Why does chocolate kill dogs?
Be careful folks, especially at chocolate-rich times of year like Easter, Valentines, birthdays and Xmas!
Actually it doesn’t. For 97 out of 100 dogs.
And it's something called theobromide in the chocolate that causes the damage.
But while plain chocolate is the most dangerous, milk is in the middle and white is the least toxic, it will make them all very sick indeed, and could also cause long term problems even if they seem to recover well, so why risk it?
Keep those human sweeties well out of a dog’s reach! At least with humans obesity and dental cavities are the worst effects of over eating chocolate, unless another condition like diabetes is present.
So chocolate is potentially lethal to dogs.
But it’s not that simple.
Chocolate is derived from the roasted seeds of the plant Theobroma cacao
Yes, this is where chocolate and cocoa come from!
and the main toxic components are something called methylxanthine alkaloids
Notice caffeine is here too- so chocolate has caffeine AND this sneaky theobromine stuff!
theobromine (above)
and caffeine
which humans can get very sick from if taken in too high a quantity (this is a link to a case study on that.)
However, luckily for us we can usually easily digest and excrete these methylxanthines, the half life- or how long it stays in the body- of theobromine being 2-3 hours. However absorption in dogs is slow, processing mostly in the liver before excretion in the urine. And the half life of theobromine in dogs is about 18 hours, so it takes 6 times as long to stop having an effect.
WHAT PARTS OF THE DOG ARE AFFECTED BY THIS THEO THINGY STUFF?
Theobromine primarily affects the
central nervous system
cardiovascular system,
respiratory system
as well as having a diuretic effect (it will make you dog want to pee a lot) so it has an effect on the gastro intestinal system too!
WHAT ARE THE SIGNS OF CHOCOLATE POISONING?
The first signs of poisoning in dogs include
vomiting and/or diarrhoea
haematemesis (vomiting of blood)
and polydipsia (increased level of thirst)
Other signs may include
hyperexcitability, (over excited, won’t calm down)
hyperirritability, (anxious and angry for no reason you can see)
tachycardia- which is the posh word for an abnormally rapid heart rate. It is usually characterised by heart rates greater than 140 bpm in large dogs, 160 bpm in medium sized dogs, 180 bpm in small dogs, or 220 bpm in puppies and can result in heart failure or death.
excessive panting,
ataxia- loss of balance due to damage to the brain, which is responsible for movement and coordination. This causes abnormal movements, especially of the head and eyes, that lead to dizziness. Cerebellar ataxia is sometimes confused with a stroke because they may have similar symptoms
and muscle twitching.
If too a high level of chocolate was ingested by the dog, effects may progress to
cardiac arrhythmias, (irregular heart beat)
seizures,
and death.
Most symptoms will begin to appear within two hours of ingestion, but, as theobromine is metabolised slowly, it can take as long as 24 hours for them to appear and up to three days for recovery. Although there is no specific antidote, watch out for vomiting and make sure you have in your doggy first aid kit some easy to store and give the dog like activated charcoal. The most convenient way to (if they will eat) such a thing if you don't have any is charcoal dog biscuits crushed up or in a broth as they will need fluids. If they are struggling to breathe do not try and feed them anything. They will need to go to the vets to be put on oxygen, and intravenous fluids.
The lethal dose of theobromine is reported to be 100-500 mg (a very small amount!) per kg of body weight in dogs.
Here are the amounts in oz (ounces) as some chocolate products especially cocoa and hot chocolate can come in ounces.
So as we can see- not all types of chocolate contain the same amount of theobromine.
Metric version:
cocoa powder and plain chocolate contain the highest concentrations (20 mg/g and 15 mg/g) ,
milk chocolate has much less (2 mg/g)
white chocolate has the lowest concentration (0.1 mg/g).
Using this table could help, especially for the foodstuffs in the second part of the chart.
Be careful folks, especially at chocolate-rich times of year like Easter, Valentines, birthdays and Xmas!
It’s much better, especially as many dogs are also lactose intolerant (their bodies have an allergic reaction to milk proteins) to give special “pet chocolate” like carob based treats that do not contain theobromine instead, (but can still cause obesity) or peanut butter treats that do not contain xylitol- a sweetener occurring naturally in many fruits for example but is also toxic to dogs. We sell these in our shop, and incoming are yoghurt drops and strawberry drops too!
And if you garden- cocoa shells often used as fertiliser or mulch also contains very high levels of theobromine (25 mg/g). It has that sweet chocolate smell too so it may be attractive to dogs but just a few mouthfuls could kill them.
Remember, dogs will absolutely eat chocolate if they find it—so keep it all, including tins of cocoa or drinking chocolate, out of paws’ reach.
HOW DO I KNOW IF MY DOG HAS EATEN TOO MUCH CHOCOLATE?
Super fast method as seconds may be all you have!
Check the weight on the bag or wrapper. Use the table below for grams, the table above for ounces (oz) or use this handy converter- 1 ounce (oz) = 28g and x by 28.
Then decide if your dog's small (10kg and under), medium (25kg and under) or large (over 25kg.) Here we will say the dog is medium as our example dog is 22kg.
Then make sure what kind of chocolate it is- white is least harmful, plain is worst so if it had plain chocolate in it, work it out just for plain chocolate (worse case scenario)
Then calculate the amount of chocolate eaten: if it was a 200g bar and your dog ate half then ÷ 2 = 100g, for example. If it was something more complicated like a bag or box of chocolates, get the calculator out on your phone and divide the weight on the bag by how many pieces about there are, and compare to what's left (like 7 pieces and you think the bag had about 15 bits in for example like a pack of Fun Size Mars bars; which are milk chocolate usually. If the bag is 350g you'd put 350÷ 15 which is about 23g per bar, then x 8 (15-7) to get how much chocolate could have been eaten. 23 x 8 = 184g. Yikes, that's a lot for any dog but not awful for a medium dog! )
Here we will say it was all solid dark chocolate (always do worse case scenario).
Check the quick chart below (to make it worse, there's a lot of caffeine in dark chocolate too!) = here for a medium dog the danger levels are 70g for plain chocolate and here the dog has eaten 100g of plain chocolate in our example, or 450g for milk chocolate and in our example the dog ate 184 g of milk chocolate.
At these levels- in this case 100g of plain chocolate from the bar the dog is in great danger of developing serious clinical signs if he is not promptly treated at the vet’s. With the 184g of milk chocolate from the bag example a medium dog is on about a 40% dose (184 ÷ 450 as in the chart) below fatal but take nothing for granted and do look out for symptoms as listed above.
QUICK CHART
adapted from
Fiona Finlay consultant community paediatrician, Child Health Department, Bath NHS House, Bath (fiona.finlay@banes-pct.nhs.uk)consulting with Simon Guiton, veterinary surgeon, 12 Raby Place, Bath.
FURTHER READING
ON THE 156 DOG SURVEY
out of 156 dogs suspected of eating chocolate:
One hundred and twelve dogs had no clinical signs.
Forty-four dogs had clinical signs of chocolate intoxication.
Twenty-eight of these 44 dogs ingested dark and bitter chocolate.
Reasons for presentation were
agitation (33),
tremor (22),
vomiting (21),
panting (11),
polyuria/polydipsia (seven)
and diarrhea (two).
Common clinical findings were
sinus tachycardia (28),
tachypnea/panting (14),
hyperthermia (10)
and dehydration (seven).
Clinical pathological findings in 34 of 44 dogs consisted of
hyperlactataemia (23),
hypokalaemia (16),
mild hyperglycaemia (16)
and mild alanine aminotransferase (ALT)
and aspartate aminotransferase (AST) elevation (14).
After decontamination (apomorphine, activated carbon) and symptomatic treatment (including forced diuresis, sedatives), 43 of the 44 dogs survived. clinical significance: In dogs with potential chocolate intoxication, the type and amount of chocolate and the time of ingestion are important factors. Cardiovascular, neurological and gastrointestinal signs are the most common clinical signs. In this case series, the prognosis after decontamination and symptomatic therapy was good, with a mortality rate of less than 3%.
and
ON SYMPTOMS AND HOW TO WORK OUT IF YOUR DOG HAS OVERDOSED ON CHOCOLATE
by Sharon Gwaltney-Brant DVM, PhD, ASPCA Animal Poison Control Center, 1717 S. Philo Road, Suite 36, Urbana, IL, 61802; (888) 4ANI-HELP.
Copyright © 2001, Veterinary Medicine Publishing Group. Reprinted with permission from the February 2001 issue of Veterinary
Medicine. All rights reserved. For more on Veterinary Medicine, visit www.vetmedpub.com.