Hi,
Right now I am concerned with his blood sugar dropping.
Right now getting food and fluids in him is the top most priority. Try to get him to eat something even if it is a meat such as hamburger or chicken. If you have Pedialyte give him this to replace his electrolytes (If you have none available put a small amount of sugar and salt in a water bowl and send someone for pedialyte)
If you can not get him to eat at all or drink he needs to see a vet asap. If he is eating try feeding him in small amounts more frequently to prevent another drop in his blood sugar. You will need to call your vet and advise them of the situations so they can get him in and examined.
The diarrhea could be from a number of things but the dehydration is a big concern. Low urine output is a sign of dehydration as is the lethargic behavior. If he will not drink you can use a syringe to force him to drink. If he begins eating and drinking you will want to keep him on a bland diet of boiled chicken and rice. This will help firm up his stools and sooth his stomach. Continue with the pediatlyte for at least 24 hours. If he is not feeling better within 24 hours he will need to see the vet to determine if this is just a upset stomach or if there are more serious concerns. Though if you can not get him to drink or eat he will need to see the vet tonight.
I hope he is feeling better soon, please let me know if you need anything and let us know how she's doing.
Walter
Breeder
Breeder and pet health consultant. Have spent a number of years with Behavior Training &health care.