The single most practical predictor of clinical performance is whether a leech is properly fasted. It determines whether the animal attaches and draws when you need it to.
Leeches feed infrequently and can take a large meal relative to body size. After feeding they are sated and uninterested in attaching for days to weeks. A clinical leech must arrive in the hungry, ready state.
What fasting delivers
- Prompt, reliable attachment at the target site
- A meaningful draw rather than a token bite
- Predictable behaviour for the clinical team
Why it depends on the supplier
Correct fasting is a husbandry outcome — it depends on feeding cycles, holding conditions and timing of dispatch. It cannot be improvised at the bedside, which is why it belongs in the supply chain, not the clinic.