Hello, thanks for your question today! I am Dr. Drew, and I am a licensed veterinarian. I'll be happy to help you in any way I can.
A senior-aged cat who is eating well, and seems hungry, but is losing weight, may have a condition where the metabolism is too fast,
caused by an over-active thyroid gland.
This is known as Hyperthyroidism.
It is common in cats,
and it is relatively simple to diagnose and to treat.
Blood tests are needed for diagnosis,
treatment is one of 3 options:
A special prescription diet (very strict),
or a one-time injection of a radioactive iodine, which destroys the excessive thyroid tissue.
Your veterinarian can perform the blood test to diagnose this issue.