Fever Coat in Cats: Vets Explain This Strange Phenomenon

Fever coat in cats refers to a phenomenon in which a kitten is born with a specific coat appearance that typically has a frosted silver or gray appearance, as if they rolled around in a pile of ashes. The term “fever coat” might sound alarming, but don’t worry — kittens with fever coat are usually completely healthy.

So, what causes this peculiar phenomenon, and how long does it last? We spoke to veterinarians to get all the important details.

What Is Fever Coat in Cats?

Also referred to as “stress coat,” fever coat presents as a newborn kitten having a coat that’s partially lighter in color than what their genetics would typically dictate. For example, a kitten that you’d expect to be entirely black might be born with black fur with frosted gray tips. 

This occurrence is believed to happen in kittens whose mothers experienced fever, prolonged stress, or were administered certain medications during pregnancy. Fever coat exclusively affects kittens in the womb (in utero) and can impact one or all kittens in a litter, says Dr. Doug Mader, a triple board-certified veterinarian based in the Florida Keys and author of The Vet at Noah’s Arc.

What Does Fever Coat in Cats Look Like?

“Fever coat in cats results in a temporary lightening of the kitten’s fur color, often accompanied by faint striping or tabby markings,” says Dr. Nicole Savageau, a veterinarian with the national mobile pet care service The Vets.  

There aren’t formal classifications for different types of fever coat, Dr. Savageau says, but variations can occur. It can be subtle, with just a few patches or stripes of lighter fur, to very pronounced, making the entire kitten look frosted.

In addition to a silver-gray color, fever coat may also manifest as a cream or light reddish color.

Black Smoke vs Fever Coat

Fever coat can easily be mistaken for a genetic coat color pattern known as “black smoke,” yet there are distinct differences between the two. With fever coat, the fur appears lighter at the tips but maintains the kitten’s natural darker color at the roots. Black smoke presents the opposite pattern, with darker tips and lighter or white roots. Additionally, fever coat is temporary while black smoke is a permanent genetic trait. 

It’s not uncommon for people, including cat breeders, to confuse fever coat with black smoke. Additionally, some dishonest breeders may take advantage of this confusion to deceive buyers into believing they’re purchasing a black smoke cat when they’re actually getting a kitten with a temporary fever coat. Black smoke cats can drive a high demand and value, resulting in this deception.

If you’re considering adopting a black smoke cat, it’s essential to educate yourself about these differences to ensure you’re making an informed decision.

Feline Fever Coat Causes

Unfortunately, there isn’t any solid research about fever coat in cats. The rarity of this condition makes it challenging to gather enough cases for a thorough investigation. Plus, it would be unethical to cause the mother cat stress or induce a fever for research purposes.

The lack of research leaves veterinarians, researchers, and cat experts only able to theorize based on experiences. So, what might cause the color changes in a kitten’s coat? Some of the proposed causes, all of which affect the mother cat during pregnancy, include:

• Fever-inducing illness: An illness or infection (such as a viral infection) is the most commonly suggested cause.
• Prolonged stress: Stressful situations, such as living in a shelter environment or on the streets, changes in environment, relocation, or alterations in social dynamics, are considered potential triggers.
• Medications: Side effects of medications administered to pregnant cats may play a role. Unfortunately, there isn’t any solid information about which specific medications, if any, might have an impact. 

Stress, fever, or medications during pregnancy may disrupt normal physiological processes, including those involved in pigment production in the hair follicles of the developing kittens, resulting in color changes in the kittens’ coats, Dr. Savageau says.

Does Fever Coat Go Away?

Yes, fever coat is temporary. “As the kitten grows, they will eventually shed out the abnormal colored fur and their normal color coat will replace it,” Dr. Mader says.

Dr. Mader adds that fever coat does not suggest that your kitten is ill or at increased risk of illness. “They are normal in every way except for the unusual color.”

What about the health of the mother cat? It depends on what caused the fever or prolonged stress, and how that affected the mother cat’s health. In most cases, a fever or stress will resolve, leaving the mother cat healthy. But, it’s always best to take a mother cat who falls ill during pregnancy or gives birth to a kitten with fever coat to a veterinarian for a thorough examination.

Cats with Fever Coat: Conclusion

Fever coat in cats remains an intriguing yet poorly understood phenomenon. Despite its mysterious origins and rarity, veterinary experts reassure us that it poses no health risks to affected kittens. 

As we continue to unravel the mysteries of feline biology, fever coat serves as a reminder of the complex interplay between genetics and environmental factors in shaping the appearance and well-being of our feline companions.