An anaphylactic reaction in cats is a severe and life-threatening allergic response. It occurs when the immune system has an extreme reaction to an allergen (a foreign substance). Fortunately, such reactions are relatively rare, but can occur in cats of any age or breed.

Typical symptoms of an anaphylactic reaction in cats include: difficulty breathing, excessive drooling, sudden diarrhoea or vomiting, and collapse. Cats displaying these signs require immediate veterinary care, as this is a critical emergency. Common triggers for anaphylactic reactions include insect stings and adverse reactions to medications.

What is an anaphylactic reaction in cats?

An anaphylactic reaction in cats occurs when the immune system has an extreme response to an allergen, leading to a severe, full-body reaction.

• When a foreign substance enters the body, whether through ingestion, inhalation, or another route, the immune system identifies it as a threat and rapidly releases a large amount of chemicals, such as histamines. This sudden chemical release causes blood vessels to dilate, causing a drop in blood pressure. Fluids begin to leak into tissues, causing swelling, while the airways swell and narrow, forcing the heart to work harder. As a result, the body may go into shock.

• Cats can experience allergic reactions to various substances. Common triggers for anaphylactic reactions include snake bites, bee or wasp stings, some foods, and certain medications.

• Anaphylactic reactions typically occur within 30 minutes of exposure to the allergen and can escalate rapidly.

• Anaphylactic reactions are more likely to occur if the cat has been exposed to the allergen previously, such as after a second bee sting.

Anaphylactic reactions can be life-threatening; if your cat is showing signs of one, take them to the nearest vet. If your cat is showing mild symptoms of an allergy, the Joii vet team is available 24 hours a day for advice.

Symptoms of anaphylactic reactions in cats

Anaphylactic reactions are different from chronic allergies. Cats are less likely to show skin symptoms first, like dogs do. Common symptoms in cats include:

• Breathing difficulties: struggling to breathe, constant panting, gasping and distress.

• Severe drooling, vomiting and diarrhoea

• Weakness and incoordination

• Pale gums

• Swelling of the face and neck

• Rapid heart rate

• Collapse, seizures, and loss of consciousness

Are some cats more at risk of anaphylactic reactions than others?

While any cat can develop anaphylaxis, these factors can increase the risk.

• Prior exposure: Cats that have had a previous allergic reaction to an allergen are at a higher risk of experiencing an anaphylactic reaction if exposed to the same allergen again. The immune system's response can be more severe with subsequent exposures.

• Underlying health conditions: Older cats and those with other health issues, especially those involving the immune system, may be more prone to anaphylaxis.

• Breed Predisposition: While anaphylaxis can affect any breed, some research suggests that certain breeds, like Siamese cats, may be more prone to allergic reactions in general.

How are anaphylactic reactions diagnosed in cats?

Diagnosing anaphylactic reactions in cats is difficult. Vets will often diagnose based on the symptoms the pet is showing and the speed of onset.

After emergency treatment, the following tests may be recommended:

• Blood and urine tests

• Imaging (x-rays, ultrasound)

In the long term, investigation into allergies may be advised, such as:

• A food trial

• Allergy testing: blood or skin tests

What’s the treatment for anaphylactic reactions in cats?

Cats showing signs of anaphylactic shock require emergency treatment for stabilisation. Treatment often includes:

• Oxygen therapy

• Assisted breathing

• Emergency medications, given into the vein

• High doses of fluids, given into the vein

• Hospitalisation and monitoring for a minimum of 24 hours

How to look after a cat at home after an anaphylactic reaction

When your cat is ready to come home, you can support their recovery by:

• Providing a comfortable and quiet space for rest

• Ensuring they are eating and drinking properly

• Administering prescribed medications on time and at the correct dosage

• Keeping a close eye on them to ensure no new symptoms arise

Tips on how to prevent anaphylactic reactions in cats

Unfortunately, many anaphylactic reactions are unavoidable. Where possible:

• Monitor your cat when they are outdoors.

• Avoiding known triggers: Allergy testing via skin or blood tests can help determine what allergens to avoid in food and the environment.

• Be aware of the signs and what to do if they occur.

• Feed your cat a complete and balanced diet to ensure a healthy immune system.

• When changing foods, transition slowly from one to another. Avoid giving your cat human food.

When to worry about anaphylactic reactions in cats

Seek help from a vet in practice immediately if your cat shows any signs of an anaphylactic reaction.

• Breathing difficulties: struggling to breathe, constant panting, gasping and distress.

• Severe drooling, vomiting and diarrhoea

• Weakness and incoordination

• Pale gums

• Swelling of the face and neck

• Rapid heart rate

• Collapse, seizures, and loss of consciousness

Speak to one of our Joii vets for advice if your cat has chronic allergies.