In an otherwise pleasant mid-summer, the persistent presence of low, light grey cloud seemed melancholy, stifling the emotions along with any movement of the leaves on the trees. It was chillier than expected too, making me wish I had put on an extra layer for the early morning dog walk. For a vet, melancholy moments are not uncommon. In the olden days, this was blamed on a disease called Brucellosis, which caused problems for cows, farmers and vets.