When it comes to eating healthy, humans have it down to a science. Eat your vegetables, don’t overdo it on the snacking, and wolf down a salad every now and again. Pretty simple, right? Well, the same goes for your dog—only, not the salad part.

Your dog needs the full list of carbohydrates, fats, proteins, vitamins, and minerals to live a happy, healthy life. Although, with dogs, it’s much harder to know whether or not they’re getting everything they need. Sure, they’ll never run off for a “cheat” day, but all their food is held up in a single pack of kibble. Can you trust what’s inside those crunchy nuggets? 

The short answer is: it depends. Knowing the signs and symptoms of dog nutritional deficiencies can ensure your dog is receiving everything they need to thrive.

The Main Sources of Nutritional Deficiency

Most people would immediately assume nutritional deficiencies come from the quality of food dogs are eating. But that’s not always the case. The main three sources of malnutrition come from:

  • Not enough food
  • Malnutritional food
  • Digestive diseases preventing absorption of nutrients

Food Insufficiency

Are you feeding your dog enough? There are some basic guidelines to follow (typically written on the side of the pet food product) that point toward the right ratio of portion to weight. However, this doesn’t account for dogs with slower metabolisms or highly active dogs.

In general, once your dog is past the puppy stage, it will maintain roughly the same weight for the rest of their life. Knowing this, if your dog is gaining or losing weight, this will be indicative of how much food they need. 

Malnutritional Food

Unfortunately, many dog foods labeled as “complete and balanced” still don’t offer the best quality nutrition for your dog. Many come with preservatives, artificial colors, and stabilizers to make the food appear tastier. But as anybody who’s ever seen a dog EVER knows, the last thing on a dog’s mind when it sees food is, “but what color is it?”

Reading ingredient labels for harmful additives is a useful practice for pet owners to follow to ensure your dog is eating healthy. It also helps to have a general understanding of what ingredients are beneficial and which are harmful. For example, many dogs have adverse allergic reactions to over-farmed ingredients. Be on the lookout for the following, as they may be connected to digestive issues:

  • Corn
  • Soy
  • Wheat
  • White flour
  • Meat*
  • Corn syrup
  • Additives
  • Salt

*Meat as in, unspecified “meat”—It begs the question, what kind? And, why aren’t you telling me what kind?

Dietary Supplements

There are two main reasons to use a dietary supplement for your dog. One: when your dog’s digestive tract is not absorbing enough nutrients and needs a supplement to provide it with bioavailable vitamins and minerals. And two: when their diet is not providing them enough nutrients in the first place.

When using a dietary supplement, talk to your veterinarian about testing for any vitamin or nutrient deficiencies. You want to be careful not to overdo it with unnecessary supplements. Over-supplementing can cause issues from kidney stones to copper and zinc toxicity. 

Digestive Disease Preventing Absorption of Nutrients

If your dog is vomiting or has diarrhea, chances are they’re not absorbing those valuable nutrients before they come spilling out on the lawn. Unfortunately, almost any digestive disease, infectious or noninfectious, comes with one or both of these symptoms. Treating the digestive disease is necessary before returning your pup to its happy, nutrient-rich life.

Notable Signs of Nutritional Deficiency

There are some key signs and symptoms that tell whether a dog is eating a proper diet. In fact, each nutrient deficiency has its own telltale sign. For a generalized list of symptoms, dogs will experience the following when not properly fed:

  • Change in feces – There are four main principles to a healthy bowel movement: color, consistency, content, and coating. Your dog’s feces should be chocolate brown, malleable like playdoh, contain no foreign objects, and should be free of mucus residue. Any abnormalities outside of this (for more than 24-48 hours) could be a signal of some health digestive issues, including nutritional deficiency.
  • Depression – A dog’s gut biome, much like that of humans, signals everything from what type of bowel movement they’re going to produce to what their mood will be that day. An unhealthy gut biome can lead to depression and lethargy. Noticing a change in your dog’s behavior can clue you into any malnutrition.
  • Skin or coat disorders – Dogs need a wide range of vitamins and minerals to maintain their healthy skin and fur. Without a nutritious diet, they become prone to hair loss, skin disease, and infection. 
  • Lack of energy – Another telling sign of malnutrition, especially in the carbohydrates department, is a lack of energy. Carbs are a dog’s main fuel source, and they provide dogs with the energy needed to bounce off the walls in that excited let’s-play-fetch-today kind of way.

Getting Your Dog Back on Track

Once you’ve identified that a nutritional deficiency is an underlying problem, there are simple treatment options to follow. If your dog is losing weight, you may not be feeding your dog enough. If their diet and exercise habits haven’t changed, maybe they’ve got a stomach bug. If they’re not vomiting or having diarrhea, maybe they need a supplement. Using this type of deductive reasoning will help figure out the problem quickly and get your dog back on track to a healthy life.

As pet owners, it is your duty to care for your dog and treat them when they’re sick. If you think their health is in jeopardy for any reason, evaluate your dog’s diet, talk to your vet about their nutritional requirements, and monitor any symptoms that may indicate problems within the intestinal tract. When in doubt, always visit your local veterinarian to give your pooch the optimal care they deserve!


Pets WebMD. How to Read a Dog Food Label. https://pets.webmd.com/dogs/guide/how-to-read-a-dog-food-label#1

Whole Dog Journal. Choosing Canine Supplements Wisely. https://www.whole-dog-journal.com/food/choosing-canine-supplements-wisely/


Dr. Melinda J. Mayfield-Davis, DVM, WCHP-AH, brings over 20 years of experience in veterinary medicine.  She is the Technical Services Veterinarian with Innovacyn, Inc., parent company of Vetericyn Animal Wellness. She received her DVM from Oklahoma State University and now resides in Southeast Kansas with her husband, two children, four dogs, and six horses. Prior to working with Innovacyn, Dr. Mayfield owned and operated the Animal Care Center in Columbus, KS.

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