Dealing with a Discolored Cat: Effective Solutions!

One: Why Does a Black Cat Change Color?

Firstly, genetics may determine the basic color of a cat, but other factors can influence the intensity or variation of the color. These factors can be influenced by the environment.

Two: Why Are Black Cats Black?

The reason lies in the presence of melanin, which is the primary pigment in a cat's skin and fur. Tyrosine, an amino acid synthesized from phenylalanine (another amino acid), is essential for the production of melanin. Amino acids are the building blocks of proteins.

If the body lacks tyrosinase, the enzyme responsible for producing melanin, the resulting melanin will be reduced, and the originally black areas will appear less dark. For instance, animals with albinism cannot produce tyrosinase, leading to the inability to produce melanin and resulting in pale skin and fur.

However, an excess of tyrosinase can lead to hyperpigmentation and melanoma. This brings us to Siamese cats and cats with pointed colors, which have thermosensitive tyrosinase. Siamese cats are a type of albino cat, meaning that their TYR gene has mutated. The mutated TYR gene produces a defective form of tyrosinase that cannot function at normal body temperatures but is active in areas of the skin where the temperature is below 33°C. The active tyrosinase promotes melanin synthesis and pigment deposition, causing Siamese cats to become darker.

This means that the darkening and blackening of Siamese cat fur is due to the melanin formed through the conversion of tyrosinase. The thermosensitive tyrosinase is sensitive to external temperatures, and when temperatures are low, the tyrosinase can function normally, catalyzing the conversion of tyrosine into melanin.

Therefore, Siamese cats become darker in winter due to the lower temperatures. Similarly, the graying of human hair as we age is also related to a lack of tyrosinase. So, the reason why black cats change color is the same principle.

Research has shown that black cats with a diet lacking in phenylalanine and tyrosine will see their black fur turn reddishbrown. This is due to a decrease in melanin (pigment) in the fur and a reduction in the total melanin concentration of tyrosine in the plasma.

However, besides the lack of phenylalanine and tyrosine, there are other factors that can cause black cats to change color:

① Copper Deficiency: One of the early signs of copper deficiency in cats is the loss of hair color (chromatin) and a change in hair texture. The reason for the color change is the alteration of tyrosine metabolism. Copper helps tyrosine work as a pigment factor.

② Zinc Overload: Excessive zinc in the diet can lead to copper deficiency, which in turn can cause iron deficiency, affecting hair color.

③ Thyroid, Kidney, and Liver Issues: These organs also affect hair color and interact with tyrosine. The liver metabolizes tyrosine, which is necessary for the synthesis of thymosin, a hormone produced by the thymus.

Three: What to Do When a Black Cat Changes Color?

Experiments have shown that the relative proportion of two types of melanin in black fur is controlled by the activity of tyrosinase. When enzyme activity is low, it promotes the production of brown melanin; when enzyme activity is high, it promotes the production of true melanin.

More importantly, the activity of tyrosinase is stimulated by the concentration of tyrosine, meaning that the higher the concentration of tyrosine (and phenylalanine, which can be converted into tyrosine), the higher the enzyme activity, and the higher the proportion of true melanin produced, resulting in darker fur.

The recommended dietary concentration of tyrosine and phenylalanine for feline species is 4.5 grams of tyrosine plus 12 grams of phenylalanine per kilogram of amino acids to ensure maximum growth rate and nutritional balance in kittens.

However, some experiments suggest that this may not be enough to maintain a rich black fur color in black cats.

This means that even cat food that complies with NRC and AAFCO standards may cause black cats to change color.

Therefore, for black cats, the key is to supplement tyrosine and phenylalanine.

Four: How to Supplement Your Cat? Do You Need to Buy Special Additives?

There's no need for such麻烦. Simply feeding your cat a variety of foods rich in tyrosine and phenylalanine, including beef, lamb, fish, chicken, and other meats, is sufficient.

By ensuring your cat receives adequate meat nutrition, their fur will quickly return to its pure black color.

Tip: Click on "Five Essential Tips for Cat Hair Care" to learn more about maintaining your cat's coat health.