Jackson Galaxy provides advice on when to euthanize your cat
Jackson’s approach to the difficult decision as to when to euthanise your cat is spiritual. Provided the cat’s guardian is in the right place psychologically, her cat will tell her when it is time.

My cat shortly before I said goodbye
I am using my own words and interpretation but have provided some quotes from his book Total Cat Mojo (quite a complicated and in depth book which surprised me). I felt I had to, to ensure I passed on the flavour of his advice and to make sure the article is accurate.
You have to be objective in the decision making. You have to get rid of the white noise of your own emotions because the decision is about what is right for your cat.
If you hide away from this difficult decision you are liable to keep putting off the moment which can mean unnecessary pain for your cat.
Jackson relies on the phrase:
“Never on their worst day.”
..as a guide. I think he means that the focus for the decision is all on your cat. He keeps the phrase in his mind which brings him back to the moment,
“It’s not about me…It’s not about my pain and suffering..It’s not about how I will fall apart in the days and weeks after losing my best friend..”
Also the phrase means that on the day,
“I want their last memories of this particular time around to be of love and light, not pain and suffering.”
Jackson believes that we are transient as spirits and our time on earth, including animals, is:
“…a pit stop in physical form. I also believe that, unless they feel a bit of emotional detachment on your part when tuning into this sacred bond, they won’t feel ‘permission’ to make that transition [into the spirit world].
The background your mental state will be the declining health of your cat. It will probably be a terminal illness or if you are lucky just old age and a noticeable decline in health which may speed up.
He then says that your cat will tell you when it is time. This is quite a metaphysical concept but I believe that he is correct.
I can remember one day looking into the eyes of my cat, she looked at me as if to say that it is time. I felt that strongly and clearly. It was a whole bundle of factors which came together and coalesced. And she made the final decision for me. By then I had got rid of my emotions and fears and as Jackson says, I was firmly focused on my cat.
He says that if you are armed with what he calls the ‘toolbox’ of equipment to deal with all aspects of cat guardianship and if you adhere to the pointers mentioned above, you’ll know when to say goodbye.
And the cat guardian should be there at the final moment; strong and loving, no tears in front of your cat at that moment. The crying should happen in another room together with any other human behaviour which does not serve your cat at that moment. It is tough advice.
When it is all done arrange an individual cremation and watch it happen to be sure that you have your cat’s ashes. More tough stuff to contend with.