After more research on Alpaca Nation, I decided to buy a microscope and centrifuge, as well as the various supplies needed to run the fecals at home. Some of the basic supplies are:
- microscope (with a movable stage if possible)
- test tubes that will fit the centrifuge (mine are 12 mL)
- glass slides
- glass cover slips
- popsicle sticks
- paper/plastic cups
- tea strainer
- gloves (latex, rubber, vinyl, etc.)
- plastic baggies or small tupperware containers
- float solution (saturated sugar solution in water)
|My supplies all set out to use! From L to R: tupperware containers with liquid fecal mixture, sugar float solution, strainer and paper cup, test tube rack with tubes, and centrifuge.|
- A day or two in advance, make up the saturated sugar float solution. You can also use a saturated Epsom salt solution, or even buy prepared solutions, but this seemed easy and cheap, and was widely used. Heat 12 oz water, add 1 lb sugar, and stir til the sugar is dissolved. Allow the solution to cool, then store in the fridge. I like to allow the solution to warm to room temperature before using.
- Collect your samples. I tend to go out in the evening after we feed (which only works in the winter, summer is harder since not everyone gets grain), or sometimes I catch everyone and take them to the pile one by one. Ideally you should collect samples from everyone, but I realize that isn't always possible. I've been lucky enough for the past few years to have exactly 6 animals, and my centrifuge holds 6 tubes! If I had a large herd, I would take a representative sample, and probably take more samples from "at risk" groups, such as new moms, weaned babies, older animals, etc. When I take samples from the pasture, I turn a plastic baggie inside out, and use it as a scoop to collect 5-6 beans from each animal.
- Next is the overnight soak. The best new tip I have is the importance of weighing samples. Beans can vary widely in weight, so the only way to be able to compare an animal's parasite load over time is to start with the same amount of material, and follow the same procedure. I've started using 3 g of fecal material for testing. I place this in a small tupperware container (or a new baggie works too), and then add 15 mL of water. Mix up the beans as much as possible, and let sit overnight (preferably outside in the cold or in the fridge).
|The LABELED tupperware containers filled with 3 g fecal matter and 15 mL water.|
- After a soak of 8-16 hours, I start the bulk of the procedure. The next step is the first spin. I pour the liquidy sample through the strainer, into a paper cup. The contents of the cup goes into a clean test tube, the solid stuff in the strainer gets discarded. Sometimes not all of the liquid will fit, and sometimes I need to add more water to get the same amount of liquid in each tube. It is very important that all the tubes have the same amount of liquid, otherwise the centrifuge may get off balance. I spin the tubes for 15 minutes.
|Straining the liquid solution into the cup.|
|Filling the test tubes with the liquid solution.|
- After the first spin, I pour the liquid out of the tubes (and discard), and add the sugar float solution (again, the same amount of liquid in each tube). I mix the solution with the remaining fecal pellet in the tube, and then centrifuge for another 15 minutes. The parasite eggs have a higher specific gravity than water, so they sink in the first spin. Thus, the water poured off shouldn't contain any eggs. The sugar solution has a higher specific gravity than the eggs, so it makes the eggs float. The liquid after the second spin should contain the parasite eggs.
- I have a fixed rotor centrifuge, so I don't feel comfortable filling the tubes all the way while they are in the centrifuge. Thus, I have to add more sugar solution after the second spin, in order to get a meniscus (bubble of liquid) on top of the tubes. After the second spin I add the sugar solution little by little until a little bubble appears on the top of the tube. I place a glass cover slip on top of the tube, and it should come in contact with liquid on the top of the tube. If liquid spills over, I dab at it with a paper towel so that it stops spilling. There's a bit of discrepancy in how long to let the cover slip set on top of the tube... Originally I did a 1 hour float, which seemed to work well, but a recent recommendation has me now running a 4 hour float. In the future I want to do my own comparison and see how which is actually better. You could even let the cover slip sit overnight, but the heavier eggs tend to sink faster, so you may not see as many of them.
|Filled test tubes with glass cover slips.|
- After the float time is up, I remove the cover slip and place it on a glass slide. I label my tubes and slides with the numbers 1-6, and each number corresponds to a specific animal.
- Then the fun part...reading the slides! Starting in one corner, I work back and forth across the slide, zig-zagging my way to the opposite corner. You will want to move slowly so that you observe and count every egg visible on the slide, and don't miss anything. I typically use the 10x magnification lens. I make tally marks on paper to count the number of eggs I see for each type, and then add them up at the end. If you weigh out your sample at the beginning, you can divide that number by the number of grams you started with to get a EPG value (eggs per gram). (Sorry, these pictures aren't as zoomed as I had hoped...)
|A view through the microscope. The green/yellow stuff is digested vegetable matter (grass/hay), the big silver/black dot on the right is an air bubble, but the three small grey ovals are strongyle eggs.|
|More plant matter and a bubble, with a nematodirus egg in the middle. These are quite a bit bigger than the strongyle eggs.|
- The last step is the hardest...deciding who to treat and with what! This is very subjective, and I definitely suggest you involve your vet! For me, a lot depends on the physical health of the animal, and what their parasite load was in the past few months. If I had a young animal who had a sudden increase in parasite eggs, I would probably treat at a lower level than if the animal was fully grown and had a fairly constant level of eggs.
- Some parasites are more dangerous than others. Typically strongyles aren't considered as dangerous, but if you see a really high load, you should consider the possibility that the animal has Barber Pole worm (Haemonchus). It is a very nasty strongyle that causes anemia and often leads to death. Unfortunately, it is impossible for the naked eye to distinguish between barber pole and a less-dangerous strongyle, so samples must be sent to Oregon State or the University of Georgia for specific testing. Barber pole is now fairly wide-spread, and very easy to pick up at shows... E. mac is a more dangerous type of coccidia, which is also important to watch for. Small coccidia are not quite as bothersome, unless a young animal has a very high load. Nematodirus and trichuris are two more that are typically treated even if the load is light. Tapeworms are one of the few internal parasites that are almost impossible to see in a fecal, but they are very obvious in the manure piles so they are easy to spot. Most vets don't worry about treating for tapeworms, but I liked to get rid of them just for my peace of mind!
- What you decide to treat with can also be dependent on which animal you are treating, as well as what part of the country you are in. In most areas, ivermectin is no longer effective against internal parasites due to being overused to prevent Meningeal worm. Safeguard/Panacur is becoming less effective, unless given at very high doses. Valbazen is still fairly effective (we have seen resistance in strongyles, but it works for nematodirus and trichuris), but should not be given to young animals or bred females. I love using Equimax to treat tapeworms, but I haven't tried it for anything else. Strongid may also work for strongyles, but I haven't used it in years. One of the new "big guns" for strongyles (Barber pole in particular) is Quest. It worked great for us in eliminating a load of strongyles. For coccidia, different meds are required. Corrid is the old standard, but you should supplement with vitamin B. Albon is what we typically used, and it seemed to work well.