Why Is There Ash in Your Dog’s Food?

If you’ve seen ‘ash’ listed on food packaging you’ve no doubt thought, “The stuff you find in a fireplace? Surely that’s a mistake? How could those burnt remnants make their way into my dog’s kibble?”

You’ll be relieved to find that’s not what’s meant by ‘ash content’, and there’s no actual ash added to your dog food. 

We explain all you need to know below in our complete guide to ash in dog food.

What is ash?

In dog food, ash is not like it sounds. Not at all. 

Contrary to what you may have heard, ash is not a filler intentionally added by unscrupulous food manufacturers to dilute a recipe. Dog food makers are not pouring ash into the food you’re giving to your hungry pup.

Instead, despite it being a confusing piece of terminology, ‘ash’ is a unit of measurement used to determine the amount of minerals contained within the food.

This measurement is essentially the nutrients that would remain in the food after it’s been incinerated, i.e. the end product of food combustion. 

So if, hypothetically, you completely incinerated your dog’s food, all three major nutrients (protein, fat, and carbohydrates) would burn away, leaving just the recipe’s minerals behind. So it’s a handy way to measure the inorganic content of the food – bone, tendons, cartilage, etc. Just not such a handy term they chose to use to label it.

The mineral nutrients that remain in the ash include calcium, phosphorous, zinc, iron, etc (see full list below). This is the ultimate residue of food combustion, called ash content and it’s presented as a percentage on some food labels.

These nutrients are essential to dogs’ development and health. It’s recommended dogs get at least 2% ‘ash’ (AKA minerals) in their diet to meet their nutritional needs to help them grow, develop, and recover. 

What’s the typical ash content found in dog food?

The amount of ash varies from product to product. The AAFCO guidelines advise that dog food manufacturers must meet a certain level of mineral content to hit nutritional standards, although there is currently no minimum ash level that manufacturers must meet.

In general, the average ash content of most commercial dog food is about 5-8%.1

In the U.S., most companies don’t report ash content on their labels as advertising the ash content in food is voluntary, so you may not see it on every food label. In the E.U., meanwhile, FEDIAF (European Pet Food Federation) nutritional guidelines make it compulsory for brands to declare the ash level, so you’ll find it on labels in E.U. countries. The Dog Food Advisor arbitrarily uses an 8% figure for all dashboard calculations.

The ash number by itself is not hugely revealing. Knowing the actual amount of each mineral included in the total ash figure would be much more useful. But, as you’ll see, it’s not easy to measure the amount of each mineral present in the food, so the ash total is a way to estimate the total amount of non-organic minerals present in the food.

Alternatively, some manufacturers might choose to list select nutrient levels in the food, for example, calcium, zinc, phosphorus, and sodium. This is useful in terms of knowing how much of those minerals are present, but it doesn’t provide an overall ash content.

What does ash contain?

Ash content will comprise some, or all, of the following minerals:

Phosphorus

Dogs require phosphorus for bones, teeth, and a well-functioning metabolism.

Calcium

For healthy bones and teeth, and a strong heart and nervous system.

Magnesium

For bone strength as well as healthy muscles.

Potassium

Aids nerve impulses and muscle movement.

Iron

For carrying oxygen in the blood, and enzyme function.

Zinc

Important for thyroid function, the immune system, and enzyme and hormone production.

Sodium

Helps keep your dog’s fluids in balance.

Copper

Aids in making red blood cells and absorbing iron.

Chloride

Chloride balances pH levels and helps with enzyme production.

Manganese

An important trace mineral for providing energy, and growing bones and cartilage.

Selenium

Essential for metabolism function.

Iodine

For healthy thyroid function.

Is ash in dog food a bad thing?

Some dog food companies provide a breakdown of the amount of each mineral, others provide a more general ash content reading. An ash reading is easier to measure, as it’s not an easy or straightforward process to break down the amount of each mineral contained within the food without the use of advanced laboratory testing. 

The amount of ‘ash’ content in dog food is usually between 5% and 8% in dry food, and 1-2% in wet dog food. 

If the ash content is a low number, it could potentially mean the meat used in the food is lower quality. If the percentage is higher, it might mean something like bonemeal from fish or meat has been added, boosting calcium and phosphorus levels in the food. But as ash isn’t a digestible part of the food (once the minerals are absorbed), excessively high levels of ash can reduce the food’s digestibility.

As with any nutrient, vitamin or mineral, there’s a risk your dog could have too much ash (minerals). If the food contains high levels of minerals it could cause imbalances and end up being unhealthy for your dog.

The best way to ensure your dog gets the right amount of minerals is to feed them a balanced diet packed with a good mix of protein, carbs and fat. If you have any concerns about whether your dog is getting enough minerals in their diet, speak to your veterinary surgeon who can advise you further.