Scratching The Itch: Understanding Allergies in Your Pets

Allergies are one of the most common health issues affecting dogs and cats, often requiring veterinary care. Pet allergies generally fall into two main categories: food allergies and seasonal allergies. While both can cause discomfort, their triggers, symptoms, and treatments differ significantly. In this post, we’ll break down the differences between these allergies to help you better care for your pets.

Food allergies occur when your pet’s immune system mistakenly reacts to certain proteins or ingredients in their food as harmful. Common food allergens for pets include beef, chicken, dairy, wheat, and soy.

On the other hand, seasonal allergies also known as environmental allergies or atopy—are triggered by allergens in the environment, like pollen from trees, grasses, and weeds, as well as mold spores and dust mites. Certain breeds are more susceptible to seasonal allergies, but any pet can develop them.

Complicating matters, pets can have multiple allergies, making it harder to pinpoint the cause. To manage these conditions, it’s crucial to identify the allergen and either eliminate or manage it.

Here are some key questions to help identify the type of allergy affecting your pet:

1. Does the itching occur year-round or seasonally?
2. When did the symptoms start—was it before 6 months of age or after 5-6 years?
3. Have previous treatments worked?
4. Are there any gastrointestinal issues like vomiting or diarrhea?
5. Where are the lesions located on the pet’s skin?

Let’s dive deeper into each question:

1. Does the Itching Occur Year-Round or Seasonally?

If the itching only happens during certain times of the year, it’s likely due to seasonal allergies, triggered by environmental factors like pollen. Year-round itching suggests a food allergy, especially if it’s not related to weather changes.

2. What Age Did the Itching Start?

Seasonal allergies typically start between ages 1 and 3 in dogs. Food allergies, on the other hand, may start in pets younger than 6 months or older than 5-6 years. Food allergies require time to develop; most animals have been eating the offending diet for years with no trouble.

In cats, age is a less reliable factor in determining the type of allergy.

3. Have Previous Treatments Worked?

Seasonal allergies often respond well to corticosteroids like prednisone and dexamethasone. Food allergies are less responsive to steroids and are best treated with a novel protein diet or hydrolyzed protein diet. An elimination diet trial helps diagnose food allergies but is not a treatment on its own. During the trial, pets are fed a novel protein (a protein that a pet hasn’t been exposed to like venison, rabbit, or duck) and if symptoms improve, this new protein can be incorporated into their long-term diet.

4. Are There Gastrointestinal Issues?

Seasonal/environmental allergies and food allergies often exhibit similar symptoms. Food allergies, however, can cause digestive problems like vomiting or diarrhea in addition to itching, whereas seasonal allergies typically don’t.

5. Where Are the Lesions on Your Pet’s Skin? Lesions caused by seasonal allergies often appear on the paws, ears, around the eyes, armpits, abdomen, and anal region. Food allergies commonly cause chronic and recurring ear infections, licking of paws, and itching around the anal region.

Food and seasonal allergies rarely cause itching in the lower back area, also known as the 'flea bite zone.' If your pet is scratching this region, ensure flea control measures are in place before considering other causes.

In cats, the irritation pattern is not as characteristic and can be found in numerous other skin conditions. In fact, up to 25% of atopic cats have multiple types of allergies.

Once you’ve considered these questions, it’s time to consult your veterinarian for a proper diagnosis.

• For food allergies, an elimination diet trial is performed where a hypoallergenic diet is introduced for a set period. If symptoms improve and return when the original diet is reintroduced, a food allergy is diagnosed. Unfortunately, there is no other way to determine if a pet has a food allergy by performing blood, saliva, or hair tests.
• For seasonal allergies, allergy testing on the skin or blood might be done to identify specific allergens and formulate a treatment plan, including hyposensitization (allergy shots).

• Clearing Secondary Infections: Treating secondary infections is the first step for both seasonal and food allergies. These infections, caused by bacteria or yeast, thrive in the irritated areas of the skin. Normally harmless, these organisms can invade deeper skin layers when irritation occurs, often worsening the allergic response and perpetuating the itch.
• Hyposensitization (Allergy Shots): For seasonal allergies, hyposensitization is the only treatment that modifies the immune system to reduce allergic reactions. While it can take 6-12 months to show results, it offers long-term benefits. Up to 75% of dogs see improvement, with some requiring fewer medications over time.4 Your vet will walk you through how to administer these shots to your pets. In some cases, referral to a veterinary dermatologist may be necessary.
• Steroids: Steroids are commonly used to relieve itching, but long-term or high-dose use can lead to significant side effects. These include increased thirst, hunger, urination, immune suppression (making infections more likely), and elevated blood sugar, which can contribute to diabetes. While steroids are effective for acute flare-ups, long-term use should be limited. Topical steroids are preferable, as they provide itch relief with fewer side effects.
• Oclacitinib (Apoquel): Apoquel quickly alleviates itching but doesn’t treat the underlying inflammation. It’s ideal for itch relief, though infections causing itch must still be managed.
• Canine Atopic Dermatitis Immunotherapeutic (Cytopoint) Injections: Cytopoint provides relief for seasonal allergies, reducing itching for up to a month in 80% of dogs. This injection is effective within 24 hours and helps manage allergic reactions without the need for daily medication.
• Environmental Management: To help manage seasonal allergies, here are a few tips:
• Bathe your pet weekly to remove allergens.
• A therapeutic moisturizing shampoo can be used to restore the skin’s natural barrier.
• Wash bedding regularly to minimize dust mites.
• Use air conditioning and air filters.
• Keep your pet indoors during peak pollen times and away from freshly mowed lawns.
• Minimize houseplants.
• Maintain year-round flea control.
• Omega-3 Fatty Acids: Omega-3 supplements can help manage inflammation, reducing the need for steroids. It may take six weeks to see results, but they offer a natural approach to controlling allergic symptoms.
• Elimination Diet Trial (EDT) for Food Allergies: An elimination diet trial is the only reliable way to diagnose a food allergy. This process involves feeding your pet a hypoallergenic diet for 6-12 weeks, then reintroducing the suspected allergens to see if symptoms return. This trial must be strict—no treats, flavored medications, or food-sharing with other pets.

Once the problematic allergen is identified through the elimination diet trial, you can begin preparing a long-term novel protein diet or a hydrolyzed protein diet to manage your pet's food allergy. Your primary care vet can provide further details about constructing the right diet. A novel protein diet consists of a single protein source your pet has not been exposed to previously, such as venison, rabbit, or duck. A hydrolyzed protein diet includes a protein that has been degraded into smaller fragments, thereby aiding digestibility. GI symptoms usually improve within two weeks, and 90% of dogs and cats show improvement in skin-related symptoms within eight weeks.

Allergies are a chronic condition that require ongoing communication with your primary care provider or a veterinary dermatologist. However, acute issues like itching or infections can sometimes arise suddenly and unpredictably. Ruby Veterinary Urgent Care is here for all your itchy pets, regardless of the underlying cause.