HOW DO DOGS REACT AGAINST COLDNESS?

The zone of thermic neutrality or homeothermy zone corresponds to the temperatures where the dogs spends the least energy to maintain its internal temperature constant (i.e 38 - 39 °C in dogs).

This zone stretches between 10 and 20 °C according to the breed. The interval takes into account the variety of hairs in dogs. As soon as the temperature drops below this limit, the energetic consumption of the dog increases.

Evolution of the energetic requirement with dicreasing temperatures External température Facteur multiplicateur du besoin énergétique d’entretien 10°C to 20 °C x 1,1 - 1,2 0 to 10°C x 1,2 - 1,4 -10 to 0°C x 1,4 - 1,6 -10°C to - 20 °C x 1,6 - 1,8 (from Blaza, Decombaz, Hill, Hinchliff)

We can point out the fact that smaller dogs are the ones that spend the most energy to fight against coldness. Because they are the ones that have the largest body surface related to their bodyweight. Proportionnally, they consume more energy than larger dogs for their thermoregulation.

Mechanisms of thermoregulation

To defend dogs against coldness, several physiological reactions are involved. Some aim at limiting the caloric loss, the others tend to produce more energy.

Decrease of caloric loss Hair adaptation Winter hair is longer and thicker than the summer hair, especially in dogs living outdoor. In case of intense coldness, the hair bristles, which captures an isolating air layer. Adipose tissue It is also a way to improve thermic isolation under the skin. Constriction of pheripheric vessels It dicreases the blood output in the skin, then the energy loss. Behaviour changes The dog curls itself, in order to protect sensitive parts and to minimize the exposed surface. In a kennel, dogs form a group. Production of energy Shivering These muscular contractions aim at producing heat when the temperature drops. Physical activity 75 % of the energy consumed during physical work is wasted under heat form. So, this heat can be deducted from the energy requirement due for thermic regulation. Utilization of fat reserves To replace the fats stored in the adipose tissue, the dog has to eat a more energetic diet.

Advantages of a high-fat diet to fight against coldness

Fatty acids are the most useful nutrients to reconstitute the adipose reserves. They rate of using is interesting as no chemical transformation is necessary. This is why high-fat diets are known to be the most efficient under cold conditions.

Indications of Energy products

This type of foods is specially advised for dogs that have to face cold temperatures, even if they do not have intense physical activity. Let’s focus on:

• short-hair breeds (ex: Pointers);
• kennel dogs that have often to face: coldness + humidity + air drafts, 3 factors that dramatically increase the caloric loss.

During winter, 2 meals per day are better than a single one: the energy supply of the body is then more regular.

Something not to forget either: watering dogs frequently (be careful with frozen water!). Contrary to a false idea, dehydration is also a risk in winter: because of the air wich is often dry, and because coldness stimulates urinary elimination.

Donated by the Borg Cardona and Co. Ltd. visit Borg Cardona website