As a veterinarian who has gone back to school to get an advanced degree in toxicology, I thought this blog might be a good way to practice putting this knowledge into lay terms.  In other words, when I finish, this time, I want to avoid the experiences I had after vet school when clients gave me that glazed over look and my technician would look at me and say "You’re speaking Doctor again."  I've decided to periodically post on some topic related to toxicology and animals.  

In honor of our next holiday (that would be Halloween for those who haven't looked at a calendar for a month or so), I thought it would be appropriate to discuss something Trick-or-Treatish. Like candy, or more specifically chocolate.  Did you know that Chocolate can be toxic to animals?  Dogs tend to be the most likely victims.  They tend to be a little less picky than many other companion animals, they often have access to things in your house, and you can’t hide it from them. 

So, how much chocolate is too much?  It really depends on the individual animal and especially the type of chocolate.  Baker’s chocolate is about ten times more potent than milk chocolate.  Clinical signs of chocolate poisoning can be seen with less than ½ oz. of milk chocolate.  According to the Merck Veterinary Manual the LD50 (the dose that will kill 50%) is between 250 and 500 mg/kg of theobromine (the substance in the chocolate that causes the problems).  For those who like math:

 A 10kg (22lb) dog X 250mg/kg theobromine = 2500mg theobromine

2500mg theobromine / 15mg/g (theobromine in baker’s chocolate) = 167g or

5.9 oz of Baker’s chocolate will kill 50% of 22lb dogs

         

          Some dogs are much more sensitive, likely because they are predisposed to heart conduction problems.

            If your dog gets into your Halloween chocolate, please don’t wait.  Call your veterinarian soon.  The sooner the dog is treated the better the prognosis.  So for the safety of your pets you should eat your own chocolate.  Happy Halloween.