Someone was concerned about their cat who was 5 or 6 years old and lost 2 lbs in three weeks. The other symptoms were he was drinking a lot, he was trying to eat but couldn’t get very much down. He wasn’t moving much. They took him to vet and was awaiting bloodwork.
I told them that it was good that they had taken their cat to the vet’s to have bloodwork done as this would most likely rule out kidney disease, diabetes, or liver disease. Cats are prone to kidney disease. I’m sure they could also develop an intestinal blockage maybe due to a fur ball.
I once had an older cat that developed kidney disease and didn’t want to eat much but he was older when he developed it. I had to feed him a special diet which he hated. I made sure his water was fresh every day and gave him lots of loving.
He eventually had to be put down because of his kidney disease and it was one of the hardest days of my life.