Do-it-yourself Fecal Exams
- tortoises & other animals -
Supplies for a fecal float test for parasites: microscope, slides, cover slips, test tubes, and floatation medium. This one is a digital trinocular microscope with an attached USB camera on top (off picture).
Internal parasites are one of the most frequently encountered medical problems in captive tortoises. Most tortoises carry some parasites and they can proliferate to large numbers when tortoises are stressed or live in crowded enclosures. When tortoises are kept in poorly sanitized environments they keep on reinfecting themselves and each other.
Many tortoise keepers perform periodic microscopic evaluations on their tortoises' feces to detect the presence of common parasites like pinworms and roundworms. This can be handy if you keep a large number of chelonians. For one or two tortoises, it's easier just to take a fecal sample to the vet. :O)
In addition to gross examination, two primary methods for performing fecal exams at home are the direct smear and the fecal floatation. For more accurate results, it's best to use a combination of both techniques. Scroll down for exam info.
DIY fecal exams are great for early detection and routine screening for common tortoise parasites. Frequent home screenings increase the change of detecting parasites that may only be seen intermittently in the poop. If three or more subsequent DIY fecal floats and smears are negative over a period of several weeks, your tortoise is probably free of common parasites or has a low parasite load.
DIY fecal exams also work well as pre-screenings. In other words, a positive finding will alert you to take your tortoise to a reptile veterinarian. If you do find something suspicious, it's always smart to verify the findings with your veterinarian.
Vet & medications
If you are a new tortoise keeper, always consult your veterinarian for the correct medication and dosing. Some deworming medications, like Panacur (fenbendazole, FBZ) used for nematodes (worms), are available over-the-counter, but many others need a prescription.
If you can't figure out what parasites you found in your tortoise's poop, take photos and show them to your veterinarian. It's also a good idea to take a fresh fecal sample with you for a thorough, professional lab analysis.
WARNING! Never use an ivermectin dewormer, e.g. Heartgard for dogs/cats, on tortoises or turtles. It's toxic and deadly for them!
Not everything you see moving under the microscope is pathogenic (disease causing). Tortoises have many beneficial bacteria present in their bowels to help break down food. This bacterial action is further helped by "good parasites". Routine deworming may disrupt this essential process.
For example, Nyctotherus, a ciliated protozoan, is considered an important part of the intestinal microflora. The 2008 book "Zoo and Wild Animal Medicine Current Therapy" by Fowler, DVM, DIPL ACZM, ACVIM, ABVT & Miller, DVM, DIPL ACZM lists both Nyctotherus and Balantidium ciliates as beneficial organisms in giant tortoises and thus should not be treated. Mader's book (see books) agrees with the nonpathogenicity. Though, Klingenberg (see books below) writes that Balantidium coli is the only ciliate known to cause disease in tortoises.
To deworm or not?
As with most areas of tortoise care, there's not always a consensus of opinion among tortoise experts and keepers about parasite treatment. Many keepers feel that tortoises should not be dewormed unless a fecal exam shows a heavy enough parasite load and/or the tortoise exhibits symptoms. Others think that routine deworming is a necessity for captive tortoises to help keep the parasite burdens low.
Using a microscope is fun, but it takes some practice to recognize what you are looking at. You may see so many different bits, pieces, sprinters, dashers, stretchers, and swirlers in the fecal sample under the microscope. Sometimes it's just a big party there. :O)
The books listed below will help you to identify the most common reptile parasites. For more veterinary books, see the books page.
1.) Simple digital microscopes
There are many digital microscopeson the market. I often use my inexpensive Celestron 44330biological microscope for quick fecal exams (pic below). It can be used by itself with the eyepiece as an optical microscope, or it can be hooked up to a computer to view the images digitally on the screen.
The eyepiece is 20x and the objective lenses allow 5x (100 power), 10x (200 power), and 20x (400 power) magnification. The 2 MP digital camera and attached USB 2.0 cable come with the microscope.
The Celestron 44330 microscope is simple, very basic, small, and portable
I don't like looking through tiny eyepieces, so I mostly view my slides on the computer screen. That's why I like to buy microscopes with digital cameras. :O)
The entry-level Celestron 4430 microscope is small, lightweight, and portable. It is very easy to use, even for a beginner or a kid. Just prepare the fecal slide, choose the magnification, and focus. Or attach the camera and view the slides live on the video screen.
The two photos on the right show computer screens with live video of fecal float slides using the Celestron microscope and attached camera (200x and 400x magnification).
Even though the Celestron 4430 microscope is quite simple and moderately priced, it's fine as a basic screening tool for detecting common parasites in the poop of reptiles and other animals (dogs, cats, goats, birds etc.) at 100x to 400x magnification.
The Celestron 44330 microscope comes with a CD-ROM for Windows, but it also works as plug-and-play on Mac's and on PC's running Ubuntu (a Linux-based operating system). I have used this microscope on all three systems.
On a Windows PC, I installed the ArcSoft software that came with the microscope. On a Mac, I viewed the microscopic images with Mac's Photo Booth. On an Ubuntu PC, I used the free Cheese web cam software. In addition to live viewing, these software programs also allow you photograph and record video of your discoveries.
Note: This page was originally written in 2008. This particular microscope may or may not be available later, but I'm sure there will be many other simple digital microscopes to choose from.
2.) Trinocular microscopes
A higher precision microscope with a 1000x magnification capability and special stains (coloring with dyes) may be required to identify some of the smallest protozoan parasites. For the sharpest image, a total magnification of 1000x and above requires the use of immersion oil on slides and an objective lens specifically designed for it.
My other microscope is a 40x-1600x digital trinocular microscope (pic) with a USB camera (imager). This microscope allows simultaneous focusing, in other words, it allows me to view images on the computer screen and through the eyepieces at the same time. This microscope is a lot bigger, heavier, and more expensive than the small Celestron above. It's definitely not portable. :O)
3.) Microscope imagers
If you already have an optical microscope, you can buy a digital imager for it. Digital imagers allow you to view microscope slides on your computer screen and photograph/record your findings.
For example, Celestron released an updated version of their digital imager (pic) for 2010. The Celestron 44421 Digital Microscope Imager replaces the older model 44420 which has been discontinued. It has a 2 MP sensor and connects with a USB cable. It comes with imaging software for PC's, but it also works with Mac's Photo Booth as plug-and-play.
The Celestron 44421 imager is very low-priced and adapts to most types of microscopes. I've tested it on my trinocular microscope and it works just fine. For the price and reasonable quality, some users have rated it as a "best buy" microscope imager.
Note: Digital imagers are not stand-alone cameras. They need to be connected to a microscope to view and capture images and video.
1.) Fecal gross exam
First, perform a gross examination on the poop. In other words, inspect the poop visually for color, texture, and consistency.
Is the poop dark and solid, in other words, normal? Any diarrhea? Diarrhea can be caused by parasites or a wrong kind of diet. Does it contain mucus or blood? Both can be signs of parasites.
If you see adult worms in the poop, it's obvious the tortoise has intestinal parasites. However, not seeing any worms does not necessarily mean the tortoise is parasite free. Usually, intestinal parasites are diagnosed by finding worm eggs, larvae, or protozoan parasites under the microscope. They are invisible to the naked eye.
A recently imported tortoise passed a bunch of these roundworms with feces while bathing. They were 3-5" long.
2.) Fecal smear exam
A direct fecal smear can be used to detect mobile protozoan parasites (e.g. Giardia) in the trophozoite stage (motile feeding stage). Use a poop sample that's less than one hour old. In an older poop sample, trophozoites will degenerate and became non-identifiable.
Just put a very small bit of fresh poop onto a slide and add a drop of distilled water or saline. Saline solution for rinsing contact lenses is ok to use. Stir gently with a toothpick. Put on the cover slip and observe under the microscope.
Fecal smear is a simple test to perform, but it may give a false negative, especially with low parasite levels, because only a tiny piece of poop is used for the exam.
Always use disposable gloves when dealing with feces and parasites. Disinfect all used surfaces afterwards.
3.) Fecal float exam
Performing a fecal float involves more steps than the direct smear. In addition to the microscope, glass slides, and cover slips, you'll need a floatation fluid and test tubes.
The fecal float test is used to detect parasite eggs, larvae, oocysts, and cysts in poop. The higher specific gravity of the floatation fluid causes them to concentrate on the surface (and attach to the cover slip) due to their lighter density. Consequently, parasites are easier to track down under the microscope because there are more of them in the sample.
a.) Floatation medium
Fecasol (sodium nitrate) by Vetoquinol and its generic version Fecamed are commonly used solutions for floatation technique fecal analyses. They are typically sold in one gallon bottles for $12-$30 depending on the brand and seller.
I fill small, plastic dispensing bottles with floatation fluid and saline. These bottles are available in many sizes. The ones in the photo on the right are 8 oz. Dispensing bottles are great because they allow me to both squirt the solutions to float test kits and add them drop by drop. For example, to add a drop of saline to a slide or to add drops of floatation medium to a test vial to form the meniscus.
b.) Vials & kits
You can use a small vial for the poop sample, but using a fecal floatation system kit (Fecalyzer by Vetoquinol or a generic), makes the test process easier. Float kits are used for poop collection and testing. They include cylinders (cup), caps (lid), and strainers (green insert). You can buy these test tubes individually for less than $1 each, or in a box of 50 for $25-$30.
c.) Slides & cover slips
Microscope glass slides and cover slips are inexpensive. A box of 70-100 slides and/or cover slips costs $5-$8.
d.) Steps in fecal float
- Put on disposable gloves.
- Remove the green insert from the Fecalyzer test cup.
- Pick a small piece of fresh poop, about the size of a pea or more, with the tip of the green insert.
- Put the green insert with the poop back into the cup and snap it down to secure it.
- Add fecal floatation solution, like Fecasol or Fecamed, into the cup up to the arrow, about half-way up.
- Stir and agitate the poop well in the fluid using the green insert. In other words, turn the green insert back and forth rapidly to break the poop apart. (Or, smash and stir the poop well with a toothpick in a small vial if you don't have a fecal float kit.)
- Fill the cup with Fecasol all the way to the top. The solution should arch over the top forming a curved upper surface called meniscus. Do not overflow.
- Put a cover slip over the cup. It must touch the Fecasol solution (pic).
- Wait about 20 minutes to allow the microscopic nematode eggs to float to the top and collect onto the cover slip. The recommendation for the wait time varies from 10 minutes to 30 minutes.
- Carefully lift off the cover slip straight up and put it wet side down on a microscope slide.
- Put the prepared slide under the microscope and examine immediately.
- To start, try using 100x or 200x magnification for scanning and 400x for closer identification.
- If you are viewing the slides on the computer screen, photograph and/or record your findings for later review.
- When done, disinfect all surfaces and throw away used cups, slides, gloves, and other contaminated items.
- Cyst - dormant cell with protective walls, a stage for a protozoan parasite
- Nematodes - roundworms, worms that are tubular in shape, e.g. pinworms (Oxyurids) and roundworms (Ascarids)
- Oocyst - microscopic stage of coccidia, a thick-walled spore that can survive outside a host for long periods
- Ova - eggs, sg. ovum
- Protozoa - unicellular organisms, sg. protozoan
- Trophozoite - motile stage of protozoa; growing and feeding stage inside the host