Ozarks sheep and goat producers know that spring is the time to gear up for a never ending battle against parasites. While the external varieties; ticks, lice, flies and mosquitoes, are summertime skirmishes, internal parasites wage their war secretly, almost invisible until their damage begins to surface.
Gone are the days when producers could feel good about regular herd-wide medicating with chemical dewormers. “We don’t expect any new chemical dewormers to come out for the next ten years,” stated Missouri State University Assistant Professor, Beth Walker. “Producers need to use management practices and should not rotate dewormers. It has been common practice to use a different type of chemical dewormer at each treatment to hopefully prevent the worms from becoming resistant, but it hasn’t worked like that. Most scientists are now recommending that producers use the same dewormer until it quits working for them.”
Parasites can become resistant to dewormers. Deworming kills the worms that are genetically susceptible to the chemical used in the dewormer. Those that are genetically resistant survive to pass on their resistant genes to the future generations making an army of resistant parasites in a short time.
Selective treatment with FAMACHA©
“Twenty percent of goats contain 80 percent of the parasites in a herd,” Walker said. “That 20 percent pass along the eggs to reinfect the herd.” By focusing on fixing or culling that 20 percent, producers can dramatically reduce their parasite population.
Because internal parasites such as the barber pole (Haemonchus Contortus) or the brown stomach worm (Ostertagia circumcinta) feed on large amounts of blood, anemia is one of the first sign of infection. These parasites also cause ‘bottle jaw’ due to fluids flowing out of the blood stream and resting in areas such as the jaw, but the lungs are also affected.
FAMACHA is a new method of identifying individual goats and sheep suffering from anemia and rating the severity of the anemia by comparing the inner lower eyelid color to FAMACHA's trademarked color chart. “Remember, ‘the redder the better’,” Walker said.
Named for its originator, Dr. Francois “Faffa” Malan, (think FAffa MAlan CHArt) FAMACHA has greatly impacted South Africa’s meat goat industry, which has been ravaged by Haemonchus Contortus. With the FAMACHA method, two people can move through a flock of sheep or goats checking each one. If the eyelid shows signs of anemia, the dosage of wormer can be adjusted to the severity of the parasite load.
The FAMACHA program recommends that fecal egg counts be taken every two years to be certain that the dewormer is effective.
FAMACHA© techniques
With one person restraining the animal, the other should roll down the bottom eye lid. Match the color of the membrane to the five-level color chart on the FAMACHA scale card. Tag or dose the animal as necessary and move on to the next.
Check both eyes in bright sunlight.
Do not hold the eye open for more than a few seconds.
Keep records and tag the animal so problem individuals are easily spotted at the next check.
Re-examine every two weeks during warm, moist seasons and every four to six weeks during dry or cool times.
FAMACHA certification workshops are held by University Extension offices. Those wishing to know more should contact a veterinarian certified in the technique or their local extension office.
Other Parasite Management Techniques
In addition to practicing FAMACHA, there are some standard management practices that can reduce the parasite population in the herd and in the soil.
First, don’t overstock the land. Practice rotational grazing between species by alternating sheep and goats with cattle and horses.
Practice dilution strategies by running two or more species at the same time.
Rest pastures for at least two months.
Don’t over graze. Parasites only go 2 to 3 centimeters up the blade of grass.
Consider homeopathic strategies. Studies are ongoing involving tannins such as Quebracho extract and Sainfoin hay in the control of internal parasites. Sericea Lespedeza is also reputed to be an excellent dewormer, however, it is now considered a noxious weed in Missouri because of its aggressive growth, and is illegal to plant anywhere in the state.
