Wednesday, June 22, 2011

Daisy's Butt – Treating Flea Allergy Dermatitis

by Tom King (c) 2011


Poor old Daisy, my half something, half something else black and white hound dog suffers with what one vet told me was “fleas” and another, more helpful, veterinarian explained was flea-allergy dermatitis. The first vet acted like I was some neglectful redneck living in a trailer park that left his dog outside in a bare dirt yard. The second doctor knew me and rather than assuming I neglect my dog, he explained what flea-allergy dermatitis (FAD) is.


Notice where Daisy has pulled the hair off
on her lower back and at the root of her tail.

FAD is an allergy to the saliva of fleas. It differs from flea-bite dermatitis because there is no relationship between the number of fleas found on the animal and the severity of the reaction the animal has to being bitten. FAD is charachterized by persistent scratching, red, painful-looking sores called hot spots that appear almost overnight. FAD's most common symptom is a Christmas tree pattern of hair loss on the lower back and the root of the tail. The bares spots appear scaly, rough and may ooze a little if the dog scratches or chews to frantically. Most animals with FAD actually have very few fleas. They itch so badly they groom themselves obsessively and eliminate any evidence of fleas. Sadly, though you may treat for fleas, but if one or two get to your dog every few weeks, it will keep your pet itchy all the time. They will scratch themselves, lick their paws, bite, chew, rub their body against the ground or furniture and pull out tufts of hair.


Step 1 Control the Fleas

Fleas are nasty little blood-suckers and can live up to a year. They like temperate weather and especially like high humidity. You absolutely must get rid of fleas around your house all at once. Treat all the cats and dogs in the place at once or they will reinfect each others. Dipping your dog is a good way to make sure all the fleas are cleared out. Spray the house, treat the carpets with borate-based flea powder and spray the yard with a flea-control product designed for each application. Outside, watch for moist, shady areas, piles of pine needles, wood scraps or garbage under plants and shade trees. Be sure you get areas your dog likes to lie around as these are the most likely places the fleas hop on board. For a natural flea repellent, try cedar or rosemary oils on bedding and even on the dog to keep any stray ones off her. Sticky flea traps won't get rid of your fleas, but they are a good way to tell if your eradication program worked. Hang them about and see if you collect any flees. They are small, dark, flat bodied about the size of a comma. Finally, use a topical flea killer like Front-line or one of the new combination anti-flea and worming treatments you can get from your veterinarian.

Step 2 Treat the Symptoms

Allergic skin can easily become infected with bacterial or fungal infections. These are secondary symptoms of the primary cause, but the animal's reaction to the itching does the most damage in FAD. A topical application of witch hazel to help the healing process along. If the skin becomes infected, apply a topical anti-bacterial ointment. If the problem becomes too bad, the veterinarian may give your dog cortisone shots to relieve the itching for several weeks. This will give you time to treat the underlying causes of the condition. Diphenhydramine anti-allergy medication can also help. Talk to your vet about dosage. Especially important is treating developing hot spots with a mixture of one part water and one part tea tree oil in a spray bottle. Another treatment is Absorbine Jr. applied a few times a day until the area dries up. Medicated shampoos may help, but the only real treatment for the condition is to keep the fleas off the dog.

Step 3 Address the Underlying Cause

Dogs' bodies manufacture essential fatty acids that help maintain healthy skin and fir. Omega 6 and omega 3 fatty acids include linoleic acid, an essential fatty acid produced by dogs. Linoleic acid is essential for a healthy epidermis. If there is a linoleic acid deficiency, the skin can become dry and flaky, fur may become dull and fall out and the skin may be more susceptible to inflammation. Fatty acid supplements in the diet can help reduce skin irritation and skin itching. It may take three to 12 weeks of supplementing the dog's diet to determine if supplementation will help. Besides promoting healthy skin, fatty acids also help support the immune system, growth, development of brain, kidneyw and other organs. They are also needed to help the body absorb vitamins A, D, E and K, all of which are important to healthy bones and skin and help prevent cancer. Omega 6 fatty acids are converted to inflammatory compounds and Omega 3's conver to anti-inflammatory substances. Because the acids compete for the same enzymes when they are metabolized, so they need to be balanced. The best ratio of omega 6 to omega 3 fatty acids is somewhere between 5:1 and 10:1, though veterinarians aren't sure. The best places to get these fatty acids are found in poultry, pork fat and plant oils like corn oil, canola, sunflower, and evening primrose oil. There aren't many omega 6's in beef or dairy products. Omega 3's are found in cold water fish oils (salmon, herring and mackerel) and in soybean, canola and flax seed oil. Vets prefer fish oils as fatty acid supplements for dogs since they are already balanced properly between omega 3 and 6. Most dog foods contain balanced omega fatty acid levels, but you may want to supplement your dog's diet if they are experiencing symptoms of dermatitis. Pet stores carry these and they can be purchased without a veterinary prescription.

Long Term Prognosis

Dog's with flea-allergy dermatitis will always be allergic to fleas. It will get worse as the dog ages. Some work is being done by veterinary dermatologists with allergy shots for the condition, but the jury is still out on the efficacy of the treatment. Keep your buddy treated with something like Frontline, K9 Advantix, Advantage or Revolution to kill any adult fleas on contact.


Be careful when killing fleas. If your dog experiences heavy drooling or shaking, you may be seeing early symptoms of chemical poisoning from the flea treatment. Call the vet immediately to prevent the dog from going into convulsions, collapse, coma or even death.


Recovery SA (Natural Remedy for Flea Dermatitis)
Pet Shed: Flea Allergy Dermatitis
Rural Area Veterinary Services; Foothills Animal Hospital; Flea Allergy Dermatitis; Bob McKee
University of Vermont Vetmed: Flea Allergy Dermatitis


  1. We're in Washington now and the hydrocortisone spray I bought at Wal-Mart and the cooler temperatures, her hair has all grown back and you can't tell where she had a flea problem. I'll post a picture in a couple of days.

  2. I have five dogs roaming 22 acres containing woods, pond and grassland. Two of them have flea allergy dermatitis. We bathe them regularly with flea and tick shampoo and treat them with Frontline Plus at least once a month. The fact is it is impossible to eradicate the flea population on that much area and all products are designed to kill the fleas, but nothing is available to discourage them from hopping on the dogs. I don't want to confine the dogs any more than I'd want to be in a cage. You mention cedar and rosemary oils on the dogs may help keep "the stray flea" off the pet. I'll try that and anything to keep my friends healthier. If you'd invent an effective flea repellent, you'd make a fortune...

  3. Outstanding! We also have a mutt named Daisy with a hairless butt secondary to FAD. Feel like I'm fighting a losing battle, but my vet hadn't mentioned anything about the Omega 3s and 6s. So glad to have this info to help her coat and skin heal rather than "just treat the fleas". Thank you!!

  4. Flea treatment is time consuming and complex. Without proper treatment our loving pets need to suffer a lot. Good pesticide can prevent infestation without any negative effect.

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