Chocolate contains three components that may be harmful to dogs and cats, namely fat, caffeine and theobromine. The levels of caffeine and theobromine vary between different types of chocolate. For example, white chocolate has the lowest concentration of stimulants and baking chocolate and cocoa have the highest concentration.
When chocolate is eaten in low doses the high fat content may result in vomiting and possibly diarrhoea. In high doses toxic effects are seen mainly from the effect of theobromine. You may notice restlessness, hyperactivity, muscle twitching, increased urination and possibly excessive panting. Heart rate and blood pressure levels may also be increased. Seizures may occur in severe cases.
Toxic amounts vary considerably but as little as 40g of dark chocolate can cause poisoning in a 10kg dog.
Generally, within a few hours of eating a toxic amount of chocolate, signs of hyperactivity, tremors, panting and excessive urination are seen. It is important that you call immediately even if you suspect the possibility of chocolate poisoning.
Diagnosing chocolate ingestion is generally based on the finding of an empty box of chocolates in the lounge with chewed tin foil wrappers everywhere! Pets that have ingested toxic levels of chocolate are generally hyperactive, panting, have increased blood pressure, increased heart rates and sometimes seizures. Dehydration may also occur if there has been significant vomiting and diarrhoea.
Treatment depends on the severity of the clinical signs and may include continuous intravenous fluid therapy, medications to cause vomiting or even help control vomiting and sedatives to counteract the stimulant effects of chocolate.
Most pets treated for chocolate toxicity recover and return to normal within 24-48 hours of treatment.