Allergy Testing

As if having fleas crawling and biting at our pets is not reason enough for itching, many dogs and cats are allergic to flea saliva. This means a single flea can cause a terrible “flea bite dermatitis.” Many times pet owners never see any fleas because pets often swallow the adult fleas in the process of biting and grooming.

We recommend keeping your pets on Frontline Plus year-round. Even cats that never go outside can get fleas. How? Fleas don’t live on pets, just feed from them. Fleas live in the environment and a flea can easily hitch a ride in on your shoes or pant-hem without you ever seeing it, especially if you walk through or along grass getting to your front door.

This is a skin condition caused by microscopic mites. There are at least seven species of these nasty critters, each causing their own skin disorders, but for general discussion we will focus on two of the most common varieties — Demodex and Sarcoptes. Demodex are mites that live within the hair follicle of all mammals, including us. They are not contagious and feed only on debris (dead cells, etc) within the hair follicle. However, if the pet has a compromised (weakened) immune system, these normally harmless mites run amok, clogging the hair follicles, which results in a deep infection that can become chronic.

Treatment for demodex includes shampoos, antibiotic therapy and in certain circumstances, immune stimulants. Sarcoptes on the other hand is a burrowing mite that causes extreme itchiness, and if one pet in the household is diagnosed with sarcoptic mange, all animals in the house need to be treated or re-infestation will occur. People living in the house do not require treatment as the mites cannot reproduce on people. (Please note: people can be susceptible to their own species of mites called scabies which does require treatment.)

Otherwise known as “Dermatophytosis,” ringworm is a fungal disease, not a worm at all. It affects dogs and cats, often spreading to their human caregivers. The round skin lesions or “rings” from which ringworm gets its name is also a bit of a misnomer as rings are rarely visible. To make matters worse for pets and veterinarians alike, animals with ringworm may have no outward symptoms. If they do have symptoms, they may include hair loss in patches, a rash or skin lumps — all of which are common symptoms of many other skin diseases.

Murphy’s Law prevails here in that the pets with the least symptoms are most likely to have the greatest amount of fungi. The contradictions don’t end there for this condition. The quickest and most common test for ringworm is examination by Wood’s lamp to look for fluorescence. However, only one of the three most common dermatophytes in dogs and cats fluoresces and that one only fluoresces about 40% of the time.

The most reliable way to accurately diagnosis ringworm is with a fungal culture, but a culture can take up to three weeks. The skin condition caused by ringworm can vary as well, from a mild nuisance that will recede over time to a major chronic skin disease that can be debilitating for over a year.

Once all the above has been ruled out for your itchy pet, we’d like to tell you that your pet is on easy street, but that is not the case. The allergic pet and it’s owners have a long road ahead with many detours and possible dead ends. As mentioned at the start, pets can be allergic to just about anything and figuring out just what is at the root of his problem may not be easy.

The first step on the allergy journey is to check for food sensitivities. Our pets can be allergic to the dyes or preservatives in their food. They may be allergic to the protein source, ie: beef, chicken, lamb. They could also be allergic to the carbohydrate ingredients, ie: wheat, corn, rice. The only way to test for a food allergy is with an elimination diet. This is done by only feeding your pet a diet of novel ingredients (things she/he has never eaten before.)

The tough part of a food trial is the timing. Each new diet tried must be fed exclusively for 10 to 16 weeks before any significant change will be noted. This means no treats, no table food, no rawhides or dental chews throughout the trial. If over-the-counter dog food brands do not make a significant improvement for your pet, there are prescription diets you can purchase through veterinarians that are hypoallergenic and low antigen. If a food allergy is confirmed, your pet will need to remain on the new diet or the itching will return.

So what if you have ruled out everything else and your pet is still miserable? Well, then it looks like you are fighting atopic dermatitis.

This is the condition related to hypersensitivity that results in many different skin issues. For some pets the allergen causes dry, itchy, flaky skin. For other, a moist, red pyoderma results from contact with the allergen. The allergen (or source of sensitivity) can be any of a variety of everyday, regularly harmless substances. Pollen, grass, house dust, mold, wool, cedar chips, even fellow housemates can be the source of severe allergic reactions in our pets.

Few itchy pets have only one or two allergens to which they are reacting. Most are dealing with a daily myriad of allergens, from both indoor and outdoor sources. They may feel a little better over the winter months, but they mostly itch year-round.

Although some pets find relief through topical sprays, oral antihistamines like over-the-counter Benadryl or the prescription Hydroxyzine, and medicated shampoo, for others the reaction is much more severe and injections of long-acting steroids or oral steroids is required. Steroids are very effective, but they are not a long-term solution due to side effects that can harm the liver and kidneys.