There is a semi-feral cat that lives, by all indications happily, in my yard. I feed her mainly dry food and sometimes treats. Today I went to get the food bowl and there was blood on the rim and then when I gave her a few treats she likes (crunchy) she meow-cried and didn't want to eat them at first. But then did. Pretty obvious what happened.
For something like this, let's just treat it like going to the vet is not an option at all. She's not approachable enough to be crated. And I can't afford a kitty dentist regardless.
This cat survived outdoors in subzero (subzero in °F, which means below -18 °C) temperatures a few years back, as well as surviving a 90 °F (32 °C) heat wave this summer which another "cat from my yard" apparently did not, because I have not seen him since. She's way tougher than you, me, or anyone else who is going to see this ;) and she probably is not out there going "I wish he would give me an aspirin". But still, I want to help her if I can.
As for food, I had some wet food which I gave her and she was able to eat, but it's going to be impractical not to mention slightly uneconomical to feed her wet all the time. For tonight I ground up some dry food in the blender. We'll see what's left in the morning.
Did a quick readup on dosing cats with aspirin and it sounds "safe" as long as you do the math correctly. I'd say she's 10-15lbs, maybe a bit more, but to be on the safe side let's say 10lbs which = 4.5kg = 45mg dose of aspirin (10mg per 1kg of body weight) every 48 hours should be safe, i.e. half a baby aspirin. This is in-line with what I have seen on some other forums, as well as what a vet told me a long time ago when I took one of my cats (RIP) to them for ... I don't remember what ... but I can still hear those words "you can give her half a baby aspirin, but the trick is getting her to take it" ;) Also, she's ear-tipped (though not by me) and so I presume she is not and will not become pregnant.
As for how I would dose her: I'd grind it up in the wet food. Note that a vet will advise you against this for important meds as there is no certainty that the cat will eat it all, thus may not get their meds, but this cat will eat it all, trust me. :)
I am also clear that aspirin is aspirin (acetylsalicylic acid), and not Tylenol, acetaminophen, ibuprofen, etc.; all those things are dangerous for cats and I'm not going to give her any of those.
I am an animal lover but also a "let nature take its course" kind of person (by the way, an ex-roommate started feeding this cat against my strong advice, and now look who's left with the situation) but ... dang ... it's going to be a cold winter and she needs to eat, not to mention do other cat things to stay warm and I don't want this complicating things for her. (She has decent shelter and is super fluffy and in general she seems fine in the cold, but still.)
Bottom line: I'm going to make this decision and you are not responsible, but any advice/insight from anyone who has good experience in a similar situation would be helpful. Thank you.
P.S. Stack Exchange is prompting me with "similar" questions and it's nice to see others are out there taking care of ferals and semis-. <3 kitties.