What Is Ferrous Sulfate in Dog Food?

Ferrous sulfate is a form of the mineral iron that pet food manufacturers include in your dog's food to support red blood cell formation. Iron, vital to your pup's health, helps to prevent anemia. Red meat contains iron, but your pup's food may not have enough of it naturally, which is why manufacturers supplement it with ferrous sulfate.

  1. Ferrous Sulfate

    • Ferrous sulfate is a naturally occurring mineral that supplies iron to your pup's body when he ingests it. This "iron salt" is formed as a byproduct of the production of titanium dioxide. It has a blue-green hue. Manufacturers include ingredients like ferrous sulfate and ferrous proteinate to enrich their formulations with iron. Ferrous sulfate itself is odorless and generally regarded as safe, according to the U.S. Food and Drug Administration. The FDA considers ferrous sulfate to have an adequate level of bioavailability, meaning that a dog's body can easily digest and absorb the supplement.

    Daily Dose

    • According to the nutrient profiles established by the Association of American Feed Control Officials, the recommended minimum amount of iron that a dog food should contain is 80 milligrams per kilogram, with a maximum amount of 3,000 milligrams per kilogram, reports the FDA. A typical healthy dog needs around 7.5 milligrams of iron in his diet daily, recommends the National Research Council. Lean red meats like beef, lamb, pork and veal, along with organ meats like liver and gizzards, are high in iron, according to the University of Rochester Medical Center. While these types of meats are usually included in your dog's food, they alone don't provide enough iron to supplement his needs. Thus, manufacturers include ferrous sulfate in their formulations.

    Iron Deficiency

    • Without proper supplementation of his food with minerals like ferrous sulfate, your dog could become iron-deficient, according to the Canadian Veterinary Journal. Iron helps your dog's system form healthy red blood cells that carry oxygen in the blood throughout his body. Insufficient amounts of iron cause the body to form red blood cells that are too small to carry enough oxygen, thus resulting in anemia, according to petMD. Anemia is a serious condition that could result in decreases in growth for puppies, lethargy, lack of appetite, weight loss, dark stools or increased susceptibility to disease. To ensure your pooch doesn't become anemic due to diet, feed him an AAFCO-approved dry or wet food.

    Ferrous Sulfate Dangers

    • While iron in the form of ferrous sulfate supports your dog's health, too much of this essential mineral is actually toxic to him. Because dog food that adheres to the profiles of the AAFCO has sufficient iron in it, in the form of ferrous sulfate or another iron salt, supplementing your pup with iron or vitamins containing iron, can poison him if he's not anemic. Excess iron can cause vomiting, diarrhea, stomach ulcers and gastrointestinal bleeding. In especially high doses, such as 20 milligrams per 2.2 pounds of a dog's weight, iron is actually lethal to your pup, according to petMD. For this reason, consult your vet before supplementing your pup's diet with iron beyond what is contained in his food.