You may know someone who has a severe allergy. They may be allergic to a particular food, medicine, or insect sting. When they are exposed to the trigger (or ‘allergen’), a potentially life-threatening reaction can develop very quickly. The throat may swell, they may have trouble breathing, the skin can become clammy and often they will feel faint. When an allergic reaction involves the whole body, the condition is known as anaphylaxis, with the body experiencing ‘anaphylactic shock’. The reaction occurs within a few minutes and will progress alarmingly quickly. Sufferers may be given an EpiPen® (an adrenaline auto-injector) to use in the event of such an emergency. So what about cats?

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Yes – cats can also experience anaphylactic shock in response to a severe allergic reaction. Fortunately, anaphylaxis is not commonly seen in cats, but when it does happen it is an emergency that requires prompt veterinary treatment.   

What can cause anaphylaxis in cats?

Anaphylaxis is caused by a problem with the immune system. The cat’s body overreacts to an allergen and responds excessively to destroy it. The anaphylactic reaction won’t happen the first time the cat encounters the allergen. On first exposure, the cat’s body reacts silently, storing up a memory in the immune system ready for when the same allergen is encountered again. Subsequent exposures lead to an excessive immune response and when severe, this causes anaphylactic shock.

It is unusual for cats to develop anaphylaxis. When seen, the allergens responsible have included insect bites, food, plants or certain medications. Unfortunately, it’s not possible to predict whether a cat might have an anaphylactic reaction before they experience one for the first time.

How can you tell a cat is having an anaphylactic reaction?

During an anaphylactic reaction, the immune system floods the body with chemicals that cause inflammation. These chemicals have a negative effect on breathing, blood flow and the gut. The body’s cells do not get enough oxygen and nutrients to function properly, and many organs can be damaged as a result. 

In cats, some of the signs of anaphylaxis include:

  • Difficulty breathing (in cats, they may open their mouth to pant, and the belly may heave in and out with an increased effort to breathe)
  • Vomiting
  • Diarrhoea
  • Salivation
  • Itching and scratching at their face

How is anaphylactic shock treated in cats?

Treatment is needed straight away, as anaphylactic shock can be fatal. People with severe allergies often carry adrenaline in an EpiPen®, and likewise cats may also need adrenaline to treat anaphylaxis. It would be very rare for a cat to be given an EpiPen® however, as most cases occur out of the blue. Cats should be taken straight to their vet, where adrenaline and other medications can be administered as soon as possible. The vet may also want to give oxygen and fluids. In some cases, inhaled medication is given to help open the airways. Usually, cats will need to be kept in for monitoring and the vet may want to run some tests to check for any long-term organ damage. 

Can anaphylactic shock be prevented in cats?

It’s impossible to predict whether a cat will have an anaphylactic reaction before they experience one for the first time. To prevent such a reaction happening again, it’s important to try to identify what may have triggered it and then to avoid any future exposure. Looking at diet, access to outdoors and recent medication may give some clues. 

Fortunately, this condition is rare in cats. If you suspect your cat is having an anaphylactic reaction, take them to your vet without delay.

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