Hello, my name is***** and I have over 20 years of experience as a veterinarian. I am sorry to hear that your fellow has had watery diarrhea and loss of appetite for 2 days and I understand that you are concerned.
I am pleased to hear that he is still drinking normally, otherwise I would be concerned about dehydration. Because he is drinking normally and seems strong I think he will be fine until morning.
There are some things that we can do for him tonight.
Since his appetite is off he may have some stomach
upset and reflux that can go along with his loose stools.
To try and settle his stomach today you can try either:
1) Pepcid-ac (famotidine
) at a dose of one 10mg tablet per 20 to 40 pounds of body weight every 12 hours.
2) Prilosec (omeprazole) at a dose of one 10mg tablet per 20 to 40 pounds of body weight every 24 hours.
These will reduce stomach acid and should help if this is related to simple nausea and gastrointestinal irritation.
I would offer him small amounts of water or ice cubes frequently as he needs fluids after all that he has lost with loose stools. You can give him pedialyte to replace electrolytes too but Gatorade is much too high in sugar which can make his intestinal irritation worse.
Today a couple hours after the acid reducer is given you can start Kao-pectate at 1ml per pound or 1 tablespoon per 15 pounds of body weight every 6 to 8 hours. This is quite safe and will coat his irritated gastrointestinal tract as well as absorbing bacterial toxins. You can use it for several days until his stools look normal. You can find kao-pectate at the drug store. I like the kao-pectate formulation with kaolin and pectin better then Pepto Bismol as Pepto has salicylates which are in the same family as aspirin, and can further irritate the intestines.
If he has a tense painful abdomen, becomes very lethargic, begins vomiting or runs a fever greater than 103.5F then he really must be seen by a veterinarian as soon as possible, he cannot wait until tomorrow.
Whenever you take him to be seen by a veterinarian make sure to take a fresh stool sample with you when you go. Parasites are always a possible cause of loose stools.
You can offer a bland diet of 1/3 boiled, lean hamburger (or boiled, white skinless chicken
), all fats and juices drained off, mixed with 2/3 boiled, plain white rice. Feed several small meals a day. You might wish to add 2 tablespoon of canned pumpkin (not pie filling, just pumpkin) to each meal if you are seeing any mucous or blood in his stools as fiber helps soothe an irritated colon.
I would also add a probiotic designed for dogs, either Benebac, Proviable or Fortiflora, to his meals if you can get him to eat anything.
If he feels better (no diarrhea for 48 hours) start mixing in his regular dog food very slowly. Less bland more regular with each day. It should take a week or so to convert him back.
Best of luck with your pup, please let me know if you have any further questions.