Selontra® is a cholecalciferol (vitamin D3) rodenticide bait previously only available in the US, South Africa, New Zealand and Australia. However, the manufacturer BASF have now launched this product in the UK for professional use only and therefore please be aware of this when handling rodenticide cases. The bait contains cholecalciferol at a strength of 0.075% (75 mg/g) and treatment would be required if a dog/cat ingested over 0.67 g of Selontra®/kg bodyweight. The product is presented as 20 g pale green, soft square bait blocks which are shrink wrapped in non-absorbent, transparent film which distinguishes them from other rodenticides with different active ingredients. The blocks are usually secured in bait stations or on wire.
The onset of clinical signs of cholecalciferol toxicosis is variable, but is usually within 12-36 hours. Clinical signs are initially non-specific, with polyuria and polydipsia, anorexia, weakness, lethargy, vomiting and diarrhoea. As the calcium concentration rises there may be severe vomiting, anorexia, constipation, ataxia, dyspnoea, tachypnoea, arching of the back, twitching and convulsions. In severe cases, hypercalcaemia, hyperphosphataemia and deposition of calcium in tissues may cause initial tachycardia, then bradycardia and renal insufficiency or renal failure.
The long half-life of cholecalciferol means that treatment is often ongoing and monitoring is required for weeks. The aim of treatment is to keep the serum total calcium concentration <3 mmol/L, reduce serum phosphorous concentration, and ensure adequate hydration and urine output. Prognosis is good if treatment is started early, and calcium concentrations are controlled. If signs are severe or advanced (especially if there is calcification of tissues), or if haematemesis is present, prognosis is guarded.
The risk of secondary exposure after ingestion of an animal which has died from cholecalciferol poisoning is LOW.