Signs and symptoms of allergies may vary but most are often marked by persistent itching and mild discoloration of skin, coughing, sneezing, wheezing, and mucus discharge (most common in inhalant allergies), and nausea, lethargy, vomiting, and diarrhea (common to food allergies and other ailments.)
Over-the-counter medications and treatments for most common dog allergies are available and may be purchased at any quality pet supply store, but extra care should be taken when choosing which treatments to use. Consultation with a vet should always be the first course of action for several reasons. First, what you may think is an allergic reaction could actually be signs of a more serious ailment and a veterinarian should be the one to determine whether that is the case. Secondly, if the allergy is severe enough, an over-the-counter treatment may not be sufficient to treat the problem and a prescription strength treatment may be required.
Just like humans, dogs that suffer from allergies can live comfortably with them as long as they are properly diagnosed and treated. It is important to keep in mind that this is not a time to “play doctor” by attempting to diagnose or treat a possible allergic condition. Only a veterinarian is qualified to determine whether your dog is suffering from allergies and what course of action you should take.