Onion Poisoning in Dogs

Onion Poisoning in Dogs

Dog owners must have a fair understanding about foods that can be toxic for canines. This article deals with the various aspects of onion poisoning in dogs.
DogAppy Staff
You might have heard about the possible ill effects of chocolate on canine health. There are various other food items that can affect your pet dog's health detrimentally. This include macadamia nuts, grapes and raisins, avocado, rhubarb leaves, etc. While most of the pet owners are found to be aware of canine chocolate toxicity, many are found to have no idea about other toxic foods that include onions too. As onions are among those commonly used ingredients in a wide range of food items, the probability of feeding your dog with this vegetable is also very high.

Why are Onions Toxic for Dogs

Onions are among those oldest foods that has been used by humans. Though safe for humans, this vegetable that belongs to the Allium family are found to be toxic for dogs. In fact, other members of this family, like garlic and chives are also toxic for canines. However, onions are found to be more toxic, as compared to garlic. Onions, in any form, like, raw, cooked, dehydrated or powdered can cause symptoms of toxicity in dogs. This is because of the presence of thiosulfates in this vegetable.

While, humans are capable of digesting this compound, dogs lack this capacity. So, this compound is readily absorbed into the animal's bloodstream, where it acts upon and breaks down the hemoglobin molecules. This in turn damages the red blood cells, which get accumulated with Heinz bodies (which are nothing other than accumulations of damaged hemoglobin molecules). Such damaged red blood cells are rigid and are found to be incapable of normal functioning. They will eventually burst and get filtered out of the bloodstream. This leads to anemia (termed as Heinz body anemia) that may further lead to damage of vital organs like heart and kidneys. This explains why onions are toxic for dogs.

Signs of Onion Poisoning in Dogs

A mentioned above, intake of onions can be detrimental to a dog, who will develop symptoms that may range from mild to severe. The severity of such symptoms may vary according to the amount of intake, age, breed and size of the dog. Intake of onions in very small amounts may not produce any symptom in a dog. But, it may cause damage to the red blood cells and this may be detected with diagnostic tests. In order to produce symptoms, the dog must consume large amounts of onions in a single ingestion. Even repeated consumption of small amounts of onions within a short period of time may also produce symptoms of onion toxicity in dogs. The severity of toxicity may vary with the age, size and breed of the dog and the amount of onion consumed. However, in general, it is said that a dog may develop onion toxicity, if it consumes onions that amount to more than 0.5% of its body weight.

In case of single ingestion of onions in large amounts, symptoms can be severe. In some cases, dog may exhibit symptoms within a 24 hour. In case of repeated ingestion of onions in small doses, the development of symptoms will be more gradual. Symptoms of onion poisoning in dogs start with gastroenteritis. The dog will have vomiting and diarrhea, along with weakness and loss of appetite. The red blood cells will get damaged, thereby affecting the transportation of oxygen and nutrients to the organs. So, within a few days, the animal will develop pale to bluish gums, breathing trouble, increased heart rate, etc. It is also said that such dogs may develop a smell of onions in their breath. The urine of the dog may get reddish in color, as the damaged red blood cells pass out. Immediate medical attention has to be provided for dogs with such symptoms.

Onion Poisoning in Dogs - Treatment

Onion toxicity may range from mild to moderate and severe. Diagnosis of this condition is often done with blood tests. Early diagnosis and treatment is very vital for the survival of the affected dog, especially those with severe symptoms. While mild cases may not even require treatment, severe ones need urgent medical attention for saving the life of the animal. The mode of treatment may vary with the condition of the affected dog. The animal will be provided with intravenous fluids and supportive care. In case of severe symptoms, blood transfusions and oxygen therapy may also be required.

In short, onion poisoning in dogs can be fatal, if the amount of consumption is quite large. Even though, instances of onion poisoning are not common in dogs, it is not rare. There are chances that your dog consumes foods with onions. This include canned spaghetti, pizza, sandwich meats, Chinese dishes, certain commercial baby foods, onion rings, salads and even raw onion. So, store onion and garlic out of their reach and stop feeding them with leftovers and other human food. Make sure to go through the label of ingredients, before giving them any packaged food products.