Ethanol (5%) and isopropyl alcohol (2.5%) are effective and safe immersion anesthetics for ramshorn snails (Planorbarius corneus).

OBJECTIVE

To evaluate 2 immersion anesthesia protocols in adult ramshorn snails.

METHODS

In this experimental study, adult ramshorn snails were immersed in ethanol or isopropyl alcohol. In the pilot phase, ethanol (2.5% to 20%) or isopropyl alcohol (1% to 10%) were evaluated. Subsequently, in a randomized, blinded, complete crossover study with an 11-day washout period, ethanol 5% and isopropyl alcohol 2.5% were compared. Anesthesia parameters were recorded every 5 minutes, and data were compared using nonparametric tests.

RESULTS

Ethanol 20% and isopropyl alcohol 10% resulted in 100% mortality (n = 8) within 2 days of the pilot trials. Ethanol 5% and isopropyl alcohol 2.5% immersion achieved anesthesia within 75 minutes in all snails (n = 16). The median time to induction was faster for ethanol than isopropyl alcohol (median, 35 [15 to 75 minutes] and median, 42.5 [30 to 75 minutes], respectively; P = .009), and the median time to return of normal movement was faster for isopropyl alcohol than ethanol (median, 17 [8 to 46 minutes] and median, 22 [8 to 110 minutes], respectively; P = .005). There was no difference in time to first movement between protocols (isopropyl alcohol median, 9 [6 to 16 minutes]; ethanol median, 9.5 [6 to 22 minutes]; P = .8). Adverse effects were limited to mild to moderate mucus production with both protocols (28%; n = 9).

CONCLUSIONS

Ethanol (5%) and isopropyl alcohol (2.5%) are effective and safe anesthetics for ramshorn snails.

CLINICAL RELEVANCE: Isopropyl alcohol is widely available, representing a simple and effective protocol for immersion anesthesia in this species.