Are all ingredients in dog food the same?

Written by Dr Andrew Miller MRCVSDr Andrew Miller MRCVS is an expert veterinary working in the field for over 10 years after graduating from Bristol University. Andy fact checks and writes for Pure Pet Food while also working as a full time veterinarian. Pure Pet FoodPure Pet Food are the experts in healthy dog food and healthy dogs featured in media outlets such as BBC, Good Housekeeping and The Telegraph. Working with high profile veterinary professionals and nutritionists, Pure Pet Food are changing dog food for the better. - Our editorial process

In this article we’re going to look at the way ingredients are used in dog food and discuss the differences between ingredients in different types of food, whether how the dog food is made affects the ingredients’ quality too.

Human grade vs feed grade

Two different types of ingredients go into dog food, human grade and feed grade. If you don’t see a company advertise their food as human-grade, they’re feed grade. Some companies will try to sneak it past you by using the phrase human-grade ingredients; this means that the ingredients they put in the food are human grade but brings the food in to question as to whether or not that is human grade.

So, what’s the difference between human grade and feed grade?

Human grade

  • Made in a human-grade facility

  • Same quality ingredients you’d find in your own food

  • Regulated by both pet and human food regulatory boards

Feed grade

  • Made in a pet food facility

  • Ingredients may include by-products (e.g. horns, feet, feathers), heads of poultry, hatchery waste and much more

  • Could also use products of animal origin or processed animal protein no longer intended for human consumption

As you can see, feed grade foods can include low-quality ingredients that aren’t ideal for your dog’s health or wellbeing. We would strongly recommend feeding a human-grade diet.

Meal vs actual meal

One of the low-quality ingredients used in a lot of dog foods is meat meal or rendered meat. For example, if a dog food’s packaging says 30% chicken or 30% chicken breast and thigh, it’s muscle meat. However, if it uses chicken meal, dried chicken or chicken derivatives, it’s very much a lower quality ingredient. Meat meal involves taking remnants of the animal that are not fit for human consumption and then processing them under extreme heat into a powder form; it's then added to kibble and wet food.

Filler ingredients

Many low-quality foods and processed dog foods (think brown biscuits) include filler ingredients. These are often grains like wheat or barley.

Some news sources have run headlines in the past that grain-free dog food causes heart disease and dilated cardiomyopathy (DCM) in dogs. However, the report (not study) did not show a real association, and veterinary professionals have dismissed this, citing. If you dig further into the data, the vast majority of affected dogs were fed a processed dry food (kibble) diet. While there could be several nutritional factors that play a part in contributing to DCM, protein deficiency, and poor quality ingredients are likely the most significant contributors.


This is possibly the most significant factor when choosing a dog food. No matter what level of ingredients you use in a dog food if it’s highly processed, it’s not going to be ideal for your dog. We proved and compared how conventional pet foods do this here.

Think about it from your point of view, if you’ve eaten lots of processed convenience or fast foods you know it made you feel sluggish, bloated, irritable and nowhere near your usual self. And it’s exactly the same with dogs.

Brown biscuits (dry dog food) are highly processed (some vets say they’re ultra-processed even) as they’re made using a process called extrusion. Extrusion takes ingredients and heats them to extreme temperatures while putting them through extreme pressure at the same time. This kills vital nutrients in the ingredients. Often preservatives and additives are added to ensure the food has enough nutrients and is the right consistency. The mix then gets pushed through a small hole which a machine then cuts the kibble to size.

A study was carried out on the digestibility and amino acid content of chicken before and after extrusion processing. This study found that after extrusion, the digestibility of high-quality ingredients was significantly negatively impacted.

Further studies show applying heat, above 140 degrees centigrade to carbs and proteins found in kibbles/biscuits, will result in carcinogen production and heat-medicated toxins through the Maillard Reaction. This can be a big contributor to cancer in dogs.

As well as this, if you’re feeding a food that isn’t very digestible like a processed brown biscuit, your dog may need to eat more than otherwise necessary to get all the essential nutrients which will lead to obesity. Obesity is a massive influence in the length of your dog’s life and how often they need to visit the vet.

Heat is a significant factor in ingredient integrity when creating dog food. Here’s a breakdown of the most popular ways of creating a dog food and what temperature these are exposed to.

  • Raw (No heat, risk of salmonella, E.coli etc.)

  • Air dried (40°C – 90°C)

  • Cooking (90°C)

  • Extrusion/rendering dry dog food (120°C – 150°C)

  • Retort canned food (121°C)

As you can see air dried uses the lowest temperatures when air-drying food which locks in the goodness, ensures the nutrients are retained as naturally as possible and doesn’t run the risk of salmonella, E.coli and various other raw food risks. This, coupled with human-grade ingredients, is the perfect combination and a super healthy diet for your dog.


A study from Sweden by Dr Kollath found that young animals fed a cooked, processed diet initially appeared to be healthy, but once they reached maturity, they began to rapidly age and develop degenerative disease symptoms. There have also been multiple studies on how fresh food affects your dog and how this can be beneficial later on down the line.

Degenerative diseases like cancer have risen alongside the rise of brown biscuit (dry dog food) feeding showing a correlation between the two.

Proactively investing in your dog’s health and ensuring they’re eating well throughout their life will lead to lower vet bills, longer healthier lives alongside many other benefits like a glossier coat, happier bellies and more.


Ingredients in dog food aren’t all the same. There are human grade and feed grade ingredients, but also ingredients subject to high levels of processing aren’t what we should be feeding our dog.

If a brown biscuit (dry dog food) uses high-quality ingredients, we know that the processing these ingredients go through negatively affect the food your dog eats and can lead to complications later in life.

We found that air-drying ingredients is the best way of locking in the ingredient’s goodness. And if we couple this with human-grade ingredients then we have the perfect diet for our dog.