Tapeworms is the biggest risk. Many a barn dog have had a steady diet of all kinds of poop and lived to tell the tale however.

I usually expect diarrhea to resolve within 24 hours, if it lasts more than that I take my pooch to the vet.  Are you sure he/she is not running a temperature?  

This is a prompt for you to learn some home care techniques that can help in any situation. Also a good prompt to buy some books on holistic care for dogs.  Then you will be able to help your dog quickly move through most problems. 

I strongly recommend getting some training in understanding the wide range of
approaches to health so you can be in charge of what you choose for treatments
for your animals – given by you or by your integrative veterinarian. There are so many different ways to stimulate healing that
you never need to give up trying to treat any problem. Of course, this time I assume the diarrhea cleared up. When dogs are healthy, though, they can eat almost anything and not get any diarrhea.  From books, on-line and in classes you can
learn Reiki (which can take the “bad” out of vaccines and any needed
drugs, or even make food healthier), massage, HTA (healing touch for animals), TTouch, acupressure, flower
essence therapy, all of which are 100% safe to use for any problems. There are
many more approaches you can do to help heal your animals with some training
since they need to be used more carefully – homeopathy, herbal medicine,
Chinese herbs, aromatherapy. In addition to classes there are many very good
list serves filled with people experienced with not vaccinating and feeding raw
meat diets. Classes are found through your health food store, by phone or
on-line. As with human health approaches, there are many different opinions, so
you need to experiment and see what makes your animals more or less healthy. 

I also recommend finding an integrative veterinarian with whom to work, and I know there are some good ones in Montreal. This
is a person trained in many different approaches, including using conventional
drugs only when absolutely needed. Working with one can increase the chance
that your cherished companion can live a long and healthy life after recovering
from this current problem. There are good ones and great ones, and a few
homeopathic veterinarians will consult by phone or email. You can go to the web
sites for each type of holistic practice and use their referral list to find
one near to you. Many practitioners are members of only one or two of the
organizations, so you do need to go to every site to find who is near you:
1. Wide range of other treatments: http://www.AHVMA.org, American Holistic Veterinary
Medical Association and http://www.civtedu.org.   
2. Homeopathic veterinarians (these can often help you by phone if no other
holistic practitioners are nearby that you like): http://www.theAVH.org and
http://www.DrPitcairn.com.
3. Chiropractor – http://www.animalchiropractic.org
4. TCVM (Acupuncture and Chinese medicine): http://www.IVAS.org,
http://www.avaa.org & http://www.TCVM.com

5. Herbal
– http://www.VBMA.org

6. Postural rehabilitation – dogs and horses – http://www.posturalrehabvets.com/Postural_Rehabilitation/Find_a_Practitioner.html