Durable Remission is when there are no measurable signs of cancer in the body for a “durable” length of time. What’s durable, for some illnesses, fourteen days without signs of cancer, and for others twenty-one days. If your dog is in durable remission, that does not mean she will never relapse (show signs of cancer) again. It means that for now, she is in remission and is holding steady. When a dog doesn’t achieve a durable remission, the treatment may not be effective for that dog’s cancer.