Copper Sulfate In Dog Food

What Is Copper Sulfate?

Copper Sulfate is a mineral that is a combination of Copper and Sulfer. Copper Sulfate is most commonly used as an anti-fungal or anti-bacterial agent in agricultural and non-agricultural settings.

In addition, Copper Sulfate also has several other documented uses, such as in the textiles, leather, wood, battery, ink, and petroleum industries.

However, dog owners who have carefully studied their dog’s food’s ingredient list may notice that there are small quantities of Copper Sulfate present which often causes confusion and questions.

Why would a chemical that is used in industrial processes be found in a dog food recipe?

Copper Sulfate Crystals

Why Is Copper Sulfate In Dog Food?

The reason that Copper-based ingredients like Copper Sulfate are added to dog food recipes is that for them to be classed as “Complete & Balanced,” they must contain a sufficient amount of Copper to meet AAFCO nutrient profile standards.

Now for some dog food recipes, this is not a problem as the ingredients used within the recipe will naturally contain enough Copper to satisfy the requirement.

The best example of this is dog food recipes that contain some form of liver, such as Chicken Liver or Beef Liver. The liver is a rich source of Copper, and a small portion could easily satisfy a dog’s needs.

However, for other recipes that utilize ingredients that are naturally low in Copper, minerals like Copper Sulfate have to be added to top these levels off.

Why do these dog food brands use Copper Sulfate over whole Copper or other Copper compounds? The AAFCO does not permit dog food brands to use some other Copper compounds, such as Copper Oxide, as they have poor bioavailability.

Is Copper Sulfate Bad For Dogs?

Almost all minerals can pose a risk to dogs if they are present in sufficient quantities. Copper is no different, and if a dog were to consistently consume high levels of copper, they could experience serious health problems.

However, the level of Copper or Copper Sulfate in most dog food recipes is very small and way below the 250mg maximum per KG of a dog’s weight.

Regardless, some studies have shown that indiscriminately adding mineral supplements, such as Copper Sulfate, to dog food recipes poses risks of toxicity.

This is why detailed laboratory testing of dog food recipe contents is such an important part of the formulation and production process.

Brands that do detailed testing such as this have had to recall pet food in the past as the levels have been far above what is permitted, and they posed a risk to those pets.

We want to take this moment to highlight some dog food brands that go above and beyond to show the vitamin and mineral contents of their recipes far beyond what is required.

One brand worthy of mention is Health Extension which has incredibly detailed information about the nutrient profiles of its recipes on its website.

Nature’s Logic is another brand that deserves recognization, and it makes this information readily available on its site in the format shown below.

Nature's Logic Mineral Example

Dog Food Brands That Use Copper Sulfate

While most dog owners would be completely unaware, there is a huge number of dog food brands that utilize small quantities of Copper Sulfate in their recipes.

Some of the well-known pet food brands that use Copper Sulfate include Purina Pro Plan, Hill’s Science Diet, Taste of the Wild, Blue Buffalo, Rachael Ray Nutrish, Royal Canin, Victor, and Nutro.

You can see an example of this in the ingredient list of Hill’s Science Diet Adult Chicken & Barley Recipe dry dog food recipe.

Hill's Science Diet Copper Sulfate

As you can see above, Copper Sulfate is present in this dog food recipe in tiny quantities, among other minor ingredients such as minerals, vitamins, and taurine.

If you are looking to avoid feeding your dog Copper Sulfate, we’d recommend carefully studying the ingredient list of any prospective recipes to see if it is present.

If you are looking for more information on dog food, including topics like nutrition, ingredients, and recalls, check out our Dog Food Guide for an in-depth breakdown.

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