Many of us find onions delicious. Raw as cooked, it is eaten daily in various dishes. But did you know that onions are very toxic to our dog friends?
The sulfur compounds in onion responsible for its toxicity for dogs
Onion is a vegetable that has been used since Antiquity not only for its taste qualities but also for its many pharmacological properties for humans. Hypotensive, diuretic, antimicrobial, antifungal, anti-hyperglycemic. We can no longer count its many benefits on human health.
However, beyond its many vitamins and compounds beneficial to humans, onion also contains sulfur derivatives that are very toxic to domestic carnivores such as cats, ferrets and dogs.
Onion poisoning causes hemolytic anaemia. In other words, the sulfur compounds in onion are responsible in dogs for destroying the red blood cells circulating in their blood. Cooking does not destroy the sulfur compounds in onion, so it is toxic to dogs in all its forms, raw as well as cooked, fresh as frozen or dehydrated. Small amounts of onion are enough to show signs of poisoning in a dog, starting at 11g of onion per kg of body weight.
These same sulfur compounds toxic to dogs are found in plants belonging to the botanical family of onions called the Alliaceae family. This family includes garlic and leeks, which are also toxic to dogs.
Signs of onion poisoning
The telltale symptoms of onion poisoning are actually visible or noticeable consequences of hemolytic anaemia. Thus, in the case of onion poisoning, one or more of the following symptoms may be observed:
Hemoglobinuria, or the presence of haemoglobin in the dog’s urine which stains it red or brown. This is referred to as a “coffee grounds” aspect of urine. This symptom usually appears within 12 to 24 hours after ingesting the onion. It may be the only visible clinical sign of poisoning and should prompt you to see a veterinarian right away.
A dejection of the animal.
Very pale or yellowish mucous membranes.
An increase in the respiratory rate intended to compensate for the lack of oxygen in the blood linked to the destruction of the red blood cells responsible for transporting this gas to the organs.
An increase in heart rate called tachycardia.
Splenomegaly (enlargement of the spleen, which becomes palpable).
More rarely, diarrhoea, vomiting and abdominal pain within 13 to 48 hours after ingesting onion.
Onion poisoning in dogs: what remedy?
If your dog has eaten onions or if you suspect onion poisoning, it is necessary to have your pet examined by a veterinarian without delay.
The veterinarian may perform urine examinations and blood tests to confirm or deny the poisoning.
If it really is onion poisoning, the prognosis is very rarely bad. The dog usually recovers spontaneously within a few days from this type of poisoning, but sometimes with severe poisoning, its symptoms must be treated. An infusion to protect kidney function damaged by the destruction of red blood cells may be given by the veterinarian. He can also prescribe vitamin E to his four-legged patient, the antioxidant properties of which have the effect of protecting the membranes of red blood cells. For the holders of an animal mutual, the care, as well as the treatment, are covered by your insurer.
The animal should be well supervised for 5 to 6 days after eating onions. To this end, the veterinarian may recommend hospitalization for a few days.