Introduction
Food allergies are one of the most common causes of allergic reactions in dogs, affecting up to 10% of the pet population. Dogs, like humans, can develop allergies to certain foods over time. While some allergies are caused by meat-based proteins like beef or chicken, dogs can also have adverse reactions to other common ingredients found in commercial pet foods, including cat food.
But can dogs actually become allergic to cat food specifically? As it turns out, some of the same ingredients found in cat food that trigger allergies – like fish, grains, and dairy products – may also provoke an allergenic response in dogs. Understanding what in cat food dogs react to and how to diagnose and treat a suspected cat food allergy is key to protecting your pup’s health.
What is a Food Allergy?
A food allergy in dogs occurs when the dog’s immune system overreacts to a particular ingredient in their diet, usually a protein. The immune system mistakenly identifies the protein as a threat and produces antibodies to fight it. The antibodies then cause the release of histamine and other inflammatory chemicals in the body, which leads to an allergic response and corresponding symptoms.
The most common food allergens for dogs are beef, dairy products, chicken, lamb, fish, chicken eggs, and wheat. However, dogs can develop allergies to any protein or carbohydrate ingredient in their food. Food allergies in dogs usually develop after repeated exposure to the offending ingredient.
Unlike food intolerances, which are digestive issues caused by difficulties digesting ingredients, food allergies trigger an immune response. Food allergies can develop at any age, but often first appear in dogs between 1-3 years old. Certain breeds like Labradors, Golden Retrievers, German Shepherds, and Cocker Spaniels are more prone to food allergies.
The symptoms of a food allergy can range from mild to severe and usually involve the skin, gastrointestinal tract, or respiratory system. Typical symptoms include itchy skin, chronic ear infections, vomiting, diarrhea, and wheezing. Diagnosing a food allergy involves an elimination diet trial and may require testing. Treatment involves identifying and avoiding the allergy-causing ingredient(s).
Sources:
https://vcahospitals.com/know-your-pet/food-allergies-in-dogs
https://vetnutrition.tufts.edu/2017/01/food-allergies/
Common Dog Food Allergens
Some of the most common food allergens for dogs include:
- Beef – One of the most frequent food allergens for dogs, beef is found in many commercial dog foods. Dogs may be allergic to the proteins found in beef as well as beef by-products like broths and oils [1].
- Dairy – Like humans, some dogs are lactose intolerant or allergic to the proteins found in cow’s milk. Dairy allergies in dogs can cause gastrointestinal issues as well as skin irritation and itching [2].
- Chicken – After beef, chicken is one of the most common food allergens for dogs. Allergic reactions are usually to the proteins in chicken meat, fat, broth or eggs [3].
- Wheat – Some dogs have sensitivities to grains like wheat. It’s usually the proteins in wheat that trigger an allergic response. Wheat allergies can cause digestive upset, skin irritation, ear infections and more.
- Soy – Like wheat, soy is another common food allergen for dogs that can cause itchy skin, digestive issues, and other allergy symptoms.
- Corn – Corn is a very common ingredient in many commercial dog foods. The proteins in corn can trigger an allergic reaction in some dogs.
Other less common food allergens for dogs include eggs, lamb, pork, rabbit, fish and more. Dogs can develop allergies to any protein or food they are regularly exposed to.
Can Dogs be Allergic to Cat Food?
Yes, dogs can be allergic to ingredients commonly found in cat food [1]. While food allergies are less common in dogs than environmental allergies, they can develop adverse reactions to ingredients in cat food.
Cat and dog foods contain different nutrient formulations to meet each species’ nutritional needs. Cat foods are very high in protein and fat, with increased levels of nutrients like taurine. While not inherently dangerous in small amounts, some dogs may be sensitive or allergic to the higher protein, fat or individual ingredients.
Common culprits are protein sources like fish, beef or chicken. Grains like corn, wheat or soy may also trigger an allergic response. Artificial additives present in many cat foods like colors, flavors and preservatives can also cause issues for some dogs.[2]
Allergic reactions happen when the immune system overreacts to a particular food protein. Signs like gastrointestinal upset, skin irritation or respiratory issues can develop. While cat food allergies are less common than other food allergies, dogs should not eat cat food regularly due to differences in nutritional requirements.
Cat Food Ingredients Dogs May React To
There are certain ingredients commonly found in cat food that dogs may have adverse reactions to, including:
- Fish – Fish proteins like salmon, tuna, and whitefish are common cat food ingredients. Dogs with fish allergies can react to the fish proteins in cat food.
- Meat by-products – Cat foods often contain meat by-products as a source of animal protein. These can include organs like liver that dogs may not be accustomed to eating and have sensitivities to.
- Grains – Cat foods frequently contain grains like corn, wheat, and soy. Dogs with grain allergies may react negatively when eating cat food containing grains.
- Dairy – While less common than in dog food, some cat foods contain dairy products like cheese or yogurt that dogs sensitive to dairy may react to.
- Eggs – Egg protein is another potential allergen for dogs that may be present in some cat foods.
The different protein sources, carbohydrates, fat sources, and other ingredients in cat food compared to dog food mean that dogs unaccustomed to a cat food diet could develop an allergic reaction or intolerance when fed cat food. Checking the ingredient list for any known allergens is important for dogs showing signs of an adverse food reaction after eating cat food.
(https://www.mspca.org/angell_services/the-itchy-pet-food-allergies-in-dogs-and-cats/)
Symptoms of Allergy to Cat Food
If your dog is allergic to an ingredient in cat food, they may exhibit a variety of symptoms indicating an adverse reaction. Some of the most common symptoms include:
Gastrointestinal Issues: Vomiting, diarrhea, excessive gas, abdominal pain, and loss of appetite are common digestive upset signs if a dog eats cat food they are allergic to. The allergen ingredients may irritate the gastrointestinal tract, causing inflammation and discomfort.
Skin Irritation: Dogs with a cat food allergy may develop irritated, itchy skin with signs like redness, bumps, rashes, and hair loss. They may excessively lick or chew at their paws, belly, armpits, or ears. This is caused by the immune system overreacting to the allergen.
Respiratory Issues: Some dogs exhibit coughing, sneezing, runny eyes, and nose discharge. The allergen cat food proteins can trigger an IgE mediated immune response leading to typical allergy symptoms.
Ear Infections: Recurring ear infections are another indicator of food allergies in dogs. The allergens cause inflammation that allows yeast and bacteria to accumulate in the ears.
In severe cases, dogs may suffer from anaphylaxis with life-threatening symptoms like difficulty breathing, swelling of the throat, or collapse. Owners should monitor their dog closely after eating any new food for signs of an allergic reaction. If serious symptoms develop, immediate veterinary care is required.
Diagnosing a Cat Food Allergy
To diagnose a cat food allergy in dogs, veterinarians will typically do a thorough physical exam and take a detailed history of the dog’s diet and health. They may recommend certain diagnostic tests to confirm a cat food allergy:
Elimination diet trial – This involves feeding the dog a novel protein or hydrolyzed protein diet containing ingredients they have never eaten before, like venison, duck, or rabbit. The dog cannot have any other foods or treats during this trial which usually lasts 8-12 weeks. If symptoms resolve on the elimination diet, it indicates an adverse reaction to the previous food. Food trials are considered the gold standard for diagnosing food allergies in dogs (https://todaysveterinarypractice.com/nutrition/food-allergy-diagnostics-therapeutic-food-options/).
Skin testing – Intradermal or patch testing for IgE antibodies against suspected food allergens. A positive skin reaction indicates an allergy. Skin testing is less reliable for food allergies in dogs compared to environmental allergies.
Blood testing – Measuring allergen-specific IgE levels against food proteins in the blood. While available, it is not commonly used due to issues with accuracy and reliability.
Endoscopy – Taking biopsies of the stomach and intestinal lining to analyze for signs of food allergies under a microscope. This is an invasive procedure and generally not recommended just for a suspected food allergy.
Fecal testing – Analyzing a stool sample for the presence of food antigens and antibodies secreted in response to an allergy. Still an emerging diagnostic tool for canine food allergies.
Overall the elimination diet trial is considered the most definitive way to diagnose cat food allergies in dogs. Symptoms improving on the elimination diet, then returning when the original food is reintroduced helps confirm that a dog has an allergy to the ingredients in their regular diet.
Treating a Cat Food Allergy
If you suspect your dog has developed an allergy to ingredients in cat food, the most important treatment is strict avoidance of the allergen. This means eliminating any exposure to cat food and treats. Your vet will likely recommend a strict elimination diet consisting of a novel protein and carbohydrate source your dog has never eaten before.
This elimination diet should be fed exclusively for at least 8-12 weeks to allow your dog’s immune system to calm down and gastrointestinal system to heal. All table scraps, flavored medications, dental treats, and chews should also be avoided during this time.
Your vet may also prescribe antihistamines like diphenhydramine or hydroxyzine to help control itching during the elimination trial. They may also recommend antibiotics, antifungals, or probiotics if secondary skin or ear infections have developed.
Once symptoms have fully resolved, your vet can help you slowly reintroduce regular dog foods one at a time while watching for reactions. This will help identify ingredients that may have been triggering the allergy.
If your dog has a true allergy to an ingredient in cat food, they will likely need to avoid it for life. Preventing any exposure to the allergen is key to managing the condition.
Preventing Exposure
There are several tips to help prevent dogs from eating cat food:
Use separate feeding areas for cats and dogs. Place the cat’s food bowls up high where the dog can’t reach, like on a cat tree or counter top. You can also place the cat’s food behind a baby gate that has openings too small for a dog snout (source).
Feed cats in a separate room and keep the door closed. This ensures the dog doesn’t have access while the cat is eating (source).
Use puzzle feeders or timed feeders only accessible to cats to make it harder for dogs to access the food.
Store cat food in a tightly sealed container or bag that makes it harder for dogs to smell. You can also keep dry food bags in a closet or pantry behind closed doors.
Consider feeding cats more frequent smaller meals so food isn’t sitting out as long.
Use treats or training to teach your dog “leave it” when around the cat food area.
Conclusion
In summary, while it is possible for dogs to be allergic to ingredients found in cat food like fish and chicken, a true allergy is rare. The symptoms of an adverse reaction can include itchy skin, ear infections, digestive issues, and breathing problems. To diagnose a cat food allergy, an elimination diet trial is needed under veterinary supervision. Treatment involves removing the problem ingredient from the dog’s diet. Preventing access to cat food and monitoring your dog are key. Some dogs are simply intolerant of cat food and may get an upset stomach. Overall the takeaway is that cats should eat cat food and dogs should eat dog food, but sampling cat food likely won’t seriously harm most dogs.