What Foods Are Toxic for Dogs: A Comprehensive Guide

List of Foods You Should Avoid Feeding To Dogs

When it comes to feeding our canine companions, it’s crucial to be aware of the foods that can be toxic to them. Dogs metabolise foods differently than humans do, meaning certain foods that are safe for us can be harmful or even deadly to them. This guide outlines known foods that are toxic to dogs, detailing the causes of toxicity, symptoms to watch out for, and potential treatment options.

1. Chocolate

• Causes of Toxicity: Theobromine and caffeine, both belonging to a group of chemicals called methylxanthines, stimulants found in chocolate, cannot be metabolised efficiently by dogs and may induce toxicosis. (1, 2)
• Dosage That May Induce Toxicosis: In general, mild signs (vomiting, diarrhoea, polydipsia) may be seen in dogs ingesting 20 mg/kg of bodyweight, cardiotoxic effects may be seen at 40–50 mg/kg, and seizures may occur at dosages ≥60 mg/kg. 55g of milk chocolate per kilogram of body weight is a potentially lethal dose in dogs and far smaller dose of dark chocolate.
• Symptoms of Toxicity: Vomiting, haematemesis, polydipsia, rapid breathing, increased heart rate and seizures.
• Treatment Options: Inducing vomiting, administering activated charcoal, IV fluids, medications to control symptoms. (3)

2. Xylitol

• Causes of Toxicity: Xylitol, a sugar substitute found in many sugar-free products, can cause a rapid release of insulin in dogs, leading to hypoglycaemia as well as seizures, liver failure, or even death in dogs. (4, 5)
• Dosage That May Induce Toxicosis: Dogs that ingest doses of >0.1 g/kg of bodyweight of xylitol are at risk for developing hypoglycaemia, while dogs that ingest >0.5 g/kg may develop acute liver failure. (6)
• Symptoms of Toxicity: Weakness, lethargy, vomiting, loss of coordination, seizures and coma. (7)
• Treatment Options: Immediate veterinary care is crucial. Treatment may include IV dextrose and monitoring liver function. (8)

3. Grapes and Raisins

• Causes of Toxicity: It is understood the substance in grapes and raisins that causes toxicosis in dogs is tartaric acid. This compound can cause kidney failure in dogs. (25, 26)
• Dosage That May Induce Toxicosis: The lowest documented toxic grape or raisin dose is 0.32 to 0.65 oz/kg bodyweight which is as few as 4-5 grapes (9)
• Symptoms of Toxicity: Clinical effects include development of vomiting and/or diarrhoea within 6–12 hours of ingestion, lethargy, anorexia, polydipsia, dehydration, and elevation of serum creatinine and BUN concentrations; progression to oliguric or anuric renal failure may occur within 24–48 hours. (10)
• Treatment Options: Inducing vomiting, activated charcoal, aggressive IV fluids to protect the kidneys. (11)

4. Onions, Garlic, Leeks and Chives (Allium Family)

• Causes of Toxicity: These foods contain disulphides and thiosulfinates, which can cause oxidative damage to red blood cells, leading to anaemia. Contrary to the myths, garlic is actually beneficial for dogs but should be fed in moderation, as extreme doses may prove toxic (12)
• Dosage That May Induce Toxicosis: Dogs are highly susceptible to onion toxicosis, consumption of as little as 15 to 30 g/kg for dogs has resulted in clinically important hematologic change. (13)
• Symptoms of Toxicity: Weakness, lethargy, pale gums, red or brown urine.
• Treatment Options: Fluid therapy, oxygen therapy, blood transfusion in severe cases.

5. Alcohol

• Causes of Toxicity: Alcohol, and specifically ethanol, affects dogs in the same way it does humans, but even small amounts can be more toxic to them.
• Dosage That May Induce Toxicosis: The published oral lethal dose of ethanol in dogs is 5.5 to 7.9 g/kg bodyweight of 100% ethanol. (14)
• Symptoms of Toxicity: Vomiting, diarrhoea, difficulty breathing, tremors, coma.
• Treatment Options: Supportive care, IV fluids, monitoring of respiratory and cardiac functions. (15)

6. Avocado

• Causes of Toxicity: Persin, a fungicidal toxin in avocados, can cause vomiting and diarrhoea in dogs. The large seed also poses a choking hazard. (16)
• Dosage That May Induce Toxicosis: The dosage of avocado that may induce toxicosis in dogs is not known although there are dosage figures for other animals (17)
• Symptoms of Toxicity: Vomiting, diarrhoea, myocardial damage and pancreatitis. (18)
• Treatment Options: Supportive care for gastrointestinal symptoms, surgical intervention if the seed is ingested and causes obstruction.

7. Macadamia Nuts

• Causes of Toxicity: The toxic compound hydrogen cyanide (HCN) released from the hydrolysis of cyanogenic compounds in Macadamia causes a safety risk. Macadamia nuts can affect the digestive and nervous systems of dogs. (27)
• Dosage That May Induce Toxicosis: Dogs experimentally dosed with commercially prepared macadamia nuts at 20 g/kg developed clinical signs within 12 hours (19)
• Symptoms of Toxicity: Weakness, depression, vomiting, tremors, hyperthermia.
• Treatment Options: Supportive care, including IV fluids and pain relief.

8. Caffeine

• Causes of Toxicity: Caffeine is a methylxanthine and, similar to chocolate, caffeine is a stimulant that dogs cannot metabolise well which can cause toxicosis when ingested by dogs. (20)
• Dosage That May Induce Toxicosis: Caffeine is a methylxanthine alkaloid with a reported canine oral median lethal dose (MLD(50)) of 140 mg/kg (range 120-200 mg/kg bodyweight) (21)
• Symptoms of Toxicity: Vomiting, diarrhoea, panting, excessive thirst and urination, abnormal heart rhythm, tremors, seizures. (22)
• Treatment Options: Inducing vomiting, activated charcoal, supportive care. (23)

9. Yeast Dough

• Causes of Toxicity: Although GDV (gastric dilatation and volvulus) can be life threatening, death from yeast dough in pets is usually due to the effects of ethanol. Yeast fermentation produces alcohol and carbon dioxide, leading to gas accumulation and alcohol poisoning. (24)
• Dosage That May Induce Toxicosis: The published oral lethal dose of ethanol in dogs is 5.5 to 7.9 g/kg bodyweight of 100% ethanol. (14)
• Symptoms of Toxicity: Distended abdomen, vomiting, lethargy, alcohol poisoning.
• Treatment Options: Preventing absorption of alcohol (if caught early), supportive care, monitoring for signs of ethanol toxicity.

10. Bones and Fat Trimmings

• Causes of Toxicity: Bones can splinter and cause obstruction or lacerations in the digestive system. Fat trimmings can cause pancreatitis.
• Symptoms of Toxicity: Vomiting, diarrhoea, choking, abdominal pain, pancreatitis.
• Treatment Options: Surgical removal of bone fragments if necessary, supportive care for pancreatitis.

Conclusion

This guide highlights the importance of being vigilant about what foods our dogs consume. If you suspect your dog has ingested any toxic substance, immediate veterinary care is crucial. Preventing access to these foods can help ensure the health and well-being of our beloved pets.

If you are a subscription customer with Bonza, you have access to a free VidiVet online vet service. Should your dog consume any of the above toxins, this will provide you with 24/7, 365 days a year access to qualified veterinary help.