This post will give you everything you need to know about the complex and toxic relationship between onions and dogs, including what makes onions a major no-no for canines, what will happen to your dog if he happens to ingest an onion, and what action you should take should such an instance occur. In most cases, it’s important to take your dog to the vet as soon as possible.
Is It Bad If My Dog Ate Onions?
Dogs can actually get sick from both raw and cooked onions. And the harm an onion can cause a canine goes well beyond bad breath — it can even be life-threatening.
The agent in onions that is toxic to dogs is known as N-propyl disulfide or thiosulfate. This is a compound that causes a breakdown of red blood cells because dogs do not have the enzyme needed to digest this substance. This can lead to anemia in dogs, among other potential canine health problems.
More specifically, the toxic portion of an onion can cause damage to your dog’s red blood cells by attaching to the oxygen-transporting protein, called hemoglobin, in your dog’s red blood cells. This will reduce the red blood cells’ ability to carry oxygen throughout the animal, and will also trick your dog’s body into thinking that the blood cell is an invader. This triggers a process known as hemolysis, which will destroy the red blood cell and result in hemolytic anemia.
When hemoglobin is oxidized, it will form clumps called Heinz bodies. These Heinz bodies cannot carry oxygen, and will cause the red blood cells to carry oxygen less efficiently.
What Part of an Onion is Toxic to Dogs?
No specific part of an onion carries the toxin that is harmful to dogs — they’re in the whole thing! Onion Toxicosis can occur from ingestion of: