The medications are
Frusol for 7 days
Metacam for 7 days
Vetmedine for possibly long term
Metaclopramide for 7 days
Engemycin for 7 days
She weighed 850g when she went into the vets on Sunday, after coming home last night she weighed 722g, I got her up to 733g with syringe feeding last night. This morning she is back down to 722g. I have just syringed her this morning.
Your vet has obviously prescribed you a very carefully considered cocktail of heart drugs, diuretics, gut stimulant, painkiller/anti-inflammatory and infection inhibitor. There is nothing wrong with that.
Has your vet considered fortekor? It is licensed for dogs and cats with congestive heart failure. I am however not knowledgeable enough to know whether it is working for an enlarged heart, only that it is a commonly prescribed heart drug together with vetmedin in guinea pigs with heart disease. Frusol is a diuretic to prevent the build up of fluid in the chest as a result of an inefficiently working heart, and it is very effective.
Please be aware that you measure weight in guinea pigs in a 30-40g wide band when weighing frequently over the course of a day; the daily weight swing between a full and empty bladder/bowel is 30-40g. What you are looking for is whether the weight is staying stable within that band or whether that band is moving upward or downward over the course of several days. Initially your aim is to stabilise the weight as much as possible.
Just keep on syringe feeding, as much as your piggy will willingly take; do not force anything in if she is apathetic and be careful to adjust the quantity of each mouthful according to how strong she is and how well she can swallow to prevent anything going up the nose or into the lungs. The less she will take in one go, the more often through the day (and if necessary night in case of total loss of appetite) you feed. As long as your piggy is still eating on its own, you are supplement feeding.
Complete Syringe Feeding Guide
Please be always aware that any medication can only do so much, and so can you with the care you give at home. You cannot stem the force of nature against all the odds; you and your vet can only ever do your best - which your vet is doing; there is nothing wrong with what they have prescribed. Concentrate on treasuring every extra day you have with her for as long as you are given. You can never control for how long she will be with you, but you have full control over making each single days filled with love, care and quality of life. Guinea pigs don't measure their life as to how long it is; they measure it in happy todays.
Unfortunately guinea pigs are only small animals with a very quick metabolism; that is counting against them when you come up against a serious illness or - in your case - organ failure compared to larger pets like dogs and cats. Rodents (which is what guinea pigs are) live on fast forward compared to them.
All the best! I hope that with the right medication you can have her a for a goodly while yet.
It is never easy when you are at the sharp end of an illness but try to also find time for love and for little pleasures; that is very important as well. Life is never just about length, it is about quality and the memories you create while you still can. I have found that it really helps me to reset the life clock at zero after a bad diagnosis/crisis and cherish every shared day from then on as an added bonus. That way I can only win and end up with lots of special and precious memories, whether that is an extra year or just some extra weeks. In one case, it was even an extra 5 1/2 years after surviving some rare post-op complications by the width of a hair and after being given up by the operating vets!