My dog has a sudden, painless lump on its rib cage. What could it be?

Thanks for using Petco Pet Education Center, formerly Petcoach! This could be a benign or malignant growth. This is often differentiated by a test called a fine needle aspirate (FNA) which is a pain free, inexpensive and easy procedure which in most cases will help reach a diagnosis. Sometimes a biopsy is needed for a definitive diagnosis. I recommend that you have him evaluated by your veterinarian for further assessment and treatment. I am really hoping for something benign. Good luck and have a good day!

You are correct with all of your possible causes. Bug bite, benign growths, and even tumor are all possibilities. If it does not resolve within a few days, or if it is getting any larger then I would highly encourage you to have him evaluated by your veterinarian soon. A needle aspirate may be done to help determine the diagnosis and best treatment plan. Best of luck and thank you for using Pet Coach.

This could be a cyst or a benign tumor. Any suspicious lumps 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 lump to get a sample of its cells, and examines the cells on a slide under a microscope. It's usually painless to the animal, and relatively quick to perform. Once the cause of the lump is diagnosed, the vet can discuss treatment options if needed. I would give Lily's vet a call in the morning to make her an appointment. Best of luck.

Based on these photos, it does appear there is a little dot at the center of the lump, and you could be correct that this is some sort of insect bite. I would watch this lump over the next week or two. As long as it is slowly getting smaller, then I would not be concerned, however, if there is no change over the next couple of weeks, or it is getting bigger, firm, red, or painful, then seek veterinary attention. Thanks for using Petco Pet Education Center, formerly Petcoach.

Thanks for using Petco Pet Education Center, formerly Petcoach! I'm sorry to hear Abby may have a swelling on her side. Swelling under the skin in dogs can be due to a variety of reasons, including soft tissue injury, a growth, or a cyst or abscess, among others. If this is a new development for her, I would recommend it be evaluated by a veterinarian to determine what it may be, and if anything needs to be done for it. Good luck!

This kind of lump/growth needs to be ideally assessed by your veterinarian to have a definitive and specific answer. Usually there are two ways your vet can do that a part from examining it directly during physical examination. A biopsy can be taken under local or general anesthetic, otherwise a smaller sample through a fine needle can be aspirated (this technique is called FNA= fine needle aspiration). Differentials include skin cysts, infections, benign (very common hystiocytoma for example) or more sinister type of tumors (unlikely given the age). Hope this answer was helpful, but please do not hesitate to contact us again on the forum or by requesting a consultation if you have any more questions or to discuss it any further. If this answer was helpful please let us know, this will be used to improve our service!

Has he been licking at it? Can you identify a wound on it? It may be an abscess (localized infection) under the skin, as thise can show up very quickly. You can shave the hair over the top and clean it with dilute Betadine (available at any pharmacy - use water to dilute it so it looks like tea). Put an ecollar (cone) on him to prevent him from biting or chewing on it, and make an appointment with your vet as soon as you can—but it’s not something you need to see an emergency vet for as long as it’s not seeming painful and he’s eating and acting normally. Other possible causes would be some type of tumor (though less likely with his age), or a fluid accumulation called a seroma. Your vet may Do a fine needle aspirate (poke the bump with a needle and then look at cells under the microscope) to see what it is and then know how best to treat it. Thank you for asking Petco Pet Education Center, formerly Petcoach!