Human Foods That Are Harmful To Dogs

For centuries dogs have been fed on scraps of human food and much of what is nutritious for us is good for our dogs too.  For example, chicken and turkey, rice and pasta are often recommended to be fed to dogs who have had a stomach complaint.  Carrots and other root vegetables, apples and pears make tasty treats for dogs that are watching their weight; however other human foods that are innocuous to us can be dangerous when fed to dogs.  Here are some of the main offenders:

Avocado – Persea americana   
The Gautemalan variety (rough skinned) or hybrids such as “Fuerte” contain persin which can cause myocardial necrosis (cell death of the heart muscle) when the leaves, fruits or trees are ingested by animals.  Goats are particularly susceptible to poisoning of this kind.

Beer, Wine and Alcohol
Alcohol of any kind can cause coma and lead to death.  Times to be vigilant are during parties where guests leave their glasses on low tables or on the ground and dogs might be tempted to have a taste!

Chocolate – Theobroma cocao     
Chocolate contains theobromine and caffeine.  These substances are rapidly digested and increase heart rate, cause bronchodilation and, in high doses, can lead to convulsions.  Dark chocolate that has a higher content ratio of theobromine and caffeine to milk is the most dangerous.  For example a 10 kg dog could be poisoned by eating 18oz of dark chocolate. 

Dairy Products
These products will not kill your dog but they do contain a high fat content.  Some dogs more than others are lactose intolerant which can lead to gas and diarrhoea.  Most dogs can tolerate small amounts of cheese and yogurt.

Eggs
Feeding raw eggs to dogs can carry the risk of Salmonella poisoning.

Fatty Foods
Foods with a high fat content can lead to obesity and related disease (click Obesity in dogs for more details).  Excessive fatty foods may also lead to pancreatitis.

Fruit Pips and Seeds
Most fruit pips and seeds are harmful because they contain cyanogenic glycosides that can cause cyanide poisoning in dogs.  Fruit such as apples and pears (without the pips) will not harm the dog but citrus fruits can cause severe diarrhoea and grapes are a definite no no!

Grapes and Raisins – Vitis    
Vomiting can occur in dogs within 24 hours of consuming grapes or raisins leading to dehydration, collapse and eventually renal failure.  No one is quite sure what toxin is contained in grapes that makes dogs so ill although tannins, fungal myotoxins and pesticides have been muted as a possible cause.

Green potatoes and the green parts of tomatoes.
These contain oxalates which can harm dogs by affecting the nervous, digestive and urinary system.

Macademia Nuts - Macademia
Again no one is quite sure of the toxin in these nuts that affects dogs adversely, however if these nuts are eaten by dogs within 12 hours they can develop weakness, depression, vomiting, muscle tremors, stiffness, and paralysis. Usually the dog will recover with 24 hours.

Onion – Allium        
There are approximately 700 species of Allium which include onions, chives and garlic, but onions are considered the most significant in terms of toxicity to dogs and cats.  Small amounts of garlic generally will not do any harm to dogs.  Poisoning can occur if animals are fed raw, hydrated or cooked onions or products containing onion powder.  Onions have the potential to cause haemolytic anaemia.  Infected animals will become weak and anorexic and their urine may be tinged brown.  Raw or cooked onions present a significant risk to all dogs but certain breeds, such as the Akita, may have a genetic predisposition to the effects of onions.  Cats, in particular, should not be fed any products containing onions. 

Salt
Large amounts of salt will cause an electrolyte imbalance and can lead to muscle spasm and even heart failure.

Xylitol
Xylitol is a natural sweetener used in confectionary and chewing gum.  The BVA (British Veterinary Association) are particularly concerned about its use as a baking ingredient in cakes, biscuits and other patisserie.  This sweetener stimulates insulin to such a degree that it can cause hypoglycaemia (low blood sugar) in dogs and can lead to liver damage.  The Veterinary Poisons Information Service are calling for products containing Xylitol to be clearly marked and to have visible warning and information of its effects and for retailers to be informed of the potential risks.