We all hate the thought of fleas, but they’re a common threat to our pets and, by extension, to our homes, so understanding what fleas are and how to treat them should be on every pet owner’s agenda. The most common flea found on dogs is the cat flea (Ctenocephalides felis), and these microscopic insects are blood-suckers — causing irritation and, in some cases, severe itching in dogs. Some pets can also suffer from flea allergy dermatitis: a hypersensitivity that may cause intense skin inflammation from saliva in just a single flea bite.
A common myth is that only pets in poor condition become infested with fleas. While it's true that pets with an impaired immune system are more likely to succumb to parasites, even pets in the best of health are at risk. Despite your best efforts, at some stage your pet is likely to come into contact with fleas. Luckily there are numerous treatments and preventatives available, ranging from conventional medications to more alternative remedies.
Common natural flea treatments
None of us want to use more chemicals than absolutely necessary, and there are a number of alternative treatments for flea infestations. Some of these are traditional methods for eliminating fleas, prior to the usage of modern pharmaceuticals, and others are championed as natural, non-chemical methods for flea control. However, it's important to remember that ‘natural’ does not always equate to a safe treatment for your pet.
Your dog has a very sensitive nose, and essential oils can have strong fragrances which could irritate your pet's airways. These oils are produced by distillation and are highly concentrated, so they could actually be toxic to your pet if used carelessly or incorrectly. However, you can try applying small drops of oils such as lavender, cedar, and lemon plants to your pet's collar, or diluted and sprayed over the fur. The active component of lemon, limonene, is extracted from citrus peel and is an effective insect repellent and home cleanser. However, limonene has been known to cause skin irritation in people and pets, and can lead to liver damage — so be very careful when using essential oils as a flea treatment.
Apple cider vinegar has been heralded by many as being able to provide health benefits for many pet ailments when added to their water or food.1 Some even advocate using it as a rinse after shampooing. However, there have been very few scientific studies investigating its efficacy or any side effects it may cause, and because of this we don't really know how much is safe to use, or at what frequency, when treating any pet-related disease, not just flea infestations.
Garlic has no lasting health benefits for your pet and can be very dangerous, even toxic when given in large doses. Advocates of garlic do feed small amounts daily for a number of purported benefits, but its use as a flea treatment has recently been debunked.2
Commercial prescription flea treatments
Commercially available prescription treatments are the result of rigorous scientific investigations and testing to ensure that your pet receives the most efficacious and safe medication available.
Imidacloprid is an active insecticide in solutions for monthly application to the skin between the shoulder blades of dogs, and is known to kill adult fleas and the larval stages of the flea by affecting the central nervous system — potentially causing paralysis. Imidacloprid has extremely weak activity with minimal effects on your pet, however there have been rare occurrences of itching, skin rashes, and vomiting with occasional hypersensitivity reactions at the application site.3
When should you choose medications containing imidacloprid, you can apply these solutions if your pet has an infestation with fleas, biting lice, mange, or ear mites. Commercial products often combine this with moxidectin to treat worm infections in your pet in a single application; however in some areas there is resistance to this worm treatment. For example, if your pet is a Collie, Old English Sheepdog or a related breed, then special care should be taken to correctly administer the product and monitor for any adverse effects. You should also avoid bathing your dog and do not allow them to swim for 48 hours after application.
Fluralaner is available in chewable tablet form for dogs and is given at 12 week intervals for the treatment and prevention of fleas. Essentially, fluralaner prevents messages from traveling between nerves in the flea, causing the paralysis and death of the flea before they can lay eggs.4 Side effects are uncommon, but generally may include short term diarrhoea and excess saliva production after dosing. If your pet is pregnant, you should discuss any possible effects to unborn puppies with your vet before administration.
As a chewable tablet, this medication means you can be sure your pet has taken their medication and you needn’t be concerned about bathing after treatment and potentially washing it off. Fluralaner is also licensed for the treatment and control of a number of ticks that can transmit disease to your pet, albeit for a shorter time. If your pet is younger than 6 months, this medication is still safe, however it may not remain in their system for as long as 12 weeks.
The use of spinosad was the first oral flea medication available. As with other medications, it interferes with the flea’s central nervous system: causing paralysis and death within thirty minutes of ingestion. Generally available in tablet form and used in monthly doses, it’s advisable to give it to your dog after feeding to maximise the medication’s absorption.
If your pet suffers from flea allergy dermatitis, a flea bite allergy causing intense skin irritation, then preparations of spinosad have been used to help reduce the symptoms in these pets.5 As with oral fluralaner, you can be sure your pet has received his/her treatment and you can bathe your pet. It’s difficult to accurately dose very small pets, however, so vets don’t recommend using medications containing spinosad in dogs weighing less than 1.5kg.
Healthspan's spot-on flea treatments contain Fipronil. By spreading across the body of your dog through the natural oils in its hair and skin, fipronil stays on for up to month — killing all fleas and any ticks within 24-48 hours, and also making sure none of the larvae survive. Fipronil-containing medications can also be used to treat infestations with lice and a variety of ticks and mites in dogs; and sprays can be used to treat your pet’s bedding and environment safely. If your pet has skin damage from scratching, you should have a chat with your veterinarian before using topical pesticides.
There are many more flea treatments available for your pet that are available on and off prescription. Your pet's health is important, so it's always advised that you discuss any treatments with your veterinarian before embarking on any flea treatment. Treating fleas is perfectly manageable for any pet owner, as long as you understand how to do it safely.
Author info: Dr. Grey graduated from University College Dublin in Ireland in 2013 and then completed an equine internship and a post-graduate qualification in Equine Sports Medicine. Currently loving working in a mixed private practice.
1 "The Benefits of Apple Cider Vinegar to Dogs - Page 1 | Whole Dog ..." 2011. 23 May. 2016 2 "Can Garlic Help Keep My Dog's Fleas Away? - Vetstreet." 2011. 23 May. 2016 3 "The Use of Imidacloprid (Advantage®) in Dogs and Cats - Pet Education." 2010. 23 May. 2016 4 Williams, H. "Fluralaner, a novel isoxazoline, prevents flea (Ctenocephalides felis ..." 2014. 5 "Flea Allergy Dermatitis: Fleas and Flea Allergy Dermatitis: Merck ..." 2015. 23 May. 2016