Island of Terror.
It may have been a 'made for tv' film. I watched it on tv between 1970 and 1976. It was set in a village, the creatures looked like a tubby sausage dog, but dod not have legs, or a head as such, they had very long necks. If they grabbed a human they were able to dissolve their bones (or something similar). Each one became two every 4 hours. The villagers ended up in the village hall, they managed to destroy the creatures but it was a close thing, and i do not remember how they did it