I'd euthanize as soon as the illness caused untreatable/expensive suffering or loss of quality of life for the animal. The only way I'd just let the animal die was if it was due to old age or sudden catastrophic illness or accident (and even then, given the time, I'd help it die peacefully).

Spending large amounts of money to keep an animal alive for only a few extra weeks/months seems odd to me, since at that point there is little chance of the animal enjoying this extended period of life, and I'd rather have the last moments and memories of a pet be of it happy and relatively vibrant, rather than a miserable, suffering cause of stress and worry.

(expensive to treat)

When my cat was diagnosed with cancer a year ago, I asked the vet if she was in any unremitting pain. At that point she could hardly move and picking her up obviously hurt (it seemed like rather sudden onset - she stopped moving in the span of about a week but the vet said she'd probably been in pain for a while). He said she was probably in a constant state of pain that wasn't going to improve. At that point, I had her put to sleep, right then, no waiting. Just long enough for me to say goodbye, and I held her as the vet did it.

Five years ago my uncle euthanized his cat. He took a long time to get to the point where he felt that was necessary. The cat was alive for about a year before he was put down, but obviously was failing: blind, deaf, and incontinent because for the most part he wasn't aware of his surroundings. I visited my uncle about 6 months before the cat died and I asked why not put him down - my uncle said it wasn't time yet.

The answer is very individual, I think, and never easy. I miss my cat a lot. My uncle misses his cat a lot. Both of us knew when it was right to act, and we did. I don't regret my decision one bit, because I know that if I were in that position, I'd want relief from the pain.

My thoughts are with your friend.

This is a hard question to answer. I've been through this with three cats, and helped a friend with her dog. This might sound like a non-answer, but the day comes when you really DO know it's time.

Two of my cats had hyperthyroidism, which, although treatable over a long time with tablets, eventually can cause heart failure. My other cat had cancer.

At the end of their lives, the last month or so, I could see in all three a deterioration in their health - eating less, listless, sleeping more - but nevertheless with some appetite and tempted to eat by their favourite food, able to use a litter box, a desire to go out into the sunshine and, most importantly, a responsiveness, and purring, for example to a favourite tickle (head massage for Bella, chin stroke for Ricky, cheek rub for Barry).

Then, one day, it was almost as if a switch had been thrown and the 'light' inside was dimming rapidly. The appetite went, and the cat wouldn't, or couldn't respond to me. The purr had gone. Then I knew it was time.

And the weird, weird thing is, that with each cat, as I was being driven down to the vet with the cat wrapped in a towel (by this time they were all too weak to both with the carrier), at the SAME POINT in the journey, each cat let out this weird yowl that I'd never heard before, and rested his or her head on my shoulder. It was almost as if the cat was saying 'ok, I'm ready to go'. That might sound like the ramblings of a crazy cat woman, but for all three cats to do this, well, I can't explain it but I like to interpret it as a sign that I was being told I was doing the right thing.

If your friend's pet isn't in any apparent or unmanageable pain, is eating and (more importantly) drinking, is peeing and pooping and is responsive, I would say give it as long as possible.

Animals tend to go downhill pretty rapidly, over the space of a few hours, certainly not days or weeks, so there will be very clear signs when the time comes that a decision has to be made.

Of course I am assuming we are talking about a mammal here, and not a snake or something where I would have no clue if it was giving off signals that it was desperately ill.

I lost a cat to cancer, as well- a tumor in a leg muscle. She lived over a year from the time it was diagnosed, and was perfectly happy for most of that. She let us know when the time had come, because she started licking the lump on her leg, indicating discomfort, and stopped eating, all in the space of a week. So, we felt like she had decided for us.

If you're in a situation where you know the animal is suffering, I feel like it's only humane to help them end it. It's a hard, horrible decision to have to make, but I think it's one we owe the animals we love. Waiting to let them die slowly is just not right, IMO.

I knew somebody would be able to express it better than I could, and essexjan just did.

Sorry, I should have said CAT, not PET.

I appreciate your answers, I know this is a tough subject to approach.

I think you really do know; it's difficult to explain, but you can tell when the moment has come. I agonized over my dog Toby - he was 14 and had arthritis and I knew he was in pain but I couldn't bring myself to do it even though he was getting older and older and more confused. Then one morning he woke up under my bed and I could tell that he didn't know where he was and he couldn't figure out how to get out and he started crying. It was absolutely awful and I knew right then that it was the end. I took him to the vet that morning and sat with him through the whole thing and cried for hours and hours. When my cat Fred had a sudden heart attack and we took him to the emergency vet at 3:00 am we knew he was in terrible pain - he was howling in pain - and the vet said that the chances of his recovery were so slim and yet it might take him hours to die naturally, well. That was quite clear.

So I think that your friends, as difficult as this sometimes is, must trust themselves that they will, actually know when the moment is right. They'll just know. And it will be difficult and terrible and sad but it's the right decision to make.

My childhood cat had diabetes and cataracts. He couldn't see very well, and he was an "outside only" cat due to his loss of bladder control. However, he lived a long, happy, and pain-free life until the last week. He became listless and stopped eating - my parents were going through this very same agonizing decision when they found he had died.

In other words, we let our cat live with some physical deterioration, since it was obvious that he was still pain-free and happy to be out in the sunshine or curled up under the dryer.

With rabbits, you're often faced with the realities of having a prey animal for a pet. This means they hide illness and infirmity until it's pretty much too late to do anything. When our previous two, who were both about 12 years old, lost the use of their hind legs, we knew it was time. The vet told us we could try some experimental anti-inflammatory injections, but they were painful and not likely to help. The decision still wasn't easy.

We swore that we'd never get another rabbit. But a friend knew of one that was headed to the shelter because a new baby was allergic. Now we have Hoover. When his time comes, I'm sure we'll make that same pledge again.

This is a tough call, always, no matter how ready to go the cat appears, no matter your own feelings, no matter the advice from the vet, it's heavy. Sometimes it can just help having something clear to reference to help you make the decision, and with that in mind this page and this page have some sound and heartfelt advice which may help your friend out at this tough time.

Best wishes to your friend and the puss.

The best I've ever heard this described is that your pet will tell you when it's time. Whether you're ready to listen and let go - that's another question. Best wishes for your friend.

I sincerely thank you all for warm thoughts and well wishes. She is lurking the thread (non-mechazen), and she thanks you all from the bottom of her heart to the tip of her cat's tail.

My cat had a stroke or some other equally traumatic event - she started hiding and stopped eating. The hiding and not eating were the things that made me make the appointment. (She was 19 years old and had had great health up till then.)

I have seen a lot of this both ways, and as my cat is getting older and starting to slow down, it is something I will have to deal with in the next 1-3 years.

The example I will use is my cousin. She had a toy poodle that was blind, deaf, and could not smell and had to be led to his food, not surprisingly, with the lack of senses, he was confused all the time. That is clearly letting it go too long. The pet had let her know, she was unwilling to deal with it.

If we take an animal, domesticate it, dictate its life by deciding where it lives, what it eats, and even its reproductive future, we had damn well better be able to accept the responsibility of when to end its life. The question is, do we prolong the life of the animal for the animal and its enjoyment of life, or because we don't have the guts to put it down?

In my experience, you just know.

In my experience you just know; but in my friends' experience, she held on too long and put her cat through too much. Case in point: She had had a cat for roughly 18 years. Said cat developed an abcess under her chin that leaked fluid nearly continuously. At the same time, they found a large tumor. This poor cat spent nearly all her time curled up in a cat bed. She didn't groom herself, she barely ate, she lost weight rapidly. My friend had the vet install a "radioactive seed" in the cat's tumor to kill the tumor from the inside. I saw that poor thing - she looked like she had died weeks before but no one told her. Her release finally came when my friend left for her honeymoon and gave care of the cat to her best friend. The cat wouldn't eat at all, and he had her put to sleep. I just can't see putting an animal through all that just to keep it around a bit longer.
I had a dog who went blind, deaf, and developed severe arthritis in the space of a year. When he could no longer get up to go outside without crying, I took him in to have him put to sleep too. I cried for days. It's been 13 years, and I still miss him.
I lost a cat nearly three years ago. She was like a kitten until the day she died. We woke up in the morning to find she had congestive heart failure. I rushed her to the vet, but she was so far gone she couldn't recover, and we helped her along. I miss her too.
The most important thing is the best interests of the pet. Continous pain and a poor quality of life are the biggest indicators for decisions. I wish your friend all the best, because even though it's best for the cat, it's still extremely hard on the cat's human.

I've been on both sides of the table in this one, all too many times. In my experiences as a lifelong pet owner and a former vet tech, I believe that it's always better to let them go a tiny bit too soon than too late, it's the ones you wait too long for that haunt you. Once you start finding yourself wondering if today's the day, you can do it at any time with a pretty clear conscience, I think.

My own personal rule is when the bad days outnumber the good, when the pet can no longer do the things which bring it pleasure (which is very individual, but you must be honest about assessing this), or when there is unrelieveable pain, then it's time. You do "just know" much of the time, but not always. Please try to keep in mind that animals only really seem to care about quality of life, not about quantity, and the tragedy is in leaving an animal to suffer when you have the means to do otherwise.

I'm sorry your friend is going through this, it's hard, but it's often the only thing we can do for our furry friends, and at least we can do this for them.

My first dog was put to sleep when she could no longer walk--she'd had a stroke eight months earlier.
My second dog died at the emergency vet's--several hours after chupahija ranted that I had to go to a family dinner--even though I also had a sinus infection.
She let her second to last dog lie on the cement patio for several days in his own shit before taking him to the vet when he could no longer walk. "Oh the poor dog had no dignity", when she fucking denied him that.