Hello & welcome, I am Dr. B, a licensed veterinarian and I would like to help you today. I do apologize that your question was not answered before. Different experts come online at various times; I just came online, read about your wee one’s situation, and wanted to help.
Again I do apologize that my colleagues could not aid you sooner, but wanted to touch base with you.
With regards ***** ***** question, if there is a mass in the abdomen that the vet is sure isn't a gut blockage (less likely at her age) or stool in the GI, then it is highly likely to be a tumor. There are very few things that can appear in the abdomen and feel like a mass (especially as an enlarged normal organ would just feel bigger not mass like). Enlarged lymph nodes certainly can and this is why your vet is suspicious of lymphoma. That said, we can see masses associated directly with other organs (liver, stomach, etc) and those too can feel as you have described. So, those would be our main concerns here given what they have felt and her age. And while an ultrasound will tells us where the mass is coming from and a needle aspiration will give us an ideal if it is cancerous; you thoughts about palliation are reasonable. Especially if chemo (the treatment for lymphoma) isn't an option. So, in this case, we need to weight the benefits and risks. For a scan and needle aspirate, the risks are low but if we are just going to treat conservatively with the aim of keeping her comfortable, then these aren't wholly necessary. You could still have a scan (which is very non-invasive) just so you know where this is arising from and thus what it is likely to be; but you could decline an aspirate with a view to just keeping her on steroids/pain relief if needed to reduce its size and try to keep her comfortable for as long as we can do so.
I aim to provide the best care for you just as I do for my own clients & their pets. If you have any other questions, please ask – I’m happy to help but please take the time rate me with the **STARS** (or leave a written rating of 1-5; 5 being great) afterwards as otherwise the site does not credit me for helping you. There is no extra fee for this (its included in your question fee). Once you rate, your question will not close & you can still ask follow-up questions. Thank you for helping me to keep helping everyone here. : )**