Weakness, tremors, and depression associated with macadamia nuts in dogs

The ASPCA National Animal Poison Center managed 29 cases of ingestion of co mmercially available macadamia nuts in dogs during a 5-y period. Clinical s igns included, from most to least, weakness, depression, vomiting, ataxia, tremor, hyperthermia, abdominal pain, lameness, stiffness, recumbency, and pale mucous membranes. The onset of clinical signs was reported as < 12 h i n 79% of the cases. The duration of clinical signs for the majority of case s was < 24 h. The amount of macadamia nuts ingested was estimated in 72% of the calls with a mean of 11.7 g/kg bw. In an attempt to reproduce the synd rome, 4 dogs were gavaged with 20 g macadamia nuts/kg bw in a water slurry. The experimentally dosed dogs developed weakness, manifested by the inabil ity to rise 12 h after dosing, mild central nervous system depression, vomi ting, and hyperthermia, with rectal temperatures up to 40.5 C. Mild elevati ons in serum triglycerides and serum alkaline phosphatase were detected. Li pase values peaked sharply at 24 h and returned to normal by 48 h after dos ing. Other serum biochemical and electrolyte determinations were unremarkab le. Serum lipoprotein electrophoresis determinations were unchanged from ba seline. The mechanism of the syndrome is unknown. All field and experimenta l dogs recovered uneventfully within I to 2 d whether treated by a veterina rian or not.