Allergies in dogs and cats are nothing to sneeze at

Spring is in full swing, which means pollen and other allergens are wreaking havoc on the 50 million Americans who experience seasonal allergies. 

But humans aren’t the only species that suffer due to allergens — other animals, including our pets, can have allergies, too.  

What is an allergy?

The immune system is made up of white blood cells, antibodies, and other components that attack and break down foreign substances. For example, if a virus enters the body, the immune system first detects the virus and then springs into action to kill the pathogen. 

The immune system is complex and efficient, but sometimes it gets things wrong. An allergic reaction occurs when the immune system overreacts to substances that are typically harmless, which are called allergens. 

When allergens are touched, breathed in, or ingested, the immune system goes into overdrive to defend the body, resulting in swelling and other symptoms. 

“Allergies in pets most commonly manifest as itchy skin or ears with secondary infections cropping up,” said Jenny Marin, clinical assistant professor in Community Practice (C-PRAC) at the Virginia-Maryland College of Veterinary Medicine. 

Flea allergy 

Flea allergy dermatitis (FAD) occurs when your pet’s immune system goes haywire in response to proteins in a flea’s saliva. FAD can affect both cats and dogs, and it’s the most common dermatologic disease in dogs in the United States.

FAD causes itchiness and fur loss, and it can result in crusty or weepy patches of skin. That skin is then susceptible to bacterial and yeast infections. 

A pet doesn’t need to have a full-blown infestation of fleas to get FAD — only a bite or two can result in skin problems. Fleas are around year-round but are more active in the late summer, when many cases of FAD are seen.

“It is crucial to keep your pet on flea and tick prevention year-round to prevent flea allergy dermatitis, Marin said. “This is especially important in animals with a history of allergies because preventing exposure to as many allergens as possible will decrease their overall symptoms.” 

Airborne allergies

Pollen, mold, dust, and other airborne particles can cause an allergic reaction in both dogs and cats. 

For humans, an airborne allergy typically results in sneezing and a runny nose, but in cats and dogs, the primary symptom is itchiness. 

Itchiness results in agitation, scabs, and patches of hair loss. Dogs and cats with airborne allergies may also develop asthma-like symptoms, or discharge from the eyes or nose. 

Food allergy 

For cats and dogs, food allergy symptoms can look very similar to that of airborne allergies: crusty, itchy skin, hair loss and gastrointestinal symptoms. Unlike airborne allergies, food allergies do not vary by season. 

The most common food allergies in cats are:

• Fish 
• Beef
• Chicken

The most common food allergies in dogs are: 

• Eggs
• Wheat
• Chicken
• Beef
• Dairy

Determining if your pet has a food allergy can be a long process, as it requires either an elimination diet (where foods or food groups are removed from the diet to determine the cause of the allergy) or a hydrolyzed diet (where the proteins in the food are broken down). This can be particularly tricky for cats, who tend to turn their nose up at new foods. 

When your pet is going through these diets, they can’t eat anything else — that includes treats and even toothpaste. 

Food allergy diagnosis is a time-consuming process. It can take months on an elimination of hydrolyzed diet to determine the exact allergen.  

Diagnosing pet allergies

Flea, airborne, and food allergies all cause itching and discomfort in pets, symptoms that overlap with many other conditions. If your pet is suffering from itchiness, it’s important for you to take your pet to the veterinarian to determine the cause and make a treatment plan.

“If your pet's itching becomes severe enough to notice itching several times a day, causes noticeable skin irritation or interferes with normal activities you should take them to their veterinarian," Marin said.

Your veterinarian will conduct a physical exam and will ask questions about your pet’s symptoms and history. They might gather skin scrapings and other samples for testing. 

Your veterinarian will work with you to determine the best treatment for your pet’s allergies. They will treat any secondary infections; provide medication to prevent the itchiness, including shampoos and other topical treatments; and discuss diet trials or allergy testing.

With diagnosis and treatment from a veterinarian, you can manage your pet’s allergies so they can lead a happier, less itchy life.