PERSPIRATION IN DOGS.

Hawera & Normanby Star, Volume LXXI, Issue LXII, 11 May 1912, Page 10

PERSPIRATION IN DOGS.

No matter how far or how fast a dog may have run, or to how hot a sun it may have been exposed, its body never betrays any increase of temperature by the presence of drops of perspiration on the skin. This fact has given rise to the idea that a dog does not perspire at all. But (writes "J.R." in the Scotsman), there must be some means of compensating for an increased temperature, and the necessary lowering is brought about by a rapid evaporation of moisture from the surface of the lungs. This at once explains the open mouth and rapid breathing of a dog which has been exercised, as well as the beads of condensed moisture which drip from his rolling tongue. Yet, in addition to this internal transpiration, there is external but less marked, perspiration. Place a dog before a blazing fire, and, though at first he may curl up comfortably, soon he unrolls himself and spreads his limbs Why? Certainly not in order that he may expose himself the more to the fire;'but that slow, cooling evaporation may take place from the surface he lays open. Even if the temperature be still raised, no visible signs of perspiration show on his coat; but his paws have a distinct moist feeling, and should he walk over, say floorcloth, damp footprints remain where on ordinary occasions no mark is made. Still more convincing is a simple chemical test, with silver nitrate, which shows distinctly that the salty residue of perspiration is present in varying quantities on the dog's skin —most abundant on the surface of the paws and amongst the roots of the hair on the back. The point of interest lies in this—that, in spite of the usually accepted idea, transpiration does take place through a dog's skin even under ordinary conditions, although it is naturally more marked (for the results of the chloride tests are stronger) after the animal has been coursing, or has been exposed to a high temperature.