What To Know About Allergy Shots For Dogs, According To A Vet

If your dog has allergies, it can feel like you’re always buying her allergy medicine.

And sometimes, even pricey prescription medications can seem like they’re not helping much.

That’s why some pet parents choose to get allergy shots, or immunotherapy, for their dogs. It’s literally the only drug-free method that reduces (or gets rid of) environmental pet allergies for good — which means no more expensive prescriptions.

So, how does it work?

The Dodo reached out to Dr. Lydia Harbour, a veterinary dermatology resident at Dermatology for Animals in Arizona, to find out everything you need to know about allergy shots for dogs.

JUMP TO: How allergy shots for dogs work | Pros and cons | Dog allergy testing | Immunotherapy vs. cytopoint | Side effects | Allergy shots cost

Immunotherapy is a great option for many dog parents because it’s the only thing that can permanently change a pet’s immune response to environmental allergies.

“Once the [allergy] medications are stopped, [allergy] signs will return,” Dr. Harbour told The Dodo. Allergy medications only control symptoms, but shots work by actually building immunity to specific allergens.

Keep in mind, though, that allergy shots are only effective for pets dealing with environmental allergies and won’t work for pets with flea or food allergies.

With allergy shots, your vet will test your dog first to find out what substances in her environment she’s allergic to, then create a formula based on her allergies. The formula’s injected periodically so your dog becomes desensitized — and ideally no longer allergic — to the allergens.

“Allergen-specific immunotherapy (ASIT) works by giving the patient small doses of what he/she is allergic to,” Dr. Harbour said. “Over time, the immune system starts to change how it responds to the allergen and develops ‘tolerance.’”

The amount of allergen in the shots is gradually increased so your pup slowly builds up a tolerance.

When your dog first starts getting allergy shots, she might need them a few times a week, but eventually it’s possible that she’ll only need them around once or twice a month.

“If it's working, this is typically continued long-term for maintenance,” Dr. Harbour said. “Sometimes we can decrease the frequency of injections. Typical frequency is every two to three weeks at a maintenance dose.”

Just like with any medication, there are both pros and cons of immunotherapy for dogs.

Allergy shots are considered to be pretty effective. Even in cases when they don’t completely get rid of a dog’s allergies, they can still help improve her symptoms.

“It's about 70 to 80 percent effective, but that's along a spectrum,” Dr. Harbour said. “Some patients will completely improve. Others will have less severe flares, and we can potentially reduce their medications over time, and [in] others it may be hard to notice actual improvement, but it may be simply preventing progression/worsening of disease over time.”

So even if the allergy shots don’t seem to be helping with symptoms, it’s possible that immunotherapy can actually prevent her allergies from getting worse in the long run. (Though in some cases, it doesn’t work at all.)

Not only can allergy shots for dogs be effective in some cases, but there are relatively few side effects, too. Your pup might have some increased itching right after she gets her shots, but severe side effects are rare (more on side effects below).

You won’t see immediate results with immunotherapy. It can take anywhere from three months to a year for allergy shots to start working. And once they do start working, you’ll need to continue with the shot every so often for maintenance.

“This is not a quick fix,” Dr. Harbour said. “Typically we tell clients that this is something we commit to for the long haul.”

In the meantime, your vet might recommend a prescription medication, like Apoquel or Atopica, to manage your dog’s symptoms.

Or they might recommend a dog-safe over-the-counter (OTC) antihistamine, which is usually best paired with an omega-3 supplement.

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Immunotherapy for dogs isn’t exactly cheap. But if you take into account the cost of giving your dog prescription allergy medications or OTC antihistamines for her whole life, plus the fact that she’ll have to deal with constantly having annoying allergy symptoms, it may be worth it in the long run.

Before your pup can get allergy shots, your vet will have to perform allergy testing to identify what she’s allergic to so they can create the serum for the shots.

Your vet will check your dog for other possible causes of irritation, like fleas or infections. They might also have you feed your dog a hypoallergenic food for a few weeks to see if she has a food allergy that could be causing her symptoms.

Once these causes are ruled out, your vet will either perform a skin test (intradermal allergy test — IDAT) or a blood test (serology). “Skin testing is preferred, as this gives us a live clinical reaction and tends to be more accurate, but blood allergy testing is also a suitable method,” Dr. Harbour said.

For a blood test, blood’s drawn and analyzed for allergens.

To perform a skin test, an area of your dog’s fur will be shaved, and your vet will inject small amounts of allergens into her skin to see what she reacts to (basically the same as a human allergy skin test).

Cytopoint allergy shots are different from immunotherapy shots. Cytopoint shots are intended for short-term relief rather than as a permanent solution for allergy symptoms.

“[Cytopoint] is an anti-itch injection given at the veterinary practice that lasts four to eight weeks,” Dr. Harbour said. “This is a monoclonal antibody that targets the itch mediator (IL-31) and prevents the signal of itch from going to the brain.”

So instead of training the immune system to reduce allergy reactions for good, like with immunotherapy, cytopoint basically just tricks your dog’s brain by making her think she’s not itchy.

Luckily, there are very few side effects of immunotherapy in dogs.

Your dog might have an increase in itchiness for the first couple of days after an injection. “This can occur up to 48 hours after the injection and can last for hours to days,” Dr. Harbour said.

A more severe (but rare) side effect of allergy shots for dogs is anaphylaxis, or a severe allergic reaction, which can include the following symptoms:

“Signs of anaphylaxis are extremely rare in dogs and cats, but because this is possible, we start with low doses and increase the volume of injections to a maintenance dose that the patient can tolerate,” Dr. Harbour said.

You might have to pay a bit extra up front for your dog’s immunotherapy — but for many pet parents, it’s totally worth it in the end.

You can expect initial allergy testing costs to be around $1,000 or more (which may be lower if you have insurance), and each allergy shot can cost anywhere from $5 to $25.

Keep in mind that once you reach a maintenance schedule for the allergy shots, you might actually save money by not needing to buy prescription allergy medicine, OTC antihistamines or medicated dog shampoo anymore.

Plus, if your dog has serious allergies that cause a lot of discomfort, the benefit from allergy shots can be life-changing (for both you and her).

If your dog develops allergies before you buy pet insurance, it’ll be considered a pre-existing condition, and allergy treatment won’t be covered by your insurance, which is why it’s always a good idea to get pet insurance as early as possible.

But if you already have pet insurance and your vet recommends allergy testing and shots, it’ll likely be covered.

If your pup has bad allergies, allergy shots for dogs can be a great solution to get rid of those annoying symptoms, so talk to your vet to find out if they would be a good option for her.

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