The human animal isn’t the only one affected by allergies. Like you, your adult dog can suffer from allergic reactions to any number of things—in the air, on his skin, and in his food. Allergies must be diagnosed and treated by your veterinarian, but first, you must know what to look for.
The most common signs and symptoms of allergies include:
The most common allergy symptoms in dogs are the skin reactions, regardless of the cause. And they can they can crop up at any age. Just because he didn’t have allergies as a puppy, doesn’t mean your dog won’t have them now that he’s an adult. Inhalant, food, contact, and flea allergies are four of the most common types of allergies that might affect your dog.
Inhalant allergies in dogs are caused by the same common allergens that affect you—dust, grass, trees, mold, pollen, ragweed, etc. They can be seasonal or persistent and, while some breeds (especially short-snouted breeds) might experience the same sniffly, sneezy symptoms you might suffer, skin reactions are most common. Inhalant allergies often can be treated with the same medications you take, but please don’t treat your dog’s allergies without veterinary supervision.
Food allergies can be the most difficult to diagnose and manage. Treatment involves a hit-and-miss approach involving a restricted diet and the gradual reintroduction of possible allergens to determine the culprit. Skin reactions to food allergies are common in dogs, but frequent vomiting or diarrhea also can be a sign. Keep in mind that if there is a change in your dog’s diet (or he just ate something he wasn’t supposed to), he might experience an episode of vomiting or diarrhea, but this doesn’t necessarily mean your dog has an allergy. Watch and see if it becomes a persistent problem before scheduling a costly trip to the vet.
Contact and flea allergies generally cause skin irritation and are treated topically. You might be surprised to learn that most dogs are only vaguely bothered by fleas. But those that are allergic can suffer—and so can their owners. Dogs with contact and flea allergies often chew their skin raw, leading to hair loss, odor, and infection, so fastidious flea control is a must.
Allergies can vary from dog to dog, so it is important that you work with your vet to make sure your dog gets the best possible treatment. You’ll both be happier for it.

Nutrients such as protein, fat, vitamins, and minerals are important players in the skin and coat health of dogs. To understand the role of these nutrients, it is necessary to start by understanding skin and hair.
The purpose of skin and hair is to block things from leaving (such as water or heat) or entering (such as viruses and bacteria) the body.
The hair coat is composed almost entirely of protein. If the animal's diet doesn't contain adequate protein quantity and quality, hair may fall out, or become dry, weak and brittle.
Skin is made up of squamous cells, flat cells tightly packed together. These cells have tough membranes that are composed of proteins and fats. Without proper amounts of these nutrients, cell membranes weaken, allowing water to escape and bacteria and viruses to enter more easily.
Proteins are found in both animal-based and plant-based ingredients. Animal-based proteins contain all the essential amino acids dogs need, whereas plant-based proteins may contain only some essential amino acids. Animal-based proteins help dogs achieve optimal health.
Fats can also be found in both animal-based and plant-based ingredients. They are incorporated into skin cells as fatty acids. There are two essential fatty acids for skin and coat health. Linoleic acid maintains skin and coat condition in dogs. Without enough linoleic acid dogs may experience dull, dry coat, hair loss, greasy skin and increased susceptibility to skin inflammation.
Both of these essential fatty acids are omega-6 fatty acids and are found in animal tissues like chicken fat. Linoleic acid is also found in some vegetable oils, such as corn and soybean oils.
Most commercial dog diets contain more than adequate amounts of omega-6 fatty acids. Because these fatty acids can be converted to compounds that increase susceptibility to skin inflammation, it is important to balance the amount of omega-6 fatty acids in the diet with omega-3 fatty acids, which reduce susceptibility to inflammation.
Omega-3 fatty acids are found in oils from fish and some plants (canola and flax).
IAMS research has found that combining fat sources in the diet at a ratio of 5-10 omega-6 fatty acids to 1 omega-3 fatty acid results in excellent skin and coat health.
Vitamins and minerals are essential for the development of healthy skin and hair coat. The best way to provide these nutrients is through a complete and balanced diet containing appropriate amounts of essential vitamins and minerals rather than through supplements.
| Vitamin or Mineral | Importance to Skin and Coat Health |
|---|---|
| Vitamin A | Necessary for growth and repair of skin |
| Vitamin E | Protects skin cells from oxidant damage |
| Biotin | Aids in the utilization of protein |
| Riboflavin (B2) | Necessary for fat and protein metabolism |
| Zinc | Necessary for fat and protein metabolism |
| Copper | Involved in tissue pigment and protein synthesis |
Diet is often believed to be a factor when changes in skin and coat condition are noticed. The most common causes of these changes, however, are season and life stage.
As cold weather approaches, most dogs grow a thick coat to help keep heat in and cold air out. As the weather begins to warm up, they shed the thick, heavy coat.
Most puppies are born with soft fuzzy hair, but as they age, a coarser coat grows. Pregnant or lactating dogs also may experience a change in coat condition or hair loss. And, as with humans, the hair on dogs may thin out and become coarser and white as they reach their senior years.