Hi, my guniea pig rocky has been diagnosed with parasites about 5 days ago, before the diagnosis he was slightly underweight due to complications and I was working on bringing that weight back up which going ok until this diagnosis, and now throughout treatment he has been going alarmingly lower in weight due to his condition and the medicine affecting him, the parasites give him diarrhea, and now just today the veterinarian said to take them off the medicine due to how it may have been suppressing there appetite, and making them lethargic, she is mainly worried about rocky in his state right now and may try a new medicine in a couple of days based on conditions. The day i brought rocky for parasites he weighed 890grams, and now today he's at 690grams which has me extremely worried for him, today I've just started the critical care syringe feeding which has been hard to do because he doesn't take syringes to well, will he eventually get use to it or is there a certain way I can do it ?