Taking a mucus scrape

Before ANY parasitic treatment should be applied to a pond the specific parasite should be confirmed. The wrong or guessed treatment can result in more stress on the koi and even lead to death.

Analyse which koi has the symptom's the most, (if any), by watching their movements and general condition. The down-side with selecting the 'weakest' koi is that adding stress to its condition, makes the matter worse, but you have to be cruel to be kind. If you feel the koi is too weak then select another! To do this, take one or two-mucus scrapes from a koi, and analyse each slide for parasites under a microscope.

How to take a mucus scrape:-

Different people have different techniques for taking a mucus scrape, all as effective as each other, but I will take only two scrapes from a koi in normal circumstances, or three at other times. The third being from the gills, only to be done by experience.

Until you have had practice I would anaesthetise the koi gently, to take two scrapes. It can be done without, but help is needed until the skill has developed.

It is always a good idea to have everything ready before hand:- Tissue, Bowl, Anaesthetic, two or three slides, cover-slips (plastic or glass), a help mate, experienced if possible, a wet towel or treatment mat, gloves and of course a microscope with a magnification of between 100x & 400x

After the koi is calm, and placed onto the mat or towel, take a spare slide and gently scrape from just behind the peck, in the muscle pocket towards the back of the koi. (see picture 1)

You don't have to apply too much pressure, enough to see mucus building up on the scraping tool, whilst moving.

The arrow indicates roughly how far to scrape.

You must always take the front to back direction, to avoid damaging scales etc.

A good idea I heard of is using a lollipop stick, to take the scrape, it is more unlikely to do any damage, I wouldn't advise using a sharp scalpel at any time.  (see picture 1)

Once you have acquired some mucus, then this is the tricky bit, you have to then transfer the mucus onto another slide and place the mucus as central as possible and put this slide out of the way. (see picture 2)

Then take a second scrape from the back of the head to the dorsal (see picture 3), taking care that you don't remove any pigment (colour) from the scales, again repeat the above and swap the mucus to another clean slide. Place the koi back into the water, and insure everything is ok.

Take a cover slip and squash out the mucus to near the edges of the cover slip, (see picture 4). The amount of mucus required is not that relevant, and will differ each time a scrape is done. Again repeat with the second sample.

If you feel the mucus is too thick then add a drop of pond water to the sample, but I find most of the time this is not necessary.

Both slides are then ready for examination under the microscope. (see picture 4)