Midwest living is great – unless you’re a dog or cat with environmental allergies! Those of us with itchy pets know how frustrating it can be to constantly manage the symptoms, with only varying levels of success.
Understanding the concept of “pruritic threshold” can make this constant struggle a little better.
Most allergic pets are allergic to more than ONE thing. Many allergens are often in play. Some are seasonal, such as tree pollen, grasses, weeds, and molds. Some are always present, such as house dust mites, the other pets in the house, or even houseplants. Then there are the parasitic possibilities that are preventable, but require treatment, such as fleas and mange mites. Finally, food allergies are common causes of itch, specifically chronic ear infections. If a pet has a food allergy, it is often to the protein or carbohydrate source that’s found in most pet foods (ie –chicken, beef, rice, corn, lamb). Therefore, simply switching brands is ineffective, as these ingredients are often found in most OTC foods, even if they are not on the label!
So with all these possibilities, what’s a pet owner to do? This is when we look at the pruritic threshold. Every animal has a threshold of itch, and when that threshold is reached, symptoms occur. If the allergen load can be maintained below that threshold, the dog or cat is comfortable.
In Patient A, the animal has allergies, but is not itchy or showing symptoms, because the allergens have not added up to reach the line, or the “symptom threshold.” Patient B, however, is itchy, probably has hair loss, skin infections, the works. Patient C is actually the animal from B, but with treatment, so he or she feels better and is no longer itchy. Maybe this patient had a couple environmental allergies (yellow and red) AND food allergy (blue). Even without doing much to reduce the environmental aspects, by addressing the food, we’ve gone from itchy (above the line) to non-itchy (below the line). Or, maybe Allergen 1 was fleas – get rid of those, and life is better.
Another scenario I see a lot: Patient A does fine in the winter. He probably has some allergies, but they don’t bother him much. We add a third allergen to that (pollen in the spring, fleas, etc) and we have Patient B – a pet that went from comfortable to itchy in no time! Those seasonal allergens go away, and we have happy Patient A again!
What does this mean? For starters, some animals have a very very low threshold, while some animals can handle allergen exposure galore and never itch! Our goal is to treat what we can. The animals with low thresholds are difficult, as we don’t have much wiggle room, and have to address every. Single. Allergen. It’s exhausting!
If an animal has allergies to food, fleas, house dust mites, and tree pollen, that’s probably one miserable pet. Let’s say these allergens caused a secondary bacterial infection in the skin, and a yeast infection in the ears as well!
The first step is to treat any and all infections, as these cause itch as well. Then eliminate the allergens we can control, which means strict flea control, and a prescription diet to address the food allergy. For some pets, this is enough and they are no longer itchy. For example, is the animal in B has a food allergy (let’s say it’s yellow, allergen III) and we put the pet on a hypoallergenic food, we might turn them into situation A, which is a non-itchy animal, despite the presence of other allergens.
For other pets, prescription foods may help, but we have a ways to go (those with lower thresholds or more numerous allergies).
Addressing environmental allergens is tough – can’t really live in a bubble, so avoidance is often impossible! For this, we’ll use various treatments that can chip away at the itch. One alone often won’t cut it, but combined, it may be enough to eek under that line! They may take Patient B to Patient C, by making “allergen 1 and 2” smaller.
- Oral antihistamines are a great option (ie – Benadryl, Zyrtec, Claritin, etc).
- Omega fatty acids (AKA fish oil) have been shown to mildly inhibit the inflammatory pathway, as well as strengthen the skin’s integrity.
- Bathing with prescription shampoos can also remove allergens from skin as well as prevent secondary infection and offer some soothing.
- Steroids often stop the itch, but have side effects and are not a good long term solution.
- Immune modulators, such as Atopica, work very well to calm down the body’s over-exuberant immune system. These are very costly, unfortunately.
- Immunotherapy is an option when the other treatments still have not gotten the pet below the symptom threshold. This involves testing for which species of tree, dust, etc, the pet is allergic to, then giving “allergy shots” to teach the body to live with these allergens without over-reacting.
Each pet is an individual, and some treatments are more of a realistic option than others. Our goal is to use as many treatments as necessary to reduce the allergen stimulus to below the threshold, which means a symptom-free, happy pet! Unfortunately, this is more possible for some pets than others, but reducing allergens’ effects on the pet as much as possible is always a worthy fight.
