the spray and so safety precautions should be taken. These can often be difficult to apply if the pet is uncooperative. They are not effective against life stages in the environment.
Tablets that kill fleas: Are often effective for as long as the components of the tablet are in the body. After 24 hours the liver and kidneys may have broken down and excreted the active ingredients of some preparations so protection can be short lived. Has no effect on the life stages in the environment and pets can be easily reinfested. Can be useful when moving a pet into a new environment where no fleas are present to prevent the pet bringing fleas with them.
Injection: Only available for cats from veterinary surgeons. Does not kill fleas but prevents them from breeding for up to 6 months. Can safely be used at the same time as other flea preparations and prevents the build up of life stages in the environment. Also available in an oral form which is effective for 1 month.