Internet Has Wild Theories After Black Cat Suddenly Turns Brown

A cat owner has been left baffled after their pet's coat appeared to change color from black to brown.

In a post on Reddit's r/cats subreddit, the owner u/Sheolmonium posted a picture of their cat with the caption: "Why is my black cat suddenly brown?"

The user added: "I swear she's 100 percent black with white spots, but for some reason under light she has a brown/rusty looking fur??"

A cat's fur color is determined by its genes. The mix of dominant and recessive genes decides whether the animal will be a ginger tabby, have sleek plain black fur, or be covered in splodges and spots of varying colors.

Black cats are known to be great at camouflage and even have their own annual appreciation day. However, there are a few reasons that your black cat might look brown in certain situations.

Why Does My Black Cat Look Brown?

Celia Haddon, feline expert and author of Being Your Cat, told Newsweek: "Black cats often look brownish in direct sunlight. This color change is only temporary and, back in the shade, the cat will look all-black again. My black cat George used to show brownish tabby markings in the sunlight, but if I called him back into the shade, these would be no longer visible."

Explaining why the sunlight might show a different cat coat color, Daniel Mills, professor of veterinary behavioral medicine at the University of Lincoln, England, told Newsweek: "Black cats are not necessarily black. A cat's fur is made of both color and pattern, and when a cat has a coat pattern—even if the color of that pattern is black on black—there can be a slight lightning so that sometimes the cat appears to be slightly off black."

For cats with subtle patterns on their coat, certain sunlight may show the pattern and coloring may appear a very dark brown rather than the usual black.

Some people also believe that cat fur can lighten in the sunlight, giving an almost bleaching effect as it does on humans. "If a black cat spends a lot of time in the sun, its fur may be slightly bleached in the areas exposed to the sun, just like our human hair changes in a lot of sunlight," said Haddon.

Despite the likelihood being that a change in a cat's fur is just a quirk of their coloring, it is something that owners should pay attention to. Sudden and long-lasting color changes could signal something more serious.

"We cat owners should take notice if the cat's hair color starts permanently changing as permanent change may be a sign that something is seriously wrong either with their diet or their health," said Haddon.

Mills explained: "Black cats need an amino acid tyrosine to produce the melanin that maintains their black-colored fur."

Studies have recorded cases of black kittens being born with a reddish coat color as a result of the mother cat's tyrosine-deficient diet during pregnancy. But tyrosine is found in meat, fish, eggs, dairy products, beans, nuts, oats and wheat, and so should be in most cats diets sufficiently.

Tyrosine deficiency is rare, but can cause coat and skin issues, hormonal imbalances and even changes in regulation of mood, behavior and cognitive function.

"I would say that if your cat goes from black to brown, get it checked by the vet. It suggests that there is something limiting—whether it's diet or a metabolic issue," said Mills. "That said, if it is minimal, or your cat is just getting slightly old, I wouldn't worry too much."

In more than 500 comments on the Reddit post, other cat lovers shared their theories for why the pet's coat may have changed color.

"Has he been sitting in the sun a lot? That usually does it," wrote one commenter, while another posted: "Most black cats are actually such a dark brown we perceive them as black, till they spend time in the sun."

Meanwhile others shared some jokes about the cat's unusual coat coloring. "Did you use gentle cycle?" commented one Reddit user, while another wrote: "He is running low on ink. Insert a new cartridge."

Newsweek has reached out to u/Sheolmonium via Reddit for comment.

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