Canine Nutrition Basics: Fat

Is your dog getting too much fat in their diet? Let’s chat about how much fat your dog should be getting from their diet depending on their age, activity level, and how medical conditions might influence diet choice.

It’s important to remember that nutritional needs are highly individual. When we consider how much fat our dogs need. We need to look at different aspects of their lives to decide what diet composition will work for them.

The purpose of fat in Dog Food

Most people tend to focus on their dog’s protein needs when they choose a dog food, looking for the highest amount possible. However, it’s important to realize that fat, or essential fatty acids are just as important in our dog’s diet and serve vital functions within the body.

So what is the purpose of fat in dog food?

  1. Provides a source of essential omega 3 and omega 6 fatty acids
  1. Transports fat-soluble vitamins (A, D, E, and K)

Practically what this means is the these vitamins are unable to get where they need to go within the body without minimal amounts within the diet.

  1. Provide a concentrated source of energy

Per gram consumed, fat provides over twice as much energy in comparison to either protein or carbohydrates! Making it the best source of energy for highly active dogs, but also a nutrient we likely need to potentially limit for dogs who are obese-prone or overweight.

  1. Enhance food palatability and texture

Fat Requirements in Dogs

OrganizationRequirement of Fat
National Research Council (NRC) Adult10g / 1000 kcal
National Research Council (NRC) Puppy21.3g / 1000 kcal
AAFCO Adult Maintenance13.8g / 1000 kcal
AAFCO Growth & Reproduction (Puppy)21.3g / 1000 kcal
FEDIAF Adult Maintenance13.75g / 1000 kcal
FEDIAF Growth21.25g / 1000 kcal
Most Dogs (Low to Moderate Activity)30-50g / 1000 kcal
Highly Active (6-8+ hours Activity)50g+ / 1000 kcal
Weight Loss (caloric restriction)~35g / 1000 kcal

Fat in Dog Food

When we consider the amount of fat that your individual dog might need within their diet. We will base this on age, activity level, medical conditions, and individual preferences.

Minimal Fat Requirements:

We have established overall minimal fat requirements for age from both AAFCO and the NRC, and we have established minimums for certain essential fatty acids. For puppies, this is eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and linoleic acid (LA). But for adult dogs, it’s for linoleic acid (LA) and alpha-linolenic acid (ALA). We also have established maximum ratios of omega 3 fatty acids to omega 6 fatty acids from AAFCO of 1:30, however most Ph.D. and boarded veterinary nutritionists try to design diets with a ratio around 1:4 if possible, as it is believed to be a better balance of fats for our dog’s bodies to perform optimally.

The Active Dog:

For most puppies and adult dogs that are healthy, the main drivers of fat needs will be related to body condition and activity level. Fat can provide almost twice as much energy as both carbohydrates and protein within a diet. Which is great for more active dogs, but can be an issue for dogs that are more obese-prone.

As activity level increases, fat needs will also increase (since it’s being used for energy!). Dogs in particular actually start to burn fatty acids rather than glucose as an energy source after the first 30 minutes and shift almost entirely to fat metabolism for energy at around 60-90 minutes of activity.

  • A highly active dog’s diet may only be 25-30% protein, and 50-70% fat on a caloric basis.
  • A moderately active dog’s diet is typically 25-30% protein and 40-50% fat on a caloric basis.

When we consider the needs of the canine athlete, protein needs will easily be met on a diet that is 25-30% protein, however, energy needs may not be met if higher amounts of fat are not consumed. Providing too much protein in place of fat can cause weight loss and poor performance.

The Obese-Prone Dog:

When we contrast the highly active dog’s needs with that of the overweight or obese-prone dog. Fat needs are basically the opposite. A dog that is overweight or obese needs a diet that is less calorically dense in order to maintain/achieve a healthy weight and one of the easiest ways to lower the caloric density of a diet is by lowering the fat content of the diet.

  • An obese-prone dog’s diet may actually need more protein 30-40%, and less fat 25-30% on a caloric basis than the highly active dog.

Typically this composition of protein and fat is paired with higher amounts of fiber to help these dogs feel “fuller” for longer. Higher amounts of protein are also needed in order to meet protein needs even with reduced calorie consumption.

Medical Considerations and Fat:

There are many different diseases and conditions where fat restriction may be advised. Usually, with these conditions, we aim for the lower end of the normal range for fat and focus on nutrient-dense fats that are concentrated in essential fatty acids. Fats like Corn or Canola Oil are often used in ultra-low-fat diets as a source of linoleic acid (an essential fatty acid for dogs) because these ingredients are highly concentrated in linoleic acid.

  • Diseases we commonly need to limit the fat with are: Pancreatitis, Obesity, Gastritis, IBD, and High Triglycerides.

For these dogs, we tend to use the “next best” energy source, which is carbohydrates, in order to supply energy. Thus if you have a highly active dog with a “sensitive stomach” you may find you need to reach for recipes that use highly digestible carbohydrate sources like rice, oats, or wheat in order to supply sufficient energy to maintain a healthy weight.

Essential Fatty Acids in Dogs

Essential Fatty Acids

As I alluded to earlier – fat isn’t just a source of energy within a recipe, but it’s also a source of essential fatty acids. These essential fatty acids cannot be manufactured by the body, thus they must be provided within our pet’s diet.

There are five fatty acids of note for dogs: linoleic acid, alpha-linolenic acid, arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid. However, requirements for individual requirements change depending on the formulation guidelines you are using.

Linoleic Acidomega 6 fatty acid
Arachidonic Acidomega 6 fatty acid
Alpha-linolenic Acid omega 3 fatty acid
EPA + DHA omega 3 fatty acid

Bioavailability & Conversions

Our essential fatty acids come in two forms, omega-3 fatty acids, and omega-6 fatty acids. You see that the adult dog generally has less essential fatty acid requirements than the puppy. 

However, it should be noted that certain essential fatty acids can actually be converted to others. Meaning that just because we are providing the direct essential fatty acid, adult dogs can actually produce sufficient amounts from ingestion of the precursors. These requirements are different for puppies because a puppy’s requirements are larger, and conversion rates are poor. Thus we can’t rely on conversion to effectively cover all a puppy’s nutritional needs.

  • Linoleic Acid (omega 6) can be converted to Arachidonic Acid (omega 6)
  • Alpha-Linolenic Acid (omega 3) can be converted to DHA (omega 3), which is then converted to EPA (omega 3).

Arachidonic Acid and EPA are actually the bioactive forms of these essential fatty acids within the body. Dogs are better at converting LA to AA, and extremely poor at converting ALA to EPA. It’s believed that dogs can only use about 1% or less of the ALA they consume. This means giving dogs a highly bioavailable form of EPA within their diet is extremely important.

Fat Digestion in Dogs

Fat Digestion

  • Lipids or fats are digested mostly within the first section of the small intestine called the duodenum. Since lipids are not soluble in water they first have to be emulsified so that the lipids can be held in a suspension.
  • Emulsification occurs when a lipid combines with bile salt from the liver. The bile also aids in the breakdown of large fat droplets into smaller droplets, increasing the surface area of the lipase enzyme to attach.
  • After emulsification occurs, then lipase breaks down the lipids (triglycerides) into monoglycerides and free fatty acids.
  • Monoglycerides, fatty acids, and bile salts come together to form micelles, which are globe-like structures that are soluble in water. These Micelles are then able to carry the monoglycerides and fatty acids to the intestinal cells for absorption.
  • These micelles typically make their way to the brush border lining of the small intestine in the jejunum (the second section of the small intestine). The fatty acids and monoglycerides then diffuse through the intestinal cells. Bile salts however will be absorbed in the third section of the small intestine called the ileum where they are then recycled into the liver.
  • Once within the intestinal cells monoglycerides, and free fatty acids are resynthesized into triglycerides, and then packed into a protein called a chylomicron.
  • Chylomicrons then work to transport these triglycerides from the small intestine into the lymph system to different body tissues.
  • Lipoprotein lipase breaks down protein to release fatty acids within tissues. These fatty acids can then be used as energy (via fatty acid oxidation), used for the synthesis of lipid-containing compounds in the body, or stored as triglycerides within adipose tissue, muscles, or the liver. Only saturated fats and omega-9 fatty acids can be stored. Omega 6 and 3 fatty acids can’t be produced or stored within the body.

Fatty Acid Deficiency in Dogs

There are several causes of fatty acid deficiency within pet foods labeled to be complete and balanced. The first is oxidation or rancidity of the fats. This can happen due to poor food storage – aka high temperature or humidity. Also some disease states such as pancreatitis, biliary disease, and hepatic disease can affect lipid digestion and/or absorption leading to deficiency.

Clinical signs associated with deficiency of fatty acids include:

  1. Dry and dull hair coat, or hair loss. This is typically due to linoleic acid deficiency.
  2. Skin Lesions or Poor wound healing
  3. Nervous system and retinal abnormalities – a reduction to learning or memory. Typically due to omega 3 deficiency.
What happens if you feed your dog too much fat?

What happens when you feed too much fat?

There is a safe upper limit for both total fat and the essential fatty acids EPA & DHA described in the NRC (National Research Council).

A complete and balanced diet will likely not have excessive amounts of EPA and DHA, however, some canned, lightly cooked, or raw diets can be particularly high in total fat content. Some dogs will tolerate these diets without issue, however, others may not.

Common clinical signs associated with excessive fat intakes are:

  1. Fatty stools or diarrhea
  2. Obesity
  3. The rapid growth rate in large/giant breed puppies is due to excessive calorie intake, causing them to gain weight faster than their skeletons develop. This can cause bone and joint abnormalities.
  4. Nutritional Deficiencies due to nutrient density not being appropriate for calories consumed.
  5. Nutritional Deficiencies of Vitamin E – vitamin E is oxidized before unsaturated fatty acids, protecting them from rancidity, but destroying the vitamin E in the process. If not enough is supplied to offset losses, a deficiency could occur.

Comparing Fat Content in Premade Diets

To compare the macronutrients of diets that are moisture-rich you will need to look at them on a g/1000 kcal basis. Diets above 50g/1000 kcal are considered a high fat diet. Most diets fall between 30-50g/1000 kcals, which is a moderate fat diet. For dogs with certain medical conditions that need fat-restriction we look for diets less than 30g/1000 kcals, but as low as the NRC minimum.

You can learn about the calculations required to convert a guaranteed analysis to g/1000 kcals in detail here.

Sources of Essential Omega 3 Fatty Acids in Dog food and how to Calculate them for supplementation.

Calculating EPA and DHA for Supplementation

Many people choose to add fish oils to their dog’s diet in order to help with different diseases and conditions. The issue with adding in additional fish oil to a recipe is that…

  1. It’s very calorically dense.
  2. You can unbalance the omega 3:6 ratio
  3. You can provide too much EPA+DHA

In order to figure out how much fish oil to add you need to:

  1. Figure out how much EPA and DHA come from diet, g/1000 kcal. 
  2. Calculate how much your dog is consuming from their diet g/day consumed from diet.
  3. Calculate the total dose needed of EPA and DHA for the disease/condition you are looking to provide support for.
  4. Take the Total dose needed for the condition and subtract the amount already provided by the food. 
  5. Take the concentration of the fish oil you wish to use (of EPA and DHA) g/ tsp or g/mL.
  6. Calculate how much additional you need to add in order to get to the total dose needed.

Yes, this is a lot of math. If you don’t want to do this calculation then I highly recommend working with your veterinarian to do this calculation for you. 

Just make sure to provide both the typical analysis or guaranteed analysis of EPA+DHA for the diet you are feeding, and the fish oil you wish to use. Since EPA and DHA are not required on the guaranteed analysis for dog foods, you may need to actually contact the pet food company directly for this information.


My 22lb dog eats Open Farm Turkey and Ancient Grain which provides 0.11% DHA guaranteed on the label, and is 3750 kcal/kg.

>> 3750 x 0.11 / 10,000 = 0.04g / 100kcal

My dog eats 1 cup per day. 1 cup is 425 kcals/cup. Thus 425 kcals per day.

>> 0.04g /100 kcals x 425 kcals = 0.17g per day EPA + DHA, or 170mg / day

Dose of EPA+DHA for Allergies for a 22 lb dog is 59 mg/kg/day, so my dog needs 536 mg EPA+DHA per day to suppor their skin/coat health for environmental allergies.

>> 536 mg – 170 mg from diet = 366 mg needs to be provided via supplementation

Nordic Naturals Omega 3 Pet Small Breed Dog Liquid = 247 mg EPA+DHA per mL

>> 366 mg / 247 mg per mL = dog needs 1.5 mLs Nordic Naturals Omega 3 Pet Liquid per Day for allergies added to their complete and balanced diet.

Additional Resources:

Fat Dog Food Basics – Take Aways

I know I covered a lot here when it comes to fat and essential fatty acids within dog food. But here are the main points I want you to take away from this article.

  1. Dogs have requirements for both total fat, and essential fatty acids (omega 3 and 6 fatty acids)
  2. Make sure your dog’s diet is complete and balanced and appropriate for their age, activity level, and medical conditions.
  3. Do not just supplement fats to your dog’s diet – remember it’s about balance, not just a certain dose.
  4. When supplementing Omega 3s, make sure that your dosing is accurate, and discuss supplementation with your vet prior.

If you’re not sure what diet would be most appropriate for your dog, or you need help – feel free to reach out and schedule a consultation so that we can chat about your dog’s nutritional needs in detail.

Is your dog's food too high in fat? How do age, activity level, and medical conditions influence your dog's need for fat within their diet?

About the Author: Nikki is a Registered Veterinary Technician (Veterinary Nurse) and Dog Mom with over a decade of experience with dogs and cats. Since graduation from college (BS Biology, Dip. Animal Nutrition, AS Animal Science) she has adopted two mixed breed dogs – Ranger and Ash, and has focused her time learning about pet food and nutrition.

Nikki shares information on a range of dog nutrition topics: from how to create a homemade complete and balanced dog food recipes, to how to choose a dog food. Nikki strives to give dog parents the information they need in order to make the best nutrition decisions for their pup!

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