Antique 'St. Bernard' Brandy Barrel

I've recently acquired this small old barrel, complete with leather carrying strap, which was advertised as an 'antique St. Bernard barrel' - although the story of mountain rescue dogs carrying brandy in barrels around their necks has been debunked as a myth.

The barrel appears to be well made, probably of oak, and not simply a cheap souvenir. There are thick clear glass panels at either end. The leather strap appears to be genuinely old and has seen better days.
From what I can see of the inside of the barrel, it would appear that no liquids were stored in this particular vessel.
It occurred to me that barrels like this were perhaps made for -and purchased by- owners of St Bernard dogs, who wanted their pets to project the traditional image associated with their breed. A fashion accessory, if you like.

I've checked on the net and found two similar items, one described as dating from c.1900 and the other described merely as 'vintage' - but little else .

I would sincerely appreciate any further information about this item, such as origin, age and intended use.

Many thanks !!!!!!!!!!!!!!

 

What size is it? Your photos make it seem on the small side.

 

Size - About 10 inches across. Sides approx 4 inches diameter.