Why is Chocolate Toxic to dogs

WHY IS CHOCOLATE POISIONOUS TO DOGS 
 
Many of us know or have read that chocolate is poisonous to dogs, and many small animals cats rabbits etc .. but what exactly makes it toxic and how does it affect their central nervous system making it so dangerous, to find this information I went in search of toxicology reports, looking for the WHY ??????
 
Intentionally or unintentionally eaten there are lots of common food stuffs that shouldn’t be fed to dogs with chocolate being perceived by some unsuspecting dog owners as a treat 
 
Dogs have a different metabolism to humans we know this because they sadly don’t live as long as us, with an average life span of 11 years. This plays a big part in how their bodies react to certain stimulates. 
 
There is a group of ingredients called methylxanthines 
Methyi – xan-  (zan) - thines 
These include coffee beans, cocoa beans, tealeaves, caffeine and some medications 
The coca bean is a type of methylxanthine called Theobroma 
 
Although methylxanthines can be broken down easily in the human body it takes considerably longer to break down in dogs body causing toxic levels to build up over a few hours. 
 
The toxicity of the chocolate depends on the size of the dog, wether it was eaten on a full or empty stomach, and  the type of chocolate with dark chocolate being the most toxic and milk and white chocolate less so 
 
So what happens when a dog eats chocolate ? 
 
we know the main toxic component in chocolate is Theobromine which is a methylxanthine, methylxanthine in a dogs system will cause cardiac and respiratory hyperactivity which means the heart  becomes abnormally active, this can cause tremors , rapid breathing, also the working of the stomach  becomes more  active and the dog experiences vomiting and diarrhoea, the overstimulation can also cause seizures and sometimes death 
 
These signs generally appear between 2-4 hours of ingestion but depending on dogs size could take as long as 12 hours . 
treatment is removal or neutralisation of the chocolate with activated charcoal which is known to absorb many poisons, plenty of fluids and control of the cardiac distress with medication. 
 
In a study done between 2015 – 2019 in the UK 
156 dogs presented having eaten chocolate, of the 156, 44 showed signs of toxicity with symptoms ranging from tremors and vomiting to cardiac distress of the 44 dogs all had digested dark chocolate, 43 of the 44 survived.
Its important to understand that the toxic nature of chocolate can take up to 12 hours to cause distress to a dog so if you are aware that chocolate has been digested don’t become complaisant if the dog doesn’t show signs immediately be vigilant for many hours after, and always call your vet for advice. The cases of death after ingestion of chocolate are low around 3% but not impossible, remember the darker the chocolate the more potential for toxicity and harm.