Which of the following is a common clinical sign of acorn toxicity?

Perirenal edema is a recognized clinical sign associated with acorn toxicity, particularly in livestock such as cattle and sheep. Acorns contain tannins and other compounds that can be toxic in large quantities, leading to gastrointestinal distress and renal damage. The presence of fluid accumulation around the kidneys signifies the body's response to damage and can indicate significant underlying issues related to acorn ingestion.

In cases of acorn toxicity, it is important to monitor for renal function, as these toxins can lead to nephrotoxic effects. The accumulation of fluid, or edema, around the renal area highlights the systemic impacts of these substances on the animal's health.

The other signs mentioned, while relevant to various types of poisonings or health issues, do not typically reflect the specific manifestations of acorn toxicity. Jaundice is more often seen in hepatic conditions, neurological symptoms can arise from a variety of different toxins, and skin lesions are not a hallmark of acorn-related poisoning. Therefore, perirenal edema stands out as a clear indicator of this particular toxicity.