If you’ve noticed that your black cat’s fur has taken on a rusty red hue under normal lighting conditions, there may be a simple solution: a change in diet. It’s a well-known fact that food can affect a cat’s appearance, including the color of their coat. While the phenomenon of a rusty-colored black cat due to a lack of tyrosine is rare, it’s still an intriguing topic to explore.
Many foods, such as fish, contain an ingredient called tyrosine. Tyrosine, or “l-tyrosine,” is an amino acid that is essential for the creation of color in a cat’s fur. The pigments responsible for the coloration of hair strands, known as eumelanin and pheomelanin, are synthesized from tyrosine. Eumelanin provides the brown/black color, while pheomelanin imparts a yellow/reddish brown hue. Collectively, these pigments are referred to as melanin, and their levels in the fur determine the coat’s color.
Rusty Black Cat. Ziggy, a black and white cat with rusty black fur. Photo: Julie.
Inadequate levels of tyrosine in a cat’s diet can result in an insufficient amount of melanin being deposited within the hair fibers. This imbalance leads to the prominence of pheomelanin, causing the fur to appear reddish brown. Alternatively, the pigment may be thinly spread throughout the hair, transforming the black/brown coloration into yellow/reddish brown.
Interestingly, the amount of tyrosine required to ensure a full amount of melanin in the fur is greater than what is needed for a kitten to grow normally. This implies that black hair may naturally possess a rusty hue. In fact, black cats often appear rusty red when backlit, as the light passes through the hair strands.
In conclusion, if your black cat’s coat has turned rusty in color, consider supplementing their diet with tyrosine. However, it is essential to consult your vet before making any changes. It’s worth noting that there may be other potential causes for color changes in a cat’s coat.
Interesting fact: The pattern seen in a cat’s coat is mirrored in their skin, partly due to the presence of fine down hairs that are barely visible. However, polar bears have pigment-free hairs but possess black skin. Melanism occurs when a patterned cat, usually a brown tabby, turns black with a ghost pattern due to a genetic mutation.
Note: The information for this article has been sourced from the Journal of Nutrition.
There are several studies available on the internet that delve further into this topic. One study, titled “amino acid tyrosine,” states: “Reddish hair coat was induced in black kittens born to queens given a tyrosine-deficient diet during pregnancy. Black hair color was maintained or restored by diets containing a high concentration of tyrosine or phenylalanine.” Tyrosine is one of the 20 standard amino acids used by cells to synthesize proteins.
Another study conducted on tyrosine focuses on humans and reveals that its role in the creation of melanin is similar in both humans and cats. The scientists conclude that: “Results from studies with human melanocyte cultures derived from different racial skin types reveal an excellent correlation between the melanin content of melanocyte cultures and the in-situ activity of tyrosinase.” The study is titled “Role of Tyrosinase as the Determinant of Pigmentation in Cultured Human Melanocytes.”
While tyrosine deficiency may not be a common health issue, it is worth mentioning that it might cause hyperthyroidism, which is linked to low thyroid hormone levels.
The key to resolving such issues lies in providing a high-quality balanced diet. Treats rich in tyrosine include lean pork chops, chicken breast, and salmon. Pumpkin seeds are also a great source of tyrosine, containing 1079 milligrams of the amino acid per 100 grams.
What is eumelanin in cats?
Cat hair pigmentation types (fully illustrated)