Wednesday, April 18, 2012

Animal Health: Fecal Egg Counts (FEC)

By Leona Grearson Bizzozero

This spring I attended a conference on gastrointestinal parasitology hosted by a SARE Research & Education Project to Improve Small (& modified) Ruminant Parasite Control in New England. I am not a veterinarian or vet tech, but like most folks that raise camelids, sheep, goats, and other livestock, it is my mission to ensure that I provide the best possible environment & humane treatment for the animals under my umbrella of care. I partner with my veterinarian team, yet I recognize that camelids remain 'exotic' in North America. Knowledge, understanding, and husbandry techniques continue to evolve within university and professional communities. For example, not all available anthelmintics (anti-parasite drugs) are currently approved for alpacas or llamas. This is problematic for new and seasoned camelid owners alike. To further complicate matters, there are differing views on if, when, and how often to treat alpacas & llamas for internal parasites.

Fecal Sampling

Periodic fecal sampling, including fecal egg counts, will provide information as to types and numbers of parasites present. This information will allow you to review your herd data with your veterinarian to determine the best deworming program, if any, to improve herd health.

Average Cost Per Sample: $5 — $20

I fancy that all camelid owners are smart, savvy, and sensitive. How could we not be? We choose to dedicate time, effort, and means to simply commune with the stoic Zen of alpacas & llamas. So before throwing hands up into the air and exhaling a deep resigning sigh, inform yourself about the parasite loads carried by your herd. Once you have an informed snapshot, then you can make sound decisions on how to reduce the parasite burdens and increase the health & well being of your animals, rather than blindly treating an entire herd for parasites that they may or may not carry. I encourage you to test the poo before you do any gastrointestinal anti-parasite treatments.

Fecal Sampling

A technique that involves examining dung from an individual or a group of animals to determine the number (and/or type) of gastrointestinal parasite present. Fecal sampling will only identify parasites that live in the digestive tract. What does fecal sampling involve?
  • Collection of specimen: Fresh manure is collected and should be stored in a clean, air-tight, dry container such as a plastic sandwich bag, mason jar, or the like.
  • Collect either from individual animals or from communal dung pile.
  • Label each specimen with date, animal name/dung pile location, and your farm name.
  • Store sample(s) in cool, dry place (refrigerator) until you can provide to your vet or other testing facility.
  • Sample Process & Analysis: A portion is mixed with a solution that causes the eggs to separate & float to the surface.
  • The mixture is filtered removing all possible debris and the residual is observed under a microscope where eggs are counted.
  • The results are measured as eggs per gram (epg) of dung.
Some owners believe it's a waste of time and money to perform fecal testing. On the contrary, administering chemical dewormers when not warranted is not only a waste of money, time & effort, but may inadvertently develop drug resistance in parasites while lessening the overall effectiveness of available products.

Drug Resistant Parasites?

When an alpaca or llama is exposed to parasites, bacteria, viruses, etc. it will develop specialized cells to fend off infections from the foreign organisms. Some of these cells will produce life long immunity after a single exposure. Other cells may produce immunity for as little as several months. Low level repeated exposure to a foreign organism can stimulate the immune system to continue producing the specialized cells reducing the severity of future infections. Resistance is very common in sheep and goats and increasing in alpacas and Ilamas. The fact is that anti-parasite drugs are unable to completely eliminate an entire population of parasites. The few that remain are resistant to the drug and with time, reproduce creating a new population that is also resistant. Given that indiscriminate use of chemical dewormers, shipping animals, open herds, and inadequate biosecurity only encourage resistance; performing routine fecal sampling will help take the guess work out… To keep costs minimal while obtaining meaningful herd parasite load data, begin your sampling focus during the times of year when worm egg counts increase.

Birthing Times

Worm egg counts will rise during birthing times as females are under stress. Testing at this time of increased egg levels will determine the parasite burden that will be present in the cria fields. Autumn fecal egg counts performed in the fall will yield infection levels from summer grazing and ensure animals are not going into winter with worm counts high enough to adversely affect health & welfare. Anthelmintics should complement but not replace good management and sanitation practices. Camelids are not immune to parasites, but there are practical ways to reduce the need for anti-parasite drugs. As simple as it may sound, practicing sanitary barnyard management strategies, including feed bunkers for hay & grain, eliminating standing water and wet areas around waterers, and routinely removing dung will reduce the favorable environment most parasites need to become infective.

  • Frequent cleanup of the dung piles, effectively planned pasture rotation and grazing multiple species on pastures reduces parasite load while lessening the possible chances of exposure.
  • If you are not removing dung piles, especially large seasonal piles, then fence them off to exclude animal exposure for several seasons, allowing the manure to compost.
  • Incoming animals are stressed from transportation, new surroundings, and removal from existing herdmates. The stress can cause a mild immunosuppression, causing an increase shedding of parasites or other organisms. When a new animal arrives on your premises, practice quality biosecurity measures by quarantining the animal from all other similar species for thirty days. Utilize distant pens, paddocks, & pastures for all incoming animals to help reduce exposure of the existing herd to new parasite species as well as other diseases. 
Don't Guess… Test!

Further Information: Contact your Vet for fees/services available locally. The Southern Consortium for Small Ruminant Parasite Control provides a variety of guidance for farmers including a guide to egg per gram (epg) counting. You can also visit Leona operates Hespe Garden Ranch & Rescue in Washington, VT providing a safe haven for camelids in need while practicing symbiotic agriculture to humanely enhance animal health, happiness and overall yields.

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