
The other night, I broke one of my cardinal rules and got involved in a discussion about pet health care on Facebook.
Someone posted about their dog’s chronic ear problems, and asked for help, particularly from the veterinary community.
I find this sort of situation frustrating. Obviously, this person has struggled to find an answer for her dog’s problems. Having been to several vets without success, she turned to social media. The amount of incorrect and potentially dangerous information I see on these kinds of posts makes it hard for me to resist weighing in, but most of the time, I can fight the urge.
But this time, I tried to help, and very quickly, the poster became defensive at both my line of questioning and recommendations.
“We’ve already switched her food several times. We’ve already tried this product. That drug didn’t work.”
I don’t blame the poster for feeling as though my questions were unhelpful or that we were treading down the same road previously traveled without success. It made me realize two things: social media really isn’t the best place to disseminate information and I needed to write a blog post about the itchy dog.
When you are first trying to work up any sort of medical problem, your veterinarian begins with the signalment and history.
Signalment means: what kind of dog, how old is it, has it been spayed or neutered, and so on. Signalment is important because certain kinds of dogs are prone to certain kinds of problems. Also, some issues start at a certain point in life, and are unlikely if the patient isn’t in that age bracket. Other problems may not exist at all in the spayed or neutered pet–or may be more likely in the spayed or neutered pet. Signalment gives you a starting point for determining what’s going on.
History is equally as important, especially in working up the itchy dog. We need to know when the problem started, does it respond to treatment, does it relapse when the course of medication is completed, does there seem to be a pattern to when it occurs? Has there been a diet change, move to a new environment, new stressors in the house, are you using flea control, are there other pets in the house, and so on.
If I see an itchy dog in mid-summer in my region (Mid-Atlantic U.S.), and there is clear evidence of chewing at the tail head, even if the client tells me they have been using flea control, I’m going to look for fleas first until proven otherwise. Why? Because the flea populations explode at this time of year, many people are forgetful about using products until a problem gets out of control, and we can see resistance to medications over time. Or the client may not be treating all the animals because only the dog goes outside.
Did you know that cat fleas cause more allergic skin reactions on dogs than dog fleas do? Also, some of the worst flea infestations I’ve ever seen–to the point of needing blood transfusions–have been in 100% indoor cats because their people didn’t believe indoor pets could get fleas, and they were trapped in the house with them as the numbers rose. So make sure you discuss with your vet what your safe flea and tick control options are, and at the very least, run a flea comb through your cats the first of every month to make sure they don’t have a problem before it gets out of hand.

But in other parts of the U.S., fleas aren’t even a issue! (Where are these parts and can I move there?) It’s true, some places out West, due to altitude, don’t have to deal with fleas.
Regardless, when presented with an itchy pet, the first thing I do is rule out ectoparasites. This means parasites that live on the outside of the body, such as fleas, skin mites, and lice. Many of these parasites can affect other members of the household, so history becomes important there, too. Are any of the other members of the house (including people) itchy as well? If so, the cause is more likely to be something contagious or that they are all exposed to, which puts an allergy to a specific thing lower on the list. Allergies aren’t contagious!
Ruling out ectoparasites isn’t always easy. Sometimes you find evidence of them by combing or performing skin scrapes. But just because you can’t find any signs of fleas or see mites under the microscope with a skin scraping doesn’t mean they aren’t there. Sadly, I’ve seen people spend thousands on working up their pet’s skin problems when a good dose of flea and tick control was all that was needed. Some of the newer oral medications also kill lice, as well as demodex and sarcoptes mange mites, even though they aren’t labeled for it. So don’t balk when your vet recommends a good flea product as part of the work up. It may save you money and heartache in the end.
But suppose your dog has been getting good ectoparasite control and is still itchy. Where your pet scratches and licks can be very important in narrowing down the problem. Does your dog have ear problems as well? Are there also digestion issues? If so, food may be a factor. Cats tend to demonstrate their allergic problems differently from dogs, so we’ll do a post about them in the future.
Generally speaking, working up allergic skin problems falls into two broad categories: seasonal or all year round. Seasonal allergies typically begin between 1-4 years of age and are worst during the spring and fall. Unfortunately, with age, they can start sooner and last longer until they are present almost year round, but initially there is a strong seasonal pattern.
“All year round” allergies tend to fall into two broad categories: food and environmental. Most vets recommend starting with a hypoallergenic food trial to rule out a food allergy because it can be easier to get definitive results and improvement than trying to manage environmental allergies. This is where I often run into resistance with clients. They don’t want to change their food. The guy who works at the pet store told them this was the best food to feed. They’ve already tried switching diets, freeze-dried food, avoiding chicken, etc.
Many years ago, there were not any commercial diets for hypoallergenic food trials for dogs. When a veterinary dermatologist wanted to put your dog on a food trial, they told you to cook lamb and rice, not because there was anything special about lamb and rice but because since they weren’t common ingredients in the kibble of the day, your dog was unlikely to already be allergic to it. This was called a novel protein diet. If it worked, it was because your dog had never eaten lamb before. There is nothing magical about a lamb and rice diet.
There is nothing magical about a lamb and rice diet.
When the dog food companies realized “lamb and rice is good for skin”, they began producing it. Many people fed it to their dogs. So vet dermatologists, looking for another novel protein diet for food trials, told their clients to feed fish and sweet potato… see where I’m going with this? Now there are so many specialty foods with so many specialty ingredients, finding a novel protein/novel carbohydrate diet can be challenging.
The grain-free pet food craze grew, in part, out of a culture where more and more people were eliminating glutens and grains from their lives, and also because wheat is a common food allergen in dogs, so by going grain-free, many dogs showed improvement in their allergies. At one time, I myself recommended grain-free diets to clients who couldn’t afford the pricey hypoallergenic foods. The dog food companies jumped on the bandwagon, sensing a new market and a clientele willing to pay higher prices for foods perceived to be healthier. The last time I checked, 90% of the kibble on the “Ten Best Dog Foods of the Year” kinds of lists were grain-free.
Then veterinarians began noticing a huge jump in an uncommon heart condition of middle-aged dogs known as cardiomyopathy. Dogs as young as 4 months of age as well as breeds not known for developing this disease were getting it. Breed clubs began working with vets to compile information and a pattern emerged. Of the 500+ cases examined in one study, 93% of the pets were on a grain-free diet. Now, correlation is not causation (meaning just because you see a pattern, doesn’t mean it’s the cause of the problem) but it was enough for the FDA to recommend not feeding grain free foods to your pets. Cardiologists, nutritionists, and dermatologists all speaking at the last veterinary conference I attended said the same.
The weird thing is that these foods have all the right ingredients in them in all the right amounts, but there is something about the pea/legume or potato-based diets that are preventing the heart-protective amino acids such as taurine and carnitine from being bioavailable to your pet (this is important in cats too).
So what do you do if you’re trying to figure out if your dog has a food allergy? The easiest way is to talk to your veterinarian about doing a true hypoallergenic food trial. Not playing dog food roulette by changing brands and flavors every few weeks. Not going grain free. Not even going “limited ingredient.” There are still prescription novel protein diets out there, but their effectiveness has decreased with the advent of so many dog foods containing a whole smorgasbord of ingredients. Also, we’re seeing now that if your dog is allergic to chicken, it may be allergic to duck as well. Same with beef and bison or venison.

A true hypoallergenic food uses hydrolyzed protein instead of a novel one. In order to trigger an allergenic reaction, the protein must be of a certain molecular weight. By hydrolyzing the protein (using a chemical process to make it smaller on a molecular level) the source used doesn’t matter. A dog that’s allergic to chicken can’t react to hydrolyzed chicken.
Depending on the diet chosen, your typical food trial runs 4 to 12 weeks. NO OTHER FOOD OR TREATS but the hypoallergenic food are allowed during the trial (the exception being once-a-month heartworm or flea and tick meds). What we’re looking for is a 50% improvement in that time: less itching, less inflammation in the ears, less stomach or digestive issues. If you are seeing some improvement by 4 weeks, it’s usually recommended to extend the trial a bit longer to see if it is making a real difference. One of the problems of working up allergies is your pet can be allergic to multiple things. If you are seeing no improvement by the end of the food trial, then you can probably take food off the list and move on to looking for another source of the allergies.
Ears often take the longest time to show improvement, but in my opinion are the part of the body most frequently affected by food allergies. I’ve seen some dogs do great on a hypoallergenic diet only to relapse during spring and fall because of seasonal allergies on top of the food issues. Allergies are cumulative, meaning they add up, so if you know your pet has food or seasonal issues and then you get a flea problem on top of that, expect the skin problems and itching to explode!
You can try a novel protein diet instead. It may take longer to see results if you’re feeding rabbit and green peas than a hydrolyzed protein but it’s still valid to consider as a trial. Just be sure to get a prescription version (that has extra taurine and carnitine in it over the boutique versions), and understand that not only does cross-reactivity occur with certain proteins, but it is possible to develop an allergy over time to the new protein as well (which can’t happen with the hydrolyzed foods).
You can also cook for your dog. As I said before, this is what veterinarians used to recommend before there were prescription diets. The challenge here is finding a protein and carbohydrate source that you can get on a regular basis for the length of the trial that your dog hasn’t already eaten (because you typically aren’t allergic to foods you’ve never been exposed to before) and getting the vitamin and mineral balances right. I recommend using the website balanceit.com for creating a home cooked diet for your dog. You can plug in the protein and carb source you wish to use (for example, venison and brown rice) and they will help you determine proportions as well as create a vitamin and mineral combination to meet your home cooked diet’s needs. The new site even allows for combinations of additional oils and vegetables too. One of the advantages of cooking for your dog is this method can also eliminate less common food allergens, such as allergies to preservatives and grain mites. I had one client whose dog’s severe food allergies was controlled by freezing the food first, as her dog had a grain mite allergy. But that’s not the typical case!
The key here is that it’s crucial to conduct a true hypoallergenic food trial so you can rule food in or out as a player in your dog’s allergies. You may think you have, but unless you’ve conducted a trial with a prescription diet, this may not be the case.
If your dog turns out to have a food allergy, clap your hands and jump up and down with joy because this is truly one of the easiest types of allergies to manage and see real improvement! I believe every dollar spent on food will save you in medical bills and you’ll have a happier, healthier pet as a result.
We’ll talk about environmental allergies, how to identify them and manage them, in another post.
