The reasons for the redness and swelling around the cat’s nails may be as follows:

It may be due to the cat's exercise Inadvertently inserting a foreign object into the sole of the foot and failing to remove it in time, resulting in redness, swelling and infection in the muscle tissue of the sole of the foot.

It may be due to pathogenic infection, such as fungal infection, bacterial infection, etc., which causes inflammation, redness and swelling of the cat's paws.

It may be due to the decrease in skin resistance caused by long-term moisture, which may lead to bacterial infection.

If you have specific symptoms and problems, please consult a doctor or professional for advice in a timely manner.