Substance or exposure,Species,Dose as published on this site,Note
Chocolate (methylxanthines),Dog,About 20 mg/kg: mild signs,"Vomiting, diarrhoea and restlessness typically begin 6–12 hours after ingestion"
Chocolate (methylxanthines),Dog,40–50 mg/kg: cardiotoxic range,Heart-rhythm disturbances are likely; contact a veterinarian now
Chocolate (methylxanthines),Dog,60 mg/kg and above: seizure risk,Seizures are expected at this dose; get to a clinic immediately
Chocolate (methylxanthines),Dog,LD50 100–200 mg/kg: potentially lethal,"Seizures, collapse and fatal heart rhythms are reported in this range"
Chocolate (methylxanthines),Cat,About 20 mg/kg mild; 40–50 mg/kg cardiotoxic; 60 mg/kg and above seizures; LD50 100–200 mg/kg,The cat calculator grades against the same Merck bands as the dog one
"Milk chocolate, rule of thumb",Dog,About 1 oz per lb of body weight is potentially lethal,"Rule of thumb from the same Merck source, quoted in the dog calculator's FAQ"
White chocolate,Dog,About 1 mg theobromine per oz (negligible),The fat and sugar can still cause vomiting or pancreatitis in a small dog
Theobromine content used by the dog calculator,Dog,"Milk 57, semisweet 136, dark 70–85% 227, baker's 364, cocoa powder 808 mg per oz",Per-ounce content values multiplied by the amount eaten; not doses
Theobromine content used by the cat calculator,Cat,"White 0.04, milk 2.3, semisweet or dark 5.5, baker's 15.5, cocoa powder 28.5 mg per g",The cat calculator measures chocolate in grams rather than ounces
"Onion, raw, cooked or dried",Dog,15–30 g/kg: reported clinical-signs range,1.5–3% of body weight; about one medium onion (150 g) for a 10 kg dog
"Onion, raw",Cat,From about 5 g/kg,The site notes cats are affected at roughly a third of the canine dose
Garlic,Dog,3–5× more toxic than onion (the calculator counts it at 4×),"Its worked example swaps a 150 g onion for 600 g of onion-equivalent garlic; chives, leeks and shallots count too"
"Grapes, raisins, sultanas, Zante currants",Dog,More than 1 grape or raisin per 4.5 kg (10 lb) of body weight may pose a renal risk,"A risk reference, not a safe line: no established safe dose exists"
"Grapes or raisins, lowest documented toxic dose",Dog,0.32–0.65 oz/kg,About 181–369 g for a 20 kg dog; case reports describe injury below this range
Xylitol in sugar-free products,Dog,No numeric dose is published on this site,Named as a cause of hypoglycaemia and liver failure; read the ingredients list