Study reveals why dogs have cold noses

A new study has revealed that dogs’ noses are usually cold because they serve as ultra-sensitive heat detectors — contrary to assumption such is used to regulate body temperature.

According to the study published in Scientific Reports journal, when the ambient temperature is 86°F (30°C), a dog’s rhinarium – the bare end point of the nose – is some 5°C (9°F) cooler.

The research team from Sweden’s Lund University and the Eotvos Lorand University in Hungary also found that when the outside temperature is 0°C, a dog’s nose will be around eight degrees.

According to the study, such differences was indicative the tip of the nose serves a sensory function.

To arrive at their premise, the researchers studied three dogs – Kevin, Delfi and Charlie.

The dogs were trained to identify which of two identical four-inch wide objects had been heated to around 22°F (12°C) warmer than room temperature.

Findings from the study also showed a dog’s nose can detect often very faint heat sources – such as the presence of a small mammal – from five feet away.

“All three dogs could detect stimuli of weak thermal radiation in double-blind experiments,” the study said.

“In addition, we employed functional magnetic resonance imaging on 13 awake dogs, comparing the responses to heat stimuli of about the same temperatures as in the behavioural experiment. The warm stimulus elicited increased neural response.

“All stimuli of radiating heat used in our experiments were too weak to be felt by human hands, even at very short distances. We had to touch the surfaces to feel the warmth.”

The experiment concludes that a dog’s rhinariums serves a sensory function — since they can detect heat, rather than just regulating their body temperature.