Fleas are an ongoing problem in dogs and cats, not only in summer but in the cooler months as well, despite the development of newer, more effective flea treatments in recent years.
The reason this is the case is because of the flea’s life cycle. Adult fleas live on dogs and cats and lay eggs. The eggs fall off the host and end up in the environment where they hatch into larvae. After a few months the larvae spin a cocoon and become pupae. Pupae live deep in the carpet pile or deep under organic debris allowing them to be protected against flea sprays as these don’t generally reach this deep. Adults are attracted to stimuli such as body temperature or movement and emerge from the pupae when a potential host passes by. Once the adult flea has found a host it begins to feed almost immediately. Mating occurs on the first day and egg production starts soon after. One flea can lay over 2000 eggs during their life. Adult fleas are dependent on their host and can only live off the host for a short period of time.
The life cycle of the flea is very dependent on climatic conditions. In general, a temperature of 23-25 degrees and 78% relative humidity is optimal for the various stages of the life cycle. Very high temperatures (higher than 35 degrees) or very cold temperatures (under 0 degrees) and very dry conditions (relative humidity of less than 50%) are quite detrimental to the flea development.
Inside most homes climate control, heating and related humidity favours the survival of the flea stages, even in winter. Outside the home, shady, moist areas under bushes and under the house, especially with plenty of organic matter that the larval stages live off can harbour many stages of the flea, whereas in open grassy areas with strong persistent sunlight the immature stages can’t survive.
FLEA CONTROL STRATEGIES
In case of persistent flea infestations a complete flea control program should be implemented. This involves:
· Treatment of the infested pet
· Treatment of ALL contact animals
· Thorough treatment of the environment (indoors and out)
In order to:
· Eliminate newly emerged fleas
· Inhibit the immature life cycle stages
· Provide continual control of emerging fleas
CONTROL STRATEGIES FOR YOUR PET
Ideally, a combination of Insect Growth Regulators and Adulticides is used.
Insect Growth Regulators (IGR’S) play an important role in breaking the life cycle of the flea by acting as a “flea contraceptive”. The eggs, when affected by IGR’s, won’t hatch, therefore preventing a new generation of fleas to emerge. Unfortunately, there is no effect on the adult fleas so if fleas are present adulticides must also be used. For IGR’s to be effective all animals sharing the same environment must be treated otherwise viable eggs will still be able to hatch and complete the life cycle resulting in a continued source of environmental contamination.
For dogs a monthly IGR tablet is available called Program. The same monthly product is also available combined with a heartworm preventative called Sentinel. Frontline Plus top spot contains an adulticide and egg killer. For cats Program is available as a monthly liquid or a 6 monthly injection. Program and Sentinel need to be given with a full meal for the IGR to be properly absorbed into the body. (Program products will be ordered in for you on request).
Various adulticidal products are available to kill the adult fleas on your pet, ranging from shampoos, powders, flea collars to the newer, better sprays and spot ons as well as some oral products (tablets).
Frontline Plus is a liquid that is applied onto the dog or cat’s skin at the back of the neck. It soaks into the skin and then spreads throughout the whole coat. It works as an adulticide and has a second ingredient that kills eggs and larvae as well. It can be applied every 2-4 weeks and all animals in a household should be treated for the best result. It also controls paralysis ticks if used every 2 weeks (Note: nothing protects 100% so regular tick searches are still very important).
Advantage is a similar spot on application. It kills adult fleas on your pet and kills larvae in the pet’s environment. It can also be used every 2-4 weeks as necessary and is safe for rabbits and ferrets as well. It also controls lice in dogs.
Advantix is advantage with an extra ingredient that repels biting insects, and if applied every 2 weeks it also controls paralysis ticks – this product is only for dogs, not cats!
Revolution is another spot on product that targets fleas. It kills adult fleas on your pet as well as the flea eggs and larvae in your pet’s environment. It also controls heartworm, ear mites, sarcoptic mange. Revolution for cats also controls roundworms, hookworms and (indirectly) tapeworms.
Advocate is another combined treatment that targets fleas and also controls heartworm, intestinal worms and mites.
Other spot on products are available from pet shops and supermarkets. Usually these contain the old fashioned ingredients that a lot of fleas have become resistant to and therefore are not usually quite as effective as the products mentioned above.
One quick acting oral adulticide is Capstar. It is available for dogs and cats. The big advantage of Capstar is that it starts killing adult fleas in about 15 minutes. Unfortunately it gets metabolised rapidly by the body so one dosing only works for one day. It has its place as an added knockdown in combination with the longer acting products such as the ones mentioned above.
Comfortis is a tablet for dogs that, given with a meal will kill fleas for up to 1 month. It can be used in conjunction with some other top spot treatments.
Panoramis is a monthly tablet that kills fleas and controls Heartworm and most intestinal worms.
Activyl is the newest product on the market. It is a spot-on monthly product, for dogs and cats that kills fleas on contact. It gets activated by the toxic ingredient inside the flea so it is safe for us and our pets.
Permoxin is a spray or rinse, ONLY FOR DOGS that kills fleas and ticks and also works as an insect repellent. It is safe enough to be used on a daily basis. Depending on the flea burden, treatment routines will range from daily to weekly. For tick control, weekly rinse treatments are necessary but don’t forget the daily tick searches. Permoxin comes in a concentrate, and may be an economical way to treat your dog, a bit more time consuming than spot ons.
Flea shampoos have no residual effect, in other words, they will kill the fleas on the pet during treatment but the pet will soon be reinfested from the environment. They can usually only be used once a week, so on their own are not a sufficient flea control program. In cats, make sure to use a product that is safe as some dog flea shampoos can be detrimental to cats.
Flea collars generally contain a repellent and an adulticide product to reduce the flea burden on your pet. Unfortunately flea collars are located on the neck and their effect may not completely reach the back part of your pet. Fleas have developed resistance to most of the “old fashioned ingredients” used.
Flea Powders have more of a repellent effect than a true adulticide effect and are no longer considered effective flea control products. These products were the first developed products against fleas and over time fleas have developed a resistance.
ENVIRONMENTAL CONTROL STRATEGIES
· Mechanical removal of flea eggs and larvae is possible through repeated vacuuming of carpets, furniture, floors and skirting boards. The higher the density of carpet pile, the less effective the vacuuming will be.
· Steam cleaning is more effective than normal vacuuming.
· Floors should be mopped with special attention paid to cracks and crevices where organic debris and flea eggs accumulate.
· Wash the animal bedding in hot water for at least 60 degrees for a minimum of 10 minutes. Don’t forget the bed sheets if your pet sleeps on your bed.
· Aerosol foggers and sprays can be used to treat the environment. Choose a product that has both an adulticide flea killing effect and an IGR to prevent flea eggs from hatching. We recommend Indorex, a spray that kills adult fleas for up to 3 weeks and protects the sprayed area for up to 12 months against the emergence of fleas from eggs and larvae.
· In case of a high environmental contamination it may be most effective to get a professional pest control person in to treat the area using both adulticides and IGRs.
· Flea stages can only survive in moist shady organic areas outside and attention should be given to these areas.
· Remove organic material (the larval food source) by mowing, raking and discarding the debris, especially in areas with no direct sun exposure.
· Pay close attention to areas where your pet rests such as under the veranda or inside a kennel. These areas can be sprayed with products containing residual insecticides and photostable IGR’s, make sure not to contaminate waterways and the surrounding environment or get professional pest control people in to treat the area.
WHAT IF FLEAS ARE FOUND DESPITE FLEA CONTROL?
In most cases we’re not dealing with product failure due to developing resistance but several scenarios are more likely to blame.
· Pupae can lay dormant in the environment for up to 184 days and won’t all emerge at the same time. The newly emerged fleas will jump on to the pet and if spotted by the owner before they are killed by the adulticide the owner may believe the flea product used has failed.
· Environmental contamination from non-treated animals e.g. neighbours pets or rodents entering your pets domain is possible in some cases. In this case the focus needs to be on environmental treatment of the sensitive outdoor areas such as moist/sheltered garden areas or under the house.
· Incorrect use of the flea control products can lead to a breakdown in adequate flea control. The main problems here are usually:
Extending the treatment intervals beyond the advised application frequency, errors in application methods e.g. using less product than advised, either calculating insufficient spray amounts or sharing pipettes between pets or using the wrong size of spot on for the pet’s weight and not treating all animals in the household. Excessive washing or swimming may also reduce the duration of the activity of a flea product.
If you have any concerns regarding the flea control on your pet/s please don’t hesitate to contact Cronulla Veterinary Clinic.