Hello, my name is***** and I have over 20 years of experience as a veterinarian. I am very sorry to hear about Abby's loose stools today and now with a little blood.
Of course anyone would be concerned about blood in the stool. The fresher the blood appears the closer the source is to her rectum.
The important factor in all of this is how Abby feels otherwise. If she feels great then that is a good sign.
There is a condition in dogs called hemorrhagic gastroenteritis. These dogs have profuse dark, jelly-clot like, bloody diarrhea and are often vomiting or at least very nauseous and weak too. They are very sick dogs and get dehydrated quickly so they need immediate care. Thus if she seems lethargic and/or begins vomiting an emergency veterinary visit is best.
But colitis or inflammation of the large intestine, can be due to stress, a change in diet, parasites, a viral or bacterial infection, inflammatory bowel disease or even a food allergy. Rarely a mass in the colon can be the cause, or exposure to anticoagulant rodenticides. Another possibility is an anal gland infection. These are scent glands that are located just inside the rectum and an infection can cause a bloody discharge, though should not cause loose stools.
A raw, irritated colon can take a few days to heal. Do you know if she got into anything that may have started all of this? The bleeding should clear completely with treatment over the next 2 to 3 days. Since she has an appointment scheduled tomorrow as long as she is fine otherwise you can have them check her anal glands tomorrow. Well worth checking at least a couple fresh stool samples too tomorrow as parasite eggs/cysts are shed intermittently and they may be picked up on the second sample or third test if the first is negative.
If she still feels well now though we can try some things at home.
If her appetite is off and his stomach is gurgling she may have some stomach upset and reflux that can go along with loose and bloody stools.
To try and settle her stomach today you can try either:
1) Pepcid-ac (famotidine) at a dose of one half of a 10mg tablet per 10 to 20 pounds of body weight every 12 hours.
2) Prilosec (omeprazole) at a dose of one quarter of a 20mg tablet per 10 to 20 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 not feed her any food for 24 hours. This should help stop gut spasms and restore normal gut motility. Small amounts of water or ice cubes given frequently are fine as she needs fluids after all that he has lost with bloody stools. You can give her pedialyte to replace electrolytes too but most dogs don't like the taste so she may not want to drink it. Do not give Gatorade as the sugar content is too high.
Today even with the fast you can start Kao-pectate at a dose of 1ml per pound or 1 tablespoon per 15 pounds of body weight every 6 to 8 hours. This is quite safe and will coat her irritated gastrointestinal tract as well as absorbing bacterial toxins. You can use it for several days until her 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 she has a tense painful abdomen, becomes very lethargic, begins vomiting or runs a fever greater than 103.5F then she really must be seen by a veterinarian as soon as possible. Make sure to take a fresh stool sample with you when you go.
After her food fast start a bland diet of 1/3 boiled, lean hamburger (or boiled, white skinless chicken), all fats drained off, mixed with 2/3 boiled, plain white rice. Feed several small meals a day. You might wish to add 1-2 tablespoon of canned pumpkin to each meal as fiber helps soothe an irritated colon. I recommend adding probiotics like Fortiflora, Proviable or Benebac to her meals daily to re-establish normal gut bacteria levels too.
Once she feels better (no bloody diarrhea for 48 hours) start mixing in her regular dog food very slowly. Less bland more regular with each day. It should take a week or so to convert her back.
If your pup is vomiting and feeling poorly though it would be best that she see a veterinarian now as anything you give orally will just come back up worsening her dehydration.
Best of luck with your pup, please let me know if you have any further questions.