Allergic Reactions to Insects in Cats

An allergic reaction to insects in cats can be caused by bites or stings from ants, hornets, wasps, bees, and spiders. These insects are the most allergy-promoting culprits due to the venom that is released in their bites and stings. A reaction usually occurs within 20 minutes of a bite or sting, but the feline should be observed for the next 12-24 hours as these symptoms can increase in severity over time. If your feline’s allergic reaction to an insect bite or sting is mild, her condition may resolve itself within a couple hours. However, if your cat is having difficulties breathing, is in pain, or has gone into anaphylactic shock, you need to see a veterinarian right away. 

An allergic reaction to insects is an overreaction of the cat’s immune system to the venom of an insect. The immune system is designed to detect and destroy harmful invaders that come in contact with the body. The feline’s immune defense attacks these foreign invaders by creating specialized antibodies to engulf the allergen. These antibodies trigger the body’s various types of white blood cells, which have an inflammatory response causing the swelling, itching and redness associated with an allergy. The allergic reaction can be mild with just a few symptoms of sluggishness, a slight fever and a decreased appetite. It can be moderate with marked signs of urticaria (hives), facial swelling, and extreme pruritus (itchiness), which may progress to a severe reaction. A severe allergic reaction is termed  anaphylaxis, a sudden allergic reaction that makes breathing difficult and ends in collapse or sudden death. 

A feline may present mild, moderate or severe allergic reaction symptoms depending on a few factors: 

• How many times the cat was bitten/stung. 
• Where the feline was stung (inside the mouth could cause breathing difficulties).
• How hypersensitive the feline’s immune system is to the allergen. 

Mild Allergic Reaction

• Temporary loss of appetite (about 12-24 hours)
• Sluggishness
• Fever 

Moderate Allergic Reaction

• Pruritus (itchy skin) 
• Urticaria (hives) 
• Wheals
• Redness
• Swelling (head, neck, eyes)

Severe Allergic Reaction

• Very sudden allergic reaction
• Rapid swelling 
• Hives 
• Breathing difficulties 
• Wheezing 
• Diarrhea
• Vomiting 
• Decreased blood pressure 
• Pale mucus membranes
• Cold extremities 
• Trembling
• Collapse 
• Death 

An allergic reaction to insects in cats is caused by the venom or saliva injected into the skin during a bite, as well as venom delivered by a stinger. Spiders, wasps, bees, hornets, and ants are the common culprits to cause an allergic reaction in cats, but this lies dependent on your geographic region. Felines that spend a lot of time outdoors and those that live in warmer regions of the world are at higher risk. 

There is no true diagnostic test for an allergic reaction to insects, but your veterinarian can deduce your cat’s condition from routine procedures. Physically finding a stinger or bite, hives, or swelling on a physical exam is the most common diagnostic exam for insect bite allergies. Your veterinarian will also review your cat’s medical history, as many felines will hyperactive immune systems are often allergic to more than one element. You will also be asked about your cat’s lifestyle, such as how much time she spends outside and if you have any hornets’ nests around the area. Any information you have to share will the veterinarian about your cat’s condition will prove extremely helpful.

Felines will a mild case of an insect allergic reaction may not need treatment, as mild case symptoms often resolve on their own within a few hours. However, cat owners will need to continue observing the cat for the next 12-24 hours to ensure the condition is not progressively becoming worse. 

If the feline has been stung, the stinger will need to be properly removed without injecting more of the venom that lies in the head of said stinger. Although this can be done at home, it is highly recommended to take your feline to the veterinarian, especially if this is the first time your cat has ever been stung. The veterinarian can remove the stinger properly, show you proper stinger removal technique and administer medication for inflammation if necessary. 

Cats with severe allergic reactions to insects need to be rushed to the veterinary emergency clinic right away. The doctor will begin administering life support to the feline including intravenous fluids and oxygen. Felines that are stabilized will survive anaphylaxis and return back to normal.

The prognosis for an allergic reaction to insects in cats is generally good, but anaphylaxis patients may not have as promising of a prognosis if life support is not received in time. Your veterinarian may prescribe your cat an epinephrine pen to have on hand if she has a history of anaphylactic shock. It is also advised to avoid stings and bites whenever possible to discourage another allergic reaction to insects in your cat.