Allergen-specific immunotherapy for a dog or cat costs roughly $800 to $2,500 in the first year, including allergy testing, and considerably less thereafter. It involves giving tiny, gradually increasing amounts of the specific things your pet is allergic to, retraining the immune system to stop over-reacting.
A note on the word: in a veterinary services list, "immunotherapy" almost always means this — treatment for environmental allergy. Cancer immunotherapy is a separate field; if that is what you are looking for, our [chemotherapy guide](/procedures/chemotherapy/) covers cancer treatment.
What makes it different from everything else
This is the central point, and it justifies everything awkward about the treatment.
Apoquel, Cytopoint, steroids and antihistamines all suppress the symptom. They interrupt the itch signal or damp the inflammation. They work — often quickly and impressively — and when you stop, the allergy is exactly where it was. The immune system has not changed its mind about anything.
Immunotherapy is the only treatment that modifies the underlying immune response. Repeated controlled exposure gradually shifts the reaction away from allergy toward tolerance. It is slow, it is unglamorous, and it is the only option that treats the disease rather than the signs.
Those two approaches are not rivals. Most pets use fast-acting drugs to stay comfortable during the many months immunotherapy needs to take effect, then reduce or stop them.
First, rule out the other two allergies
Immunotherapy treats environmental allergy — pollens, dust mites, moulds, grasses, storage mites. It does nothing whatsoever for the other two common causes of itching:
- Flea allergy. A single bite can set off weeks of itching in a sensitised animal, and you will not necessarily see fleas. Rigorous year-round flea control on every pet in the household comes first, always.
- Food allergy. Diagnosed with a strict elimination diet — a novel or hydrolysed protein and nothing else for 8–12 weeks. No treats, no flavoured medications, no table scraps. Blood and saliva tests marketed for food allergy are not reliable, and the diet trial remains the only dependable method.
Starting immunotherapy without working through these produces an expensive failure that gets blamed on the immunotherapy. Many pets have more than one allergy at once, which is why a dermatologist works through them methodically rather than guessing.
Testing selects the allergens
Two methods identify what to include:
Intradermal skin testing injects small amounts of allergens into a shaved patch and measures the reaction. It is generally considered the reference standard, requires sedation, and is usually performed by a veterinary dermatologist.
Serum allergy testing measures allergen-specific antibodies in a blood sample. Easier, no sedation, available in general practice, and somewhat less precise.
Both require steroids to be withdrawn for a defined period first, since steroids suppress the reactions being measured. Neither test diagnoses allergy — the diagnosis is clinical, made from history and examination after ruling out fleas, food and infection. Testing only decides what goes in the vial. This distinction gets muddled constantly, and it matters: a positive test in a non-itchy pet means nothing.
Shots or drops
Subcutaneous injections are given under the skin, starting frequently during a build-up phase and settling to every 1–3 weeks for maintenance. Owners are taught to give these at home, which sounds daunting and is genuinely straightforward — the needle is tiny, most dogs barely notice, and it avoids the cost and stress of a clinic visit every fortnight for life.
Sublingual immunotherapy — drops under the tongue, twice daily. No needles, useful for needle-averse pets or owners, and requiring genuine consistency: twice a day, every day, indefinitely. Effectiveness is broadly comparable, and the honest deciding factor is which routine you will actually keep up.
Set your expectations before you start
This is where the treatment succeeds or fails, and it has nothing to do with the medicine.
- Improvement typically begins at 3–6 months.
- Response is judged at 9–12 months.
- Roughly two-thirds to three-quarters of dogs improve meaningfully.
- Most still need some additional therapy, particularly during peak season — a good result usually means far less medication, not none.
- It is generally lifelong. Some pets can reduce frequency after several stable years; a minority stop entirely.
The single biggest reason immunotherapy fails is owners stopping at month four because "it isn't working." At month four it is not supposed to be working yet. If you are not prepared to commit to a year, the money is better spent on something else — and saying that plainly is more useful than optimism.
Mild injection-site swelling or a temporary itch flare after a dose is common and usually settles. Anaphylaxis — facial swelling, hives, vomiting, collapse, difficulty breathing — is rare but real, which is why the first doses are often given at the clinic and why you should know what it looks like.
Cost, itemised
- Dermatology consultation: $150–$400
- Intradermal skin testing: $300–$700
- Serum allergy testing: $200–$400
- First year of immunotherapy serum: $300–$800
- Ongoing serum, per year: $200–$500
- Sublingual drops, per year: $400–$900
- Rechecks: $60–$150 each
- Managing secondary skin and ear infections: $100–$400 per episode
Compared against Apoquel or Cytopoint at roughly $60–$200 per month indefinitely, immunotherapy is usually cheaper over a lifetime as well as being disease-modifying. The obstacle is that the cost is front-loaded and the benefit is not.
Who isn't a candidate
- Other: Immunotherapy treats environmental allergy only. It does nothing for flea allergy or food allergy, which is why a flea trial and an elimination diet come first — starting immunotherapy without ruling those out produces an expensive failure.
- Concurrent condition: Active skin or ear infection should be treated before starting, since an inflamed, infected patient cannot be assessed for response.
- Other: Concurrent high-dose steroids suppress the allergy testing that selects the allergens, so steroids must be withdrawn for a defined period before testing.
- Other: Not suitable where an owner cannot commit to a year or more of regular dosing — this is a slow treatment and stopping at four months wastes the entire investment.
Common questions
How much do allergy shots cost for a dog?
Roughly $800 to $2,500 in the first year including testing, then $200–$500 a year for serum. Intradermal skin testing runs $300–$700 and serum testing $200–$400. Sublingual drops cost $400–$900 a year. Over a lifetime this usually works out cheaper than Apoquel or Cytopoint at $60–$200 monthly indefinitely.
How long does it take for allergy shots to work in dogs?
Improvement typically begins at 3–6 months and response is judged at 9–12 months. Roughly two-thirds to three-quarters of dogs improve meaningfully, though most still need some additional therapy in peak season. Stopping at four months because it seems ineffective is the most common reason the treatment fails — at four months it is not expected to be working yet.
What is the difference between allergy shots and Apoquel or Cytopoint?
Apoquel, Cytopoint and steroids suppress the itch and stop working when discontinued — the allergy is unchanged. Immunotherapy retrains the immune response itself and is the only disease-modifying option. They are complementary: most pets use fast-acting drugs for comfort during the months immunotherapy needs, then reduce them.
Can I give my dog allergy shots at home?
Yes, and most owners do. You are taught the technique at the clinic, the needle is very small, and most dogs barely react. Home dosing avoids a clinic visit every one to three weeks for life. The first doses are often given at the practice so any reaction is observed.
Are allergy drops as good as allergy shots for pets?
Broadly comparable in effectiveness. Sublingual drops avoid needles entirely but must be given under the tongue twice daily, every day, indefinitely. Injections are less frequent but require giving a shot. The right choice is whichever routine you will realistically maintain, since consistency matters more than the route.
Sources
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