I’ve recently spent some time within some of the top oncology (cancer) referral vets within the UK and been in consults with people who have to be told that the biopsy says it is cancer. One of the most difficult questions that pet guardians will then ask is how long a loved pet has left – this is an awful question that has to be answered so carefully because we just do not know.
We try to use evidence based studies looking at different treatments when discussing the options – however these studies over use statistics to give averages. Unfortunately within veterinary research many studies only have a small amount of patients which is caused by the way the veterinary industry works. This means that when looking at a study with average life duration from start of treatment of 3 months that some dogs may have died at 1 week whilst others lived until 9 months or a year. I am personally starting to believe that statistics should be limited to use only in sample sizes over a defined minimum limit to improve reliability (I wrote about statistics here).
However what is missing from most of these studies is perhaps even more important and is the second question that most pet guardians ask. That is what the quality of life is like. It is something that may sound strange however it is much easier to quantify quantity of life (i.e. days) than it is quality (i.e. happiness) of a pet.
This is still something in it’s infancy within veterinary medicine – with humans we can explain that it will hurt now but it will mean that they are good later. The first time I saw this discussed was within surgery decision making in the AWSELVA journal in 2014 (J. Yeates & S. Corr) to evaluate treatment options based on the amount of painful time vs the amount of pain free time.
This is something that is difficult though as we need to define how we recognise the quality of life. For example if we consider movement as an indicator as recently there have been studies using accelerometers (step counters) to monitor the activity of an animal. A study just published used this to measure the physical activity in dogs receiving chemotherapy as an oncology treatment which may be acceptable.
However if we look at dogs with neurological problems that may have abnormal circling or pedalling movements then activity may not be the best quality of life. Here is where other techniques may come into play with things such as a seizure diary being kept to record frequency and duration of seizures to allow comparison of good time vs bad time.
Hopefully soon we will have better measures for the quality of life – and be able to apply these when making decisions that may impact animal welfare.