there aren't any...every animal is so very different as is every human caring for them. but here is my take on this and how we get thru.
first off, we don't go looking for what we can't fix, you can fix thyroid problems, you can fix diabetes, you can fix infections and broken bones but you cannot fix end stage cancers, or end stage cardiac, kidney or liver disease...for these end of life illnesses we look at managing symptoms that cause them problems in their daily life.
basically as soon as an animal hits extreme age, we stop looking, we start making some really good educated guesses based on symptoms, examinations and maybe baseline bloodwork or xrays at the most.. looking hurts them, looking upsets them, looking scares them and we want to avoid all of these things for them near the end of their life.
this is not to say that they do not receive medical care but the medical care they receive is geared towards symptom control and maintaining their comfort and enjoyment of life. that is what we focus on.
a very wise woman (my mother) told me there is no such thing as "dying" you are either dead or alive with not all that much in between.
so the last thing we do is pretty much ignore the fact that technically, they are sick. we just enjoy as many swims in the pond, runs in the field, picnics in the back yard, shopping trips to the MP room that we possibly can. this is why saints is not a sad place, it is full of chaos, fun and adventure. our guys are not dead til they die and before that it is about living as much as they want too, in any way that they decide.
best of luck lindsay...it is a rocky up and down rollar coaster ride made easier by keeping the goal in sight.
if you need a post on palliative symptom control (esp. the different types of pain issues and the various drugs/combos that work best for the varying types) and some of the other drugs with multiple uses that are quite handy to know about for different problematic symptoms, let me know cuz i think it is fascinating but it might be boring to others.