Micronutrients in a domestic cat’s diet refers to essential amino acids, fat-soluble vitamins, water-soluble vitamins, minerals and essential fatty acids. Macronutrients refers to protein, fat, carbohydrates and fibre. Cats, unlike other animals, cannot manufacture essential fatty acids or essential amino acids. Neither can they manufacture vitamin A. Cats don’t automatically eat foods which are always nutritionally best for them. For instance they normally like tuna but it contains an enzyme which destroys thiamine (vitamin B).
Therefore, these micronutrients have to be introduced in their diet by pet food manufacturers in a very careful way. For instance, for a reason which I believe is unknown, wet cat foods promote bacteria which breaks down more taurine than dry cat food. As a consequence reputable pet food manufacturers make sure that their canned foods contain at least twice as much taurine as their dry foods. It can be more than 2 g per kilogram.
Although humans and dogs can survive on plant-derived protein because they can get from plant protein essential amino acids that they need, cats can’t. This is because of their evolution during which there was an abundant supply of animals to kill and therefore an abundant supply of meat to eat. Their physiology changed over millennia resulting in the loss of the ability to manufacture the essential amino acid taurine and to a smaller extent arginine.
They are added to their diet and they obtain these micronutrients from meat, fish tissue and poultry.
When taurine is absent or at too low a level it can lead to serious diseases, heart failure and blindness. Cats are very sensitive to an insufficient quantity of arginine in their diet. When the level is too low it can cause muscle spasms and vomiting followed by sensitivity to touch.
Essential fatty acids
Essential fatty acids are referred to as EFAs. Nowadays the experts are more aware of the importance of EFA’s in a cat’s diet in controlling dermatitis, nervous system function, kidney function, auto-immune disease, heart disease, inflammation, arthritis and allergies.
One EFA is omega 6. It is associated with cell inflammation and “some may also suppress the immune system”. Another group of EFAs called omega-3 are linked with reduced cellular inflammation. They do not suppress the immune system. Cats may benefit from an enhanced and more efficient immune system when their diet includes omega-3 fatty acids. A diet rich in omega-3 fatty acids results in the cells of the cat’s body being less at risk of becoming inflamed because they change the composition of the cell walls.
As mentioned, cats cannot manufacture EFAs and therefore they need to eat animal-sourced arachidonic acid and lenoleic acid, which is necessary for body growth, liver function and wound healing.
Arachidonic acid is required for “blood clotting, coat condition, and efficient reproduction”. Substances called eicosanoids which are derived from arachidonic acid stimulate information.
Minerals are important in terms of cellular health. For example, phosphorus and calcium are needed for neuro-muscular function, cell membrane function and for growth and maintenance of the skeleton. Swollen and painful joints can result in a meat-only diet which is low in calcium because it leads to an overstimulation of the parathyroid gland.
When there’s too much calcium in their diet it may result in zinc deficiency over a long period of time. Low blood calcium can be a result of lactation and it can lead to eclampsia. During pregnancy if there is too much calcium it can lead to the risk of eclampsia during lactation.
Lower urinary tract diseases in cats has been linked to magnesium but is believed to not be the only cause of the disease. Some heart conditions may be caused or linked to a deficiency in magnesium.
Healthy body tissue is maintained in part by enzyme systems of which selenium is an essential factor. Selenium plays a role in the immune system. It helps neutralise carcinogens.
Red blood cell production is dependent upon iron. And the transportation of elements across cell membranes is dependent upon sodium.
Fat soluable vitamins: As mentioned, cats cannot manufacture vitamin A. It has to be consumed preformed in their diet. It maintains good eye health specifically of the retina. It is found in fish-liver oils and animal livers. A deficiency in vitamin A can cause bone deformities especially in the neck which can lead to lameness and pain.
A cat’s skeletal development is dependent upon vitamin D together with a good balance of calcium and phosphorus in their diet. Too much vitamin D can cause skeletal deformities. The viscera of marine fish contains vitamins D which can be a health hazard if a cat feeds on fish primarily or nothing else.
Free radicals damage cell membranes and selenium and vitamin E together act as antioxidants which neutralise free radicals. Pansteatitis (yellow fat disease) can be caused by a deficiency in vitamin E. The symptoms are fever and a loss of appetite. If a cat eats too much fish oil they will need an increased amount of vitamin E in their daily diet.
Blood coagulation is dependent upon the presence of vitamin K. It is rarely deficient in a cat’s diet. If through an unfortunate circumstance a cat eats a rat killed by a rodenticide which is anti-blood clotting such as warfarin there may be a sudden “and unattainable demand for vitamin K.”
A vitamin K supplement is sometimes prescribed for prolonged antibiotic therapy.
Water soluable vitamins: if a cat’s food is deficient in vitamin B complex, you can add yeast-based tablets to their diet as a supplement. Certain species of raw fish contain an enzyme which destroys thiamine which may leave a cat with a deficiency of this vitamin. An amino acid called homocysteine is important in human heart disease and a diet deficient in folic acid may lead to an increase in the levels of this amino acid in the blood. If there’s too much folic acid it may cause gastrointestinal problems in domestic cats.
Vitamin C is manufactured by the cat so there’s no need to give a vitamins C supplement. Excess vitamin C is urinated in a substance called oxalate. Oxalate bladder stones are more prevalent a domestic cat and they were in times past.