POTASSIUM AND MAGNESIUM
These are important minerals for a dog with chronic heart failure. A deficiency of magnesium or phosphorus can exacerbate the potential side effects of cardiac medications and may cause other problems such as muscle weakness and cardiac arrhythmias. Magnesium levels should be monitored in your dog and if he/she becomes deficient then a diet with higher levels may be recommended. However, whether the dog requires a diet higher or lower in potassium depends completely on the individual animal. Again, your vet will need to check your dog regularly and moderate the diet when and if necessary.
Some of the specialist diets specifically developed for cardiac disease have a reduced phosphorus content too. Phosphorus, along with calcium is a major component of bone. Phosphorus is also found in the soft tissues and plays a role in almost all of the body’s metabolic processes. However, phosphorus restriction is important once kidney failure has been diagnosed. During renal failure the kidney’s ability to filter and excrete phosphorus declines and the build-up of phosphorus in the body can be toxic. Reducing dietary phosphorus for dogs with kidney failure has been shown to increase their lifespan by 2-3 times compared to dogs fed on a standard food. As many dogs with heart disease also have kidney disease, some companies have chosen to restrict phosphorus in the diet as well as minerals such as sodium. However, phosphorus restriction is not necessary to aid patients with heart disease if their kidneys are functioning correctly.
During normal cell metabolism (oxidation) the body produces unstable molecules called free radicals. Free radicals are responsible for normal aging but if they are able to increase in numbers they can cause disease and illness too. Contaminants such as pollution and damage from sunlight (sun burn) can increase the amount of free radicals the body produces. Antioxidants including Vitamins C and E help to neutralise free radicals and therefore reduce the destruction caused by free radicals. However, studies have shown that dogs with either Dilated cardiomyopathy or Mitral Valve disease have an imbalance between free radical production and the amount of antioxidant protection available. Therefore it has been recommended that the diet of a dog with heart disease is supplements with antioxidants such as Vitamins C and E, however scientific evidence to support the need for supplementation is still weak.
*WHAT IS DRY MATTER?
Vet’s Kitchen dry food contains 8% moisture, the rest of the food (92%) is called dry matter and this is where all the nutrients in the food are. Different brands of dry food and types of foods e.g. wet food or semi moist food all contain different moisture contents. These differences in moisture content make it difficult to do a direct comparison on nutrient levels, therefore nutrients are usually only compared on a dry matter basis instead of an ‘as fed’ basis.