Why chocolate is toxic for dogs; vets urge caution during Halloween

Pet owners beware: Essential oils can be toxic to cats and dogs

Some common essential oils which are toxic to both dogs and cats include oil of cinnamon, citrus, peppermint, pine, tea tree (melleuca), wintergreen and ylang ylang.

As Halloween approaches, veterinarians are warning dog owners about the potential hazards of chocolate. 

Why is chocolate toxic for dogs?

Why you should care:

Veterinarians and health experts warn that dogs cannot metabolize chocolate in the same way that people can due to a substance in chocolate called theobromine. 

Dog dressed as Travis Kelce and Taylor Swift for Halloween event. (Credit: Richard Lautens/Toronto Star via Getty Images)

According to Cornell’s College of Veterinary Medicine, caffeine and theobromine can cause stimulation of the central nervous system and heart. They also act as diuretics, which can quickly lead to dehydration. Dogs may also be at risk for developing gastrointestinal distress or even pancreatitis because many chocolate products are high in fat and sugar.

What they're saying:

"The substance in chocolate is actually a stimulant, and so it can affect the heart from the standpoint of a significant increase in heart rate," Dr. Edward Cooper, an emergency and critical care medical professor at Ohio State University, told FOX News. "It can cause abnormal rhythms. They can get high blood pressure."

Darker chocolate more toxic than milk chocolate for dogs

Dig deeper:

Cooper noted that darker chocolate can be more dangerous for your dog to ingest than milk chocolate.

"Milk chocolate has the least amount of the toxic substance that exists in chocolate for dogs," Cooper explained, but noted that the amount of chocolate it takes to cause concern depends on the size of the dog and the type of chocolate it ate.

Cornell University noted that the potential for toxicity is highest in cocoa powder, followed by unsweetened (baker’s) chocolate, semisweet and sweet dark chocolate, milk chocolate and cocoa bean hulls. 

For example, one ounce of milk chocolate per pound of a dog’s body weight can be deadly compared to unsweetened baking chocolate, where as little as 0.1 ounces per pound of a dog’s body weight may be lethal. For this reason, even ingesting small amounts, especially in a smaller dog, should be treated as an emergency.

Tips for dog owners

What they're saying:

"We see a chocolate toxicity at least once of month," Dr. John de Jong, president-elect of the American Veterinary Medical Association and a practitioner at the Newton Animal Hospital in Boston, told FOX News.

RELATED: These are the top 10 toxins for your pets, according to experts

Pet Poison Helpline similarly reports high frequency, receiving 95% of its chocolate calls for dogs as opposed to any other household animal.

Symptoms may occur within 2-12 hours after ingestion. Clinical signs can last 12-36 hours, sometimes longer in severe toxicities. 

According to Cornell, signs of chocolate toxicity may include vomiting, diarrhea, increased thirst and urination, restlessness, fast breathing, increased heart rate or irregular heart rhythm, hyperexcitability, tremors, incoordination, seizures, fever or coma.

What you can do:

Experts say owners who fear for their pet’s health should contact their vet.

Experts also recommend storing candy on high counters and keeping dogs out of rooms when kids start counting their sweets in case any fall on the floor.