GuideIdentify internal parasites (using a microscope)
Target groupCorvids
NOTE: In all my guides, I start from a situation where a rehabilitator takes his responsibility to take care of the animals in an ethically correct way. You should always try to minimize stress for the bird and since the birds, just like humans, are not the same, it can mean that you handle a problem in different ways by being creative! If I see different ways of doing the same thing, I try to write it down in my guides, but it is always up to the rehabilitator to take their own responsibility.
I do not have to write “I recommend killing” or “contact a veterinarian” or “according to law, you should …” because I start from the situation where you do the best for the bird and that you as a rehabilitator have learned to draw the line so that you do not end up in an unwanted or illegal situation. There may be an eternal battle between what you want and what is best for the bird.
There are also many factors where a similar situation can give different results. For example: access to a veterinarian, lack of time, lack of knowledge and previous experience can include cause large differences in the treatment and decision-making process and indirectly also the end result. Knowledge of basic things can make a huge difference in the stress level of the crow. For example. avoid anything that is black or checkered. They do not like it instinctively and it creates stress when they see that you are dealing with something that is black.
I put energy into my guides to make it easier for a rehabilitator to find information and to spread knowledge.
Do you see a way to improve my guides or do you see a mistake or do you want to add something, feel free to inform me!
If you are worried about doing something because it is new, ask other rehabilitators or a veterinarian for help.
The guides are continuously updated, so make sure to always download the latest version from

This guide describes how to find common parasites in crows using a microscope.

There are two different ways to take a sample which is then analyzed under a microscope.

Method 1) Using a drop of saline
– Take some stool from the bird (about half of a match head in size)
– Put it on a clean slide
– Take a drop of sterile saline (saline solution, the easiest to find at a pharmacy) and put the drop on top of the stool sample
– Stir around a bit using a wooden stick or the back of a match. The best is of course to buy individually packed toothpicks, but they may not be so easy to get hold of.
– Place a coverslip on top and make sure it is completely flat on the slide
– Now you are ready to analyze the sample under a microscope.

Method 2) Using the so-called “floatation method”
A big advantage of this method is that it is easier to find parasites because you get a higher concentration of parasites / parasite eggs.

You first need to prepare a flotation liquid with salt or salt and sugar or using nitrate (it is best)

  1. Saturated saline

4 grams of salt in 10ml hot or hot water
Stir well before use.

  1. Salt / sugar solution

Sodium chloride: 4 grams
Water: 10 ml hot or hot water
Sugar: 5 grams

Dissolve the salt in water to make a saturated solution.
Stir well.
Add the sugar to the saturated brine.
Stir until the sugar is dissolved.

NOTE: Crystals can form if you wait longer than 20 minutes.

3. Nitrate solution

Nitrate (NaNO 3 ): 4 grams
Water: 10 ml
Take water first, and while stirring, so to top up with nitrates

If you find a product make sure that it is Sodium Nitrate (Sodium Nitrate) because Nitrate can also be something else!

Take a small glass / test tube (preferably not wider than a slide) and fill it halfway with the solution you have prepared + add bird droppings (take a small piece first and mix, add a little more and mix, etc. . until the liquid has clearly taken on a different color.
Now add the solution to the edge so that it bulges out a little at the top but not so much that it overflows. If you have difficulty getting this result, you can use a syringe or pipette.
Now place a slide on top (see picture) and wait about 10 minutes.
Lift off the slide and cover it with a coverslip.

Now you can finally continue to analyze the results under the microscope.

Roundworm / coilworm (eggs of …)

Roundworms are usually oval and have a double cell wall. Most often they create problems in the gastrointestinal tract. Some common species are: “Ascardia spp”, “heterakis gallinarum”, “Strongyloides spp” and “capillaria spp”

Gapworm (Egg of Syngamus trachea)

 Capillaria spp. eggs from two different New Zealand passerines. A, ... | Download Scientific Diagram

The worm is located in the bird’s trachea (trachea) and makes it difficult for the bird to breathe.

Tapeworms (Eggs of Cestoda)
Google “avian tapeworm” if you want to see more pictures

Coccidia (the infection is called coccidiosis)

Trichomonas gallinae (Canker)

Yeast fungus (various parasites: candida, aspergillus, cryptococcus, and malassezia)