mass on liver 14yr old dog

[budgrrl]

my Kiila has been quite sick over the last week.
tuesday she was perfectly fine. wednesday hubby came home and discover she had vomited quite a few times.
we took her to the vet friday because as of wednesday morning, she refused to eat and had not stopped throwing up.
friday the vet said it could be a number of things - she had thrown up part of a toy, so he thought blockage was likely. he also stated it could be virus, organ issues, etc. due to her age, he first suggested the non-invasive approach and gave us sulcrate, some prescription food, as well as advised to add electrolytes to her water. he advised if by sunday there was no improvement, to bring her back.
we brought her back sunday morning for blood work, urine test, X-rays. they did not see a blockage. they advised her white and red blood count was off, as well as 1 liver test was high, and the other extremely high. the xray also showed a mass on her liver.
she stayed overnight on antinausea meds as well as iv. i brought her home yesterday and was shown how to force feed her as she was still refusing food. she was also prescribed mirtazapine 7.5mg a day as an appetite stimulant and also cerenia 36mg once a day for anti nausea.
she is scheduled for an ultrasound tomorrow at noon.

i have a million questions and know from past experience, this site is full of knowledgable people!

- how long does it take for appetite stimulants to work?
- does a 'mass on her liver' likely mean the c-word?
- if her liver isnt functioning as it should, will anesthetic be a huge risk to her? (with poor liver function as well as her age in general)
- what is prognosis with or without surgery?

they had suggested surgery even if the US doesnt find anything, but i do not want to put her through surgery just to take a looksee - that is too risky and too hard on her.

i am having such a hard time coming to terms with this as like i said, tuesday she was her usual self, then boom, wednesday we have a very sick girl on our hands.

if anyone has any insight, advice, anything at all to offer, please, please share.

thanking you in advance!
lorelei