Health Issues Caused By Feeding Your Dog Or Cat The Wrong Diet

Health Issues Caused By Feeding Your Dog Or Cat The Wrong Diet


When it comes to caring for your furry friend, adequate nutrition tops the list. A healthy diet for dogs and cats not only keeps them in tip-top shape, it contributes to their overall happiness and quality of life.

It is a common misconception that a “malnourished” dog or cat simply doesn’t get enough food. Perhaps he’s been neglected, or he’s a stray who scavenges for meals. While this is certainly the picture of a malnourished animal, it can happen to pets who look perfectly healthy, too.

“Malnourishment” can occur when pets’ bodies are lacking an essential nutrient, but it doesn’t mean they’re not loved or cared for; they just need a more balanced diet. In fact, even overweight or obese animals can be malnourished if their diet is missing certain vitamins or minerals (and they’re eating too much fat and sugar).

Over time, a nutrient deficiency can lead to certain conditions or diseases. Further, food sensitivities or allergies can cause unpleasant and uncomfortable issues. And while it’s impossible to avoid all health issues (sometimes, they just happen!), it’s important for pet parents to learn how diets can affect their companions’ health and how nutrition can be used to manage or even prevent disease.

Like humans, every pet is different and requires different nutritional needs, so it’s imperative to create a feeding plan to fit your furry friend alongside your vet or pet nutritionist. Cost prevents a lot of pet parents from feeding their pets high-quality diets, but maintaining a healthy lifestyle can save you thousands on vet bills down the road. While there is no one-size-fits-all diet that works for every animal, a good place to start is by avoiding thesecommon feeding mistakes and making sure your pet’s diet is balanced.

In addition to potentially avoiding expensive medical procedures and medications, a change and diet can be the difference between a wonderful, long life and a shorter, miserable one. Take for instance this story from Donna Anderson, owner ofPetite Pet Inn in Virginia. She rescued two Chihuahuas from a high-stress situation; one had terrible diarrhea, one was missing half its hair. Worse, no one -- not even a vet -- could figure out what was wrong and how to remedy each dog’s ailments.


“After finding out all the foods they had been eating, I was able to figure out neither one of them ever had beef or sweet potato,” says Anderson, who believed the symptoms may have been linked to their diets. “I put them on an allergy diet of beef and sweet potato. It took only days [for the diarrhea to clear up].”

She continues, “After two months I started testing other foods and added anything that did not get a reaction back into their diet. In a few short months I was able to rehome one chihuahua and I kept the other. The one I kept, well, all her hair grew back an she looked better than ever. That was 10 years ago and she is still with me.”

As it turns out, stories like this are incredibly common. Just ask Margaret and Steve Gelinas, founders ofMarket Pet Shop in Canada; they’ve seen what good nutrition can do firsthand. “[Our] dog had terrible demodex mange,” they explain. “A very good grain-free diet and lots of love (and some meds) turned her into a beautiful girl. Sometimes, good food and exercise is all the body needs to live a happy full life.”

We asked dozens more pet professionals around the world to weigh in on how nutrition has affected the lives of their clients and patients. Below, you’ll learn about some common malnutrition issues seen by vets and nutritionists, the result of feeding dogs or cats the wrong diet. Every loving pet parent wants their four-legged family member to live the longest, healthiest life possible, and it all starts with good nutrition.

1. Food Allergies, Sensitivities, & Intolerances


Food allergies, deficiencies, or intolerances are one of the most common issues that pet professionals see, and they often manifest themselves in the animal’s skin, coat, and/or ears. If your pet’s skin or coat seems to be itchy, irritated, flaky, dry, or dull, or he is prone to skin or ear infections, talk to your vet or a pet nutritionist about whether it can be caused by a dietary allergen or deficiency.

“We see a lot of issues with skin and coat, ears, digestion, and weight loss or gain because of incompatible foods being fed to pets,” mentions Emily Ellsworth ofPure Petin Ohio. “Some pets will do great on cheap grocery store food while others suffer. I explain it to people that some individual humans seem to thrive on junk food and fast food but most of us can’t.”


Did you know thatfood allergies can develop themselves at any point in a dog or cat’s life? That’s right, the food you’ve been feeding your pet for years can contain an ingredient that they’re suddenly allergic to. This occurs when the immune system reacts to the food that’s consumed, releasing histamines and causing all that itching. This often results in scratching, gnawing, licking, sores, and hot spots that make matters worse. It can also result in some nasty ear infections (more below).

Jackie Antonelli, owner ofBarks -n- Meows Grooming in New York, which uses all-natural products, has seen this first hand. “My niece’s dog has horrible allergies. She discovered that she was able to tell certain food affected him negatively just by the color of his nose.”

Believe it or not, common pet food allergens include beef, chicken, pork, corn, rice, and wheat, eggs, and soy. If you suspect your dog or cat has an allergy, take them to the vet for testing. You may be instructed to eliminate certain ingredients or to buy a prescription formula free of allergens.

Dry Skin & Coat

If your pup or kitty’s coat looks dull or their skin seems extra flaky, consider adding more omega fatty acids into his diet (this can help alleviate itchiness, too). Typically found in fish, you can purchase foods or treats that are fortified with omegas, or add a supplement to their diet. Coconut oil can also help remedy dry fur and dandruff -- most pets will gladly eat it by the spoonful! Just remember, it is high in calories, so moderation is key.

Ear infections

Another sign of food intolerances isear infections. Food allergies cause inflammation in the digestive system, resulting in bacteria / yeast overgrowth that ends up affecting the ears. In some dogs, ear infections become chronic, but quickly clear up once the diet changes.

2. Behavior


Did you know that your dog or cat’s nutrition can actually affect their behavior? While it’s common knowledge that protein is essential for our companion animals (and lack thereof can lead to malnutrition), it turns out that too much protein can actually have adverse effects.

Aggression & Anxiety

Pets that consume too much protein in relation to their activity level can developaggression and anxiety because theirserotonin levels (known as the “happy” mood-regulating chemical) are stunted. Serotonin production depends on tryptophan, an amino acid, which can be lacking in high-protein diets. Therefore, dogs that tend to be aggressive may do better on lower-protein diets or on tryptophan supplements. Their diets can also be better balanced with the addition of tryptophan-rich foods like eggs, oats, and cheese.


Diets high in carbohydrates can cause blood sugar spikes that can contribute to hyperactivity.

3. Digestive Issues


It should come as no surprise that certain dietary issues can directly affect the digestive system. Signs of digestive upset can include vomiting, diarrhea or loose stools, and gas. If pets’ systems cannot handle the food they’re eating, they’re especially prone to malnutrition because they’re not absorbing the vital vitamins and minerals that they need.

Sensitive stomach

Unlike a food allergy, some dogs or cats simply have sensitive stomachs when digesting certain ingredients. This can include some proteins, types of fiber, and fats. Signs of a stomach issue can include vomiting,flatulence, belching, diarrhea, and lots of stomach rumbling.

Intestinal Upset

The symptoms of gastrointestinal disorders caused by food can be similar to sensitive stomach issues, includingdiarrhea,vomiting, loose stool. Again, if food goes through the intestines too quickly, your pet could be missing out on essential nutrients, leading to malnutrition.

4. Low Energy


When you’re sick, you probably don’t have a lot of energy -- and neither does your pet. What’s more, lethargy or fatigue can be symptoms of some serious diseases caused by poor nutrition, such as pancreatitis, diabetes, heart, and kidney issues.

5. Diseases


Long-term malnutrition (or lack of an essential nutrient) can eventually lead to acute or even chronic diseases. These conditions often don’t manifest themselves for many years, and in these cases, prevention is always the best “medicine.”

Becky Mobley ofWild Kingdom Pet Supplies in Texas points out the diabetes and pancreatitis are two common illnesses she sees that could potentially be prevented by proper nutrition. “Seeking a [veterinary dietician or professional] who knows what kibbles are the best for your pet can help you save money down the road with expensive vet bills,” she explains. “It will also help get your pets going in the right direction, ultimately helping them to live longer and healthier lives.”

Heart disease

It was recently discovered that grain-free diets high in peas, lentils, legume seeds and potatoes can contribute toheart disease. These diets can also lack taurine, an amino acid that’s essential to heart function. Maintaining a healthy body weight also reduces a pet’s risk for heart issues.

Kidney Disease

Cats are especially prone tokidney disease, especially if they are on an all-dry food diet. It’s essential for all pets to be on diets that keep them properly hydrated so the kidneys can regularly flush themselves out. Another offender is salt, which is often a problem for pets who eat a lot of table scraps. It is often recommended that animals with kidney disease maintain low-protein, low-salt, and high-moisture diets.


Diets high in fat can cause inflammation of the pancreas, causing it to malfunction, known as pancreatitis. It’s recommended for pets with this condition to adopt low-fat diets.


When animals eat too many carbohydrates (in other words, sugar), they can develop diabetes, which effects the regulation of blood sugar. What’s more, this condition makes dogs and cats even more susceptible to other health issues including kidney disease and pancreatitis.

6. Mouth Issues

Periodontal Disease

Especially when it gets severe, periodontal disease, or other dental issues, can cause our pets extreme pain. A well-balanced diet is key to keeping plaque at bay. According to recent studies, species-appropriate, raw diets may be the best way to keep an animal’s mouth clean. On the flip side, dry, high-carb kibbles have beenlinked to plaque build-up.

In addition to eating a healthy diet, it’s important to maintain ahealthy teeth-cleaning routine, which may include tooth brushing (with pet-safe products), dental treats and chews, and regular professional cleanings by the vet.

Bad Breath

Dogs and cats aren’t exactly known for having minty-fresh breath, but when the odor becomes extreme, it’s often a sign of periodontal disease or some other oral issue. Again, mouth health begins with a nutritional, balanced diet.

7. Weight Issues


Anorexia, or refusal to eat, is often a symptom of another disease that could be a nutritional illness. For instance, it can accompany physical pain (perhaps in the mouth or stomach), kidney disease, pancreatitis and more. Or, it could simply be because the animal has an aversion to their food. (This is especially true for cats, who are notoriously picky eaters.)

Changes or loss of appetite should always be taken seriously and prompt a call to the vet. However, the solution may be as simple as changing the pet’s diet.


There are lots of factors that contribute to obesity including overeating and overfeeding. In particular, diets high in carbohydrates and sugars (or lots of treats or table scraps) can make pets pack on the pounds.

Changes in weight

Any changes in weight, especially sudden ones, should always prompt a call to the vet. Weight loss or gain can indicate an underlying disease including diabetes, hyperthyroidism, hypothyroidism, Cushing’s disease, and even certain cancers (read 10 Warning Signs Your Pet Has Cancer for more).

What’s more, being either underweight or overweight can lead to malnourishment problems that contribute to or exacerbate diseases caused by poor nutrition in dogs and cats.

Whether your dog or cat has a specific health issue or you want to make sure they’re eating the healthiest diet possible, it’s important to educate yourself on an animal’s nutritional needs. Read our next article, The Best Foods & Supplements For These 10 Common Pet Health Issues, which is based on advice from pet nutritionists. This will help you learn more about keeping your pet’s diet balanced and using food to help manage specific health conditions. As always, the decisions regarding your companion’s diet should be made based on the opinion of a trusted vet or pet nutritionist, plus your own research; and these articles are a great place to start! 



Suzie Cyrenne
Suzie Cyrenne


Suzie Cyrenne has dedicated more than 20 years of her life in making and improving natural animal health solutions in the global setting.

Being the co-founder of Zumalka, Suzie is a forerunner in enhancing the lives of pets through natural and homeopathic options using the knowledge she has gained from the Classical Homeopathy School in Quebec.

Through the guidance of her mother-in-law and fellow natural health expert, Denyse Lessard, Suzie constantly devotes herself to create premium pet products that are aimed at dealing with the root causes of wellness problems and not just their symptoms.

Besides immersing herself in books, personal development and visiting new places, Suzie also enjoys keeping herself in tiptop shape by snowboarding and taking daily hikes with her husband and Zumalka co-founder, Matt Lessard, and their Golden-Doodle, Westin.

Find out more about Suzie when you click HERE.

2 Responses


November 16, 2020

Dear MaryAlice,

We do understand your worry and concern. But rest assured we will do all we can to help. We have sent you a private email so that we can help you and your pet in the most personalized way possible,

We look forward to working with you.



November 16, 2020

This article was very helpful. I have an overweight 5 year old min pin, who as of two months ago has switched from eating everything that I would eat to now eating dog food. At first I started her on blue buffalo canned food, and now we are on Ollie Pet fresh food. These last two months have been awful and I am afraid I’m losing her. She refuses to drink water or eat food. She’s constantly lethargic and “out of it.” I’ve thought she’s been hypoglycemic a few times and have gone as far as even giving her honey on her gums, to which did perk her up for a short while. She’s had full panel blood work and Urine tests and all her labs keep coming back normal. I’m devastated and defeated. What do I do?

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