Garbage Ingestion
A 5-year-old, neutered male Labrador retriever presented in the evening with a history of vomiting, ataxia, and generalized weakness.
History. That morning the owner found evidence that the dog had raided the trash can sometime during the night. The owner was not concerned at the time because he did not believe that there had been anything harmful in the trash that the dog could have ingested.
Vomiting, Lethargy, & Ataxia in a Dog
Ataxia & Vomiting in a Labrador
Diagnostics. On physical examination, the dog was depressed and reluctant to stand, had mild hindlimb tremors, and was hyperthermic (105.5º F). Abdominal palpation was unremarkable. Bilateral patellar reflexes were slightly exaggerated, but the rest of the neurologic examination was unremarkable. Clinical blood testing showed that serum lipase and serum alkaline phosphatase levels were approximately twice the high normal value. A complete blood count showed elevated white blood cells (22,450 cell/µl) with mature neutrophilia.
ASK YOURSELF ...Following are the contents of the trash can. Which need to be considered as the potential cause of the dog's signs?A. Raw carrots and celeryB. Quarter stick of unsalted butterC. Package of dehydrated French onion soup mixD. Macadamia nutsE. Avocado pit
Correct answer: D, Macadamia nuts
Macadamia nuts are a popular food snack for humans, but they can cause significant clinical signs if ingested by dogs-the only species in which macadamia nut toxicosis has been documented. The syndrome has been reproduced experimentally in dogs, although the precise mechanism of toxicity has not been defined. A toxic "dose" of roasted macadamia nuts for dogs has been estimated as approximately 2 to 3 g/kg (equivalent to approximately 1 nut/kg body weight). Dogs ingesting macadamia nuts may vomit; become weak, ataxic, or lethargic; and experience tremors and hyperthermia. Other reported signs include joint and muscle pain. Weakness generally manifests as reluctance or inability to rise and reluctance to remain standing. Fortunately, while the syndrome caused by macadamia nut ingestion in dogs can be unpleasant, it is not usually life-threatening. Most dogs recover completely within 24 to 36 hours of ingestion.
Laboratory findings that may be noted in dogs with macadamia nut toxicosis include elevated levels of serum lipase, serum triglycerides, and serum alkaline phosphatase and elevated white blood cell counts. Most of these findings are expected to return to normal 24 to 48 hours after ingestion.
Treatment of macadamia nut toxicosis generally involves care to relieve clinical signs-which are expected to resolve without specific treatment. Withholding food and water for a few hours often allows the stomach to settle enough for vomiting to stop. Reintroduction of water may then be attempted; ice chips or cubes may be used as needed to limit initial water intake. For animals with prior health issues and pediatric or geriatric patients, admission to the hospital for fluid therapy, antiemetics, and close observation may be prudent. If a coingestion of chocolate has occurred (eg, chocolate-covered nuts or chocolate macadamia nut cookies), estimation of the dose of chocolate should be made and appropriate treatment instituted if the chocolate dose is determined to be sufficient to cause methylxanthine toxicosis.
TX at a glance: see PDF
For related articles, please see the following:Activated Charcoal & Sago Palm ToxicityIs It Aflatoxicosis? Antidepressant ToxicosisBread Dough Toxicosis
MACADAMIA NUT TOXICOSIS • Sharon M. Gwaltney-Brant
Suggested ReadingMacadamia nuts. Gwaltney-Brant SM. In Peterson ME, Talcott PA (eds): Small Animal Toxicology, 2nd ed-Philadelphia: WB Saunders, 2006, pp 817-821.Macadamia nut toxicosis in dogs. Hansen SR. Vet Med 97:275-276, 2002. (http://www.aspca.org/site/DocServer/toxbrief\_0402.pdf?docID=115)