My cat has a golf ball lump behind his ear after being outside. What's wrong?

That looks like it may be a hematoma or a wound that has become infected (very common in outdoor cats). Unfortunately, it needs to be seen by a vet in person so it can be clipped away and the area cleaned/antibiotics given as needed. If you are unable to catch him and bring him in yourself, you may see if your local humane society or animal control can come out to humanely trap him so he can be brought in fore care.

Hi there and thank you for using Petco Pet Education Center, formerly Petcoach to address your concern. Judging from your description and the fact that she is an outdoor cat, I would suspect what you are seeing is an abscess. I would recommend getting her to a vet if possible to have the lump examined so that the most appropriate diagnostic and treatment recommendations can be made. If you know who the owners are, I would try to discuss this with them before taking their cat to the vet for treatment. I hope this helps! Please let me know if you have any other questions or concerns and I would be more than happy to help you further.

Oreo could have a bite wound and associated abscesses causing the swelling, or have ear mite infestations and be working on aural hematomas. Aural hematomas are fluid pockets in between the ear cartilages and are very painful. When cats have ear issues they often scratch and shake their heads because it makes them itchy and painful. Oreo needs to see a vet to get her on the proper medications to make her feel better. She may need to be on a steroid like prednisolone, antibiotics, and anti-parasitic medication for ear mites, if that is going on.

This lump needs to be checked and analysed as there are many conditions and types of tumors that could look like that. take Snowball to the vet, they will perform a fine needle aspiration on the growth and send it to the lab for analysis. when the result comes, the vet will advise what needs to be done according to the diagnosis.

Hi, thanks for using Petco Pet Education Center, formerly Petcoach! Poor Tummy! Possible causes for a lump are: an abscess, a skin mass, or an internal mass in his belly. If Tummy has lost weight or is having any other change either behaviorally or appetite wise I recommend having him evaluated by your Vet. If the mass and in the skin (not the belly), is soft it is likely an abscess or a cyst. Sine this is a new finding I recommend having him seen by your Vet to be safe. I hope this helps and feel free to post a picture if you think that would help us better. Have a great day!

This large lump needs to be checked and analysed as there are many conditions and types of tumors that could look like that. take Bubble to the vet, they will perform a fine needle aspiration on the growth and send it to the lab for analysis. when the result comes, the vet will advise what needs to be done according to the diagnosis.

This is probably a cat bite abscess caused by Fluffy fighting with another cat. It will need lancing and flushing, and antibiotics and pain medicine. If you are thinking of adopting Fluffy, you should also have him tested for FeLV and FIV which are viruses often transmitted though bites. There may be local cat rescue groups who may be able to help catch him and take him to a vet for care.