Get to Know Your Pet's Food

Dr. Tammie


October 25, 2021

Dr. Tammie Pearce, Director of Veterinary Science at AskVet

Ooh it all looks so yummy!

It is very confusing when you go to the pet food aisle or shop for pet food online and see so many options. You are not alone in trying to decide what food is best for your pet. Food labels are confusing and multiple varieties and flavors of food have only grown in number. There are wet foods, dry foods, freeze dried foods and fresh refrigerated or frozen foods, not to mention grain free, sensitive stomach, sensitive skin, unusual proteins, it is overwhelming. 

The task is only slightly easier if your veterinarian has prescribed a prescription diet since there are usually limited choices between two or three brands. We all want to feed our pet foods that are wholesome, delicious and have ingredients that we would likely eat ourselves. Pet diets and their nutrition is a very large subject so we will limit this discussion to decoding some of the label, ingredients, some considerations to choosing a diet and how do you know it is time to make a change.

Besides the cute picture of the adorable pup or feisty kitty what can be learned from pet food label?

Food is often marketed with pictures on the bag or container of an adorable pet. The eye-catching picture may be surrounded with what appear to be healthy ingredients like raw meat or fruits and vegetables. Keep in mind the pictures on the packaging have been carefully chosen to attract pet owner. The pictures of healthy ingredients may have more to do with branding, than what is actually in the food. 

To add to the confusion not all foods are created the same. And not all pets respond to the same foods the same way. What one pet may be perfectly happy eating can cause digestive upset in another or itching red skin. Other pets may also be picky and may need to have their diets closely monitored. Most pets do not eat the same food for their whole life and may go through several changes as they age.

So how do you tell what is in the package of food?  By looking at the ingredient list, as well as other clues on the packaging, you can evaluate the quality and if the food is appropriate for your pet. The first four to five ingredients on any food label are the primary ingredients in that food.  Ingredients are listed in decreasing amounts so for example (dog food) if your food had a list like this:

Salmon, Salmon Meal, Brown Rice, Oat Groats, Poultry Fat (Preserved with Mixed Tocopherols), Pearled Barley, Natural Flavor, Sweet Potatoes, Dried Egg Product, Dried Plain Beet Pulp, Tomato Pomace, Salmon Oil, Miscanthus Grass, Brewers Dried Yeast, Pumpkin, Spinach, Carrot, Chia Seed, Kelp Meal, Taurine, Salt, Choline Chloride, Etc.

From the above ingredient list looking at the first five ingredients, once you get to “poultry fat” everything after that ingredient is in diminishing quantities in the food. The first four ingredients make up by weight most of the food, so I would consider this a salmon and rice/oat diet. Ingredients in this diet like pumpkin, spinach carrots and chia seeds are in such low quantities by volume that they may contribute to the fiber in the food, but probably are not a major contributor to the vitamins and nutrients.

Most foods do have some salt added to help with palatability and amino acids like Taurine and vitamins and minerals to help balance out the food. Taurine in particular is very important to cats and kittens since they require the amino acid in their food to prevent heart problems.

So, the first step to evaluating a food is to look at the first four to five ingredients. Look for differences between brands and flavors.  If there are large differences contacting the manufacture or your veterinarian about a particular food’s ingredients will also help to decipher the ingredient list. You can also reach out to AskVet to talk to a vet 24/7 about your pet’s nutrition.

Life Stages and Breed Specific

Another aspect of food labeling is what is commonly referred to as life stages. Puppy and kitten foods are designed to meet the needs of a pregnant or growing pets. But not all puppy and kitten foods are created equal. For example, large breed puppy foods should not be fed to toy or smaller breeds and small breed foods should not be fed to large breed puppies. Some manufacturers have taken this to extremes with breed-specific diets. The manufacturer may have tested the formula specifications but the changes in the formula maybe a matter of slight ingredient or nutrient amounts (protein levels, carbohydrate levels, and amount of vitamins/minerals) to assign it for specific breed. Sometimes they are the same formula but may have a different kibble shape or size so it is easier for a brachiocephalic breed of pet (i.e., Pug, Boston terrier Persian) to be able to eat the food than a large kibble size.   

Make sure to compared food ingredient labels between manufacturers or compare similar formulas on the manufacturer’s web site to determine what the differences between the life stage and breed diets really are. Of course, follow your veterinarian’s recommendations and when your puppy or kitten reaches about 12 months of age transition them slowly to an adult formula (more on transitioning later). 

Usually associated with the life stages statement on the package will be an Association of American Feed Control Officials (AAFCO) statement of compliance with their feeding directions. Foods that are AAFCO certified have to meet a minimal formula requirement for each life stage. Some manufactures exceed these recommendations. For more information check their web site

Guaranteed Analysis and Feeding Schedule

The next information you can get from the label, and related to AAFCO requirements, is the guaranteed analysis which will vary by kitten/puppy, adult and senior. All food labels must have a guaranteed analysis of the formula so the protein and carbohydrates listed on the side of the food label can be compared between food formulas.

Generally senior diets for pets over 7-8 years old are lower in protein than young growing pet diets. The guaranteed analysis is derived from testing the manufacturer’s formula after formulation of the diet to determine what levels of protein, fat and carbohydrates are present. Keep in mind senior diets may also have higher levels of amino acids or omega three fatty acids to help with cognition, joint and kidney health. Puppy and kitten formulas may be higher in fat and carbohydrate to help support their active lifestyle.

Feeding schedules are also included on the label and are helpful to know how much to feed. Remember feeding schedules are not written in stone - some pets will need slightly less food or slightly more to maintains their body condition score. 

Body condition score is a more accurate way to tell if a pet is carrying excessive pounds. Pets, like people, come in all sizes. Some of the feeding schedules on packaging can be very confusing. Check the manufacturer’s web site or ask an AskVet 24/7 veterinarian for help interpreting printed feeding schedule. Feeding amounts can be important in breeds that are more prone to back problems if they are carrying extra pounds and need to maintain a healthy weight. Ask your veterinarian about a weight loss program and feeding schedule that will help your pet maintain optimum body condition score and weight. You can also contact one of the Ask Vet veterinarians or Care Coaches to help keep your pet fit and trim.

Specialized Diets

Often your veterinarian will prescribe a specific diet for certain chronic diseases, like arthritis, heart problems, weight loss, food sensitivities, kidney, liver and bladder diseases. Usually there are limited numbers of diets to choose from a few manufacturers and your vet may have a preference. If your pet is picky or will not eat one diet there are likely alternatives, for example, they may eat the wet but not the dry versions of the diet. Or your pet may prefer one manufacturer’s food over another. If your pet is not wanting to eat the food that has been prescribed, ask your veterinarian about alternative prescription diets. In some cases, you and your veterinarian may need to check with one of the veterinary nutritional consultation services at a veterinary university to formulate a home-made diet that provided the needed vitamins and minerals. Here is one example of this type of service:


When your pet is on a prescription diet for a chronic condition your veterinarian will likely recommend monitoring blood work and urinalysis every 6-12 months to track any disease progression. They will also recommend looking at your pets’ feces consistency, number of times your pet eliminates each day, as well as the color of the feces or if there is any blood in the fecal. Diarrhea can indicate either a resurgence of disease, like kidney problems or pancreatitis, but can also indicate a sensitivity to something in the food.  If your pet is on a specific diet for skin problems, they will likely recommend monitoring the skin for rashes and itching as well as frequent bathing. If your pet begins to have new problems or a resurgence of previous problems like vomiting or diarrhea contact your veterinarian right away.

Along with elimination make sure to monitor pets eating habits for any changes. Often small changes in the amount your pet is eating can indicate there is a medical problem. Many things can cause a pet not to want to eat like nausea, or it can be another medical problem, like dental pain, or even that the pet ate something they should not have or there may be something going on with food like it spoiled. Dry foods generally need to be kept in their original packaging or in airtight packaging. Dry foods storage should be kept in a cool dry place. Canned foods should not be fed over several days even with refrigeration since they start to spoil once the can is opened. Fresh frozen foods also need to be kept refrigerated, but also should be used within a couple of days of opening.    

Weight loss can also be a sign of health problems. In feline patients it may be a precursor to kidney problems or hyperthyroidism (increase in thyroid hormone). Dogs that likewise lose a lot of weight quickly could have other medical problems including liver and kidney problems but also infections and cancers can cause weight loss in pets. If your pet has a normal appetite and is still losing weight or body condition have your pet seen right away.

How do you know it is time to make a change in your pets’ diet? If they are having chronic intermittent vomiting or diarrhea, will not eat the foods or have a poor appetite, are scratching, itching, scooting, licking, or having frequent ear infections it may be time for a change. Consult your veterinarian to make sure there are no medical reasons and have a frank open discussion about your pet’s diet and eating habits. A great deal of information can be gained by a physical exam, elimination history, examination of fecal matter, as well as how your pet is doing at home can give you and your veterinarian clues about the appropriate diet to keep them happy and healthy.

Food changes

Dogs and puppies can have very sensitive digestive tracts, some pets more than others. Cats and kittens can also be sensitive to diet changes. Changes in brands of food, flavors of foods, or even the type of food (changing from dry to canned diet) can cause diarrhea in pets.  These sudden changes could result in a change in the flora in the gut or allow” bad” bacteria like e coli or clostridium to over grow the digestive system. The overgrowth of the “bad” bacteria causes inflammation in the digestive tract and the digestive tract responds by trying to flush them out; leading to diarrhea. Some pets may also be sensitive to one or more ingredients in the new food or treats. For example, some pets may be on a lamb or beef diet and if they are given a chicken-based food that they are sensitive to they will develop diarrhea. It is best not to let your pet eat anything that is not approved by you for consumption and try not to make any changes quickly.

Most food changes should be made slowly over a 14-to-21-day period if possible.  Usually mixing in ¼ of the new food ration with ¾ or the old food for 4-5 days, then mixing ½ and ½ for another 4-5 days, then ¾ of the new food and ¼ of the old food for another 4-5 days to make the switch over will avoid gastric upset.  If your pet starts to show signs at any time during the change reach out to your veterinarian or an AskVet 24/7 vet. They may need a probiotic or bacterial replacement to help balance their digestive tract again. Here is some more information about the animal biome and testing:

Final Thoughts

Food choices are individual for both the pet, the pet’s health status, as well as the life stage of the pet. It is hard sometimes to look past the pretty pictures and dig down into the information on the food label. With a little perseverance and study and support from a veterinarian, the food manufacturer and research into the food, you will be able to make nutrition decisions that will promote your pet’s health and make you both very happy! 


That's another pawsitive tip from AskVet's Dr. Tammie! To learn more about food and nutrition, you can chat with an AskVet veterinarian 24x7 on the AskVet app any time, day or night.


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