Euthanasia for cats, or other companion animals, is a complex and sensitive topic. I am not a veterinary professional, but my views are informed by my experience as a cat owner, and as a former medical doctor who has worked with many dying humans in hospices and cancer wards.
In an ideal world, I believe that euthanasia should be reserved for animals who have incurable conditions and whose symptoms cannot be adequately controlled. In the real world the wishes and practical circumstances of the owners play a large part in the decision, but these are not always aligned with the best interests of the animals themselves.
I suspect that many animals get euthanised too soon, or when they do not need to be. The owners may not have the motivation or practical resources to continue caring for them when they are sick, or they may find the situation so upsetting that they just want it brought to an end. Sadly, some animals who get euthanised are not sick at all, only unwanted or homeless.
Conversely, other animals are left to suffer too long because their owners have moral or religious objections to euthanasia, or cannot face the prospect of witnessing the process or feeling responsible for killing their beloved pets.
I hope I did not delay too long before making the big decision for Felix. I had accepted that he was not going to recover from his illness, whatever the diagnosis, but did not consider that in itself an adequate reason to euthanise him. Two other cats of ours had been euthanised in the past, and although I have no doubt it was the right decision in both their cases, I found it an agonising experience. I hoped that Felix would die naturally like another of our cats, Floella, who slowly and peacefully faded away at the age of almost nineteen years.
It did not work out quite like that. One morning, after Felix had been going quietly downhill for a week or so without apparently suffering, he began to show signs of distress. I felt it would be cruel to let this situation continue and arranged for him to be euthanised the next day, when the vet would be available for a home visit, for Felix hated being taken to the surgery. Meanwhile I had a sedative analgesic prescribed for him. Soon after I gave him the first dose he fell asleep, and died a few hours later. I was very thankful that he did not need to be formally euthanised. If the medication which was needed to relieve his pain and distress hastened his death a little, I consider that a blessing.
Another aspect of this topic to consider is the impact of euthanasia upon the staff who carry it out. They have to develop a certain emotional detachment in order to be able to do it at all, but it must still affect them at some level. I suspect this is one of the reasons why the suicide rate for veterinary surgeons is so high compared with that of the general population, and also higher than that of other healthcare professionals.
Only a minority of human patients with terminal illness say they would want euthanasia provided that their symptoms can be controlled, and with good palliative care they usually can be. Maybe the same is true for animals.