Ddog is 16-18 years old and has lived with us for nearly 15 years. She's getting quite doddery but still enjoys walks and food and cuddles. She was straining for a poo yesterday and I found blood and a swollen anus, so dh took her to the vet. The vet doesn't know exactly what's wrong but has given her antibiotics and painkillers. Has anyone else experienced this? Shed any light?