Macadamia nuts are have been shown to be toxic to dogs at doses as low as 2.4g per kg body weight. They cause a variety of signs including weakness, lethargy, vomiting, tremors and weakness in the back legs and a fever. Severely affected dogs may not be able to stand.
Although the problems may resolve without treatment within 48hours, some animals have been reported to develop complications especially those with pre-existing conditions. In addition, unless there is a definite chance of access to Macadamia nuts, the signs of intoxication can often be similar to other more serious problems like snake envenomation, spinal problems, meningitis, etc.