Atopic Dermatitis in Dogs and Cats: Signs, Diagnosis and Treatment

Atopic Dermatitis in Dogs and Cats: Signs, Diagnosis and Treatment

By Dr Duncan Houston

An itchy pet does not automatically have atopic dermatitis.

Fleas, mites, food allergy, bacterial infection, yeast infection, ringworm and several other conditions can cause almost identical signs. A dog licking their paws or a cat grooming their belly bald may eventually be diagnosed with environmental allergy, but only after the common lookalikes have been properly investigated.

Atopic disease is usually chronic and cannot simply be cured with one injection, supplement or food change. The good news is that most affected dogs and cats can become substantially more comfortable when the diagnosis is methodical and treatment addresses the skin barrier, infection, parasites, inflammation and individual flare triggers together. (AAHA)

Quick Answer

Canine atopic dermatitis and feline atopic skin syndrome are chronic allergic skin conditions commonly associated with environmental allergens. They can cause paw licking, ear disease, scratching, overgrooming, hair loss, crusting and recurrent skin infections.

There is no single test that confirms either condition. Diagnosis requires a compatible clinical pattern and the exclusion or control of fleas, mites, infection and food allergy. Treatment may include anti-inflammatory medication, topical skin care, parasite control, management of secondary infection and allergen-specific immunotherapy. (AAHA)

What Is Atopic Dermatitis?

Atopic dermatitis is a chronic, relapsing and inflammatory skin disease involving an abnormal immune response, impaired skin-barrier function and sensitivity to environmental allergens.

In dogs, the accepted term is canine atopic dermatitis.

In cats, the preferred term is feline atopic skin syndrome, or FASS. This reflects the fact that allergic disease in cats is more variable and is not simply a feline version of canine atopic dermatitis. Cats may develop several different skin reaction patterns, and the role of allergen-specific IgE is less clearly defined than it is in dogs. (PubMed Central (PMC))

Feature	Dogs	Cats
Preferred term	Canine atopic dermatitis	Feline atopic skin syndrome
Typical pattern	Paw, face, ear, axillary, groin and abdominal itching	Overgrooming, miliary dermatitis, head and neck wounds or eosinophilic lesions
Diagnostic criteria	Favrot criteria may support clinical suspicion	No single clinical criteria set replaces exclusion of other diseases
Allergy testing	Used mainly to formulate immunotherapy	Used mainly to formulate immunotherapy
Common long-term medication options	JAK inhibitors, lokivetmab, ciclosporin, corticosteroids and immunotherapy	Ciclosporin, corticosteroids and selected off-label treatments
Lokivetmab	Can be used in dogs	Canine-specific and should not be used in cats

The diagnosis and treatment pathways overlap, but medication should never be transferred from one species to the other without specific veterinary guidance. (AAHA)

Is Atopy Only Caused by Airborne Allergens?

No.

The older phrase “inhalant allergy” makes it sound as though affected animals simply breathe pollen or dust into their lungs. The biology is more complicated.

Environmental allergens may include:

• House dust mites

• Storage mites

• Grass pollen

• Tree pollen

• Weed pollen

• Mould spores

• Insect allergens

• Other proteins encountered within the home or outdoor environment

Allergens may interact directly with the skin, particularly when the skin barrier is already abnormal. Exposure through inhalation, grooming or ingestion may also contribute, but environmental atopy should not be thought of as purely an airborne problem. (PubMed Central (PMC))

Is Atopic Dermatitis Genetic?

Genetic predisposition is important in canine atopic dermatitis, although inheritance is complex and involves interactions between genes, skin-barrier function, immune responses and environmental exposure.

Breed predisposition has been described in many populations, particularly among some retrievers, terriers, bulldog-type breeds, shepherds and companion breeds. However, the breeds most often affected differ between countries and bloodlines.

Breed can increase suspicion, but it cannot diagnose the disease. A mixed-breed dog can develop severe atopic dermatitis, while a dog from a commonly affected breed may be itchy for an entirely different reason. (PubMed Central (PMC))

The inherited contribution to feline atopic skin syndrome is less clearly characterised. Cats of any breed and lifestyle may be affected, including cats living completely indoors. (Wiley Online Library)

What Are the Signs of Atopic Dermatitis in Dogs?

Itching is the central sign, although the owner may first notice ear infections, saliva staining or recurrent skin infection rather than obvious scratching.

Common signs include:

• Licking or chewing the paws

• Red or inflamed skin between the toes

• Rubbing the face against furniture or carpet

• Scratching the ears

• Recurrent otitis externa

• Redness around the eyes, muzzle or lips

• Itching beneath the front legs

• Redness affecting the groin or abdomen

• Licking around the anus or perineum

• Recurrent bacterial skin infections

• Recurrent yeast dermatitis

• Hair loss

• Scabs, papules or crusts

• Thickened, darkened skin after chronic inflammation

• A strong or musty skin odour

The feet, face, ear pinnae, axillae, groin and abdomen are commonly affected. The edges of the ears and the lower back may remain relatively unaffected in classical atopic dermatitis, although this pattern is not universal. (AAHA)

Can Ear Infections Be the Main Sign?

Yes.

Some dogs present repeatedly with otitis externa before widespread skin disease becomes obvious. Signs may include:

• Head shaking

• Ear scratching

• Redness

• Increased wax

• Brown or yellow discharge

• Odour

• Pain when the ear is touched

• Narrowing of the ear canal in chronic cases

Allergy may be the underlying reason the ear canal remains inflamed, but bacteria and yeast often become secondary perpetuating factors. Ear cytology is therefore important rather than repeatedly prescribing medication based only on colour or smell. (AAHA)

What Does Atopic Skin Disease Look Like in Cats?

Cats generally develop one or more of four recognised allergic skin reaction patterns.

Self-Induced Alopecia

The cat repeatedly licks or bites the hair, causing symmetrical thinning or baldness.

Common areas include:

• The abdomen

• Groin

• Inner thighs

• Flanks

• Forelegs

• Lower back

Owners may never witness excessive grooming because many cats groom privately. The remaining hair often feels short or rough because it has been broken rather than falling out from the root. (AAHA)

Miliary Dermatitis

This produces numerous tiny crusted bumps that may feel like grains of sand beneath the coat.

They commonly occur around the:

• Neck

• Back

• Shoulders

• Base of the tail

• Sides of the body

Miliary dermatitis is a reaction pattern, not a diagnosis. Flea allergy is especially important, but food allergy, mites, FASS, ringworm and other diseases may appear identical. (AAHA)

Head and Neck Itching

Affected cats may scratch the face, ears, head or neck intensely enough to cause:

• Hair loss

• Scabs

• Deep scratches

• Bleeding

• Swelling

• Open wounds

• Secondary infection

Food allergy, flea allergy, ear disease, mites and fungal infection remain important alternatives in this pattern. (Wiley Online Library)

Eosinophilic Granuloma Complex

This describes several inflammatory lesion patterns, including:

• Moist, raised eosinophilic plaques

• Indolent ulcers affecting the upper lip

• Firm or linear eosinophilic granulomas

• Oral or tongue lesions

• Lesions affecting the caudal thighs, chin or paws

These lesions are frequently associated with allergic disease, but they do not reveal whether the trigger is food, fleas, environmental allergens or another cause. (AAHA)

Is Cat Overgrooming Usually Caused by Stress?

Not usually enough to assume so without a medical work-up.

Stress and compulsive grooming can occur, but parasites, allergy, infection and pain are common medical causes of hair removal. Cats also groom in response to bladder pain, arthritis, abdominal discomfort and neurological pain.

The mistake I see most often is calling symmetrical hair loss “anxiety” before checking for fleas, mites, food allergy and inflammatory skin disease. Behavioural overgrooming should remain on the list, but it should not become the convenient diagnosis simply because the cat looks calm during the consultation. (Wiley Online Library)

Can Atopic Disease Be Seasonal?

Yes, but not always.

A dog or cat reacting mainly to seasonal pollens may worsen during certain months. Animals sensitised to indoor allergens such as dust mites may remain itchy throughout the year.

The pattern may also evolve. A young dog may initially have a short seasonal flare and later develop year-round disease as additional allergens, infections or skin-barrier changes become involved.

Seasonality supports the history, but it neither proves nor excludes atopy. Food allergy, fleas and environmental allergens can coexist and blur the pattern. (PubMed Central (PMC))

How Serious Is Atopic Dermatitis?

Atopic dermatitis is usually a chronic comfort and quality-of-life problem rather than an immediate threat to life. The urgency increases when self-trauma, infection, severe ear pain or a separate acute allergic reaction occurs.

Risk level	What it may look like	What to do
Lower risk	Occasional paw licking or grooming without wounds, pain or infection	Track the pattern and arrange a routine veterinary examination if it persists
Moderate	Daily itching, visible hair loss, recurrent ear redness, scabs or disturbed sleep	Arrange a veterinary examination within the next few days
High risk	Raw skin, pus, strong odour, severe ear pain, bleeding, rapidly spreading lesions or reduced appetite	Seek same-day veterinary care
Critical	Facial or tongue swelling, difficulty breathing, open-mouth breathing in a cat, blue or grey gums, collapse or altered awareness	Attend an emergency veterinary hospital immediately

A pet tearing at their skin all night is not “just itchy”. Even when the problem is not life-threatening, uncontrolled pruritus causes significant distress and can create infection and injury quickly. (AAHA)

When Is This an Emergency?

Atopic dermatitis itself rarely causes sudden collapse or breathing failure.

Seek emergency veterinary treatment if your dog or cat develops:

• Facial or tongue swelling

• Difficulty breathing

• Open-mouth breathing in a cat

• Blue, grey or very pale gums

• Collapse

• Severe weakness

• Rapidly progressing hives

• Repeated vomiting or diarrhoea with swelling or weakness

• Seizures or altered awareness

• A severe reaction soon after a medication, vaccination, sting or food exposure

These signs may indicate anaphylaxis or another major emergency rather than a routine atopic flare.

Arrange same-day veterinary care for:

• Raw or bleeding skin

• Pus or a strong odour

• Fever or marked lethargy

• Severe ear pain

• A swollen ear flap

• Head tilt or loss of balance

• Wounds around the eyes

• Refusal of food

• Rapidly spreading lesions

Do not spend the day trying three shampoos and a leftover antihistamine while the pet continues removing its own skin. (AAHA)

What Else Can Look Like Atopic Dermatitis?

Atopy is only one possible cause of itching.

Flea Allergy Dermatitis

A flea-allergic dog or cat may react intensely to very limited exposure.

You may not see fleas because:

• The animal has groomed them away

• Flea numbers are low

• Exposure occurred several days earlier

• Only one household pet is visibly affected

Dogs commonly develop itching around the lower back, tail base and caudal thighs, while cats may develop miliary dermatitis, overgrooming or head and neck lesions.

The absence of visible fleas does not rule out flea allergy. (AAHA)

Food Allergy

Food allergy can look clinically identical to environmental atopic dermatitis.

Possible signs include:

• Nonseasonal itching

• Paw licking

• Recurrent ear disease

• Head and neck itching in cats

• Miliary dermatitis

• Eosinophilic lesions

• Vomiting

• Diarrhoea

• Increased stool frequency

• Excess gas

Dogs may have food-induced atopic dermatitis, environmental atopic dermatitis or both. Clinical appearance alone does not reliably identify which one is present. (PubMed Central (PMC))

Mites and Other Parasites

Important possibilities include:

• Sarcoptic mange

• Demodicosis

• Ear mites

• Cheyletiella

• Demodex gatoi in cats

• Notoedres mites in relevant regions

• Lice

Some mites are difficult to find, particularly when an animal has groomed extensively or has only low parasite numbers. Repeat sampling or an appropriate treatment trial may be recommended. (PubMed Central (PMC))

Bacterial and Yeast Infections

Bacterial pyoderma, yeast dermatitis and otitis can cause substantial itching independently of the underlying allergy.

Possible clues include:

• Pustules

• Papules

• Circular crusts

• Greasy skin

• Darkened skin

• Strong odour

• Ear discharge

• Moist lesions

• Pain

• Sudden worsening of previously controlled allergy

Skin and ear cytology can identify organisms and inflammatory cells within minutes. Infection should be treated while the itch and underlying allergic disease are managed concurrently. (AAHA)

Ringworm

Dermatophytosis may cause:

• Hair loss

• Broken hairs

• Scaling

• Crusting

• Redness

• Variable itching

• Nodules or unusual inflammatory lesions

Ringworm is especially important in cats because it may spread to people and other animals. Fungal culture, PCR, Wood’s lamp examination and microscopic hair evaluation may be used depending on the patient. (AAHA)

Contact Irritation

Cleaning products, shampoos, plants, topical medication, floor treatments and other substances may irritate the skin.

Contact disease usually affects areas that repeatedly touch the offending surface, such as:

• Feet

• Abdomen

• Groin

• Muzzle

• Sparsely haired skin

Contact irritation is much less common than owners often assume, but timing and distribution may make it clinically relevant.

Pain or Behavioural Disease

Licking one specific joint, limb or section of the abdomen may reflect pain rather than itch.

Behavioural grooming becomes more likely when:

• Medical causes have been investigated

• Grooming changes with stress or social conflict

• Lesions are compatible with self-trauma

• The pattern responds to behavioural and environmental treatment

Medical and behavioural disease may also occur together.

Less Common but Important Diseases

Conditions that may resemble allergy include:

• Autoimmune skin disease

• Drug reactions

• Cutaneous lymphoma

• Epitheliotropic lymphoma

• Mast cell disease

• Endocrine disease complicated by infection

• Nutritional disease

• Keratinisation disorders

• Other inflammatory or neoplastic skin conditions

Skin biopsy becomes particularly important when lesions are unusual, nodular, ulcerative, poorly responsive or not convincingly itchy. (AAHA)

How Do Veterinarians Diagnose Atopic Dermatitis?

There is no single definitive atopy test.

Diagnosis is built through a sequence:

1. Identify a compatible clinical pattern.

2. Investigate parasites and infection.

3. Control fleas and mites.

4. Treat secondary skin and ear disease.

5. Perform a diet trial when food allergy remains possible.

6. Reassess the response.

7. Diagnose atopy only after reasonable alternatives have been excluded or controlled.

8. Use allergy testing if immunotherapy is planned. (AAHA)

Step 1: Take a Detailed History

Useful information includes:

• Age when itching first began

• Seasonal versus year-round signs

• Areas first affected

• Indoor and outdoor lifestyle

• Current flea and parasite control

• Every food, treat and chew given

• Previous medication responses

• Frequency of ear infections

• Contact with other animals

• Travel history

• Whether people or other pets have skin lesions

• Gastrointestinal signs

• Changes in environment or cleaning products

Photographs and videos from home are useful because pets may scratch or groom less during a consultation. (AAHA)

Step 2: Perform a Complete Skin and Ear Examination

The examination should include:

• Paws and nail folds

• Ear pinnae and ear canals

• Face and lips

• Axillae

• Groin

• Abdomen

• Perineal area

• Skin folds

• Tail base

• Oral cavity in cats

• Areas hidden beneath thick coat

The distribution of lesions helps organise the differential list, but no distribution is diagnostic by itself. (AAHA)

Step 3: Collect a Minimum Dermatological Database

Depending on the presentation, testing may include:

• Skin cytology

• Ear cytology

• Skin scrapings

• Hair examination

• Flea combing

• Fungal testing

• Bacterial culture in selected cases

• Additional blood or urine testing when systemic disease is suspected

This basic work-up is often more useful than immediately ordering a broad allergy panel. (AAHA)

Step 4: Treat Itching During the Investigation

The animal does not need to remain miserable while the diagnosis is being established.

AAHA guidance specifically recommends controlling pruritus during the diagnostic process while parasites, infection and underlying allergy are investigated. Severe itch can damage the skin, impair sleep, reduce appetite and make treatment harder. (AAHA)

Medication may affect interpretation of later testing or diet response, so the veterinarian should document:

• Which drug was used

• When it started

• When it stopped

• How much improvement occurred

• Whether infection was also treated

• Whether signs returned afterward

Step 5: Treat Infection and Parasites Concurrently

Secondary bacterial infection, yeast disease and otitis should be treated at the same time as the animal’s itching and allergy investigation.

Waiting for every infection to disappear before controlling inflammation is unnecessary and may prolong suffering. Conversely, prescribing an anti-itch drug while ignoring obvious pyoderma or yeast overgrowth may produce an incomplete response. (AAHA)

Step 6: Complete a Food-Elimination Trial

A strict elimination diet is required when food allergy remains possible, particularly with year-round signs.

The diet may use:

• An appropriately hydrolysed veterinary diet

• A genuinely novel protein diet

• A carefully formulated home-prepared diet in selected cases

For skin disease, the trial is generally continued for approximately eight weeks. Everything the animal eats matters, including treats, flavoured medication, dental chews, supplements and food stolen from another pet. (PubMed Central (PMC))

If the skin improves, the previous diet must be reintroduced to see whether signs return. Improvement during the elimination phase alone does not confirm food allergy because flea control, infection treatment, seasonal change and anti-inflammatory medication may have improved during the same period. (PubMed Central (PMC))

What Are the Favrot Criteria?

The Favrot criteria are clinical features that may support suspicion of canine atopic dermatitis after other important causes have been investigated.

One commonly used eight-point set includes:

1. Signs beginning before three years of age

2. A mostly indoor lifestyle

3. Glucocorticoid-responsive itching

4. Chronic or recurrent yeast infection

5. Affected front feet

6. Affected ear pinnae

7. Unaffected ear margins

8. Unaffected dorsolumbar area

When five criteria are present, the reported sensitivity is approximately 85% and specificity approximately 79%. This does not mean the dog has an 85% probability of atopic dermatitis. It means the criteria may miss or misclassify a meaningful proportion of patients when used alone. (PubMed Central (PMC))

The criteria cannot:

• Exclude fleas

• Exclude mites

• Exclude infection

• Separate food-induced from environmental atopic dermatitis

• Replace a diet trial

• Replace clinical judgement

They are a supporting framework, not an allergy calculator.

Can a Blood Test Diagnose Atopic Dermatitis?

No.

Serum allergen-specific IgE testing and intradermal allergy testing identify evidence of sensitisation. Healthy animals and animals with other skin diseases may also produce positive results.

The main reason to perform these tests is to identify clinically relevant environmental allergens for allergen-specific immunotherapy after atopic disease has already been diagnosed. (AAHA)

The correct order is:

1. Diagnose the allergic skin syndrome clinically.

2. Exclude or control fleas, mites, infection and food allergy.

3. Decide whether immunotherapy is appropriate.

4. Perform intradermal or serum testing to help formulate the treatment.

Ordering an allergy panel first commonly produces a long list of mites, grasses and trees without proving that any of them caused the pet’s current signs.

What Is Intradermal Allergy Testing?

Intradermal testing involves injecting small quantities of selected allergens into the skin and assessing local reactions.

Dogs and cats usually require sedation. Results must be interpreted alongside:

• Geographic exposure

• Seasonality

• Clinical pattern

• Medication history

• Test controls

• The clinician’s experience

The goal is not to discover everything to which the animal has ever reacted. It is to select a sensible group of allergens for immunotherapy. (Wiley Online Library)

How Is Atopic Dermatitis Treated?

Treatment is rarely one thing.

A successful plan usually combines:

• Reliable parasite control

• Treatment of secondary infection

• Itch and inflammation control

• Ear management

• Topical skin care

• Food investigation where appropriate

• Environmental trigger reduction

• Long-term maintenance medication

• Allergen-specific immunotherapy in selected patients

The exact combination changes with severity, season, species, age, concurrent disease, owner preference, cost and how easily medication can be administered. (AAHA)

Treatment of Atopic Dermatitis in Dogs

Corticosteroids

Corticosteroids can provide rapid control of itching and inflammation.

They may be useful for:

• Short acute flares

• Severe widespread inflammation

• Localised lesions when used topically

• Temporary control while slower treatment begins

Possible adverse effects include:

• Increased thirst and urination

• Increased appetite

• Weight gain

• Panting

• Muscle loss

• Skin thinning

• Increased infection risk

• Gastrointestinal complications

• Endocrine effects with prolonged use

Oral or topical formulations can be reduced or stopped more easily than long-acting injections. Repeated long-acting injections are generally avoided for routine chronic management because the exposure cannot be withdrawn if adverse effects develop. (PubMed Central (PMC))

Oclacitinib

Oclacitinib is a Janus kinase inhibitor used in dogs.

It has a rapid onset and is both:

• Antipruritic

• Anti-inflammatory

This directly corrects the original article’s claim that it relieves itch without reducing inflammation.

It may be used for acute flares and long-term control, but it is not appropriate for every dog. Age, infection, neoplasia history, concurrent medication and general health must be considered. (AAHA)

Newer Canine JAK Inhibitors

Additional canine JAK inhibitors are now available in some regions.

Ilunocitinib has been approved for allergic pruritus and canine atopic dermatitis in dogs at least 12 months old in the United States. Its US label contains significant instructions concerning vaccination and infection risk, including avoiding vaccination during treatment and using drug-specific washout periods. (U.S. Food and Drug Administration)

Atinvicitinib received US approval in February 2026 for controlling pruritus associated with allergic dermatitis in dogs at least six months old. Current US field-safety information is limited to 28 days, and reported concerns include gastrointestinal signs and laboratory abnormalities. (Animal Drugs at FDA)

These medications are not interchangeable simply because they are all described as JAK inhibitors. Their:

• Approved ages

• Licensed indications

• Dosing schedules

• Vaccine instructions

• Infection precautions

• Monitoring recommendations

• Long-term evidence

may differ substantially by drug and country.

Lokivetmab

Lokivetmab is a canine monoclonal antibody targeting interleukin-31, an important itch-signalling cytokine in dogs.

It may begin reducing itching within the first few days and can improve associated inflammatory skin lesions. Response and duration vary between dogs, so a monthly injection should not be promised as guaranteed complete control. (Wiley Online Library)

A 2024 field study involving 150 dogs found lokivetmab was effective and generally well tolerated during longer-term use, although the study was retrospective and not every patient responded. (Wiley Online Library)

Lokivetmab may be particularly useful when:

• Giving tablets is difficult

• A dog has certain concurrent medical conditions

• Rapid itch control is needed

• Owners prefer clinic-administered treatment

• Other medications have caused unacceptable adverse effects

It remains essential to treat infection, otitis and other flare factors even when the injection reduces scratching.

Ciclosporin

Ciclosporin modifies T-cell activity and can provide effective long-term control.

Its onset is slower than corticosteroids or most JAK inhibitors, commonly taking several weeks. A faster-acting medication may therefore be used temporarily while ciclosporin begins working. (AAHA)

Possible adverse effects include:

• Vomiting

• Diarrhoea

• Reduced appetite

• Gingival overgrowth

• Excessive hair growth

• Papillomas

• Increased susceptibility to some infections

Once good control is achieved, the veterinarian may reduce the frequency to find the lowest effective maintenance schedule.

Topical Corticosteroids

Topical corticosteroids can be effective for localised lesions.

They may be especially useful around:

• Feet

• Abdomen

• Groin

• Localised inflamed patches

• Ear pinnae, when the product is appropriate

Repeated daily use on the same skin may cause thinning and fragility. Treatment should follow a veterinary plan rather than continuing indefinitely whenever the area looks pink. (PubMed Central (PMC))

Bathing and Topical Skin Care

Bathing may help by:

• Removing surface allergens

• Washing away crusts and debris

• Supporting skin hydration

• Reducing microbial overgrowth

• Delivering prescribed topical medication

There is no single ideal bathing frequency for every dog. During an active flare, bathing may be recommended more frequently. A well-controlled dog may need much less.

The shampoo should match the skin problem. A gentle emollient product may suit dry allergic skin, while bacterial or yeast disease may require a medicated product. An irritating or overly drying shampoo can worsen the flare. (PubMed Central (PMC))

Essential Fatty Acids

Essential fatty acids may improve coat quality and provide a modest medication-sparing effect in some dogs.

They:

• Do not provide rapid relief

• May take several weeks or months to show any benefit

• Are unlikely to control moderate or severe disease alone

• Should be considered an adjunct rather than a replacement for effective medication

The total formulation and dose matter more than the words “omega-3” on the front of a packet. (AAHA)

Antihistamines

Antihistamines provide limited and inconsistent benefit in canine atopic dermatitis.

They may help:

• Mildly affected dogs

• Dogs with predictable seasonal exposure

• As part of a wider maintenance plan

• When administered before a flare rather than after severe inflammation has developed

They are generally poor rescue treatment for a dog already chewing their feet raw. Human combination products should never be administered without veterinary guidance. (AAHA)

Treatment of Feline Atopic Skin Syndrome

Cats require a separate treatment plan.

Medications commonly used in dogs may be unlicensed, insufficiently studied or inappropriate for cats. (AAHA)

Corticosteroids in Cats

Systemic corticosteroids have the strongest evidence for rapid control of feline allergic skin inflammation.

They may improve:

• Head and neck itching

• Miliary dermatitis

• Self-induced alopecia

• Eosinophilic plaques

• Other inflammatory lesions

Potential adverse effects include:

• Increased appetite

• Weight gain

• Increased thirst or urination

• Diabetes mellitus

• Skin fragility

• Infection risk

• Muscle loss

• Cardiovascular complications in susceptible cats

The goal is to use the lowest effective dose for the shortest necessary period or transition to a suitable long-term plan. (Wiley Online Library)

What About Long-Acting Steroid Injections?

Long-acting injections may appear convenient when a cat is difficult to medicate.

The major disadvantage is that the dose cannot be taken back. If the cat develops diabetes, infection or another complication, the medication may remain active for weeks.

Repeated injections should not replace diagnosis and a structured long-term plan simply because giving tablets has become a domestic hostage negotiation.

Ciclosporin in Cats

Ciclosporin is one of the best-supported long-term treatments for FASS.

Improvement usually takes several weeks. Once control is achieved, some cats can be maintained on less frequent treatment. (Wiley Online Library)

Possible adverse effects include:

• Vomiting

• Diarrhoea

• Excessive salivation

• Reduced appetite

• Lethargy

• Gingival overgrowth

• Increased susceptibility to infection

Cats receiving immunosuppressive treatment should not be fed raw meat or allowed to hunt without discussing the infectious risks with their veterinarian.

Oclacitinib in Cats

Oclacitinib is not licensed for cats in many countries and remains an off-label treatment.

Smaller prospective studies and a 2026 retrospective series involving 238 cats suggest it may reduce signs in some feline dermatology patients and may be reasonably tolerated. However, feline dose requirements differ from dogs, and retrospective evidence does not establish the same long-term safety certainty available for licensed canine use. (PubMed)

A veterinarian may recommend:

• Baseline blood tests

• Repeat blood cell counts

• Blood chemistry monitoring

• Screening for infection

• Reviewing FIV and FeLV status

• Preventing raw-meat exposure and hunting

• Careful assessment of any vomiting, diarrhoea or lethargy

Do not use leftover canine oclacitinib for an itchy cat.

Lokivetmab in Cats

Lokivetmab is a canine-specific monoclonal antibody.

It is not a feline equivalent of an allergy injection and should not be administered to cats. (AAHA)

Topical Treatment in Cats

Selected topical corticosteroids, mousses, wipes or medicated products may help localised lesions.

The main practical limitations are:

• The cat licking the medication

• Difficulty reaching fur-covered areas

• Stress during application

• Systemic absorption

• Skin thinning after inappropriate prolonged use

Only products confirmed as safe for cats should be used. Essential oils, human creams, dog flea products and household disinfectants can be dangerous.

Antihistamines, Fatty Acids and PEA

Antihistamines, essential fatty acids and palmitoylethanolamide may provide mild or partial benefit in some cats.

Evidence suggests these are usually adjuncts rather than dependable monotherapy for moderate or severe FASS. (Wiley Online Library)

What Is Allergen-Specific Immunotherapy?

Allergen-specific immunotherapy involves administering gradually controlled quantities of selected environmental allergens.

It may be delivered through:

• Subcutaneous injections

• Sublingual drops in some protocols

• Accelerated induction protocols under specialist supervision

The formula is created using allergy-test results together with the animal’s history and genuine environmental exposure. (PubMed Central (PMC))

Is Immunotherapy a Cure?

Not reliably.

Immunotherapy aims to alter the immune response and may:

• Reduce itching

• Reduce flare frequency

• Reduce medication requirements

• Improve long-term control

• Occasionally produce prolonged remission

It does not provide rapid relief. Other medication is normally continued while the treatment begins working.

For dogs, published evidence suggests that approximately 60% may achieve at least a 50% clinical improvement with subcutaneous immunotherapy, although study methods and treatment protocols vary. (PubMed)

Immunotherapy should usually be continued for at least one year before being declared unsuccessful unless adverse effects or another clear reason requires earlier discontinuation. (PubMed Central (PMC))

Does Immunotherapy Work in Cats?

Evidence is less robust than in dogs, but recent results are encouraging.

A 2025 retrospective multicentre study evaluated 158 cats with FASS. Among 42 treated cats with one-year follow-up, 31 had at least a 30% reduction in medication scores, while 11 had no detected benefit. Loss to follow-up and the retrospective design mean this should not be interpreted as a guaranteed 74% success rate for every cat. (Wiley Online Library)

Immunotherapy may be worth considering when:

• FASS has been properly diagnosed

• Long-term medication is required

• Environmental sensitisation is clinically plausible

• The cat tolerates the administration method

• Owners understand that results take months

How Long Do Allergy Treatments Take to Work?

Treatment	Typical onset	Main role
Corticosteroids	Hours to days	Rapid flare control
Oclacitinib in dogs	Hours to days	Rapid itch and inflammation control
Lokivetmab in dogs	Hours to several days	Itch and lesion reduction
Ciclosporin	Several weeks	Long-term immune modulation
Essential fatty acids	Weeks to months	Adjunctive support
Antihistamines	Variable	Mild adjunctive control
Immunotherapy	Months, sometimes up to one year	Long-term disease modification

A treatment should not be labelled ineffective before its expected onset, but an animal should not be left severely uncomfortable while waiting for a slow medication to work. (AAHA)

What Environmental Changes Can Help?

Complete avoidance of environmental allergens is rarely possible.

Practical measures may include:

• Washing the pet’s main bedding regularly

• Keeping bedding dry

• Reducing cigarette smoke, vaping aerosols and strong fragrances

• Cleaning the areas where the pet sleeps

• Controlling excessive indoor humidity

• Wiping paws or coat after heavy pollen exposure

• Avoiding a clearly identified individual trigger

• Using low-dust litter for cats with concurrent respiratory sensitivity

Environmental management should be targeted. There is little benefit in removing every houseplant, rug and soft toy without evidence that these items contribute to the pet’s flares.

Published canine guidance notes that evidence is insufficient to make universal recommendations about humidity, detergent, stress or household modifications. Owners should instead observe whether specific environments repeatedly worsen their individual pet’s condition. (PubMed Central (PMC))

Should Allergic Pets Be Bathed Every Week?

Not necessarily.

Bathing frequency depends on:

• Species

• Skin dryness

• Infection

• Product used

• Coat type

• Season

• Severity

• The animal’s tolerance

Some dogs benefit from frequent bathing during a flare. Others become dry and irritated if an unsuitable shampoo is used too often.

Many cats find bathing highly stressful. Wipes, mousses or local cleaning may be more practical when topical care is needed.

The best bathing schedule is the one that improves the skin without creating irritation or a weekly wrestling event worthy of pay-per-view.

How Should Atopic Disease Be Monitored?

Useful things to track include:

• Weekly itch score

• Paw licking

• Ear redness or discharge

• New lesions

• Night-time scratching

• Sleep disturbance

• Grooming frequency

• Body weight

• Gastrointestinal signs

• Medication doses

• Rescue medication use

• Possible seasonal or environmental triggers

Photographs taken from the same angle and lighting can reveal gradual improvement that is difficult to notice day to day.

A simple zero-to-ten itch score can help:

• 0: No abnormal scratching, licking or grooming

• 1 to 3: Mild and occasional

• 4 to 6: Daily and noticeable

• 7 to 8: Frequent, disturbing sleep or damaging skin

• 9 to 10: Severe or near-constant self-trauma

The exact number matters less than using the same system consistently.

Why Does Previously Successful Treatment Stop Working?

Loss of control does not always mean the main medication has “stopped working”.

Common reasons include:

• Flea exposure

• Bacterial infection

• Yeast overgrowth

• Ear infection

• Missed medication

• An expired or empty product

• Seasonal pollen increase

• New food exposure

• Inadequate bathing or topical technique

• Progression of the underlying disease

• A new unrelated skin disorder

AAHA guidance recommends returning to the history, physical examination and minimum dermatological database whenever a previously successful protocol begins failing. (AAHA)

When Should You See a Veterinary Dermatologist?

Referral should be considered when:

• The diagnosis remains uncertain

• Itching persists despite a structured work-up

• Ear infections keep returning

• Skin infections recur repeatedly

• Several medications have failed

• Adverse effects limit treatment

• Immunotherapy is being considered

• Intradermal testing is required

• Lesions are unusual or may require biopsy

• The owner needs a sustainable long-term plan

• Treatment cost is increasing without clear progress

Referral is not an admission that nothing can be done. In many cases, it is the fastest way to stop repeatedly treating the same infection while the underlying disease continues running the show.

What Should You Do Right Now?

If the Itching Is Mild

1. Photograph the affected areas.

2. Record when the pet scratches, licks or grooms.

3. Check whether parasite prevention is current.

4. Look for ear redness, odour, discharge or pain.

5. Check the skin for crusts, pustules or moist areas.

6. Arrange a veterinary examination if the signs persist or recur.

If the Skin Is Raw, Painful or Infected

Arrange same-day veterinary care.

A recovery collar may temporarily reduce further self-trauma, but it does not treat infection or inflammation.

Do not apply:

• Human steroid cream

• Zinc cream

• Tea tree oil

• Essential oils

• Alcohol

• Hydrogen peroxide

• Household disinfectant

• Leftover ear medication

Before the Veterinary Appointment

Prepare a list of:

• Current food

• Previous foods

• Treats

• Chews

• Supplements

• Parasite preventatives

• Shampoos

• Ear products

• Previous anti-itch medication

• Response to each treatment

Bring videos of scratching, coughing, grooming or unusual behaviour when relevant.

During the Diagnostic Process

Follow each trial fully.

That may mean:

• Giving parasite control on time

• Treating all relevant household pets

• Completing prescribed infection treatment

• Feeding only the elimination diet

• Attending planned rechecks

• Avoiding unapproved treats and supplements

• Recording response and adverse effects

Half-completing several different trials creates expensive confusion. Properly completing one step at a time usually gets the diagnosis faster.

Common Mistakes With Atopic Dermatitis

Ordering Allergy Testing First

A positive pollen or mite result does not diagnose atopy. Parasites, infection and food allergy still need to be addressed.

Stopping Flea Control Because No Fleas Are Visible

A sensitive animal may react to minimal exposure, and grooming can remove the evidence.

Treating Only the Infection

Antibiotics or antifungal treatment may temporarily improve the skin, but infection often returns if the underlying allergic inflammation remains uncontrolled.

Treating Only the Allergy

Anti-itch medication may appear ineffective when a painful bacterial or yeast infection remains present.

Stopping a Diet Trial Too Early

Two or three weeks is usually insufficient for allergic skin disease.

Skipping the Food Challenge

Improvement on an elimination diet does not confirm food allergy unless the previous food causes a relapse.

Assuming a Bald Cat Is Stressed

Medical overgrooming is common and should be investigated before the problem is labelled behavioural.

Repeating Long-Acting Steroid Injections

Temporary convenience can accumulate into diabetes, infection and other adverse effects without providing a sustainable diagnostic plan.

Using Dog Medication in a Cat

Species-specific differences matter. Lokivetmab should not be used in cats, and off-label oclacitinib requires feline-specific dosing and monitoring.

Expecting One Medication to Prevent Every Flare

Atopic disease changes with season, infection, flea exposure and skin-barrier health. Long-term control usually requires a written plan for maintenance and separate flare treatment.

Can Atopic Dermatitis Be Prevented?

There is no proven method that prevents every genetically predisposed dog or cat from developing atopic disease.

Practical long-term measures include:

• Reliable flea and parasite prevention

• Early treatment of skin and ear infections

• Appropriate bathing and skin-barrier care

• Avoiding confirmed individual triggers

• Keeping bedding clean and dry

• Maintaining a healthy body condition

• Completing food trials correctly

• Recording seasonal flare patterns

• Giving maintenance medication consistently

• Attending regular veterinary rechecks

• Considering responsible breeding decisions in severely affected dogs

Rotating through many unusual proteins, feeding grain-free food or giving an “immune booster” has not been shown to prevent environmental atopy.

What Is the Prognosis?

Atopic dermatitis is generally chronic and relapsing.

It may be:

• Seasonal

• Year-round

• Mild and easily controlled

• Complicated by recurring infection

• Progressive over time

• Present alongside food or flea allergy

Most affected animals can achieve good quality of life, but many require ongoing treatment. Some need medication only during predictable seasons, while others require continuous maintenance and a separate flare protocol. (AAHA)

Flares do not automatically mean that the owner has failed or the treatment has permanently stopped working. They often indicate that infection, parasite exposure, seasonal allergens or another flare factor needs to be identified and corrected.

The realistic goal is not always completely medication-free skin. It is a comfortable animal with intact skin, minimal infection, controlled ears and the lowest treatment burden that reliably maintains quality of life.

Frequently Asked Questions

Can atopic dermatitis be cured?

It is usually managed rather than permanently cured. Some animals experience long remissions, particularly with immunotherapy, but future flares remain possible.

Can cats get atopic dermatitis?

Cats develop a related condition called feline atopic skin syndrome. It commonly appears as overgrooming, miliary dermatitis, head and neck itching or eosinophilic lesions.

Can a blood allergy test diagnose atopy?

No. Blood and intradermal allergy tests identify sensitisation and are used mainly to formulate immunotherapy after atopic disease has been diagnosed clinically.

Does every atopic pet need a special diet?

No. A strict elimination diet is used to investigate food allergy, but environmental atopy does not automatically require lifelong hypoallergenic food.

How often should an allergic dog be bathed?

There is no universal schedule. Some dogs benefit from frequent bathing during flares, while others need less. The product, infection status, coat and skin response determine the best frequency.

Is lokivetmab safe for cats?

No. Lokivetmab is a canine-specific treatment and should not be administered to cats.

The Most Important Takeaway

Atopic dermatitis is a diagnosis of exclusion, not the result of one blood test, one breed pattern or one itchy body part.

The same signs can be caused by fleas, mites, food allergy, bacterial infection, yeast, ringworm, pain and several less common diseases. A reliable diagnosis starts with the history, a complete examination, skin and ear testing, parasite control and a properly completed food trial when indicated.

Once atopic disease is established, treatment should be tailored to the species and the individual patient. Dogs may benefit from JAK inhibitors, lokivetmab, ciclosporin, corticosteroids, topical care and immunotherapy. Cats have stronger evidence for corticosteroids and ciclosporin, while other treatments require more cautious off-label decision-making.

The aim is not to chase every microscopic allergen out of the house. It is to control inflammation, protect the skin barrier, prevent infection, identify real flare factors and give the pet a treatment plan that can actually be maintained.

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If your dog or cat is constantly scratching, licking, overgrooming or developing recurring ear and skin problems, ASK A VET™ can help you organise the signs and understand what should be investigated next alongside your treating veterinarian.