Iron plays a vital role in a large number of metabolic pathways in almost every living organism, and in animals either too much or too little iron can have dire consequences.
Because iron regulation is such an important topic, it was reviewed in the May/June 2011 edition of the Journal of the American Animal Hospital Association by Drs. Jennifer McCown and Andrew Specht, veterinarians at the PETS Referral Center in Berkeley, Calif., and the University of Florida Veterinary Medical Center, respectively.
“Iron is an essential element for almost all living organisms. Disturbances in iron intake, loss or regulation can result in a number of clinical abnormalities, some of which may be severe or even life-threatening,” wrote the authors.
Iron plays a key role in hemoglobin formation. Hemoglobin is a protein found in red blood cells that transports oxygen from the lungs to body tissues. Too little intake, inadequate absorption of dietary iron, or chronic blood loss can cause anemia (i.e., too few red blood cells). Although iron deficiency is the most common nutrient deficiency in humans throughout the world, domestic dogs and cats are, fortunately, not commonly afflicted with the problem.
Signs of Inappropriate Iron Levels in Dogs and Cats
Too Little Iron
Too Much Iron
- Exercise intolerance
- Increased respiratory and heart rates
- Skin and nail changes
- Behavior changes (such as eating and licking non-nutritive objects or substances — a condition known as pica)
- Impaired growth
- Gastrointestinal irritation or distress
- Rapid pulse
- Low blood pressure
- Blue or purple mucus membranes or skin (cyanosis)
- Liver failure
- Ataxia (abnormal coordination and balance)
According to the authors of the review article, most commercial pet foods include adequate amounts of iron. Still, some animals may require more iron than others. For example, dogs and cats infected with certain kinds of worms that live in their intestinal tracts and feed off blood (e.g., hookworm, whipworms) or pets with extreme flea infestations may need extra iron. In both cases, chronic blood loss can cause anemia due to iron deficiency. Animals with other conditions such as hypothyroidism and kidney disease can also have low iron levels.
If you are concerned about your pet’s iron status, speak with your veterinarian. He or she can perform a blood test to look at the size and shape of the red blood cells, measure how well iron is being transported in the bloodstream, and estimate tissue iron stores.
The easiest way to ensure your dog or cat is receiving enough iron is to feed a high-quality pet food that will provide adequate amounts of dietary iron. For example, the National Research Council recommends that healthy adult dogs consume 1 mg of iron daily. If supplemental iron is needed, ask your veterinarian to recommend an appropriate multivitamin. If your pet is diagnosed with an iron deficiency, treatment with an oral iron supplement, usually ferrous sulfate, could help. Rarely, animals may require intramuscular or intravenous injections of iron by a veterinarian instead of the oral supplement.
Even though iron is poorly absorbed from the intestinal tract, it is still important to avoid over-supplementing your pet with iron or leave iron supplements where a pet could inadvertently ingest them. Iron toxicosis and even death can occur if an animal ingests between 100 and 200 mg/kg of elemental iron.
For more information on reading a pet-food label and canine and feline nutrition, visit: peteducation.com.