Itchy skin is one of the most common presenting symptoms at Town & Country Veterinary Clinic. During the Spring, Summer, and Fall, our caseload can be up to 50% skin cases and/or ears cases. Unfortunately, as beautiful as the Southeast can be during this time, it can make many dogs and cats miserable with itching.
As a result of all this itching, our doctors have treated many hundreds of these itchy dogs over the years, we’ve developed a two month plan that takes into account the most common reason for itching with cats and dogs.
Why Is My Dog Itching?
Most dogs and cats itch for one (and sometimes more) of these six reasons:
- Parasites – including fleas, mange mites, or ringworm fungus (much more common in cats)
- Seasonal Allergies – also known as “atopic dermatitis” or “atopy”
- Food Allergies
- Dust mite / indoor allergies
- Bacterial infection (usually secondary to allergies or parasites) and/or allergic to bacteria
- Yeast infection (usually secondary to allergies or parasites) and/or allergic to yeast
An effective plan for itchy skin, therefore, should account for all six of these causes of itching at the same time. During the initial visit to discuss your pet’s itchy skin, we will discuss and consider all 6 causes of itching and determine the best line of treatment to control your pet’s itching.
Step ONE – rule out food allergies
Cat and dog food allergies are one of those topics that gets a lot of press, but is frequently misunderstood. One of the most frustrating things for me as a veterinarian is to stand in the pet food stores and listen to the employees “educate” well-intentioned pet owners about what diet is best for their food allergic dog or cat. They mean well, but so much of what they are learning about cat and dog food allergy is PR that is handed down from the pet food companies. For example, the most frequent thing I hear is “you need to feed your pet a grain-free diet if it has food allergies”. While some pets are indeed allergic to grain, the vast majority of food allergic pets are primarily allergic to their PROTEIN source, NOT grain.
There is no such thing as a grab-off-the-shelf hypoallergenic dog food.
Do not let the friendly pet store employee convince you otherwise.
Instead, the only rational way to diagnose a food allergy in a dog, is with an elimination diet trial with either a novel .
What Is a Food Allergy?
Cat or Dog Food allergy is one type of adverse immunologic reaction to a substance in the diet (the “allergen”). In most cases, a protein, such as chicken, lamb, beef or fish is the culprit, though any carbohydrate, fat or dietary supplement may be an allergen. It is NOT a reaction to a specific brand of food, or a result of switching diets. Most commercial and home-cooked diets, treats, and raw-foods share ingredients that may be allergens, no matter how high quality they are.
The pet may have been fed the offending allergen for over two years before developing signs of a food allergy. Food allergy can occur at any age, in any breed or gender, and patients may react to one or two items or several.
How is Cat or Dog Food Allergy Diagnosed? What types of tests would a vet do to identify and treat a food allergy?
It is important to understand that currently there is no accurate test to determine if a pet has a food allergy. Simply switching from one commercial brand to another is not sufficient, as these diets have many shared ingredients. The only reliable method of diagnosing a food allergy is undergoing an “elimination diet trial.” This means that your pet will be fed a special prescription diet from your veterinarian containing a single new animal or vegetable protein, such as rabbit or beans; and a single new carbohydrate, such as yams or green peas. Some of the commercial elimination diets contain common proteins that have been altered (hydrolyzed i.e. made smaller) so the body doesn’t recognize them as allergens. There are blood tests available that claim to be able to determine if your pet has food allergies, and if so, what he or she is allergic to. These tests have MINIMAL if any correlation to true food allergies, so please don’t waste your money or your time.
Regardless of the diet chosen, it needs to be fed absolutely strictly for a period of 8-12 weeks to see improvement. No other treats, supplements or foods can be fed or even mistakenly ingested during this period. There should be absolutely no exposure to other pet’s food or food bowls. During the diet trial skin infections or other sources of itch and discomfort will be addressed by the veterinarian.
Inform friends, neighbors, family members about the diet. If necessary – have “allowable” treats – carrots, broccoli, green beans, asparagus, celery, cucumber – or pieces of their elimination diet for them to feed. Do not allow anyone to give your pet anything not approved by you first!!!
If you use food to give your pet medications, you will need to find an alternative – marshmallows make great hypoallergenic pill-stuffing treats!
Watch your pet’s weight. If there is excessive weight loss or gain, you may need to change how much or how often you feed your pet.
SUMMARY: How to perform an 8 week elimination diet trial
- Feed only your vet’s prescription hypoallergenic food (we prefer Royal Canin Anallergenic Dietfor this purpose) for 8 solid weeks, and nothing else.
- At the end of your 8 weeks, change back to your dog’s normal food. If his skin gets itchy again, you’ve officially diagnosed him with food allergies.
- If his skin does not get itchy againon his regular food, that means you’ve diagnosed him with seasonal allergies / atopy.
Any deviation from this plan will result in you completely wasting your money on the prescription anallergenic diet, so please follow these directions exactly.
Even just a bite or two of chicken may invalidate the diet trial.
Step TWO – eliminate skin parasites
- FLEAS: If your dog is suffering from allergies, adding fleas or mange mites to his misery will make him doubly miserable. Save your poor, beloved pooch that agony, and buy some awesome flea stufffrom your veterinarian (our current preference is either Vectra 3D if we’re also using ivermectin – see below – or Comfortis if we are not).
- MANGE: Your vet may also consider a second prescription drug to treat and prevent mange mites during the diet trial, to make sure no other parasites get involved and complicate the plan (we like oral ivermectinfor this). Most veterinarians will perform regular skin scraping tests during the 8 week trial to examine for these mange mites.
- RINGWORM: A fungal infection that infests hair follicles, ringworm is usually treated with oral antifungals and topical shampoo. Ringworm is contagious to humans, which is why we rule it out on visit #1.
Step THREE – eliminate bacteria and yeast
Most vets will perform an impression smear during each appointment for itchy skin, which involves squishing a clean slide against your dog’s skin, and looking for bacteria and yeast that get stuck to the slide.
We usually treat bacteria and yeast with some combination of oral antibiotics, oral antifungals, and topical antibacterial/antifungal prescription medicated shampoo.
Step FOUR – prescription medication / antihistamines
Newer medication such as Apoquel or tried and true Prednisone are commonly used drugs to reduce your pet’s itch while we’re treating the bacteria, yeast, and parasites that may be complicating her itchy skin, and while we’re running the 8 week elimination diet trial test.
Our intention is not for you to keep your dog on prescription medication for the rest of her life, but rather to keep her from getting miserable while we’re getting to the bottom of what’s causing her allergies.
Your veterinarian may also recommend human antihistamines to be given at the same time as prednisone to reduce itching.
Step FIVE – dust Mites and inhalant allergy testing & desensitization
Assuming you have successfully completed your 8 week elimination diet trial and either your dog remained itchy throughout the trial, or challenging her with her old diet did not make her itchy, now you’re left with either atopy or dust mite allergy.
Dust mite allergy FUN FACT #1!
A pet that has scabies (true “mange” mites) will test positive for dust mites.
Dust mite allergy FUN FACT #2!
Dust mites are the leading cause of allergies and asthma in humans, and more dogs and cats are allergic to dust mites than to fleas.
Where do dust mite allergies come from?
Dust mites prefer warm and humid environments, so allergies to dust mites are worst in the fall, when homes are closed up because of cool evenings and increased humidity.
Dust mites prefer mattresses, upholstery, carpeting and fabrics. So while you may find more visible dust in other areas of your home (on bookshelves, inside air ducts for instance) mites actually prefer to hide out in darker and more protected environments. Cleaning out your vents and dusting the shelves probably do very little to reduce dust mites; a visibly clean home is not necessarily lower in allergens.
Pet bedding, pet toys, and finished basements are dust mite magnets.
Because true avoidance of dust mites is not practical, most veterinarians direct treatment at minimizing dust mite allergens in the home, and desensitizing the pet to the mite allergen.
Top 10 Ways To Minimize Dust Mites and Indoor Allergies in your home
- Keep your pet out of the bedroom. Dust mites love mattresses, pillows, and pet beds, so keeping them in rooms with the least humidity or fabric is best. If that is not possible, wash bed linens at least weekly in hot water, and use allergen-proof covers on your bed and pillows. Special note: no feather pillows! If this is not possible, Use a HEPA vacuum in the room, and run a HEPA air filter near the bed when the room isn’t occupied.
- Buy a vapor steam cleaning machine. Vapor contains only 5-6% water, so the vapor doesn’t contribute to a moist environment. Vapor steam deeply penetrates whatever it is cleaning, and it is great for upholstery, couches, carpets, and mattresses.
- Replace pet beds and human pillows at least every six months, and cover the ones you have with allergen-proof covers.
- Eliminate wall-to-wall carpet, get washable throw rugs instead. (or at least keep the pets off the carpet) Wood, seamless vinyl or linoleum floor coverings are best because they can be cleaned frequently. If this is not possible, steam cleaning a carpet reduces 87% of the dust mites.
- Launder or replace stuffed toys weekly. If this is not possible, consider freezing stuffed toys in the freezer (in a tightly closed plastic bag), and shake vigorously outside after removing them from the freezer.
- Use air conditioning or central heat, plus dehumidifiers if needed, to keep household humidity low. Change furnace filters frequently.
- Keep pets out of closets (dark, humid)
- Minimize humidity-increasing houseplants.
- Do not confine your dog to the laundry room, bathroom, utility room or basement or other high humidity part of the home.
- Choose your furnishings wisely. When possible, choose: Closed bookshelves and curios instead of open shelves; Washable curtains instead of blinds and heavy draperies; Furniture with simple designs instead of ornately curved pieces; Easily cleaned decorations instead of dried flowers or straw; Wooden or plastic furniture instead of upholstery.
Veterinary treatment of itchy skin caused by seasonal allergies or dust mites
Primary therapy for dust mite allergies in pets is similar to that of inhalant allergies.
Here is how allergy testing and desensitization works:
- First, establish a list of what your pet is allergic to, either using a panel of blood allergens from your veterinarian, or a trip to a local veterinary dermatology specialist.
- Second, give your pet ever increasing doses of whatever she is allergic to, either by daily drops under her tongue, or via injections.
Allergy testing and desensitation appears to be helpful in about 80% of patients receiving the treatments, at reducing the length and severity of allergy attacks throughout the pet’s lifetime.
Allergies are never cured, only managed.