Quote:
Originally Posted by Wylie's Mom  By .5, do you mean 50% or .5% or something different? A little bit of onion won't likely do harm, but you should definitely call your vet and ask about it. Please let us know that your kiddo is okay. |
Good question! I looked it up and it's 5 g/kg for cats, and 15 g/kg for dogs, so they probably meant .5%, which is the toxic dose for cats. Here is a link to the article, and just in case it's behind a firewall, I will quote the part about onions:
https://www.vetlearn.com/_preview?_c...-dogs-and-cats Garlic and Onions
Onions and garlic are members of the genus
Allium, which also includes leeks, chives, and shallots. The toxicity of onions in dogs was first recognized in 1930, when dogs fed onions developed anemia during a research study.1 It has since been determined that onion juice, as well as dehydrated, powdered, and cooked onions, can cause hemolytic anemia in dogs and cats.2 Most cases of toxicosis are attributed to a single episode of accidental ingestion of raw onion or feeding of foods containing onions or garlic. The toxic dose has been found to be as low as 5 g/kg in cats and 15 g/kg in dogs.2 A medium-sized onion (2 to 3¼” in diameter) is approximately 150 g, and the average weight of a garlic clove is 6 g. A 10-lb dog would ingest a potentially toxic dose by eating only half of an onion. Crushing or chewing
Allium spp releases allicin, which quickly breaks down into the toxic component n-propyl disulfide. N-propyl disulfide causes oxidative damage to hemoglobin and erythrocyte membranes, resulting in the formation of methemoglobin, Heinz bodies, and eccentrocytes, which then lead to intravascular hemolysis and anemia.3,4 Cats may be more sensitive to the toxic effects of onions because of differences in feline hemoglobin that result in an increased sensitivity to oxidative damage.
Clinical Signs
Initial signs of ingestion may include vomiting, diarrhea, and hypersalivation.2,3 Clinical signs may not develop for 1 to 5 days as hematologic changes begin, resulting in pale mucous membranes, weakness, ataxia, anorexia, depression, tachypnea, and tachycardia secondary to anemia.2 Icterus and hemoglobinuria may be seen secondary to intravascular hemolysis.2
Laboratory Findings
Abnormalities seen on a complete blood count (CBC) include decreases in packed cell volume (PCV), hematocrit, and hemoglobin concentration.2–4 Increased reticulocyte counts and neutrophilic leukocytosis may be seen in response to the anemia.3,4 Methemoglobin concentrations and the percentages of erythrocytes with Heinz bodies or classified as eccentrocytes are increased. 3,4 Hyperbilirubinemia is a common finding on a chemistry panel.2 Hemoglobinuria is seen on urinalysis and may result in an increased blood urea nitrogen level caused by transient nephrosis.2
Treatment
There is no specific antidote for onion or garlic toxicosis. If the patient presents within a few hours of ingestion of a potentially toxic amount, decontamination by emesis induction is recommended. Administration of activated charcoal with a cathartic may be beneficial if emesis is unsuccessful. Once clinical signs are present, treatment is supportive care. Intravenous (IV) fluids are recommended to correct dehydration from vomiting and promote diuresis to reduce the potential for hemoglobin nephrosis.2,5 The PCV should be monitored daily for 5 to 7 days. If anemia becomes severe, transfusions with whole blood or packed red blood cells may be needed.2,5 Antioxidants have not been shown to be beneficial.2
Prognosis
The prognosis depends on the severity of the anemia but is typically good with appropriate supportive care.2 Dogs with experimentally induced toxicosis eventually had complete resolution of anemia with no treatment.1,3,4