Why does my cat have a fluid-filled lump on its arm? What's the treatment?

Since the same lesion repeatedly fills with fluid, I would suspect a cyst of some sort. While this is not an emergent condition, your cat should be examined by a vet within the next week. Your vet will be able to draw a sample of fluid and cells from the lesion that can be evaluated microscopically, as this will help to determine the underlying cause. Until that time, do not express additional fluid because this can open the lesion up to infection.

This bump on Elijah could be a cyst, a benign tumor, from an insect bite, or it could be a malignant tumor. Unfortunately without seeing him in person, I can't say for certain what it is. Any suspicious bumps should be examined by the vet. The vet can perform a test called a fine needle aspirate on it. To do this, the vet sticks a small needle into the bump to get a sample of it's cells, and examines the cells on a slide under a microscope. It's usually painless to the animal, and relatively quick to perform. I would take him into the vet on Monday to have this bump examined and diagnosed so it can be treated as needed. I hope this helps, best of luck!

You didn't include a picture so I cannot say for sure but the most common cause of leaking bumps on a cat would be an abscess, which is a pocket of bacteria, fluid, and inflammatory cells that is often caused by a wound (sometimes from a bite or scratch from another animal). I cannot rule out something like a cyst or a tumor that has grown too large and the skin has gotten stretched and broken open, or even a self inflicted injury from overgrooming, but the most likely answer is that this is an abscess. Pebbles should definitely be seen by her veterinarian, who will probably clean and flush the area and may recommend a culture of the area. They may also prescribe an antibiotic and maybe a pain medication, however in the meantime you can use warm compresses over the area to help it drain and to keep it clean if she allows you to. If you have an e-collar you can place that to prevent her from licking at the area and causing more bacteria (from her mouth) to enter the area. Good luck, I hope I could be helpful!

Hi and thanks for using Petco Pet Education Center, formerly Petcoach! Sorry to see that Chubbs has a skin problem. This could be a small area of bacterial infection or a cyst if it has fluid in it other than pus. This could be associated with one of the many glands in the skin causing a sebaceous cyst. Other causes are a bite from a parasite (flea, tick, mite) or insect (spider/ant) among others. I would warm compress the area if Chubbs will let you to see if you can get it to come to a head and drain. You can also put Neosporin right on the area, it won't harm either if ingested. Continue to monitor the area. If it worsens, spreads, persists, have your vet check it out. They can get a first hand look and advise on how to proceed. I have a feeling just by the picture that this may resolve on it's own with some simple treatment as described. Good luck with Chubbs.

Good question! Given that Lucky seems ok and is hungry with a good temperament, it's fine to wait until Monday. I would gently clean the area with warm water and antiseptic soap, and put an Ecollar on him to keep him from licking at it. You can make one at home, and I will put a link below on how to do that. Keep an eye on the area, and if the discharge increases, he becomes lethargic, and/or his appetite drops, then yes take him into an ER vet. If you would feel better having him seen now instead of waiting, then certainly take him in to the ER clinic now. I'm always an advocate for going with your gut, and having the animal seen sooner rather than later to be safe. Best of luck! https://www.youtube.com/watch?v=8ffR-LzyW1M

HI, thanks for using Petco Pet Education Center, formerly Petcoach! I wonder if Shadow is an outside cat. If he is and the swelling had a sudden onset it could be an abscess from fighting with another cat or animal. The fact you describe it as possibly liquidy could indicate puss. If her cat is older and indoors it could be a cystic mass. I would recommend that she have a Vet take a look at it today before the weekend in case it is an abscess before it possibly breaks open. If it is an abscess the Vet may open it for it to drain and provide antibiotics Good luck!.

I do recommend having it tested. It may just be something as simple as a cyst if it is fluid filled, but without being able to feel the lump it is hard to determine that. If it is a cyst and it does not bother your cat, your veterinarian may be able to drain the cyst although it can easily fill back up.