Just something that has had me wondering for a while. I have a dog that is currently sporting a pretty serious winter coat. Even though temperatures are mild/warm here in Texas this time of year she hasn’t started shedding it yet. That won’t happen for another month or two.
So what is it that triggers a dog growing a winter coat, and later to shed it? It doesn’t seem to be just temperature. My dog is an indoor dog so temperature is stable.
And what if I took my dog to Australia during the Australian summer? Will she immediately start shedding the winter coat? Or is there a delay? Or will she have a winter coat during the Aussie summer the rest of her life?
I don’t know about dogs and coat growth/shedding per se, but lots of organisms seasonal behaviors or physiological changes are prompted by changes in sunlight… usually duration but perhaps intensity as well.
The days always get shorter in fall and longer in spring quite predictably and regularly (and so on for other seasons), but the temperature change fluctuates far more.
In horses, it’s the length of sunlight that triggers the hair shedding (and also mares coming into heat). And not just sunlight, but any bright light. So when an owner wants to have a mare bred earlier, they will install automated lights in her stall, so that she sees light for more hours per day.
Note that it isn’t just normal indoor room lighting – it has to be high lumens light, like sunlight.
It’s the length of daylight. If you keep a dog outside it will shed twice a year (fall and spring) and grow in a winter or summer coat, thickness determined by genetics. Nothing to do with temperature. However, a lot of dogs who live in houses get confused by the constant light and have odd shedding cycles or just shed all year round.
I used to live around horses. I took a clue from them, and began growing my own hair longer in the fall, the better to keep the back of my neck warm all winter, and getting it cut shorter in the spring.
