My 9 year old pug continually get these cysts on both of her paws, they fill with fluid and are very painful, the vets are unable to say what is causing to, and they drain the fluid, it then heals and is fine for about a month or so, before the return. Any advice is welcome. She is a Pug, 9 years old, female, about 5kg, and this is a recurring problem, she has no other health concerns, with the exception of long quicks.

https://imgur.com/a/UVG6PHc