The dog is scratching, and scratching, and scratching. When he is not scratching, he is rubbing and whining. No one in the house can sleep, and the dog is miserable. You don't see any fleas, so you assume that the poor animal has an allergy. After all, in this day and age, everyone seems to be allergic to something, so the dog must be allergic. Thinking it has to be his food, you switch brands, but three weeks later, the dog is still scratching, you're still awake at night, and the dog is still miserable. So, what went wrong?
Well, the first mistake was assuming that every scratching, itchy dog must have an allergy. The second mistake was assuming that the allergy must be related to the food. While it is true that allergic skin disease is common in our pets, it is not the cause of all itchy skin. Many other problems can lead to scratching. These other skin diseases must be identified and treated first. Otherwise they interfere with the diagnosis and treatment of allergies. The process of reaching a definitive diagnosis can be difficult and frustrating, but is the best method to assure proper treatment for your pet. Merely assuming any itching is an allergy and guessing about treatment can lead to months and months of misery for your pet and you.
It is critical to understand that many, many different types of problems can cause itching, and look the same on the dog. All these different diseases can cause hair loss, redness, crusting, itching, bumps, and odor. So, the diagnosis is not based merely on looking at the dog, but reached by combining the history of the disease, the pet's physical examination, and specific diagnostic tests. Sometimes diagnosis is simple; sometimes it is complicated and many tests and treatments must be tried. The best way to understand your pet's skin problems is to work with your veterinarian to find the cause.
Start by creating a list of all the potential problems that could contribute to your pet's skin problem. A short list of skin diseases that cause itching might include fleas, lice, ticks, mites, bacterial infections, yeast infections, fungal infections, hormonal problems, reactions to drugs, genetic problems, dry skin, malnourishment, psychological problems, and of course, allergies. To make things worse, combinations of skin diseases can occur, so a pet could have allergies to inhalant substances, food allergies, bacterial skin infections, and fleas at the same time. Even if the dog really had a food allergy, merely switching the diet would not solve this poor animal's problems!
Once you have a list of potential problems, your veterinarian can help eliminate some causes and potentially diagnose others with simple tests. For example, low levels of thyroid hormone can be identified with blood work. Parasites can be seen on the dog or found by a test called a skin scraping (tiny bits of skin tissue are examined under the microscope). Fungal infections, such as ringworm, can be identified with a skin scraping, examination under special lights, and specific cultures, while bacterial infections and yeast infections can be seen on the skin scraping and identified with their own cultures. By performing these simple tests, your veterinarian may be able to eliminate many possible causes, reach a diagnosis, and start treatment. Even if a definitive diagnosis is not reached, many potential causes will have been removed from the problem list, and treatments can be started. Often, treatment involves combining therapies to control more than one problem. So a dog may end up taking thyroid supplements, medication to control yeast and bacterial infections, and be treated for fleas at the same time.
After all the other underlying problems are identified and treated, allergies can be considered. Allergies can be quite complicated and may by caused by many different substances. Pets may react to anything they eat, inhale, or contact. So, dogs may be allergic to inhalants such as molds and pollens. They may be allergic to substances they touch, such as carpet fibers, plants, or fertilizers. And, they may be allergic to specific ingredients in their foods, such as corn, beef, or seafood. In addition, they can be allergic to more than one inhaled substance or food, or have a combination of allergies and be allergic to both foods and inhaled substances at the same time.
A good physical examination can help make the diagnosis of allergies. For example, dogs with contact allergies show itching and irritation at the points where their bodies contact the allergen. So dogs allergic to the carpet would have problems on their feet, bellies, and sides, while dogs with plant contact allergies would show irritation on their underline and legs. Dogs with inhalant allergies could display many signs, but the most common signs are biting their feet and rubbing their faces. Dogs with food allergies could have digestive signs, such as diarrhea, but more commonly have rashes, bumps on the skin, and itching.
Sometimes, diagnosis is difficult, so treatment trials with medications are tried. If the medication works, the diagnosis is assumed to be correct. Some inhalant allergy treatment trials use medications, known as antihistamines, which block histamine release in the body and help to stop itching. The antihistamine trials involve giving the dog one type of antihistamine and watching the dog's response for the next two weeks. If the dog does well on it, everyone is happy, and the dog can be kept on the specific antihistamine for long periods of time. If the dog does not respond, another antihistamine is tried for two weeks. This process is continued until several different antihistamines are used.
Allergy testing for inhalant allergies can also be performed. Either skin testing or blood tests may be used. Each type of test has advantages and disadvantages. Blood tests are easy, less expensive, and require no practitioner experience. Skin tests are expensive and require an experienced diagnostician or a dermatologist to perform and read, but often correlate better to treatment success.
Whether you are heading to the beach for the week or vacationing in the mountains, you cannot leave home without making arrangements for your pets. Bringing them with you is an option, but only works when you are willing to put the pets' health needs ahead of your need for fun. Being crated in a hotel room for hours on end is not your pet's idea of vacation. And you cannot leave any pets in a parked car. So, before you commit to bringing a pet with you, decide how you will travel and what will happen when you arrive. Is there room in the car or on the plane for the pet? Can you bring your cat into the passenger cabin or must she go in the non-air conditioned baggage compartment of the plane? Does the dog travel with ease or is motion sickness a perpetual problem? Will there be time to play with and walk the dog? Can the pet come with you into your vacation home? You must answer these and many more questions before deciding that it is wise to travel with your pet.
Once a dog is diagnosed as having allergies, and the cause of the allergy is identified, dogs with inhalant allergies can then be treated with allergy shots. These injections are given approximately once per week for several months or longer. The injections can be given at home by the owner. Many dogs experience significant relief after a series of allergy shots.
Food allergies are more difficult to identify. A dog can be allergic to any food that he has previously eaten in his life, including dairy, rice, any grain, and any meat source. Merely switching brands of dog food does not rule out an allergy. The best way to test for food allergies is to put a dog on a diet that contains food he has never been exposed to (very difficult in most dogs) for about 10 weeks. No other foods or treats may be given. If his skin clears up, this is a presumptive food allergy. A definitive diagnosis of food allergy would then involve repeating the entire experiment by feeding the old food, watching to see if the problem returns, and retesting the new, hypo-allergenic diet. If the dog clears up again, he has food allergies. This is a very difficult, time consuming process because most dogs have been exposed to many foods and could be allergic to just about anything. It also takes months to get an answer.
Using commercial hypoallergenic diets may be easier than trying to create a balanced, home-made, allergen-free recipe. There are veterinary prescription diets specifically made for pets with food allergies. These diets either have unusual ingredients, such as kangaroo meat, or have the nutrient sources so broken down that the dog's body can't identify them as potential allergens. If a balanced diet is found that gives the dog relief from itching, he may be fed this food forever to prevent future problems.
So, let's get back to our really itchy dog that is keeping you awake at night. Let's assume that the dog does not have fleas, or lice, or mites, and has no other identifiable problems. A presumptive diagnosis of inhalant, allergic skin disease has been made. You have an appointment for allergy testing next month. But, meanwhile the dog is still itching and the allergy shots can take months to work. So what can you do?
Well, there are a few things you can do at home to help these itchy dogs. Ask your veterinarian about the use of oral antihistamines, and set up a bathing regime for the dog. Do not bathe too frequently, as this can lead to dry skin, but bathe the dog when he is miserably itchy, has a bad odor, or as your veterinarian recommends. Look for shampoos, rinses, and sprays that give relief from itching. These products are listed as hypo-allergenic, soap free, and anti-puritic, and contain ingredients such as oatmeal, fatty acids, moisturizers, or pramoxine.
Many allergic dogs also benefit from the addition of fatty acids into the diet. These fatty acids are anti-inflammatory and help control itching. Studies show that as many as 25-50% of itchy dogs get relief from fatty acid supplements. Look for those food supplements high in omega-3 fatty acids. Additional studies show that the combination of oral antihistamines and fatty acid supplements can be very effective at controlling itching. Expect it to take up to four to six weeks for fatty acid supplements to work.
There is no one best treatment for all itchy dogs. Once the cause is identified, treatment is aimed at eliminating the cause and controlling the itching. Using proper shampoos, food supplements, and antihistamines can help many dogs, but nothing will replace proper veterinary care for your pet. So stock up on supplies, but bring your pet to the vet. The dog will stop scratching and you'll both sleep through the night, at last