Perhaps it brings comfort to dogs too! Might be useful to calm nervous dogs – as long as they can’t swallow bits.
I have a terrier that does the same thing; he looks really funny.
Our dog likes to carry two balls in his mouth, as soon as he comes through the front door he rushes around the house until he finds them. He also looks very funny, like a gummy old man.
Southwick Country Park Nature Reserve 
Perhaps it brings comfort to dogs too! Might be useful to calm nervous dogs – as long as they can’t swallow bits.
I have a terrier that does the same thing; he looks really funny.
Our dog likes to carry two balls in his mouth, as soon as he comes through the front door he rushes around the house until he finds them. He also looks very funny, like a gummy old man.