Dr. C

I’ve been getting asked about how to take care of pet leeches a lot recently, so I figured I would put all the information together in one ultimate leech guide. Enjoy!

Leech species

One thing I’d like to clear up right away is that there’s over 600 species of leech, and many different types of them are kept as pets. The three most commonly kept types are the European medicinal leech (Hirudo verbana), the Buffalo leech/Asian medicinal leech (Hirudinaria manillensis) and the North American medicinal leech (macrobdella Decora). However, I only keep the H. verbana, so this guide will be specific to them.

Acquiring your leech

One of the first questions I get asked is “where the hell do you even buy a leech?!” Well, I got mine from Leeches.biz. You could also contact a private leech breeder and buy some directly from them. One of the first websites that pops up when you google leeches for sale is Leeches.com, but I’ve heard some negative things about them. Besides, Leeches.biz ends up being cheaper if you’re buying more than one leech.

Housing your leech

Leeches are super easy to take care of. Here’s a picture of my setup:

It’s a gallon fishbowl, about half full of water (it’s filled a bit more than usual in this photo) with cheesecloth held on by a rubber band covering the top. A tight-fitting lid is very important for leeches because they love to climb and can squeeze out through the tiniest gaps. I have gravel and moss for the leeches to burrow through. I always recommend keeping gravel with your leeches, because they need to rub against something abrasive to assist in shedding.

Unlike fish, leeches don’t need a heater or filter. They do best in cooler water and can actually crawl inside filters and get hurt! They’re truly a low-maintenance pet that you can keep in a bowl or jar. As long as you change the water about once a week, your leeches will thrive.

Feeding your leech

Yes, medicinal leeches drink blood. These aren’t pets for people who get sick at the sight of blood.

Leech keepers have two options for feeding their pet; feed them off themselves or buy blood. Each has benefits and downfalls. Let’s examine them both a little, because this is an important thing to consider if you want leeches.

Feeding your leech off yourself is usually the easiest and cheapest option. Hirudotherapy is also a surprisingly popular thing, and many people buy leeches just for this purpose. I’ve fed my leeches on me before, and it’s not as scary as it might sound. Leeches produce a natural pain killer similar to morphine, which numbs the bite and can even reduce anxiety and improve mood. However, they also produce a very powerful blood thinner, which means you’ll be bleeding for up to 12 hours. Just like any other open wound, there’s also the possibility that the bite could get infected, although complications occur in less than 2% of people who use leeches (unfortunately I was part of that 2%, which is why I’ve stopped feeding them on me).

So, if you don’t feel like bleeding for 12 hours, you could also do what I’ve switched over to: buying blood/raw organs from butcher shops to feed my leeches. If you choose to do that, it’ll have to be heated up to body temperature to induce the leeches to bite.

The good news is, adult leeches only feed once every 4-6 months. In fact, they can go up to a year between meals. You won’t have to deal with blood on a daily basis.

Enrichment

Leeches honestly don’t need much enrichment. They’re very simple animals and are content to spend most of their day wiggling and sleeping. However, you can handle your leeches whenever you want. They don’t really mind!

Handling leeches is actually very fun. They’re always changing shape and texture, and they will often “sniff” your hand when you’re taking them out. This doesn’t necessarily mean they want to bite you, it just means they’re checking you out. Just make sure to keep an eye on them when you take them out of the tank, because they’ll crawl around and explore.

Problems with your leech

Leeches are usually very healthy animals, but they can run into some issues. The main one is digestive problems. Here’s Squish Baby to demonstrate:

See the kink in his side? That means one of his crops (blood storing organs) is twisted and he can’t digest the blood inside.

These digestive problems can usually be solved by adding alder cones and/or catappa leaves (aka betta leaves) to the tank. Increasing the acidity of the water will boost the leech’s immune system and make it easier to recover from this kind of thing. (Squish Baby has made a full recovery, by the way)

FAQ

Do leeches bite every time you handle them?

Nope. If the leech isn’t hungry it won’t bite. When a leech is actively trying to feed, they aggressively “sniff” around an area before latching on, and you can pretty quickly recognize that behavior and put them down before they bite. If they do start to latch on and you don’t want them to, slide a fingernail under their front sucker and push up. They’ll immediately let go.

Doesn’t it hurt to let a leech bite you?

Not really. Some people don’t feel it at all. I do, but the pain is somewhere between a paper cut and a flu shot. It feels like pinpricks. It also depends on where you put them. For me, it was best to let them feed on my left forearm.

Do leech bites leave scars?

It depends on the location, whether you’re prone to developing scars, and how well the bite healed. My leech scars fade in about six months. But keep in mind, these are scars only about the size of a mosquito bite, so they’re not very noticeable anyway.

Should I talk to a doctor before letting leeches bite me?

Yes, you should. Not everyone is a good candidate for hirudotherapy. Additionally, some medications can hurt leeches, which is not ideal if they’re your pets.

Why buy a leech? Can’t I just get one out of a pond?

Yeah, you could. But wild leeches can carry diseases. It’s best not to have a pet that could give you a blood disease if it bites you. Leeches purchased from a breeder will have been given a very strict diet to ensure that they don’t transfer anything dangerous to their owner.

Why do leeches “dance”?

Leeches do a funky little wiggle when they want to breathe underwater. It’s very cute and frequently referred to as the “leech dance”.

I thought the European medicinal leech was called H. medicinalis?

There are actually at least three species of European medicinal leech. H. medicinalis was the one most commonly used in the past. Unfortunately, they’re now endangered due to overharvesting, and it’s illegal to keep them (unless you’re a professional leech breeder). The ones used in hospitals and most commonly available as pets now are H. verbana. If you ever see an H. medicinalis for sale, it’s almost definitely just an H. verbana mislabeled and sold for more money.

Is my leech a boy or a girl?

Both! Leeches are hermaphrodites and have both male and female parts.

How long can leeches live out of water? Should I be worried about them drying out while I’m handling them?

Leeches are almost always out of the water when feeding, and often travel over land. They’re adapted to be able to survive on dry land for hours, and if they’re in a moist area they could live out of the water for days. So unless they escape the tank and go for an unauthorized walk, you don’t need to worry about them drying out.

Leeches are gross and I’d kill one if I saw it.

That’s not a question. Fuck off.