Winter is a time to get outside, enjoy the crisp air and be invigorated by the cold. But, even though they sport an insulating fur coat, dogs can run into trouble in frosty temperatures.

Hypothermia, frostbite, snowballs stuck between their toes, and poisoning by ice-melt chemicals are just a few dangers seen at this time of year. As well, Christmas brings its own set of hazards.

Hypothermia occurs when the body’s warming mechanisms can’t keep up to its loss of heat, and core body temperature falls below normal. Small dogs are at the greatest risk for hypothermia because compared to larger dogs, they have a greater surface area based on body weight.

Dogs can acclimatize to low temperatures by growing thicker coats and burning calories faster, but even these dogs can succumb to hypothermia if temperatures drop low enough or wind speed increases (boosting wind chill).

A dog’s first response to a drop in body temperature is to generate heat by shivering. To preserve heat, blood flow is routed away from the extremities to the internal organs.

In extreme cold conditions, these temperature-maintaining mechanisms fail. Shivering stops, blood vessels dilate, and body temperature plummets. Pulse rate and blood pressure drop and breathing becomes slow and shallow. The dog eventually becomes unresponsive, lapses into unconsciousness and, in time, dies.

The best way to tell if a dog is hypothermic is to take his temperature. If you don’t have a thermometer, put your hand deep in his groin. A dog’s body is normally warmer than yours, so if he feels cold, he’s hypothermic. You can also look for shallow breathing and mental dullness.

How low the temperature is – the degree of hypothermia – determines what treatment is needed. If a dog is mildly hypothermic, passive re-warming is adequate. Simply move him out of the cold and wrap him in a thermal blanket.

Active re-warming is required for more severe hypothermia – heating pads or radiant heat applied to his trunk is the best way. Avoid burning the skin by placing a protective layer between the dog and the heat source.

Dogs with severe hypothermia need aggressive re-warming at a veterinary hospital. Lukewarm-water enemas, heated fluids injected intravenously, and warm, oxygen-rich air are some of the methods used. Unfortunately, most dogs with severe hypothermia don’t survive. Early recognition and intervention is the key to successful treatment of hypothermia.

Frostbite is another condition that’s caused by cold exposure. The extremities – paws, ears, tail and genitals – freeze. Going for a walk on a cold, windy day is enough to freeze the tips of the ears.

Frozen tissue has no blood supply, so it is pale, bluish, and feels cold to the touch. If you have identified what you think is frostbitten tissue, do not rub it or submerse it in warm water. This accelerates cell death and worsens the damage. Frozen tissue must be gently and slowly re-warmed using passive methods. Blood supply sometimes returns and frostbitten tissue regains its health. Sometimes, blood flow cannot be re-established and the tissue dies.

Another winter issue is snowballs that collect on the feet. When a dog first goes outside, the warmth of his body melts the snow coming in contact with his feet and the hair gets wet.

The water refreezes as his feet cool, allowing snow to stick and accumulate. Foot snowballs can become very large and uncomfortable.

To thaw snowballs, use a hair dryer set on low, or submerge the foot in body-temperature (not hot) water. After the snow is removed, check the feet for cuts or frostbite. To prevent snowballs from accumulating, keep the hair under your dog’s feet trimmed flush with the pads.

Antifreeze stops water in the car radiator (or windshield-washer fluid) from freezing. However, just an ounce (30 millilitres) is all it takes to destroy the kidneys in a Labrador Retriever.

If you are handling antifreeze, make sure it doesn’t spill, and if your radiator is leaking, get it fixed right away. Better yet, don’t use the standard ethylene glycol. Pet-friendly propylene glycol is a little more expensive, but worth the cost.

Another danger in winter is chemical ice melts. These cause irritation to the skin and, if ingested (licked off the paws), stomach upset and nervous symptoms. If your dog walks on treated sidewalks, bathe the feet or wipe them with a damp towel as soon as you return home. Instead of ice melts, use sand or clay cat litter.

Protecting your dog from the cold and hazards of winter isn’t difficult if you’re aware of the dangers. Small dogs and those with short or sparse hair can benefit from sweaters. Even thick-coated outdoor dogs should be brought inside during extreme weather. A doghouse, even if well insulated, is good only to about 5°F (-15°C). Watch for puddles of antifreeze under cars.

If your dog has snowball problems or comes in contact with chemicals on sidewalks, consider boots. These are readily available at pet-supply stores and over the Internet.