Chocolate contains an alkaloid called theobromine which acts as a neurostimulant . Theobromine is toxic to dogs and causes vomitting and in some cases death.
Dogs are “man’s best friend” and they certainly deserve a treat now and then for their undying love and loyalty. However, you have to be careful about the kind of treat you choose. Unfortunately, dogs cannot indulge in one of mankind’s most favorite delights—chocolate.
Cruel, isn’t it?
A Tempting Poison
Both humans and dogs have identical tastes. Similarly, they seek out sweets and have no issue indulging when given the chance. In any case, in contrast to people, dogs experience hazardous impacts when they consume chocolate.
Sure, humans are not immune to the ill effects of excess sugar consumption; tooth decay and obesity are two well-known dangers of such dietary habits.
However, in the case of canines, over-consumption can prove to be deadly.
Who’s to Blame?
Chocolate is made by roasting the bitter seeds of Theobroma cacao (the cacao tree). This seed contains a group of substances known as methylxanthines. This class of compounds are alkaloids, a class that includes neurostimulants like caffeine and theobromine.
While in the body, methylxanthines block the stimulation of adenosine receptors. Adenosine receptors are instrumental in making us feel tired and reducing body activity. Methylxanthines serve as stimulants by preventing such relaxation from setting in.
Both components can lead to clinical symptoms of chocolate toxicity, but theobromine is more deadly, as it is present in higher amounts in chocolate (3-10 times the percentage of caffeine).
Additionally, it has a substantially longer half-life than caffeine.
Due to the slow metabolism of theobromine, symptoms can take up to 24 hours to appear. Theobromine mainly affects the cardiovascular, respiratory and central nervous system, and also acts as a diuretic.
According to the American Society for the Prevention of Cruelty to Animals (ASPCA), mild symptoms of poisoning are observed at a dosage of 20mg/kg. The early symptoms include diarrhea, polydipsia and hematemesis. Chronic signs start at around 40 mg/kg.
The dog will show signs of restlessness and will be hyperactive. Heavy panting and muscle twitching may also follow. Ingestion of a heavy dose (around 60mg/kg) may lead to seizures and cardiac arrhythmias, resulting in death.
LD50 is the concentration of a toxin that is sufficient to kill 50% of a sample. For toxicological testing, it is a standard way of calculating a lethal dose of a drug. The LD50 is 100-200 mg/kg for theobromine in dogs.
It is imperative to seek the attention of a vet as soon as you suspect that your pet has consumed chocolate. While a clear antidote does not exist, induced vomiting and the application of oxygen, intravenous fluids and activated charcoal are all helpful treatments.
Why not us?
Humans possess certain enzymes, such as CYP1A2 and CYP2E1, which break down theobromine. These enzymes are thought to be absent in canines and any alternate metabolic pathway is yet to be identified. Theobromine is metabolized much faster by humans due to the action of the enzymes, allowing for safe digestion and excretion.
A low dose of methylxanthine can cause vomiting in dogs and only mild euphoria in humans. Thus, theobromine can overstimulate the cardiovascular and central nervous system in dogs and cats.
Yes, chocolate is also poisonous to cats, but since they do not have an affinity for sweet foods like dogs, it’s not a pressing concern.
How much is too much?
The amount of chocolate that a dog can tolerate depends on both the type of the dog and the type of the chocolate. As a rule of thumb, larger dogs can safely consume larger amounts. For toy breeds, which are usually very tiny, even a small quantity can be lethal. Genetics also play a role in how each dog metabolizes chocolate.
The lowest amount of theobromine is present in white chocolate and milk chocolate, whereas dark chocolate has approximately three times more theobromine than milk chocolate. The unsweetened variety of baker’s chocolate and cocoa powder should be especially avoided.
The former contains around six times the amount of theobromine that is found in milk chocolate, while cocoa powder contains twice the amount present in unsweetened baker’s chocolate. It is important to note that the amount varies with the brand of chocolate too!
Alternatives to Chocolate
It is difficult to not give in to those endearing puppy eyes, and dog owners know that denying your pet a tasty treat requires a heart of stone, but you can never give in when it comes to chocolate!
While it is fairly safe to occasionally treat your pet with a small amount of chocolate, it’s best not to push our luck. ‘Pet-friendly chocolate’ is void of theobromine and is therefore a safer option. Nonetheless, it can still lead to obesity.
Carob is an interesting substitute derived from Ceratonia siliqua. It is caffeine- and theobromine-free, but still possesses the sweet flavor. Carob also comprises a number of important nutrients, such as vitamins A, B, and D. It also includes iron, calcium, potassium, magnesium and protein. Carob is an excellent source of pectin and fiber.
A sharp rise in cases of chocolate poisoning in pet dogs is reported around any confection-centric holiday—Christmas, Easter, and of course, Valentine’s Day. To the great credit of veterinarians, these cases of poisoning rarely result in death. However, as a pet parent, it’s our duty to keep all chocolate boxes, cocoa tins and Easter eggs well out of paws’ reach.