It is important to thoroughly discuss these concerns with your veterinarian so that together you can work towards a common goal. Because we cannot ask our pets how they feel, we have to rely on their behavior and from this infer quality of life. Measurements of quality of life have been developed by veterinary oncologists. It considers 5 factors that affect an animal's ability to carry on its normal activities. Not only is this assessment a good indicator of how your pet feels overall, it also provides useful medical information.
Quality of life means different things to different people.
For some people it is their pet's chasing a ball or greeting them at the door. For others, it is simply knowing that pets are eating and sleeping through relaxing, painless days. One of the difficulties in evaluating your pet's quality of life is that it can decline gradually. For someone living with a pet there may be no obvious daily changes, while to someone who only sees your pet every few weeks or months there could be dramatic change. For example, it might be a pet's lack of interest in eating or going on walks.