Flea allergy dermatitis is a very real problem for dogs and cats and is caused by the individual patient’s genetic sensitivity to the flea’s saliva. Some pets are so sensitive to the flea saliva that a single flea bite every two weeks can keep the pet continuously uncomfortable. After being bitten by a single flea or by multiple fleas or by the same flea multiple times, the allergic patient develops an itch that needs scratching. For the allergic patient the itch is not local – as occurs with a mosquito bite on the average person. The allergic dog or cat becomes pruritic (itchy) all over with the greatest intensity of itch over the tail head and the withers. It is the patient’s continual biting and scratching that creates the trauma that is characteristic of flea allergy dermatitis.
Even if some action is taken by the owner to assure that the patient receives no more flea bites, once the severe pruritis (itch) has begun it will take many days or multiple weeks for the pruritis to dissipate. A highly allergic patient will be very uncomfortable during this time and is likely to create substantial self mutilation during this time. These patients usually need some form of treatment to break their allergic reactions and to treat the self mutilation wounds. Antihistamines are very rarely effective in controlling flea allergy dermatitis.
Once the allergy is controlled and the self inflicted trauma is treated, absolute or near absolute flea control is essential if a repeat episode of flea allergy dermatitis is to be prevented. Fleas are usually easily seen on dogs. Fleas are usually not likely to be seen on cats unless the cat has a very severe flea infestation of its environment and is overwhelmed with fleas. The cat’s normal grooming habits allow it to catch and destroy fleas much more effectively than is possible with a dog. Because it is often so difficult to find fleas on a cat, it is often difficult to convince some owners that the dermatitis on their cat is caused by flea bites.
The producers of the topical flea treatments (i.e., Frontline, Advantage, and others) insist that there is no flea resistance against their products. However, our experience seems to indicate otherwise. Although both products remain very effective flea control products for most dogs and cats, in a few cases, these products seem to have reduced effectiveness. Routine and proper application of these products is a ‘must’ if they are to be effective. Many clients apply these products incorrectly or irregularly and then become upset when the product does not control fleas. In either case, improper application or possible resistance, there are other effective products also available. Commercial over the counter products are generally ineffective flea control products for the highly allergic pets – those pets that require only one or two bites per day to active the allergic syndrome.
Pets with flea allergy dermatitis are usually quite uncomfortable and exhibit varying degrees of self mutilation. Flea allergy dermatitis continues through the winter months as the flea population is not destroyed by the cold weather as many people believe it to be. It may take some trial and error to determine the correct flea control medication; but, the dermatitis can be controlled and the pet can be kept free of the allergic dermatitis. Highly allergic pets may need to be treated with flea control medication year round in order to control their dermatitis.