Also, what are the symptoms please?

Metrinidazole-This medication has anti-inflammatory properties in the large intestine as well as ability to kill harmful organisms such as Clostridia and Giardia.

Sudden Colitis
A pet that has symptoms of colitis suddenly probably has a stress-related colitis (common after boarding, moving, severe weather or other change) or a dietary indiscretion related colitis (related to treats or raiding the garbage). these cases are generally minor and can be cleared with a short course of medication; metronidazole is commonly prescribed) and/or dietary therapy. Parasites can also cause colitis and may have to be ruled out as well.

Colitis is literally inflammation of the Colon, a.k.a. large intestine. The symptoms are diarrhea, possibly with blood, usually with some mucous.

There are many causes, so a fecal analasys is necessary to determine proper treatment, but it is most commonly bacterial in origin. Metronidazole is the antibiotic of choice, possibly with an injection of Ampicillin. along with the antibiotic, a low fat food is usually recommended to allow the inflammation to lessen. Hill's I/D is a prescription food that I usually suggest, but boiled chicken and rice works just as well.

Whenever our dog had colitis, our vet told us to feed her little amounts of food every couple of hours. I also made a mixture of ground beef and rice. I would boil the fat out of the meat and mix it with the rice.
Being that it is a puppy, you might want to give it a few tablespoons of chicken broth or something soft like canned puppy food.

It may just be something it ate or it could be something more serious. Don't let this go on for too long or the dog will get dehydrated. take the puppy to a vet to be sure. our pets are too precious to take any chances.

Best of luck.

The symptoms are mucus and blood in the faeces. it is treated with antibiotics.