Allergies in dogs are defined as a “complex and multifactorial disease.” Despite being overlooked and underdiagnosed, allergies are quite common. In fact, many experts believe that as much as 20% of dogs will develop some type of allergy in their lifetime.
But what are allergies in dogs? What are the prevalent allergens in canine companions? And why are dog allergies significant? If you are interested in the answers, keep reading – this article explains allergies and will scratch the surface of the most common allergens.
Allergy is a hypersensitivity to a specific substance called an allergen. In simpler words, allergies occur when the dog’s immune system identifies a foreign substance as a threat and overreacts.
The immune system is responsible for protecting the dog against threats. In the case of an allergic reaction, the immune system responds to the presence of allergens strongly and exaggeratedly, which results in allergy symptoms.
Allergen 1: GRASS, WEEDS, BUSHES & TREES
Pollen from grass, weeds, bushes, and trees is a prevalent cause of allergies in dogs. Dogs are often sensitive to pollen from orchard and timothy grass; ash, oak, and Japanese cedar trees; and ragweed and mugwort pollen.
However, it is not just outdoor vegetation that produces pollen. Houseplants can be an issue as well. For example, fern, philodendron, and spiderwort are potent allergens.
In addition to allergens, many indoor and garden plants are toxic to dogs. Before arranging your home and garden, ensure you include safe and dog-friendly plant species.
Allergen 2: MOLD SPORES
Molds are multicellular fungi that thrive in moist environments and multiply via air-borne spores. There are over 10.000 mold species, and while the black mold (Stachybotrys) is the most notorious, all molds are dangerous regardless of color.
Dogs get exposed to molds via inhalation and ingestion – a study showed that dogs could carry molds if living in contaminated homes. When grooming, the dog will ingest those molds.
In addition to triggering mold allergies, molds can cause poisoning. Unlike pollen, molds are not seasonal – they thrive year-round and can be found in unusual places. For example, unless waterproof, the inside of your dog’s bed can harbor molds.
Allergen 3: DANDER
Dander is the scientific term for the microscopic flakes of dead skin that float in the air. Both humans and pets produce dander, and dogs can be allergic to human dander and dander from other pets – dogs and cats.
Metaphorically speaking, multi-pet owners often say that their dogs are allergic to their cats if they cannot stand each other. The metaphor aside, this can actually be true.
Dander is also the reason many people are allergic to dogs and cats. The vice versa scenario is also possible – some dogs can be allergic to people. Dander triggers an allergic reaction when inhaled.
Allergen 4: DUST & DUST MITES
Dust mites are tiny pests that feed on dead human skin cells. They are an important part of house dust, along with hair, dander, clothing fiber, soil particles, bacteria, elements from dead bugs, and microscopic plastic specs.
The two most widespread dust mite species are Dermatophagoides farinae and Dermatophagoides pteronissynus. However, dust is not the only source of dust mites for dogs.
Namely, storage mites are also a risk for dogs. A study showed that commercially available dry dog food could be contaminated with storage mites, such as Acarus siro, Lepidoglyphus destructor, and Tyrophagus putrescentiae.
Allergen 5: FLEAS
Dogs can be allergic to a protein found in flea saliva. Fleas inject saliva into the dog’s skin when biting. Then, in sensitive dogs, the proteins in the saliva cause a so-called flea bite hypersensitivity or flea allergy dermatitis (FAD).
Depending on where you live, flea allergy dermatitis can be a seasonal or a year-round problem. Studies show that flea allergy dermatitis is one of the most common skin allergies in dogs. Studies also show that fleas are prevalent allergy-causing insects in dogs.
Fleas pose additional dangers. For example, they are an intermediate host for Dipylidium caninum (a tapeworm species) and act like vectors for many zoonotic diseases.
Allergen 6: CLEANING PRODUCTS
Dogs can be sensitive to common cleaning products. Such household cleaning products include floor cleaners, fabric softeners, laundry detergents, toilet bowl cleaners, counter cleaners, etc.
Considering that the average cleaning product contains around 62 potentially toxic chemicals, it is expected that some of them can also be an allergen. If ingested, these allergens can also be toxic.
Finally, we should note that sometimes the dog may not be sensitive to the actual product. Instead, the sensitivity can be due to the presence of added and usually synthetic dyes and fragrances.
Allergen 7: CIGARETTE SMOKE
Cigarette smoke is a strong allergen. Dogs usually get exposed when inhaling the smoke. However, they can also lick settled smoke particles from their coats while grooming.
Smoke can cause and worsen respiratory allergies in dogs. It can also trigger flare-ups in dogs with allergic dermatitis. In a PetHealthNetwork article, Dr. Ernie Ward, DVM, says, “I’ve seen many pets experience intense itching after their guardian lights up.”
In addition to allergies, exposure to second and third-hand smoke is linked with eye irritation and nose cancer. Plus, the ingestion of cigarette butts can result in nicotine poisoning.
Allergen 8: FOOD INGREDIENTS
Food allergies in dogs are a hot topic. However, their popularity is hype – more of a trending buzz. While common, true food allergies are not as widespread as marketed.
Food intolerances/sensitivities are much more common. The difference between food allergy and food intolerance is that the first involves the immune system, and the latter is due to the inability to digest certain ingredients.
In dogs, food allergens are beef, dairy, wheat, eggs, chicken, lamb/mutton, soy, pork, rabbit, and fish. Food allergies in dogs can cause digestive issues (usually diarrhea) or skin issues – itchiness.
Allergen 9: PERFUMES
Perfumes and other scented products, like colognes, body lotions, and candles, can all trigger an allergic reaction. Even cosmetic products for dogs (shampoos, conditioners, paw balms) can have the same effect.
According to VCA Hospitals, a dog’s sense of smell is 1000 and 10.000 times better than a human’s. A recent 2021 study showed that the dog’s nose can detect “changes in emotions” and “human cells metabolism during various illnesses.”
Considering the power of the dog’s nose, it is no surprise that strong scents can be irritating or even allergy-causing.
Allergen 10: MEDICATIONS
Finally, the last allergen on our list is medications. Both human and pet-specific medications can cause an allergic reaction.
The group of medications with allergen potential includes painkillers, antibiotics (penicillins and sulfonamides), vaccines, flea and tick treatments & preventatives, etc.
Luckily, the scariest type of allergic reaction to meds, called anaphylaxis, is rare in dogs. In a PetMD article, Dr. Jennifer Coates says that she rarely asks the owner whether the dog is allergic to a certain drug because anaphylactic shock is “quite rare.”
Final Words: The Importance of Allergies in Dogs
Allergens are everywhere, and sadly, allergies in dogs are quite common. While management is possible, its execution is often challenging and requires time.
During that time, allergies affect the dog’s quality of life and impact other aspects as well. They increase the risk of secondary conditions, infectious diseases, and systemic illnesses.
With everything being said, it is easy to understand the impact of allergies on dogs. Considering the continuous advances in veterinary medicine and increased pet care awareness among pet owners, hopefully, allergies in dogs will be easier to manage.
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