- Flea allergy dermatitis (FAD) is a condition in which dogs develop a hypersensitivity to the saliva in flea bites
- It can take only a flea or two to trigger FAD in a susceptible dog; FAD can lead to secondary disorders, including neurodermatitis
- Treatment of a dog with FAD involves using a flea comb daily to remove flea and flea dirt, frequent baths, and eradicating fleas from both your indoor and outdoor environments
- Before you automatically reach for a chemical pesticide, consider safe, nontoxic preventives that can help your dog avoid fleas, as well as all-natural remedies for flea invasions in and around your home
Editor's Note: This article is a reprint. It was originally published March 30, 2020.
Fleas feed on the blood of companion animals and their bites can lead to irritation and skin allergies. Sometimes these pests are no more than a nasty nuisance, but they have the potential to cause serious problems. Fleas can transmit tapeworms, bartonella bacteria, and can cause severe anemia in young animals.
They can also trigger a condition in pets called flea allergy dermatitis (FAD), which is characterized by a hypersensitivity reaction to flea bites. It's important to note that it's not the bite of a flea that makes your dog scratch; it's the flea saliva, which can cause overwhelming irritation disproportionate to the actual number of fleas on your canine companion.
Symptoms of Flea Allergy Dermatitis
Most pet parents assume if their pet isn't covered with fleas, the itching can't be caused by fleas. But if your dog has FAD, the saliva of just one or two fleas can make her miserably itchy and uncomfortable for weeks (long past the death of those two fleas).
The classic symptom of flea bite hypersensitivity is frequent or constant severe itching and scratching, hair loss, and hot spots. Secondary bacterial infections are a risk for dogs with open skin sores.
Most dogs with FAD have symptoms that worsen with age, and are often episodic, meaning they experience flare-ups in between periods of relative comfort. Sometimes they go on to develop neurodermatitis as a result of flea bite hypersensitivity. Neurodermatitis is a condition characterized by restless, anxious, irritated, or nervous behavior as a result of FAD.
Diagnosis and Treatment Options
There's no specific diagnostic test for flea allergy dermatitis. To confirm your suspicions, the best approach is to simply have your dog stand or lie on a light-colored towel and use a flea comb to help reveal fleas and flea dirt. Flea dirt looks like real dirt, but when you drop it into a small amount of rubbing alcohol or water, it will release a red color (blood) as it dissolves.
Resolving your dog's flea problem will depend to a large extent on whether he's reacting to just a few fleas or an infestation. Either way, you'll definitely want to use the flea comb at least once a day until you're confident there are no more fleas on him or in his environment.
Dogs with a sensitivity to flea saliva should also be bathed frequently until the fleas are gone. Even if he hates it while it's happening, his skin will feel better after a bath, and any fleas on his body will drop into the water. Another benefit: pests of all kinds are less attracted to clean animals.
An alternative to a full bath and shampoo is to simply dip your dog in a sink or tub of warm water, which will cause most of the fleas to fall off. Adding a cup of apple cider vinegar to a gallon of rinse water will help make him less appealing to fleas.
Before You Reach for a Chemical Flea Preventive
I strongly discourage pet parents from automatically applying potentially toxic chemical agents to their dogs or around their home to repel or kill pests. The use of spot-on products may cause skin irritation, paralysis, seizures and even death if used improperly, and there are effective natural alternatives that are far safer.
If, however, you live in a flea-endemic area and have a family member with FAD or an infestation that requires that you use these chemicals, follow these precautions:
- Monitor your dog for adverse reactions after you apply a chemical product — especially when using one for the first time.
- Don't depend exclusively on chemical treatments. Rotate natural preventives with chemicals, including diatomaceous earth, pet-friendly essential oil products and natural deterrent collars. An every-other-month rotation works well for many pet parents.
- Since your dog's liver will be tasked with processing the chemicals that make it into the bloodstream, it can be very beneficial to give her a supplement to help detoxify the liver. I recommend milk thistle, which is a detox agent and also helps to actually regenerate liver cells. Another product I recommend is chlorella, a super green food that is a very powerful detox agent.
Work with your integrative veterinarian to determine how much to give your dog depending on her age, weight and any medications she's taking. I recommend one dose daily for seven days following any chemical flea, tick or heartworm preventive application, especially if dogs need regular pesticides applied to their bodies.
Safe, Nontoxic Alternatives to Chemicals
There are safe, nontoxic alternatives for flea control for dogs, and they don't have side effects, unlike virtually all forms of chemical pesticides. Alternatives I recommend include:
- A safe, natural pest deterrent (see recipe below)
- Cedar oil (specifically manufactured for pet health)
- Natural, food-grade diatomaceous earth, topically (not on the head)
- Fresh garlic (¼ teaspoon of freshly chopped garlic per 15 pounds of body weight)
- Feed a nutritionally optimal, species-appropriate fresh food diet
- Bathe and brush your dog regularly and perform frequent full-body inspections to check for parasite activity
- Use a flea comb daily during flea season to naturally exfoliate your dog's skin while removing or exposing pests
- Make sure both your indoor and outdoor environments are unfriendly to pests
All-Natural Homemade Pest Deterrent for Dogs
You can make an all-natural pest deterrent for your dog very easily at home. It will help him avoid a good percentage of the pests he encounters, though not all of them (as many of you know, not even the heavy duty chemicals prevent all parasites). The recipe: mix 8 ounces of pure water with 4 ounces of organic, unfiltered apple cider vinegar and 10 drops of neem oil.
Neem oil is not an essential oil. It's expelled or pressed oil and is effective because fleas (and ticks) are repelled by it. It's also great for pets who are very sensitive to odors. Catnip oil can also be used as a pest deterrent, since it has been proven to be as effective as diethyltoluamide (DEET), the mosquito and tick spray humans use that has a number of toxic side effects.
If you want to add some extra punch to your dog's pest deterrent recipe, go with five drops of lemon, lemongrass, eucalyptus or geranium oil. I use geranium oil quite a bit because I find it very effective. In fact, I use it in my Dr. Mercola natural flea and tick products. If you have a dog who comes in contact with ticks, adding the extra punch of one of the essential oils I listed can be very beneficial.
You can store your homemade pest deterrent in the fridge, which is what I do. Before your dog goes outside mist him with it, being careful to avoid the eyes. The active ingredients, especially the oils in the recipe, dissipate in about four hours, so you may need to reapply it several times throughout the day.