How do cats regulate heat? The role of the coat, skin, and the FGF5 gene

Unlike humans, cats have very few sweat glands across their bodies; their ability to sweat for thermoregulation is limited to their paw pads. As direct descendants of the African wildcat (Felis lybica), they retain an exceptional ability to maintain their basal body temperature (between 38 °C and 39.2 °C), but they require specific biological mechanisms to dissipate heat during warmer seasons.

Their body's first line of defense is their coat: far from being a suffocating layer, feline fur acts as a bidirectional thermal insulator. Understanding feline thermoregulation and its genetic foundation is essential for protecting their health against heatstroke and hypothermia.

How Do Cats Regulate Their Temperature?

To stay within their physiological thermal range, cats combine physiological responses and behavioral adaptations:

• Peripheral vasodilation: They dilate the blood vessels in their ears, legs, muzzle, and paw pads to release excess heat to the outside.
• Salivary evaporation: When grooming, they spread saliva over their coat; as it evaporates, it creates a cooling effect similar to human perspiration.
• Air-cushion insulation: The undercoat creates a microscopic barrier of air that insulates the skin from hot ambient air in summer and traps internal body heat in winter.

The mistake of shaving in summer: Shaving or clipping a cat's coat removes its natural insulating layer, exposing its skin to direct sunburn, dermatitis, and an increased risk of heatstroke.

The Genetics Behind the Feline Coat

Coat length, density, and texture are governed by specific genetic variants that directly influence the animal's thermal tolerance:

• Hair length (FGF5 Gene): This gene regulates the hair growth cycle. Dominant variants produce short hair characterized by rapid growth (quick heat dissipation), whereas recessive mutations result in semi-long and long coats (Persian, Maine Coon), which require regular brushing to prevent mats that hinder skin ventilation.
• Absence of coat (KRT71 Gene): Hairless breeds such as the Sphynx lack guard hairs and undercoat, making them vulnerable to both cold temperatures and direct solar radiation.
• Texture and curly coat (KRT71 and LPAR6 Genes): Breeds such as the Devon Rex or Cornish Rex have very fine coats composed almost entirely of undercoat, offering low thermal retention.

Coat Profiles and Thermal Response

Protect their health from the very beginning. Explore the cat DNA test from Koko Genetics and discover everything their genes reveal about their well-being.