Managing Your Pet’s Allergies
Your guide to calmer skin, healthier ears, and fewer itchy days.
Explore the Allergy Guide
🪲Flea Allergy
Why a single flea bite can cause intense itching—and why you may never see the flea.
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🐾 Is It Allergies?
Allergies in pets often show up as skin or ear problems rather than sneezing. Some pets are itchy all over, while others repeatedly lick their feet, rub their face, or develop recurring ear infections.
👂 Ear Problems & Allergies
Recurrent ear infections are very commonly associated with underlying allergies. The allergy changes the skin barrier inside the ear canal, making it easier for yeast and bacteria to overgrow.
Why do we perform ear cytology?
Cytology helps us see whether yeast, bacteria, or both are present. That matters because treatment should match what is actually in the ear.
Why does treatment change sometimes?
An ear that was mostly yeast last time may be mostly bacteria this time. Chronic ears can also develop resistant infections or biofilm.
🍽️ Food Allergies
Food allergy is one possible cause of chronic itching, recurrent ear infections, skin inflammation, and sometimes gastrointestinal upset. True food allergies are less common than many owners expect, and the problem is usually a reaction to a protein source in the diet.
What Can Food Allergy Look Like?
Some dogs have mainly skin and ear signs, while others also have gastrointestinal signs.
How Do We Diagnose a Food Allergy?
The most reliable way to diagnose food allergy is a strict elimination diet trial. Before choosing the diet, we need a thorough history of everything your pet has eaten before—including treats, table scraps, chews, flavored medications, and supplements.
The selected diet should use either a novel protein/carbohydrate source your pet has not eaten before or a hydrolyzed therapeutic diet.
Hydrolyzed therapeutic diets
The protein is broken into very small pieces so the immune system is less likely to recognize and react to it.
Examples: Purina HA, Hill’s z/d, Royal Canin Hydrolyzed.
Novel-protein therapeutic diets
Use a protein source your pet has truly never eaten before. Your pet’s diet history determines what counts as “novel.”
Why Prescription Diets Are Preferred for a True Food Trial
Over-the-counter foods may be labeled “limited ingredient,” “hypoallergenic,” or “sensitive skin,” but those terms do not guarantee they are appropriate for a diagnostic food trial. OTC diets can have undeclared proteins or cross-contamination during manufacturing.
OTC novel-protein foods may be useful as a more affordable starting point in some cases, but they do not provide the same level of control as a prescription therapeutic diet.
How Long Does the Trial Need to Last?
A complete trial can take 12 to 16 weeks. Improvement may be gradual, so it is important not to stop early just because your pet is not dramatically better after only a few weeks.
What Can Ruin a Food Trial?
- Treats, table scraps, or flavored chew toys
- Another pet’s food
- Flavored heartworm or other medications
- Flavored antibiotics, anti-inflammatories, vitamins, joint supplements, or coat supplements
- Garbage, compost, or food from visitors or neighbors
- Free-feeding in multi-pet homes
Everyone in the household needs to follow the same plan.
Tips to Make the Trial Easier
- Use pieces of the prescribed kibble as treats.
- If using canned therapeutic food, ask us whether it can be baked into small treats.
- Tell visitors and family members that your pet is on a strict food trial.
- Feed pets separately and do not leave other food down.
- Ask us before giving any new medication or supplement during the trial.
- Take photos every couple of weeks and keep a simple symptom diary.
Understanding Novel Protein Diets
A novel protein is simply a protein source your pet has not eaten before. There is no single protein that is automatically “novel” for every dog or cat—the right choice depends entirely on your pet’s individual diet history.
For example, if a dog has eaten chicken, beef, turkey, and lamb in foods, treats, chews, or flavored medications over the years, those proteins are no longer truly novel for that dog. A better trial may require a protein source the pet has never encountered.
The most important step is reviewing everything your pet has previously eaten before choosing the diet.
Examples of proteins that may be considered novel for some pets
- Rabbit
- Venison
- Duck
- Fish such as salmon or whitefish
- Other less commonly fed animal proteins
Whether any of these are actually novel depends on your pet’s previous exposure. Many modern pet foods and treats contain multiple proteins, which can make diet history more complicated than it first appears.
Novel Protein vs. Hydrolyzed Diets
Novel Protein Diet
Uses an intact protein your pet has not eaten before. The goal is to avoid proteins that may be triggering the immune response.
Hydrolyzed Diet
Uses protein that has been broken into very small pieces so the immune system is less likely to recognize it as an allergen.
Prescription vs. Over-the-Counter Novel Protein Diets
Prescription novel-protein diets are made specifically for therapeutic use and are generally preferred when we are trying to perform a true diagnostic food trial.
Over-the-counter limited-ingredient or novel-protein diets can sometimes be more affordable, but they may contain cross-contamination from other proteins or multiple protein sources. For that reason, an OTC diet may be useful as a starting point in some situations, but it may not be reliable enough to definitively rule food allergy in or out.
The most important thing is that your pet eats only the selected diet for the full trial period with no unapproved treats, table food, chews, flavored medications, or access to another pet’s food.
How Is Food Allergy Confirmed?
If your pet improves on the elimination diet, the next step may be a food challenge. The previous food or specific ingredients are reintroduced and the pet’s response is monitored. If the original signs return, that supports food allergy.
A properly performed elimination diet trial remains the key diagnostic tool.
🪲 Flea Allergy Dermatitis
For a pet with flea allergy dermatitis (FAD), it may take only one flea bite to trigger intense itching and inflammation. These pets are reacting to proteins in flea saliva, not simply to the number of fleas living on them.
Allergic pets often groom aggressively, and adult fleas are only one part of the flea life cycle. Eggs, larvae, and pupae are mainly found in the environment.
What Flea Allergy Often Looks Like
- Intense itching or chewing around the lower back and tail base
- Hair loss over the rump, tail base, or back thighs
- Small scabs or crusts
- Red, inflamed skin
- Secondary bacterial or yeast infections
- More widespread itching when allergy is severe or chronic
Why Flea Control Is Part of Flea Allergy Treatment
Flea-allergic pets do not need to be heavily infested to have a severe reaction. Because even one bite can trigger a flare, reliable flea prevention is one of the most important parts of managing flea allergy dermatitis.
Even after adult fleas on the pet are killed, immature flea stages already present in the environment can continue developing and emerging. Staying on prevention helps break that cycle.
What We Recommend to Control Fleas
For flea-allergic pets, flea prevention should generally be used year-round. Every dog and cat in the household should be on an appropriate flea-control product so untreated pets do not keep the cycle going.
- Keep every pet in the household on consistent flea prevention.
- Give doses on time—gaps in coverage allow new fleas to emerge and feed.
- Wash pet bedding regularly during an active infestation.
- Vacuum areas where pets spend time to help remove flea eggs and developing stages.
- Treat secondary yeast or bacterial skin infections when present.
- Remember that an established flea population may take time to fully control because immature stages are already in the environment.
If itching continues despite consistent prevention, let us know so we can evaluate for secondary infection or other allergies that may also be contributing.
🌿 Environmental Allergies (Atopic Dermatitis)
Environmental allergies — often called atopy or atopic dermatitis — happen when a pet’s immune system overreacts to normally harmless substances in the environment.
Unlike people, who often develop sneezing and watery eyes, allergic dogs and cats commonly show their allergies through their skin, paws, and ears.
What Environmental Allergies Can Look Like
🏠 House Dust Mite Control
Dust mites commonly live in bedding, mattresses, carpets, and upholstered furniture. This handout gives practical steps for reducing exposure at home, including bedding care, vacuuming, humidity control, and cleaning strategies.
🥣 Storage Mite Control
Storage mites can be associated with dry foods, grains, fabrics, bedding, and other household environments. This handout explains how to reduce contamination of dry pet food and how to store food more carefully for mite-allergic pets.
Common Environmental Triggers
- Grass and weed pollens
- Tree pollens
- Mold spores
- House dust mites
- Other environmental allergens your pet encounters indoors or outdoors
Some pets flare only during certain times of year, while others develop symptoms throughout the year depending on their individual triggers. Over time, a pet that once had seasonal allergies may begin having longer or more frequent flare-ups.
Why Do Allergic Pets Keep Getting Ear & Skin Infections?
Allergy inflammation weakens the normal skin barrier. Once the skin or ear canal becomes inflamed, yeast and bacteria can overgrow more easily. These secondary infections create even more itching and discomfort.
Allergy → itching and licking → damaged skin barrier → yeast/bacterial overgrowth → even more itching.
This is why controlling the allergy alone may not be enough during a flare. Active ear or skin infections often need to be treated separately.
How Are Environmental Allergies Diagnosed?
Environmental allergy is often diagnosed after we consider your pet’s history and symptoms and rule out or control other common causes of itching, including:
- Fleas and other parasites
- Secondary bacterial or yeast infections
- Food allergy, when appropriate
Allergy testing is not usually used simply to prove that a pet has allergies. Once environmental allergy is suspected or diagnosed, testing can help identify specific allergens for customized immunotherapy.
Managing Environmental Allergies
Environmental allergens are difficult to avoid completely, so treatment usually focuses on long-term control rather than a one-time cure. Most pets do best with a combination of approaches.
💊 Control the itch and inflammation
Depending on your pet, treatment may include medications such as Cytopoint, Apoquel, Zenrelia, corticosteroids, or other therapies selected by your veterinarian.
🛁 Medicated bathing & topical care
Regular bathing can physically remove pollen, dirt, and allergens from the skin while medicated shampoos, mousses, sprays, or wipes may also help support the skin barrier and control secondary yeast or bacteria.
🐾 Wipe paws after outdoor exposure
For pets that flare after grass or pollen exposure, wiping the paws, legs, and sometimes the underside of the body after time outdoors may help reduce the amount of allergen left on the skin.
🧺 Reduce allergens in the home
Regularly washing bedding, vacuuming, reducing dust buildup, and using good-quality air filtration may help decrease environmental exposure for some pets.
👂 Stay ahead of ear infections
Allergy-prone pets may need routine ear maintenance. If an ear becomes red, painful, smelly, or develops discharge, cytology helps determine whether yeast, bacteria, or both are present so treatment can be targeted.
🧪 Allergy testing & immunotherapy
For appropriate patients, environmental allergy testing can identify allergens such as pollens, molds, and dust mites. Those results can then be used to create allergen-specific immunotherapy in the form of allergy injections or drops.
Immunotherapy is a long-term approach designed to gradually change how the immune system responds to your pet’s allergens. Improvement takes time, and medications may still be needed while immunotherapy begins working.
Can Environmental Allergies Be Cured?
Usually, no — but they can often be managed very successfully. The goal is to:
- Keep itching at a comfortable level
- Reduce the number of ear and skin infections
- Protect the skin barrier
- Reduce severe seasonal flare-ups
- Use the lowest amount of medication needed to keep your pet comfortable
🩺 Treatment Options
Allergy treatment is rarely one-size-fits-all. The right plan depends on your pet’s age, symptoms, medical history, infections, allergy pattern, and how much support is needed during a flare.
That may mean controlling itch, treating secondary ear or skin infections, maintaining flea prevention, supporting the skin barrier, and—when appropriate—addressing the underlying environmental allergy with immunotherapy.
💉 Cytopoint®
In-clinic injection Targets allergic itchCytopoint is a monoclonal antibody injection used to help control allergic itch in dogs. It works by targeting a key itch-signaling protein rather than broadly suppressing the immune system.
For many dogs, one injection can provide weeks of relief. It can be especially useful for dogs whose owners prefer an injection over daily pills or for dogs in which an oral medication may not be the best fit.
💊 Apoquel® / Apoquel® Chewable
Oral medication Dogs 12 months+Apoquel (oclacitinib) is an oral JAK inhibitor used to control itching and inflammation associated with allergic dermatitis and atopic dermatitis in dogs at least 12 months of age.
It is available as both a tablet and a chewable formulation. Apoquel can work quickly, which makes it useful for dogs who need fast control of allergic itch.
💊 Zenrelia™
Once daily Dogs 12 months+Zenrelia (ilunocitinib) is a once-daily oral JAK inhibitor used to control itching and inflammation associated with allergic and atopic dermatitis in dogs at least 12 months of age.
Zenrelia has specific vaccination-related precautions. Dogs should be appropriately vaccinated before treatment, and your veterinarian will help plan medication timing around future vaccines.
💊 Numelvi™
Once daily with food Dogs 6 months+Numelvi (atinvicitinib) is a newer, second-generation selective JAK1 inhibitor approved for control of itching associated with allergic dermatitis in dogs 6 months of age and older.
It is given once daily with food and is designed to target the JAK1 pathways involved in itch and inflammation. Because it can be used in younger dogs than some other oral JAK options, it may be useful for certain patients with allergic dermatitis.
As with other prescription allergy medications, your veterinarian will consider your dog’s age, infection history, other medications, and overall health before prescribing it.
🧪 Allergy Testing + Customized Serum / Immunotherapy
Targets underlying environmental allergy Long-term approachFor pets with environmental allergies, blood allergy testing can help identify relevant pollens, molds, mites, and other allergens. Those results can then be used to formulate customized allergen-specific immunotherapy.
The customized “allergy serum” contains carefully selected allergens based on your pet’s test results and clinical history. It may be administered as allergy injections or, for some patients, as oral drops.
Unlike medications that mainly control symptoms, immunotherapy is designed to gradually change how the immune system responds to the allergens themselves. It takes time and is usually part of a long-term allergy plan.
💊 Corticosteroids
Steroids can be very effective for controlling significant itching and inflammation. Because repeated or long-term use can cause important side effects, we generally try to use them thoughtfully and choose other long-term strategies when appropriate.
🛁 Topical Therapy
Medicated shampoos, mousses, wipes, sprays, and ear products can remove allergens from the skin, support the skin barrier, and help manage secondary yeast or bacterial overgrowth. For many allergy patients, topical therapy is an important part of long-term control—not just an “extra.”
🐟 Omega-3 Fatty Acids & Skin Support
Veterinary omega-3 supplementation may help support the skin barrier and can be used alongside other allergy therapies. Supplements usually work gradually and are best thought of as supportive care rather than a stand-alone treatment for significant allergic itch.
If yeast or bacteria are contributing to the flare, treating the allergy medication alone may not be enough. Skin cytology, ear cytology, and targeted antimicrobial treatment may be needed.
Age restrictions, infection risk, vaccination considerations, other medications, and your pet’s medical history all influence which option is safest and most appropriate. We will help choose the treatment that fits your pet.
Allergy Testing & Immunotherapy Home Care
Back to Home🧪 Environmental Allergy Testing
Allergy testing is most useful once we already suspect that a pet has environmental allergies (atopic dermatitis). The goal is not simply to prove that a pet is “allergic.” Instead, testing helps identify which environmental allergens may be important for that individual pet so we can create a customized immunotherapy plan.
We may use Heska Allercept® IgE testing for appropriate patients with suspected environmental allergies.
What Can Environmental Allergy Testing Look For?
Testing may evaluate your pet’s response to allergens such as:
- Tree pollens
- Grass pollens
- Weed pollens
- Mold spores
- House dust mites
- Other environmental allergens relevant to our region
What Is the Test Actually Measuring?
Allercept testing looks for allergen-specific IgE antibodies in the blood. These results are interpreted together with your pet’s history, symptoms, seasonality, and environmental exposure.
The results must make sense with the pet’s history and environment. That is why allergy-test results are interpreted as part of the complete clinical picture rather than as a stand-alone diagnosis.
What Allergy Testing Does NOT Diagnose
Food allergy is best evaluated with a strict elimination diet trial using an appropriate hydrolyzed or novel-protein diet, followed by a food challenge when indicated.
Likewise, we do not generally use allergy testing simply to decide whether a pet has atopic dermatitis. Environmental allergy is usually diagnosed based on the pet’s history, examination, pattern of symptoms, and exclusion or control of other causes of itching.
What Is Included on the Allercept Companion Animal Panel?
Below are examples of the types of environmental allergens that may be included on the Allercept Companion Animal Panel. These images help show clients the wide variety of potential allergens that can be evaluated.
Why Do Allergy Testing?
The biggest reason to perform testing is to create allergen-specific immunotherapy.
Instead of only suppressing itching, immunotherapy is designed to gradually retrain the immune system to become less reactive to the allergens that are contributing to your pet’s disease.
How Are Immunotherapy Allergens Chosen?
Your pet’s test results are reviewed together with factors such as:
- Your pet’s clinical history
- Where your pet lives
- Local and regional plant exposure
- Seasonal pollen patterns
- Which allergens are most likely to be clinically relevant
- Possible cross-reactivity between related allergens
The goal is not simply to include every allergen that shows a positive result. A customized formula should focus on the allergens most likely to matter for your pet.
Immunotherapy Options
💉 Allergy Shots
Customized allergen injections are given on a schedule that gradually exposes your pet to carefully selected allergens. The dose and frequency may be adjusted based on your pet’s response.
Rechecks are important, especially during the first year, so we can evaluate progress and make adjustments if needed.
💧 Allergy Drops
For some pets, customized sublingual immunotherapy may be given as drops administered in the mouth. This can be an alternative to injections for appropriate patients.
How Quickly Does Immunotherapy Work?
Immunotherapy is not an instant anti-itch treatment. It takes time for the immune response to change.
Many pets may begin showing improvement within the first several months, but immunotherapy is generally continued for at least 12 months before deciding how well it is working for that patient.
Is Immunotherapy Safe?
Most pets tolerate immunotherapy well. Mild reactions can occasionally occur, such as temporary redness, itching at an injection site, or a temporary increase in itchiness.
What Should I Expect Long-Term?
Environmental allergies are usually a lifelong condition. Our goal with testing and immunotherapy is to improve long-term control by reducing how strongly your pet reacts to important allergens.
For many pets, a successful allergy plan may mean:
- Fewer severe flare-ups
- Less paw licking and scratching
- Fewer recurrent ear infections
- Fewer secondary skin infections
- Less dependence on anti-itch medications
- Better comfort and quality of life
The best results usually come from combining allergen-specific immunotherapy with good flea control, treatment of secondary infections, skin and ear care, and appropriate anti-itch medication when needed.
Environmental Allergies Treatment Options
📘 ALLERCEPT® Allergy Serum Owner Workbook
This client workbook explains allergy testing, customized immunotherapy, what to expect during treatment, injection instructions, possible side effects, and ways to reduce allergen exposure at home.
Download Allergy Serum Owner Workbook ↗How to Give Allergy Serum at Home
If your pet is prescribed allergen-specific immunotherapy, these videos demonstrate how allergy serum may be administered at home. Follow the exact dosing schedule and instructions provided for your pet.
Allergy Serum Administration – Video 1
Allergy Serum Administration – Video 2
💧 Home Care for Allergy-Prone Pets
- Keep pets on reliable flea prevention year-round.
- Use medicated shampoo, mousse, wipes, or sprays as directed.
- Wipe feet and lower legs after high-pollen outdoor exposure when appropriate.
- Follow your pet’s ear-cleaning schedule.
- Give allergy medications consistently and exactly as prescribed.
- Do not stop an elimination diet trial early because symptoms temporarily improve.
- Ask us before adding treats or supplements during a food trial.
✅ My Pet’s Allergy Plan
Use this as a quick reminder between visits.
Back to Home🚨 When Should You Call Us?
Please contact Three Rivers Animal Hospital if your pet’s itching is worsening, an ear becomes painful or develops odor/discharge, skin becomes raw or infected, or symptoms are not improving as expected.
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