Pork Allergy in Cats

The primary function of the immune system is to protect the body from pathogens that can cause diseases. Food allergies occur when the immune system reacts to an allergen as if it were a bacteria or virus. This “battle” within the cat’s body is what causes the irritating allergy symptoms to occur.

Pork is found in many commercial cat foods. It is also a very common source of cat allergies.  Food allergies are the third most common type of allergies in cats.  

Cats can also have food intolerance toward pork. Food intolerance is different than a food allergy.  Food intolerance occurs when the body has difficulties digesting a certain food item.  The immune system is not involved; the gastrointestinal tract is just overly sensitive to certain foods.

Pork allergy occurs when a cat’s immune system reacts to pork as if it is a threat to the body.  The immune system then produces an antibody (IgE) against the allergen.  When the cat eats the offending protein, it causes histamines and chemicals to be released into his body.

Symptoms may include:

• Small fluid-filled bumps on the cat’s skin
• Excessive itching
• Biting at skin
• Skin lesions
• Weight loss
• Hair loss
• Dull coat
• Skin ulcerations
• Ear Infections
• Recurring bacterial infections 
• Reduced appetite
• Depression

Symptoms of pork intolerance may include:

• Diarrhea
• Loose stool
• Vomiting
• Flatulence 

The cause of pork allergy in cats is the immune system reacting to the allergen (pork), as if it is a threat to the body. It is a malfunction in the immune system, which can occur shortly after eating the allergen or can occur after eating pork for months, or even years.

The causes of a pork intolerance may be:

• Irritable bowel syndrome
• Stress
• Absence of a digestive enzyme
• Sensitivity to the food additives/preservatives used in the pork
• Pork was bad (expired food, unrefrigerated once opened)

A complete medical history will be taken including recent vaccinations, travel, and illnesses as well as a discussion of possible exposure to irritants or toxins. The veterinarian may also want to know if your cat is on a flea and tick preventative.  Flea bite sensitivity is the number one cause of skin allergies in cats.  If your cat was seen by another veterinarian it is recommended that you bring his medical records as the previous records can provide a baseline for the veterinarian.  During the consultation, the veterinarian will want to know what symptoms you have observed and when they began. If vomiting and diarrhea are part of the clinical signs, the veterinarian will need to know an evolution of the symptoms. 

The veterinarian may want to discuss what your pet’s current diet is and how often is he fed. The veterinarian will then perform a physical examination which may include taking the cat’s weight, temperature, pulse and blood pressure. He may also listen to the patient’s heart, lungs and gastrointestinal tract. The doctor may take a skin scraping to analyze under a microscope; this diagnostic test will help rule out parasites. A culture of a sample taken from a lesion or sore may also be suggested.  A complete blood count (CBC) and a serum chemistry test may be drawn. The complete blood count (CBC) will help determine if the cat is anemic or if he has a bacterial infection. A serum chemistry test can help evaluate organ function.  The veterinarian may also recommend a fecal test, abdominal x-rays and ultrasound.

Your cat will be treated with antihistamines and anti-inflammatory medications.  If the complete blood count (CBC) determined that the patient’s white blood cells are elevated (bacterial infection), the veterinarian will prescribe an antibiotic. A topical antibiotic ointment may also be recommended if lesions are particularly ulcerative or oozing.  The patient will need to wear a cone so that he does not lick or bite at lesions.

The long term treatment of food allergy and food intolerance is to identify the allergen. Serology testing and/or skin testing are not reliable in determining food allergens. The best way to identify the allergen is to conduct an elimination diet. The veterinarian will suggest a protein and a carbohydrate to be fed to the cat for 8-12 weeks, such as chicken and sweet potato.  At the end of the 8-12 weeks a new protein and carbohydrate are introduced; recommendations may be salmon and potato. The food elimination test may take several months before it can be determined what allergen is causing the allergic reaction.  If the cat shows an adverse reaction to one of the proteins or carbohydrates it should be discontinued from his diet.  It is a good idea to keep a log of the items you are feeding your cat and if there are any reactions to the foods. 

During the elimination diet, the cat should not be fed treats or given any table scraps.  A homemade diet is highly recommended but there are commercial diets available.  The veterinarian will help you decide what the best diet is for your pet is.

Once pork is identified as the source of the allergy, it should not be fed again to the cat.  Once the allergen is determined and eliminated from the diet, the prognosis for the patient is very good. The cat will need follow up visits to monitor his progress and to re-examine his skin.  If there was a skin bacterial infection, a complete blood count (CBC) will need to be retaken.