Updated On September 23rd, 2025
Pet's info: Dog | Mixed Breed | Male | unneutered | 12 years old | 18 lbs
I have a thirteen year old dog that has a large lump on his chest. The vet took some fluid out and was surprised that it was blood. Why? She said it could be operated on but, it could be difficult because of his age and that it was. on his chest. After looking at the fluid, she could not tell us if it was cancer or not. Why? Also, what pain meds are given to dogs that really take the pain away if any? Thank you so much. Linda
3 Answers
Published on June 22nd, 2017
It is not very common to perform an aspirate on a large mass and get blood - clear fluid or just cells would be more common. If there are cancer cells present under the microscope then you have a diagnosis, but sometimes there are no cancer cells from an aspirate even though the mass is cancerous. There are many pain medications for dogs and their effectiveness depends on the condition being treated. Some examples include carprofen, tramadol and gabapentin. Each medication has pros and cons. Talk to your veterinarian if you think Otis is painful or his pain medication isn't helping.
1Pet Parents found this answer helpful
Published on
When there is a lot of blood on a slide it can make it very difficult to identify the cells and tell if they are cancerous or not, simply because of overcrowding of the material being viewed. Also when we take samples of something, we are hoping that we remove the cells of the tumor and not surrounding fluid or blood, so this can often-times yield inconclusive results. The sure way to tell what this particular mass is, is to either debulk it and send off part of the mass for analysis or, if possible, remove it entirely and send off the whole thing. Pain medications for pets are prescribed by your veterinarian and can range anywhere from an opiate (pure pain medication) like Tramadol to an anti-inflammatory such as Rimadyl, Deramaxx or Meloxicam. You will have to consult with your vet to determine which pain medication would be best for Otis. Over the counter pain medications should never be used in pets, for high risk of acute liver and/or kidney failure caused by these medications. I hope that your pet Otis gets this mass resolved soon. Take care.
1Pet Parents found this answer helpful
Published on
Sorry Otis is having this problem. Your vet could submit the fluid to the lab for a cytologic examination to see if a diagnosis can be determined on the aspirate. If not, then a biopsy would need to be done. Surgery on an older dog comes with more risk but, if his bloodwork is normal and he doesn't have other medical issues the risk is low. Pain medications typically used in dogs include Deramaxx, Previcox, Rimadyl, gabapentin, and Tramadol; to name a few. Human OTC pain relievers are not used as they can be toxic to dogs.
1Pet Parents found this answer helpful
Book an appointment with the pros – our expert vets are here to help.