- A severe allergic reaction to a flea bite is known as flea allergy dermatitis (FAD).
- FAD can result in excruciating scratching and hurtful skin sores.
- Animals with infections risk developing secondary skin infections if not addressed.
- FAD can be treated by eliminating fleas from the surroundings and treating fleas on the pet.
- Itching and subsequent skin infections may be treated with corticosteroids and antibiotics.
A severe allergic reaction to a flea bite is called flea allergy dermatitis (FAD). FAD can strike both canines and felines. Certain proteins in the saliva of the flea, which the flea injects into the pet’s skin during biting and eating, cause severely allergic reactions in affected pets. Some animals are so allergic that simply one bite might result in an adverse reaction.
FAD makes animals unpleasant, and if left untreated, the intense itching and inflammation it causes can cause skin damage through repeated chewing and scratching. As a result, secondary bacterial or fungal infections may appear.
One of the initial symptoms of FAD is discomfort and itching. Warm, humid weather, when fleas are more active, might make FAD worse. FAD can, however, be a persistent, year-round issue if a pet’s home environment is infected with fleas or the pet resides in a warm climate.
Animals with the condition may excessively lick, chew, bite, lick, and scratch itchy or irritated areas. Hot spots, which are red, oozing lesions, can appear in regions where scratching is most frequent, usually on the rump, tail, and legs. The hair at the base of the tail and along the rump usually thins on affected dogs. Cats with the condition may lose a lot of hair and have scabs that may cover much of their bodies.
Other indications include:
- skin irritation
- hair fall
- Crusty or oozing sores (hot spots)
- afflicted skin’s darkening or thickening
- Unwelcome odour (resulting from secondary infection)
The typical method of diagnosis is examination and the discovery of flea evidence. Evidence of fleas may not be found, however, because a single bite might produce an allergic reaction and many pets, particularly cats, are very good at combing fleas off of themselves. Testing for allergies might help identify whether the pet is sensitive to flea saliva. Additional allergens may be checked for because pets with flea allergies frequently also have allergies to other chemicals.
By totally avoiding flea bites and eliminating fleas from your pet and its surroundings, the only real treatment for FAD is to completely avoid flea bites. While many solutions also target fleas’ other life stages (such as eggs and larvae), which can survive in the environment and develop into adult fleas, effective treatment primarily targets adult (biting) fleas.
There are numerous flea-controlling products that are secure, efficient, and simple to use. These medications are often given by directly administering the fluid form of the medication to the skin of the animal, usually between the shoulder blades or at the back of the neck. To eliminate fleas and stop the flea life cycle as successfully as possible, your veterinarian may suggest a combination of products.
It can be extremely challenging to get rid of fleas after an infestation has taken hold in your home. Your pet can require several treatments. Fleas must also be fully eliminated from the environment of the sick pet. As a result, it is necessary to treat the home (and maybe the yard) with flea-control solutions as well as all other animals that are present in the home.
Your veterinarian could also advise vacuuming rugs, getting rid of old pet bedding, and washing additional objects to help get rid of fleas from your pet’s environment. It may also be advised that you secure your home and yard to prevent wildlife from unintentionally reinfesting your pet’s dwelling and exercise areas because many species of wildlife carry fleas.
FAD-related secondary skin infections can be treated with antibiotics or antifungal medicines. To help inflamed areas recover, your veterinarian may also advise a brief course of corticosteroids to minimise inflammation and irritation.
Although there are more than 2000 types of fleas, cats and dogs are most frequently affected by the cat flea (Ctenocephalides felis).
How is canine flea dermatitis treated?
Killing the fleas is the top goal in FAD treatment! This entails eliminating fleas from the environment as well as from your dog and any other household pets.
Oral Flea Medications
For the quickest relief, use a medication containing Spinosad to completely eradicate all fleas on your dog within 30 to 60 minutes. Following that, you can use a product that lasts 30-90 days.
It is a good idea to bathe the dog once the fleas have died to remove all of the excreta and dead insects. You can buy over-the-counter dog shampoos that contain oatmeal and pramoxine to help alleviate the itch, or you can obtain a medicated shampoo prescribed by your veterinarian to soothe the skin.
Even when the fleas are eliminated, you still need to treat the allergic dermatitis-related skin rashes.
Benadryl can be administered to your dog at home in mild situations to stop an allergic response and relieve itching.
For dosage information and to ensure this medication is safe for your pet, always consult your veterinarian.
The majority of dogs with FAD require additional assistance, and you can discuss with your vet whether or not steroids or other allergy medications like Apoquel or Cytopoint are necessary.
How can I manage the flea allergy dermatitis in my dog at home?
Giving your dog or cat a cool-water bath at home is one of the simplest ways to help them feel less irritated. “Unless your pet hates water, this can assist by making their skin feel better and eradicating some fleas,” Zabell explains.
How can you detect flea dermatitis in your dog?
The most common cause of allergic responses in dogs is flea allergy dermatitis (FAD). The immune system of the body overreacts or becomes hypersensitive to an antigen, which is a typically harmless chemical, during an allergic reaction.
Dogs frequently experience itching due to FAD. To lay their eggs, adult fleas must bite a dog and consume blood. With the exception of the few minutes to many hours that they are feeding, fleas normally do not stay on the dog. This is why, unless there is a serious flea infestation in their immediate environment, dog owners frequently do not observe live fleas on their dog. Fleas inject a tiny amount of saliva into the skin when they feed. Sensitive dogs get a severe itching reaction to the antigens or proteins in saliva.
Itchy dogs do not necessarily have to have a flea infestation to get FAD. A single fleabite might actually cause itching to last for several days.
Are only certain dogs allergic to fleas?
FAD can manifest at any age, but in most dogs, it first manifests between the ages of two and five. In contrast to dogs without other allergic disorders, dogs with other types of allergies, such as inhaled allergies (caused by, for example, pollens, moulds, or dust mites), frequently have a high sensitivity to flea bites. As a result, they are considerably more likely to develop FAD.
How is flea allergy dermatitis diagnosed?
Clinical symptoms frequently provide the first indication that your pet may have FAD. FAD is frequently accompanied by itchiness and hair loss in the “flea triangle” region, which extends from the middle of the back to the base of the tail and down the back legs.
Your dog may have a flea allergy, which can be confirmed by intradermal allergy testing (skin tests similar to those carried out on humans) or specialist blood tests (IgE blood tests). Formal allergy testing is only occasionally required because the symptoms of FAD are frequently highly recognisable and the response to therapy happens so swiftly.
What does treatment involve?
It is crucial to keep fleas from biting your dog because the allergy reaction is brought on by the flea saliva injection. The control of fleas must be strict. Even though you haven’t noticed any fleas on the dog, it’s still crucial to keep up your strict flea treatment regimen and uphold environmental control. Most flea infestations happen in the summer months, however they can happen all year (for more details, refer to our handout “Flea Control in Dogs”). For all dogs and cats, modern monthly oral and topical flea preventives are a crucial component of responsible pet ownership. The most effective method of treatment for a dog with FAD is flea prevention.
What about desensitization?
Giving allergy injections, commonly known as desensitisation or hyposensitization, is giving a flea antigen in progressively higher dosages over an extended period of time. These allergy shots may be necessary for the pet’s survival in specific circumstances. Unfortunately, desensitisation is rarely employed and is not thought to be highly effective in treating flea allergy.
It’s crucial to distinguish between desensitisation therapy and corticosteroid or cortisone injections used to treat acute FAD flare-up symptoms.
What about steroids or other drugs?
Acute (sudden) episodes of very itchy FAD are frequently treated with corticosteroids (also known as steroids or cortisone). They frequently result in an almost miraculous reduction in itching. However, using steroids could have serious adverse effects (see handout “Steroid Treament – Effects in Dogs” for more information). Using steroids for temporary relief while implementing flea control is safe. For many patients, a regimen that combines corticosteroids with antihistamines and/or omega-fatty acid supplements is ideal. The intention is to administer corticosteroids at the lowest feasible dose and as seldom as possible, ideally every other or third day. Antibiotics can also be required if your dog’s scratching has caused a secondary bacterial skin infection.
The common treatment for acute (sudden) episodes of very itchy FAD is corticosteroids.
Fortunately, today’s treatment of FAD rarely requires the use of steroids because of the highly successful more technologically sophisticated flea control solutions.
During the assessment, your veterinarian will go over the benefits and drawbacks of the various FAD therapies with you and then prescribe the safest and most efficient course of action for your pet’s particular requirements. Prevention is crucial, and it’s also quite easy and affordable. For the best flea preventive for your pet’s needs and lifestyle, consult your veterinarian.
Does allergic dermatitis to fleas go away?
It could be challenging to persuade owners that their pet might be suffering from FAD until fleas or flea dirt (flea faeces) are discovered on the animal. Even while dogs who react to flea extract positively may benefit from intradermal allergen testing (IDAT), the mere presence of hypersensitivity does not guarantee a diagnosis. Cats do not respond well to IDAT, and results can be confusing. The only criteria for making the diagnosis are the history, the clinical manifestations, the exclusion of alternative differentials, and the outcome of a therapeutic trial. Clients can be convinced of the value of conducting a therapy trial by explaining that, in certain situations, only a few flea bites are required to cause a hypersensitive reaction. In order to diagnose these pruritic dermatoses, it is also necessary to rule out parasite hypersensitivity because the clinical symptoms might be quite similar to those of the other two most frequent differentials, AD and CAFR.
FIGURE 3. Lichenification at the base of the tail and caninealopecia on the caudal half of the body.
The objective is the same whether FAD is suspected or has been diagnosed: avoid flea bites as much as possible, treat the pruritus when flare-ups take place, and avoid secondary skin infections. In order to address the customer’s primary issue, which is often their pet’s suffering, client education on these subjects is crucial.
- Getting rid of the itch
- treating secondary yeast and bacterial infections
- The life cycle of fleas
- the use of flea preventatives on all pets in contact
- Available flea-controlling products, correct application, and client expectations
- environmental safety precautions
- Financial considerations and estimating
Treatment of Pruritus
The most effective treatment for the severe pruritus caused by FAD is corticosteroids, and oral administrations are preferable over injectable ones since they allow for dosage titration. Corticosteroids can prevent secondary infections brought on by bacterial or yeast overgrowth because they also lessen skin inflammation. More so than dogs, cats could need corticosteroid therapy for extended periods of time.
The Flea Life Cycle
Although the flea’s metamorphosis is difficult, presenting the facts doesn’t have to be. There are several eggs, larvae, pupae, and newly emerging adults in the environment for every adult flea on the host. The life cycle typically lasts three to four weeks, although depending on the environment, it may be shorter or longer (BOX 2). The female flea begins generating eggs 24 to 36 hours after her initial blood meal and can lay up to 50 eggs per day. 1 The non-sticky eggs are laid on the animal and then fall off into the surrounding area, continuing the life cycle. To understand this life cycle, picture the animal as a salt shaker.
Mandatory Treatment of All In-Contact Pets with Flea Preventatives
The FAD-affected pet should ideally be treated with an adulticide that kills adult fleas and prevents the development of their immature stages (insect growth regulator). During a therapy trial or when flare-ups happen, the interval between doses is sometimes shortened from once a month for 2-3 applications to once every 14 days. Exotic animals included, all in-contact animals need to be treated in order to stop the life cycle, whether they are indoor or outdoor pets. Other in-contact canines and felines can be treated in accordance with the directions on the product’s label, which are typically monthly administration. Although Selamectin is frequently used “off-label for ferrets, rabbits, hedgehogs, guinea pigs, rats, gerbils, and mice, there are no flea preventatives specifically marketed for exotic pets. 1,3 Treatment is advised all year round.
Products Available for Flea Control, Proper Administration, and Client Expectations
Flea remedies come in a variety of forms, including topical, oral, and injectable ones. Adulticides target adult fleas, insect growth regulators target juvenile fleas, and certain products function as both an adulticide and an IGR. Client error can be reduced by describing the proper use of flea products and giving the initial dosage of the treatment. It’s important to carefully read product labels and inform pet owners that many items intended for dogs cannot be used on cats or some exotic animals, especially those that include pyrethroids. This is crucial if customers are buying over-the-counter products (OTC). Depending on the substance used, topical spot-on drugs must be administered on dry skin and bathing is restricted for a while after application. A good general rule is to avoid showering two days before or two days after applying a topical treatment. Avoid taking excessive baths and swimming. For optimal absorption, several oral drugs must be taken with food. It is not advised to use OTC products to treat FAD.
Environmental Control Measures
Depending on how bad the infestation is, environmental management methods may or may not be necessary. The most crucial environmental factor is treating all in-contact animals, which should finally result in the elimination of fleas, but it may take up to 2-3 months due to the potential presence of multiple life phases (BOX 3). With the aim of reducing previous life stages, clients might take steps to expedite the process. Making a list of where clients’ pets spend the majority of their time will assist identify the areas to concentrate on when it comes to cleaning, laundry, vacuuming, and the application of environmental pesticides because it can be a challenging chore. Pet bedding, under or on furniture, closets, carpeting, beneath porches, shaded outdoor locations like bushes and shrubbery, dog homes, kennels, sheds, and even the family automobile are places to be wary of.
Financial Concerns and Providing Estimates
The cost of therapy may be a substantial financial burden for clients, depending on how many pets live in the home. Estimates for the various flea treatments that are available are crucial and will aid in owner compliance. Numerous flea treatments also offer protection from other external parasites like mites, lice, and ticks, as well as from internal parasites like roundworms and heartworms.