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Allergies in Pets: Dog Itching? Cat Itching? Here’s Our Expert Guide.

It’s heartbreaking to see your dog or cat go through the misery that’s caused by allergies in pets. Start your research with this expert guide.

Allergies in pets
Allergies in pets are frustrating and difficult to treat. Photo: LUM3N

Veterinarians see lots of itchy pets. Skin problems are common — and frustrating for everyone involved.

A pet scratching constantly or who has icky-yicky-licky lesions all over their body makes you take notice.

Extreme itch or irritation (called pruritus) will make pets scratch until their skin bleeds or they tear their hair out.

Cats might ingest so much hair as to create a secondary hairball problem. Dogs with severe lick sores on an extremity might chew the lesion almost to the bone.

It can be heartbreaking to watch your pet go through such misery.

In this expert guide to allergies in pets, we’ll discuss:

  • Why skin problems are so frustrating and difficult to treat in pets
  • What exactly is an “atopic” dog or cat?
  • What to expect — and why the symptoms often get worse as your pet gets older
  • Causes and treatments of allergies in both dogs and cats
  • The benefits and side effects of corticosteroids, as well as some promising alternatives to steroids
  • How to test your pet for food allergies — the right way
  • Ways you can help make an itchy pet more comfortable
  • Common mistakes you don’t want to make
  • Why you need to act as quickly as possible with an itchy pet
  • And much more…

Ready? Let’s dive in!

allergies in pets
Allergies in pets: Atopic dermatitis acts kind of like hay fever. Photo: sjem

Part 1: Background on Atopic Dermatitis

Atopic dermatitis (atopy) is a common allergic condition affecting the skin of dogs and some cats.

Potentially anything can trigger an allergic reaction — dust mites in bedding, plant pollens during the spring, food proteins in the pet’s diet and more. We’ll discuss all sorts of possibilities below, but first let’s talk about some basics.

There seems to be a genetic link to atopy.

Some breeds are much more likely to suffer from it, including:

Atopy acts similarly to hay fever in people — except that instead of sneezing and runny eyes, symptoms in dogs include itchiness and inflamed skin. This is a complex condition, and treatment is often a matter of control rather than cure.

Symptoms of Atopic Dermatitis

First and foremost, atopy is itchy.

Pets with atopy chew themselves, scratch constantly and rub their faces excessively.

An atopic dog who spends the night in your bedroom will keep you up with a symphony of itching and scratching.

Typically, dogs are so itchy that they chew the skin and damage it, leading to patches of hair loss and secondary infections. Paws, legs, belly and face are usually the itchiest (pretty much everywhere except for the back).

Perhaps you have seen white dogs, such as Westies or Bichons, with brown staining on their paws. This is from excessive licking leading to saliva staining. This is a giveaway that the dog has skin irritation, most likely as a result of atopy.

Some dogs have a bizarre reaction where mainly their ears become sore and inflamed. Any dog who regularly has inflamed ears or ear infections should be assessed for atopy.

What Causes Atopic Dermatitis?

In short, atopic dermatitis is caused by an overactive immune system:

  • Pets absorb allergens through the skin, so when an allergen comes into contact with the skin, it primes the immune system.
  • Antibodies are then released to fight and control the irritant.
  • But this releases a cascade of chemicals that result in inflammation — and itchiness.

When your pet encountered a particular allergen for the first time, they probably didn’t react because they were not yet sensitized. But repeated exposure primed the immune system — which eventually reached a threshold level, and then symptoms occurred.

Many atopic pets are younger than 3 years old when they first show signs, which frequently get worse with age.

In the video below, Dr. Wayne Rosenkrantz, DVM, DACVD, discusses more about atopy in dogs:

YouTube player

Figuring Out What’s Going On

Diagnosis can be a thorny issue and not as straightforward as you may suppose.

Skin biopsies are largely unhelpful (other than to rule out other causes of skin inflammation) because they tend to show a nonspecific inflammatory picture rather than a specific diagnosis.

Various blood tests and intradermal tests are available. While these tests are helpful, the results can be confusing.

This is because they measure the levels of antibodies to specific allergens, which do not necessarily directly correlate to the itch level — so we can get false negatives and false positives.

How the lesions are distributed on the body — paws, legs, face, tummy — is a strong indicator of atopic dermatitis, but we need to rule out other conditions before trying atopy therapies.

These other possible conditions to rule out include:

Now we’ll discuss allergies in a dog. (If you have a cat, feel free to skip to Part 3 below, though you may benefit from reading Part 2 as well.)

Cold comfort: Dogs with seasonal allergies usually get relief from their itchiness in the winter. Photo: Mari Junnola

Part 2: Allergies in a Dog

Spring and fall are the most allergic seasons for dogs because the majority of canine allergies are inhalant allergies that manifest in itching.

Dogs like yours itch because they are allergic to what is growing outside. Then again, they can also be allergic to molds growing inside, dust mites, etc.

For people, these “hay fever” seasons produce respiratory symptoms. But instead of the streaming nose and red eyes that people get, dogs get itchy skin.

Flea allergy and food allergies are the other 2 most common reasons for a dog to scratch constantly.

Let’s go through some possible causes of allergies in a dog:

Flea Allergy in a Dog

Maybe you’re sitting there thinking, “But my dog never had a flea.”

Sure, today this might be true. With the invention of products like Advantage and Frontline, skin problems in dogs have improved tenfold.

Despite the revolutionary improvement in flea prevention, dogs still get fleas and flea allergy.

Often a vet has to find a flea, or at least find the flea feces, to convince the client that, yes, their dog has fleas.

No Fleas, Now What?

When presented with an itching dog, the vet examines the patient’s skin, the lesions, the pattern, etc.

Then the first question is, “When does your dog scratch?”

After the client says, “All the time,” we ask them to narrow down the time period.

Very frequently, the dog has been itching for the past 2 weeks. We check the chart, and remind the client that they were in the clinic a year ago — same time, same complaint.

If we can determine that the dog has transient itching for maybe 1–2 months out of the year, and for the rest of the year the pet never scratches, we probably have a diagnosis of seasonal skin allergy (atopy).

Signs that your dog could be atopic include:

  • A young dog: Many are between 1–3 years old when the itch first starts.
  • Worsening itch: The itch gets more intense year after year.
  • Seasonal: This isn’t an all-year problem — the dog gets relief in the winter months.
  • Face, feet and armpits: The face, paws, armpits and groin are affected the worst. If you have a white dog, you’ll know they are an avid licker from that rust-colored fur.

How we can treat atopy:

  • Short-term or mild skin allergies can be treated with antihistamines (not very effective) and/or corticosteroids, just as with people who need help with allergies that flare up.
  • A judicious use of a drug such as prednisone (a corticosteroid) is highly effective and generally safe as long as it is used for a short time.
  • A newer treatment, Cytopoint, is available. This injection is given every 4–8 weeks and “disarms” the allergen-causing substance so that it doesn’t trigger the itch.

Unfortunately, allergies in dogs often get worse with age.

The young dog who needed to take a steroid for only 2 weeks out of the year may begin to itch for several months out of the year, and then steroids are not a great option anymore.

How we diagnose the allergies:

  • Skin testing is the gold standard for determining what your dog is allergic to. This is generally done by a veterinary dermatologist.
  • Blood tests for allergies are also available. These may not be as accurate but can be valuable and do not require a referral to a dermatologist.

If your dog needs more than occasional steroids or antihistamines to control itching, hypo-sensitizing with allergy injections can help about 75% of allergic dogs. You need to be willing to invest a bit in the diagnosis and treatment, and you need to be willing to give the injections.

It can take many months for the dog to improve.

Food Allergies in a Dog

Food allergies are less common than inhalant allergies but are a serious cause of chronic itching.

A few basic facts can help you toward a diagnosis of food allergy so that you can stop wasting your money on buying 30 different kinds of dog food:

  • If a dog has a springtime allergy, then once the season passes, so should the itching.
  • But if the dog is allergic to something he is eating, the dog should itch until you eliminate the food. Typically, a food-allergic dog is itchy all the time.

So when a dog comes in to the vet in January and the client says he’s been scratching for a year or more, we think less about inhalant allergies and more about food.

However, if an atopic dog started scratching in April and the family never did anything about it, that poor dog may still be scratching in January. A good history is important.

I Want to Test My Dog for Food Allergies

There is no reliable blood test for food allergies.

If you had “allergy testing” done and someone told you your dog is allergic to corn or chicken based on a blood test, don’t believe it.

The only way to determine a food allergy is to put your dog on a hypoallergenic diet for at least 2–3 months:

  • If your pet stops itching on a limited-ingredient diet, then you’re on to something.
  • If there is no reduction in itching, food is probably not the culprit.

Ten times a week we hear, “But the lamb and rice diet didn’t help!”

Or, “He’s been on a grain-free diet, and he’s still itchy.”

OK, let’s get to the bottom of this.

What a Limited-Ingredient Diet Actually Means

What does a hypoallergenic diet or limited-ingredient diet mean? Hopefully it means you’re using a diet that contains novel ingredients your dog has never been exposed to:

  • This means the diet should be limited to a new protein, a new grain — and nothing else.
  • That’s why fish and sweet potato is a good limited-ingredient diet to try, for example.

Most dogs have not been fed whitefish and sweet potato. But if your dog was raised on a fish farm, or if your dog dug up sweet potatoes for a living, then this is not a novel diet for this dog.

How the Pet Food Industry Misled the Public on “Limited-Ingredient” Diets

Back in the day, when diagnosing food allergies was in its infancy, vets tried to develop a diet made up of novel ingredients that people could try on their own. Dog food never contained lamb and rice back then. So we had people home-cook lamb and rice and feed it exclusively for 8–12 weeks.

This is why “lamb and rice” diets became so popular. But the dog food industry misled the public, marketing these diets as “good for skin” and “veterinary recommended.”

Veterinarians hadn’t been recommending lamb and rice because of its skin benefits. We were trying to diagnose food allergy.

These commercial lamb and rice diets were neither “limited-ingredient” nor did they offer any special skin benefits. But consumers began buying them to solve their dog’s undiagnosed skin problem. The pet food industry represented lamb and rice as a doggy version of Botox.

Now it’s getting harder and harder to find a diet that your food-allergic dog has never been exposed to.

There are now hydrolyzed protein diets, true limited-ingredient diets and home-cooked recipes available through your vet that can help us diagnose food allergies. “Grain-free” is not a hypoallergenic diet.

If a food allergy seems to be the culprit, head over to our companion article “Conducting a Food Trial for Food Allergies in a Pet.”

Not Fleas, Not Food — Now What?

So if the fleas are gone and the strictly adhered-to food trials didn’t help, we’re back to inhalant allergies as the most common cause of chronic or seasonal itching.

Again, this article does not address the other, less common causes:

Don’t let your dog scratch for too long before seeking veterinary help. The longer dogs scratch without medical help, the harder it will be to stop the itching.

Remember, allergies don’t usually begin until your dog is a few years old, but they get worse with age. Each time your dog is exposed to an allergen, the response is more severe.

How Do I Know What My Dog Is Allergic To?

Skin test or blood test. Talk to your vet about whether or not this is necessary, and discuss what to expect when you get the results.

Can I Limit My Dog’s Exposure?

Yes and no:

  • You can bathe your dog once a week and keep them inside and not let them roll on freshly cut grass, and keep them in air conditioning.
  • But they still have to go outside to potty.

Think about when there’s a high pollen count advisory for people with allergies. Staying inside helps, but you still have to breathe and open a door once in a while.

What Are My Treatment Options Again?

If your dog has mild scratching because of allergies, your veterinarian may prescribe antihistamines, corticosteroids, fatty acid supplements and shampoos, to name a few.

If your dog has been skin tested or you have sent out blood samples to a special allergy laboratory and the dog is diagnosed with allergies, you will begin giving allergy injections.

Unfortunately, there are no easy answers, and an allergic dog may need treatment for the rest of their life.

Some of America’s favorite breeds are overrepresented in this category,  including Golden Retrievers, Labrador Retrievers and Westies, to name a few. But any dog can develop allergies, including mixed breeds.

Your dog needs your help to get to the bottom of the itch. Sooner rather than later. Real help:

  • Spraying bitter apple on the problem or using “home remedies” for allergies in a dog might be as helpful as buckets of calamine lotion. In other words, no help at all. (In fact, calamine lotion may be toxic to your dog.)
  • Putting socks on your dog’s back feet to stop the damage will not last very long.

So don’t keep covering your itchy dog in Vaseline and corn starch and baking powder, particularly if these things are not working. For more, see our article “‘Natural’ Drugs Can Have Deadly Consequences for Your Pet.”

Act Early on Itchiness

The more established the itch, the more difficult it is for the dog to stop scratching.

For those dogs who are already diagnosed with atopy, this means starting meds immediately. By settling the itch early, you can use lower drug doses in a safer way.

For example, corticosteroids are highly effective anti-inflammatory drugs, but they have significant side effects. Start them early and you’ll need only a fraction of the dose. Then, to keep the itch away, it takes just low doses every other day.

But wait until the dog has licked their feet sore, and they may need 2, 3 or even 4 times the dose every day for a couple of weeks. This means more of those unpleasant side effects, which include:

  • Thirst
  • Hunger
  • Peeing in the house
  • Weight gain

Complications of Not Treating Allergies in a Dog

Have you ever had athlete’s foot? If you have, you’ll appreciate just how intensely itchy it is.

Again, when atopy goes untreated, the risk of complications such as secondary yeast infections goes sky-high.

It’s not hard to see why:

  • The dog’s skin is damaged by all the licking.
  • The normal bacteria and yeast on the surface of the skin take advantage of the skin’s weakened immunity and breed out of control.

The result? Skin infections needing treatment in addition to the underlying itchiness.

So if you have a dog with seasonal allergies, have their meds ready and waiting. And if you suspect your dog has atopy, get them checked out by the vet. But you don’t just have to rely on the vet.

Next, we look at what you can do at home to combat itchiness and keep your dog comfortable.

Washing allergens off regularly can help your itchy dog feel more comfortable. Photo: hillary h

10 Ways to Help Your Itchy Dog Feel More Comfortable

Once you know what the problem is, what can you do to relieve your dog’s itchiness?

A realistic answer is prescription medication, but even then there are things you can do to reduce the dose or even avoid drugs altogether. How do you achieve this?

Enter the “law of summation”: Lots of little things added together make one big thing. But it can also work in reverse: Take away little things, and the big thing gets smaller.

With this in mind, let’s look at 10 ways you can help your itchy dog feel more comfortable.

1. Better Skin Health

In allergic dogs, pollens trigger the itch when they contact the skin.

So when the skin is healthy, it provides a better barrier to stop allergens in their tracks.

  • Simple steps such as regular grooming improve the blood supply to the skin and condition it. Brushing also keeps the coat clean and healthy so it doesn’t harbor bacteria and yeasts that drain the skin’s immune system.
  • Also, a good-quality diet promotes healthy skin from the inside out.

2. Food Supplements

Omega-3 oils have many beneficial effects, one of which is being a natural anti-inflammatory.

They won’t reduce the itch on their own, but by strengthening the skin and interrupting the inflammatory cascade, these oils can reduce it.

  • A typical dose is 66 mg/kg each day. So, for example, a 10 kg (22 pound) Westie needs 660 mg of omega-3 oils per day.

3. Regular Bathing

OK, so allergens contacting the skin trigger allergic reactions. How about washing those allergens off?

If you live near the sea, this could mean a quick dip in the water (but keep the skin moisturized afterward) or regular bathing. Use a gentle shampoo, preferably one with moisturizing properties, such as oatmeal or aloe vera.

This way you get a double benefit: reducing the allergen load while conditioning and hydrating the skin.

In fact, the benefits don’t end there — cleansing the skin reduces the number of bacteria and yeasts on the surface, which could act as secondary invaders and make the itch worse.

Some dogs benefit from bathing every 3 days.

For much more on bathing, see these companion articles: 

Ever think that grass sap could be causing the allergies in your dog? Photo: Helena Volkova

4. Avoiding Allergens

Many atopic dogs are allergic to things like grass sap, so exercising them on freshly mown grass is like a red flag to a bull in allergic terms.

Keep them off the grass (away from the triggering allergen), or bathe them immediately afterward.

5. Consider Contributing Factors

OK, so your dog has atopy — meaning they have a sensitive immune system that’s liable to overreact.

If they react to pollens, then you can guarantee they’ll be allergic to flea bites. Make sure you regularly treat your pet with effective parasite products.

Also, consider the role of a food allergy. It’s not unusual to have both food and environmental allergies, so it’s worth putting the dog on a hypoallergenic diet for a couple months to see if it helps.

6. Immunotherapy Vaccines

The vet can develop a bespoke vaccine that reduces your dog’s sensitivity to allergens. There are pros and cons.


  • A non-drug treatment.
  • In 3–4 out of 10 dogs, it makes a big difference.
  • Can make the difference between taking meds or not.


  • Expensive.
  • Not all dogs respond.
  • It takes months to start working, so start in the autumn to benefit the following summer.

7. Antihistamines

No article about allergies in dogs can get away without mentioning antihistamines.

However, the news is not encouraging: Dogs don’t respond as well as people do, and the effects are largely disappointing.

Speak with your vet about setting up a trial of 3 different antihistamines to see which works best — but don’t bet the house on it.

8. Spray Steroid

This remedy treats the skin rather than the whole dog.

Instead of giving steroid tablets or injections, ask your vet about a steroid spray. This safe, side-effect-free option gives relief where it’s needed without entering the bloodstream.

9. Medication

Sometimes, though, medications are the best option. These include:

  • Steroids: Inexpensive and effective — yet prone to side effects
  • Atopica: Effective but expensive — fewer side effects than steroids
  • Apoquel: The golden bullet — effective and safe (but, sadly, expensive)

10. Remember, Common Things Are Common

Parasites cause itching. Don’t assume that all itchy dogs have an allergy. They may simply have fleas.

So save yourself a bucketful of bother and treat your dog regularly against parasites.

Next, we’ll discuss allergies in cats. If you don’t have a cat, just skip this next section — but please scroll down to Part 4 below because there’s some important additional information that applies to all pets.

Psychogenic Alopecia in Cats
Treatment of allergies in a cat can be challenging and lifelong. Photo: steeman

Part 3: Allergies in a Cat

Fur mowers. That’s what we call them — cats who lick and chew their fur away until they’re bald. Usually when their humans aren’t watching.

Truth be told, feline allergies remain more of a puzzle than canine allergies.

Many of the skin problems that cats suffer from can mimic one another, so a visual inspection of the cat doesn’t always lead to a diagnosis. Diagnostics and determining the reason for the allergy is difficult.

Cats suffer from inhalant, flea and food allergies — just like dogs. These allergies create pruritis (itching), sometimes intense.

People who have atopic cats are often unable to give a history of the cat’s scratching because cats prefer to do their grooming, itching and licking when no one is looking.

Likewise, it may be difficult to differentiate normal grooming from excessive grooming until the cats are actually harming themselves.

This means the allergy or disease has already been going on for some time, making it that much more difficult to treat.

When a Cat Scratches So Much That Lesions Form

The lesions caused by a cat’s scratching can vary from mild to severe.

A cat may lick until there are large bald spots. Or the pruritis can be so severe that the cat scratches, licks and gnaws until they’ve created deep ulcers, called plaques. This is known as eosinophilic skin disease.

These lesions can take months to heal. Treatment can be challenging and lifelong.

Once a cat has been diagnosed with allergic skin disease, corticosteroids are often the first line of defense. These can give the cat relief until we can get to the bottom of the allergy — but corticosteroids have may side effects and should be used with caution.

What Causes Scabby Skin on a Cat?

Scabby skin on a cat is just a symptom. It’s important to find out what’s causing the problem so the underlying issue can be treated. Only then can the scabs resolve.

Take, for example, a cat with an allergy to flea bites. Yes, steroids will improve the scabby skin, but as soon as the steroid wears off, the scabs return if you don’t kill the fleas.

Although flea allergic dermatitis is extremely common, let’s say your cat has been getting monthly flea drops. What else can cause scabbiness?

Let’s look at a list of possible problems.


  • Flea allergic dermatitis: An allergy to flea saliva causes the skin to react and form tiny pinhead scabs that makes the skin feel gritty when you stroke the cat. We’ll discuss much more on this below, because it’s usually the first suspect.
  • Mosquito bite hypersensitivity: This has a similar mechanism to flea allergies, but the saliva causing the hypersensitivity comes from mosquitoes, not fleas.
  • Ear mites: These tiny mites live in the ear canal, where they scurry around feeding off skin cells and debris. They are incredibly itchy, and the cat is liable to scratch, causing self-harm scabs to the head in the process.
Ringworm, a fungal infection, can wreak havoc on a cat’s skin in the forms of scabs and hair loss. Photo: mariposavet


  • Ringworm: The fungi causing ringworm are highly infectious. Ringworm causes scaling, scabs and hair loss — most commonly on toes, noses and ears — but it can affect any part of the body.
  • Bacterial: Any scratch or bite to the skin can allow bacteria to breach the skin’s defenses and set up infections that result in scabs.
  • Cowpox: An unpleasant virus, especially if an immunosuppressed cat picks up infection, which can result in some unsightly scabs.
  • Feline acne: Bizarrely, this tends to occur in older cats (rather than the cat equivalent of teenagers) and causes gritty scabs under the chin and around the lips.

Immune Related

  • Rodents ulcers/eosinophilic dermatitis: The body mounts an inappropriate immune attack and floods the skin with a kind of white cell called an eosinophil. This causes plaques, ulcers and scabs.
  • Food allergy: The cat reacts to a protein in the diet that causes an allergic reaction in the skin. While some cats with food allergy present with upset tummies, a lot more come in with sore, inflamed skin and generalized scabs.
  • Pemphigus: In this autoimmune condition, the cat’s immune system targets the skin itself, causing it to flake away, leaving sores that then scab over. This is typically found at the junctions where mucous membranes (such as the lips or anus) meet normal skin.


  • Reaction to medication: Certain medicines can cause the skin to erupt into angry sores and scabs. The most notorious for this are some of the drugs used to treat overactive thyroid glands. Happily, stopping that particular tablet is usually enough to resolve the problem.
  • Squamous cell carcinoma: This is a form of skin cancer that can cause scabbing in the early stages. This is most common on extremities such as the ear tips or the nose of white cats.

The First Suspect: Flea Allergy in a Cat

Many veterinary dermatologists believe a scratching cat is suffering from a flea allergy until proven otherwise.

Often we don’t find a flea on an itching cat like we do on a dog.

Why? Because cats are fastidious groomers — they eat the flea.

If it’s a very mild flea infestation but the cat is highly allergic, you may have a balding cat with no evidence of fleas, not even a speck of flea “dirt” (flea excrement).

Vets will try to persuade people to institute a flea treatment for several months to rule out fleas as a cause of the allergy.

This is true for indoor cats too. Many houses/apartments have fleas unbeknownst to people. Visiting animals can bring in fleas. Fleas can invade basements, screened-in porches, etc.

And sometimes you yourself can bring in fleas.

Why Is My Cat Chewing His Fur Out?
There is no simple test for food allergies in a cat. Photo: Jennifer C.

Food Allergies in a Cat

As we explained above with dogs, you need to do a diet trial if you want to test your cat for food allergies.

There is no simple test for food allergies in a cat. You need to feed a diet that your cat has never been exposed to before.

Make sure that the cat eats this diet, and only this diet, for around 3 months. See our companion article “Conducting a Food Trial for Food Allergies in a Pet.”

The real trick here is that cats are finicky. They get bored of the same food. And cats like to go outside. If your cat goes out, it’s impossible to assume they aren’t “dining out.”

As we mentioned above, “grain-free” is not a hypoallergenic diet. You still need to find a novel (new) protein source and keep the diet balanced.

No other ingredients should be in the diet except the novel protein/carb source. If you have a multiple cat household, all of the cats have to eat this diet.

Treating Allergies in a Cat

If you can eliminate the offending allergen, like fleas or food, the itching will cease.

You may need steroids or other drugs to stop the scratching until the allergen is discovered and eliminated.

  • Antihistamines, fatty acid supplements, baths and sprays can help somewhat, but a severely allergic cat will usually continue scratching without medications such as steroids, antibiotics or other drugs (like cyclosporine).
  • Topicals are difficult to use in cats since the skin lesions are often widespread and the cat can lick, lick, lick all the medicine away.
  • Cats hate Elizabethan collars (cones). As soon as you take off this collar, the cat often attacks the same itchy area with a vengeance.

For an atopic cat, intradermal skin testing and blood testing are available, but they are not as reliable as the canine tests. This testing often requires a visit to a veterinary dermatologist.

Talk this over with your vet if your cat’s allergies are moderate to severe.

Threshold Effect

Cats (and dogs) can be allergic to more than one thing, and to varying degrees.

If the allergies are mild, the itching might be insignificant.

  • Say your cat’s “itch” number is 100. This means the cat doesn’t start to itch until it reaches 100.
  • Now let’s say the cat has a mild flea allergy that rates an itch factor of 60. So far so good.
  • But then add to it your cat’s allergy to fish, scoring a 50, and you happen to buy a case of fisherman’s stew because it’s on sale. This bumps your cat’s total itch factor to 110, over the threshold.

If not combined, your cat could probably tolerate a few fleas or a can of tuna, because each would be well under that 100 number. But combine them, and your cat has crossed the threshold. Your cat has entered the itch zone.

Your vet will make treatment suggestions based on the severity of your cat’s condition. Photo: stignygaard

The Problem With Steroids

Corticosteroids are life-saving drugs and treat many diseases. But they have side effects, so we need to use them with caution.

Cats are more resilient to the side effects of steroids than humans or dogs, but they are a huge concern nonetheless. Steroids are beneficial in the beginning but can lose their power as the disease progresses.

There are many forms of injectable and oral steroids, and your vet will make suggestions based on the severity of your cat’s condition.

If used correctly, steroids can greatly control or eradicate itching in your cat. Following medical instructions and keeping track of the medication is extremely important.

  • Mild side effects include increased thirst and appetite — which can lead to increased urination and weight gain.
  • Continual or excessive use of the drug can cause liver and endocrine problems, including diabetes.

For more on safety and side effects, see “How Can Cats Benefit From Prescribed Steroids?”

It’s Hard to Diagnose the Problem. (Mosquitoes? Really?)

Anything you can remember about when, why and how your cat began to itch can be helpful.

If your vet prescribed medications, how well these drugs worked and for how long are also very important.

One client’s cat, Snoopy, never had a medical problem until he was 8. One summer, he presented with periorbital alopecia (hair loss and a little crusting around the eyes). The lesions went away, though.

But the following summer, Snoopy’s lesions were much worse. We used a topical ophthalmic ointment containing a steroid and gave him one injection. He improved.

His lesions occurred every year at the same time and only on his face.

It turned out Snoopy was allergic to mosquitoes (a fairly common cat allergy).

Keeping the cat indoors at the height of mosquito season — particularly at dusk when these pets are at their worst — controlled the problem.

Often, a pet’s itchiness can’t be cured, but it can be managed. Photo: alfmelin

Part 4: What’s So Frustrating About Itchy Pets

Here are 3 things that are incredibly frustrating when dealing with an itchy pet — and how you and your pet’s veterinarian can help.

1. Skin Problems Make Your Pet Miserable

Watching your pet scratch uncontrollably, seeing skin lesions worsen and getting more concerned about their discomfort are all disconcerting issues for people to deal with.

Anyone who’s ever had poison ivy or an allergic itch can identify with the desire to scratch yourself until the pain replaces that itch.

Feeling scabs or greasy coats on your pet, seeing balding areas, smelling infected ears — these are constant reminders that this dog or cat is uncomfortable and has a serious condition.

2. Skin Problems Are Chronic

Many skin problems can be controlled but not cured.

Allergic, inflammatory and cancerous skin diseases are often lifelong problems that can be managed with medications or injections, topical therapies and diet.

The key word here is “control,” not “cure” — but, often, people don’t listen to the distinction.

That’s why vets hear comments like:

  • “Those pills you gave us aren’t working now.”
  • “My pet got better, but now it’s back again.”
  • “I don’t know why we can’t get rid of the ear infections.”
  • “You mean she can’t eat regular dog food again? I have to get it from you?”
  • “He’s got that same rash, but I don’t want to come in again.”
  • “Why don’t you know how to get rid of this for good?”

Believe us — skin problems are frustrating for vets to treat not only because of the pet’s misery, but also because you’re not listening to what we’re trying to tell you.

If you see your pet struggling with itchiness, see the veterinarian sooner rather than later. Photo: live composition

3. Skin Problems Are Expensive to Manage

Diagnostics, repetitive tests, rechecks, medications. It’s no joke — dermatologic cases be expensive.

But there’s some light at the end of the itch tunnel.

Dermatology is a priority in veterinary research. There are always new discoveries about allergies, autoimmune skin disease, and inflammatory skin conditions and how to treat them.

Early detection and intervention is always the best way to go:

  • If you know your pet goes through seasonal allergies or gets recurrent skin infections, getting the problem seen early may lessen the severity of the flare-up.
  • If your pet has one of those skin problems that stumps your regular vet, and the vet recommends a consult with a dermatologist — try it. This may save you money and time in the future, as well as get some needed, first-rate relief for your pet.

Honesty and Hope

Honesty is the best policy when it comes to a vet discussing potentially chronic skin problems.

Scaring or depressing you is not our goal.

Rather, we try to explain that your pet will not simply “get rid” of their allergies, and that the allergies can be diagnosed and managed:

  • Autoimmune skin problems can go into remission — but they may recur.
  • Food allergies can be diagnosed and treated with the right diet — but your pet may develop new allergies.
  • These are usually conditions, not a one-off that just needs a quick fix.

Hope is on the rise for these suffering pets. New drugs introduced over the past few years have changed the course of how we treat these conditions.

These new medications, such as Apoquel and Cytopoint, have reduced the use of corticosteroids with all their potential side effects.

Constant itching can create anxiety in pets. Photo: torne

Part 5: Don’t Wait — If Your Pet Is Itchy, See the Vet Now

The worst thing you can do with an itchy pet is wait.

This is the season of skin allergies and flea bite dermatitis. The longer you wait to get your pet relief, the harder it will be to get Mr. Itch back to Mr. Happy.

Why You Should Act Now

So why is early treatment so important?

There are several reasons, including:

  1. The earlier the treatment, the earlier your pet gets relief. Itchy skin begins as an annoyance and develops into pain.
  2. The sooner you treat, the less medication your pet will require.
  3. Prolonged itching sets your pet up for secondary problems, like bacterial infections and yeast infections. When your pet itches excessively, the skin becomes weak and vulnerable to infections. These infections create more itch and pain for a longer period of time and require more medications.
  4. Itching creates anxiety. Pets can actually experience behavioral changes when they are stressed out by itchy, painful skin. Cats can develop GI upset from eating their fur.

Common Mistakes

Many people sit tight while their pet begins to itch.

If you notice your pet licking or scratching excessively for even a couple of days, you have already lost valuable time in treating the condition.

Imagine scratching yourself even 20–30 minutes a day for 2 days. You would not let it continue without seeking relief.

Over-the-counter products often do not work for your pet. Many people visit a pet store or big box store and buy shampoos and topicals to try and avoid a vet visit. These products are often insufficient in treating a serious itch.

You can spend quite a bit of money on stuff that may not work — and you’d be losing valuable time in getting your pet relief.

Over-the-counter products are often not effective in our pets’ itchiness. Photo: Lee Haywood

The Same Thing as Last Year

Many of you have been through this seasonal itch thing with your pet before.

Why? Because most allergies in pets (except food) are just that: seasonal.

When we can document a seasonal allergy as the cause of a pet’s itching, vets usually send people home with extra medications or, depending on the case, refill these medicines within a calendar year.

Chronic conditions like this are another reason to secure a good relationship with a veterinarian:

  • Your vet can make sure you have the medication you need — as long as you are willing to have the pet checked out when necessary.
  • In the case of a skin allergy, no pet should wait a week before beginning medication. It will only prolong the flare-up.


vet-cross60pThis expert guide to allergies in pets was written by veterinarians Dr. Debora Lichtenberg, VMD, and Dr. Pippa Elliott, BVMS, MRCVS. This article was originally published in 2012 and is regularly updated. It was reviewed for accuracy by Dr. Elliott and was last updated June 17, 2019.

If you have questions or concerns, call your vet, who is best equipped to ensure the health and well-being of your pet. This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. See additional information.