Would keeping the flat collar 24/7 on my "almost 3 months" German Shepherd puppies make the hair around their neck fall out or harm their skin??
It depends... first off, I wouldn't leave the collars on for 24/7
(especially not for young GROWING puppies) because, if they aren't
monitored carefully, after a while the collar can get too tight (as
the puppy grows) and it can start to get embedded into the skin!
When my dogs are in the house I take their collars off because it
is safer (when they are playing, etc) so the collars don't get
caught on something - the same goes for if I leave my dogs at home
unattended (or if you use a kennel / crate). There are too many
horror stories about dogs being accidentally hung / strangled when
their collars got caught.
However, if the collar is comfortably snug (slightly loose) then it is ok to leave it on for most of the day without worrying that the hair will fall out. IF the collar was too tight and the dogs were chained up, for instance, then the hair would be more likely to fall out because they'd be constantly pulling / rubbing, which would create friction on the fur.
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