| Abstract: | The coat of seven ‘Landseer’ Newfoundland dogs was irradiated using an infra-red source for 25 min. In each dog, at a site of each colour (black and white), skin and coat temperatures were monitored, and coat air humidity measured with a specially designed instrument. Almost no differences were noted at sites with differing coat colour. Skin temperature rose from 35 °C to a plateau at 39 °C, whilst coat temperature rose from 30 °C to 41 °C. Relative humidity of coat air initially rose, then fell significantly (P < 0.001). The absolute humidity initially almost doubled (P < 0.001), but then fell, although remaining significantly higher than that of ambient air. It was concluded that an initial burst of sweating was followed by lower but continuing secretion. This was not, however, of great importance in cooling. In a separate study the skin temperature of black coated dogs exposed to bright sunshine was explored. The mean temperature was almost identical to that of the plateau skin temperature noted in Newfoundland dogs. |
