Just like humans, dogs experience different allergic reactions for different allergens. Allergic reactions to food include throwing up and looseness of the bowels. Allergies and fleas are also associated with hives and rashes.
The four causes of allergies in dogs are insects, contact, food and inhalant. Insect allergies are the most common types of allergies that dogs contract due to fleas and other parasites that feed on dog's blood. Food allergies are another common cause of allergies, especially fish, beef, milk, eggs and wheat. Inhalant allergies are due to breathing in pollens, dust, mold and other allergens from the environment. The last allergy type is contact dermatitis, which is due to your dog coming into contact with a substance.
The use of apple cider vinegar can improve a dog that is suffering from allergies. First, a pet owner must section the fur, then spray the vinegar on the itchy area.