Two weeks ago, we saw a 10 year dog that had been having seizures for several days. There are several things which can cause seizures in older dogs. In my experience, the most common is a functional deficiency of magnesium. Estimates are that approximately 30% of the human population in this country is deficient in magnesium. My impression is that magnesium deficiency is probably just as common in dogs.
Most of the body’s store of magnesium is intracellular. This means that attempting to assess a dog’s magnesium status with the standard blood chemistry panel will not reveal the functional deficiencies that are the cause of seizures in many old dogs. The best way to assess magnesium is by measuring red blood cell magnesium. This is often done in a panel which measures both essential and toxic mineral content of red blood cells. If one wishes to determine a given dog’s nutritional needs, the red blood cell mineral panel is an excellent means of doing so.