Which plants cause nephrotoxicity (oxalate toxicosis)?

• A. Lamb's Quarters (Chenopodium)
• B. Beet (Beta)
• C. Halogeton
• D. Rhubarb (Rheum)

Answer: (C)

Oxalate toxicosis happens when animals eat plants that are rich in soluble oxalates. The oxalates bind calcium to form calcium oxalate crystals, which can precipitate in the renal tubules and cause acute kidney injury. Halogeton glomeratus is especially notorious for its very high soluble oxalate content, so grazing animals can ingest a toxic amount quickly. This leads to rapid kidney damage, with signs like weakness and reduced urine output, and characteristic histology of tubular injury with calcium oxalate crystals. Other plants listed may contain oxalates as well, but Halogeton is the classic source associated with nephrotoxic oxalate poisoning in veterinary toxicology contexts.