My dog has a knot on his side. What could it be and what to do?

Thanks for using Petco Pet Education Center, formerly Petcoach! This could be a benign or malignant growth. There is no way of knowing what it is just based on its appearance. 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 night!

That could be a little cyst or tumor or a black head (pimple) If your dog keeps scratching it, you should have it examined by a vet who can evacuate it in such a manner that it does not get infected, If it is a little tumor that keeps bothering him, it will be better to have it removed.

This lump on Oliver could be a cyst, an abscess, a lipoma (benign fatty tumor), or another type of benign tumor. In a dog his age, it would be rare for it to be malignant. Regardless, this is something that should be checked out 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 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'd make an appointment with the vet for him on Monday to have this lump examined and diagnosed so it can be treated as needed. Best of luck, I hope this helps!

That looks ulcerated. This could be a benign lump, but it could be malignant. 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. Give Buddy's vet a call to make him an appointment, and put an Ecollar on him to keep him from licking it. You can get one from a pet store. Best of luck.

I do always get concerned about lumps especially when they are growing. A lump can range from fat to cyst to even cancer. I would recommend taking Murphy to a vet to have an aspirate done. This is where the doctor can look at cells under the microscope to help determine the cause and if they need surgical removal. I hope this helps

If you're concerned enough about it the best course of action is to have it checked out/tested to see if it's a cyst or something else, especially if it is bothersome or growing in size. Unfortunately, without testing the site, it would be impossible to tell what it is just from looking at it. If you're having trouble affording care, this site may help give you some options to make it more affordable: https://www.humanesociety.org/resources/having-trouble-affording-veterinary-care

This could be a skin infection caused by a fungus or bacteria or and old injury or bite and in worst case scenario it could be a tumor. Please have this examined by your veterinarian. If he suspects a tumor, he will likely want to remove it and send it in to determine whether it is malignant and your dog needs further treatment. If it is an infection your dog may need an antifungal or antibiotic ointment. It may just be a scab from an old wound and might need no treatment. Your vet will be able to determine that with a hands-on exam.