My chihuahua as a stuvic stone and is one a tin food diet from the vets occasionally perhaps once a week there is a show of pale pinkish colour blood in his urine is this normal or isn't the food dissolving the stone the dog will have been on the food for 3 weeks on Wednesday but for the first few days wouldn't eat the food but being hungry I suppose it tastes better now thank how long does it usually take for a stone to dissolve