Why chocolate is toxic
Chocolate contains theobromine and caffeine, which dogs metabolise very slowly and which overstimulate the heart and nervous system. The darker the chocolate, the more toxic:
| Type | Risk |
|---|---|
| White chocolate | Almost no theobromine, but the fat can cause pancreatitis |
| Milk chocolate | Moderate; about 100 g can cause signs in a 10 kg dog |
| Dark chocolate (70%+) | High; 20 to 30 g is dangerous for a 10 kg dog |
| Baking chocolate, cocoa powder | Very high; small amounts can be fatal |
Signs
Appear 6 to 12 hours after eating:
- Vomiting, diarrhoea, extreme thirst, frequent urination
- Restlessness, panting, racing heart
- Tremors, muscle twitching, seizures
- Severe cases: irregular heartbeat, high temperature, coma
What to do right now
- Work out what type, roughly how many grams and when; bring the packaging.
- Call 2126 7440 immediately. We calculate from weight and dose whether vomiting needs to be induced.
- Do not induce vomiting yourself: salt water and hydrogen peroxide burn the oesophagus and cause aspiration pneumonia.
- Come in even if your dog seems fine: inducing vomiting works best within 1 to 2 hours, and by the time signs appear the toxin is absorbed.
At the hospital
- Within 2 hours of eating: safe drug-induced vomiting, then activated charcoal to bind what remains.
- Signs already present: fluids to speed elimination, control of heart rate and seizures, temperature monitoring, usually 12 to 24 hours in hospital.
- Dogs treated early almost always recover fully.
Other common poisons
- Grapes and raisins: acute kidney failure; no safe amount
- Xylitol (sugar-free gum, some peanut butters, baked goods): blood sugar crash within 30 minutes, liver failure
- Onion, garlic, chives: anaemia appearing days later
- Macadamia nuts: hind-leg weakness, tremors
- Alcohol, coffee
- Rat bait: bleeding days later
- Human painkillers (paracetamol, ibuprofen): liver and kidney failure, stomach ulcers
- Lilies (cats): kidney failure
For any of these, call immediately.
Prevention
Keep chocolate and sweets in cupboards dogs cannot open; be extra careful at Christmas, Easter and Valentine's; teach children not to share treats.