Maintaining Leeches


The two most important things to avoid are heat and chlorinated tap water.


Distilled water plus HIRUDOSALT is recommended. Hirudosalt is a specially formulated recipe for making up water ideally suited for the maintenance of the medicinal leech Hirudo Medicinalis. Leeches may also be kept in dechlorinated tap water. The ideal water for long term storage would be distilled water with Hirudosalt. Do not use distilled water alone as it will deplete the animals “ions”. Simply stir 0.5g of Hirudosalt into each liter of water. The water is now ready for use. Aeration is unnecessary.
Change the water every other day or more often if it begins to look cloudy. If dead leeches are found when changing the water, dispose of them as indicated below (“Disposal”) and increase the frequency of water changes to once a day. After three daily water changes without further leech mortality, you may return to changing the water every other day.

A lid is essential. Leeches are amphibious and like to crawl about. The best container is one that has a wide opening at the top such as a large jar. This allows for easy access when dispensing leeches and can be easily covered by means of a piece of cotton fabric and a sturdy rubber band. If a lid is used, perforations are advised but they must be very small indeed, as the leech body is elastic and capable of going through remarkably small openings. So, do not overcrowd. No more than 50 leeches should go into a 10 liter container. We recommend that you place the container in a cool dark place that will provide temperature no higher than 500F, or as close to 400F as possible. Never put leeches in direct sunlight. If storage in a dark area is not possible, place a cover over the leech container when not in use. Leeches may also be kept in a refrigerator. In this case, it will be necessary to remove them from the refrigerator several hours before use, letting them stand at room temperature to allow them to recover their mobility.

Container Disinfection:
Leeches from different lots must always be stored in separate containers. When all the leeches stored in a container have been used and disposed of, it is important to empty the container of any remaining water. Thoroughly rinse and disinfect the container in accordance with the disinfectant manufacturer’s instructions. After disinfection, be sure to thoroughly rinse the container again with tap water in order to remove all traces of disinfectant, which may harm the leeches. After rinsing the container, refill it with distilled water plus HIRUDOSALT, as indicated above, before using it to store a new lot of leeches.

Keep fed leeches in a separate container and properly discard as infectious material. Once used, leeches must never be reused on the same patient nor on another patient.
1. After detachment or removal from patient, leeches should be treated as a contaminated biohazard material. Each leech should be killed by immersion in 70% alcohol solution for 5-10 minutes and  disposed with other biohazard materials.
2. Return unused leeches to the pharmacy to be put back in the container for storage.