Question from :Marilyn Ann Faulkner ' I have a small but bulky pug cross jack Russell, who has had a problem with fleas, I have been using frontline every four weeks but still find the odd flea on him, have also treated the whole house with Acclaim household flea spray. Thinking of perhaps changing to advocate spot on. My dog weighs in at 10.5 kilos, so should I use up to 10kg size or maybe change to 10-25kg. This probably sounds like a silly question, but would hate to think that if I used the higher dose it would have a detrimental effect on my dog. Can you advise please.' Answer from: Shanika Winters Thanks Marilyn for your question regarding flea control on your dog. It sounds as though you are doing all the correct things by treating your pet with a flea preparation regularly as well as having treated your home. It is really frustrating for both dog and owner when the fleas just do not seem to be going away. What are fleas and where have they come from? Fleas are a parasite that lives on our pet and in our homes, the adult fleas need to feed on blood from your pet in order to survive. It is important to be aware that adult fleas are not the only thing we need to get rid of, the flea life cycle involves eggs, which hatch into larvae, these then turn into pupae from which emerge the adult fleas. Unfortunately the fleas we see on a pet are only the tip of the iceberg as most of the flea population is in the form of eggs, larvae and pupae. It is good to hear that you have used the household spray to treat your home; the household spray is aimed at killing the flea population that is not on your pet and therefore helps to break the flea life cycle. Make sure you read all the instruction on household flea sprays, use the correct amount and take care if you have pet fish or caged birds as the chemicals can be toxic to them. It is also important not to use the household flea spray on your dog itself. If the flea infestation in your home is severe and humans are also getting bitten then in some cases a professional household flea treatment may be needed. The flea eggs larvae and pupae can survive in the nooks and crannies of your home, down between floor boards, skirting and soft furnishings. Changing flea treatment product? If you are finding that a product is not working for you and your pet then it is definitely a topic to discuss with your vet. The correct product to fit your pet’s needs can then be found. Some of the flea preparations cover various worms also such as round,tape, heart and lung worms. Correct administration of the product and the correct dosage should also help ensure success in the battle against the fleas. If you are planning on bathing your pet then do this before applying the flea product and make sure your pet has a dry coat before applying its next dose. Make sure that your pet has been weighed accurately ideally on the weighing scales at your vets to decide on which dose to use. The safety margins on the products your vet dispenses to you have been tried and tested, so provided you use the correct dose then the product should be effective. Could the fleas be resistant to the drug I am using? Resistance is when the drug is no longer effective; in the case of a flea product it would no longer kill most of the fleas on your pet. It is possible that the fleas are becoming resistant to certain drugs, but until any official data is released as vets we can’t say that fleas are definitely resistant to a particular product. However as an owner if you are not happy with a particular product then you should ask your vet for alternatives. Have all in contact animals been treated for fleas? It is very important to know that fleas can be coming onto your pet from other animals from your own dogs and cats through to those of neighbours and even wildlife that passes through your garden. We can’t treat the wildlife but we can ensure our own pets are treated for fleas; flea products are available in sprays, spot on and even oral forms so even a semi feral pet cat could be treated through its food. It is tricky when the other in contact animals are not your own, a chat with the neighbours is always worth a try. I hope that I have managed to answer your question which was not at all silly. If you are ever in doubt as to whether a product is working and which dose should be used please discuss this with your vet, this is what we are here to help you with. Shanika Winters MRCVS (online vet) If you have any worries about your pet, please make an appointment to see your vet - or try our online Symptom Guide.