8 year old Chihuahua dachshund
My dog woke up one morning puking, he puked about 3 times the first two were just food and the third was white foam. Took him to the vet and they put him on 4 different meds. After the medication he hasn’t puked but he hasn’t been acting himself besides sometimes getting burst of energy and he is drinking water and he ate breakfast but hasn’t eaten dinner today. He’s been trembling off and on and sometimes doesn’t want to lay his head down. His breathing also seems to be a bit quicker than normal. I’m freaking out and I want to get him to the vet again asap but is there anything I could try and have him tested for that could be for this? What test should I have them do?