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WORMS: RESISTANCE, TOLERANCE, SUSCEPTIBILITY

The blood-sucking internal parasite H. Contortus, commonly called the barberpole stomach worm, is the most significant challenge to raising healthy goats.

Goat producers stay in a non-stop battle with this stomach worm. All goat breeds are affected by H. contortus. No goat breed is resistant to any internal parasite, especially the barberpole stomach worm. If someone tells you otherwise, they are either lying or ignorant about goats.Do you know why stomach worms are such a huge cause of goat deaths?

Haemonchus contortus worms suck blood, producing severe anemia by depleting blood volume and destroying red blood cells that carry oxygen to the goat's organs, including heart, lung, liver, kidneys, digestive system, brain, and even muscles. Goats can be so "wormy" that they cannot stand because their muscles don't have enough oxygen to make them function. A heavy wormload is a totally preventable condition. Until the goat is too far gone to be saved, the animal will continue to eat and eat and eat . . . all the while losing its struggle against the stomach worm.

To raise goats successfully, you must develop an organized plan for controlling stomach worms in your herd. You begin by doing fecal counts using McMasters slides using an MSK-01 microscope with a moveable stage and finding out the barberpole worm egg count in your goats' fecal pellets. No other diagnostic tool comes close to the accuracy of fecal egg counts.

Do not randomly select a dewormer. Get fecal counts (using McMasters slides) done by a vet to find out which internal parasites are present in your goats. Even better, buy the supplies you need and do the fecal egg counts yourself. Reference my article DOING YOUR OWN FECALS IS EASY on the Articles age at www.tennesseemeatgoats.com. Most vets don't understand how badly stomach worms affect goats and seldom use McMasters slides to determine the actual number of eggs. You must know the actual number, and my article cited above explains why.

The odds are good that the dewormer you are currently using isn't the most effective one and may not be working at all. One day you will wake up to an overload of stomach worms in your herd and it will hit you (and them) like a ton of bricks. Get ahead of the problems by doing your own fecals so you can determine which dewormer really works with your goats.

All goats have worms of some type and in some quantity. Their existence is necessary to stimulate the goat's immune system to fight them. Use the FAMACHA field test initially to confirm a potential problem. If the inner lower eye membrane isn't RED to BRIGHT RED, you have a worm problem. It is that simple. However, the extent and depth of the worm problem can only be determined by doing fecals using McMasters slides and trying different classes of dewormers in conjunction with performing microscropic fecal egg counts. You have to determine which dewormer kills 95% of the worms in a seven day period. If it didn't kill 95% of them in seven days, it failed.

Once the worm causing problems is identified, choose the correct dewormer and use it until it quits working. Do not rotate dewormers.

Sometimes you may have to use two different classes of wormers at the same time to get wormloads under control. Develop the habit of checking the coloration of the inner lower eye membrane (FAMACHA field test) every time you handle a goat for any reason. The inner lower eye membrane should be red to bright red. If it is pink to light pink, the goat is almost always wormy; if it is white, the goat is anemic and needs more help than deworming. See my article on Anemia on the Articles page at www.tennesseemeatgoats.com for treatments. Do microscopic fecal egg counts randomly at least monthly to stay on top of the wormload.

Remember that the FAMACHA field test is only good for identifying the Haemonchus contortus stomach worm. In most of the USA, other worms can also cause substantial production losses and health issues without causing anemia and death, making FAMACHA of limited value.

Goats are the step children of the livestock industry. Dewormers that we use with goats are "off-label," i.e. they have been manufactured for use with other more numerous ruminant species (usually cattle). Companies have not spent the time and money necessary to test the dewormer for effectiveness, accurate dosing, withdrawal times, and obtain government approval to label the product for use in goats. Goats as a species are not a large enough market for the manufacturers to earn back these costs and make a profit. This is true for almost all medications and biologicals that we use with goats.

Those few dewormers that have been approved for use with goats are not effective. Safeguard/Panacur has been approved for use with goats, but in most locations in the USA, it is no longer kills stomach worms. Morantel tartrate, a feed-based dewormer, has been approved for use with goats, but feed-based dewormers are not effective when goats are fed in groups because the goat needing the medication the worst will also be the lowest in the pecking order and will therefore get the least amount of medicated feed.

Goats should be individually orally drenched with a weight-appropriate dosage of dewormer. This same reasoning applies to medications put into water for liquid consumption. Back drenches, also known as pour-ons, are not effective with goats because of their hide structure. If used as a back drench, dewormers may cause neurological problems in goats.

Goats are dry-land animals who are very susceptible to internal parasites, especially stomach worms. Think of them as "first cousins" to deer in how they live, eat, and roam over multiple acres of land. They instinctively eat "from the top down" like deer to protect themselves from stomach worms. Goats made to graze on pasture will get infected with stomach worms, especially on short pasture. Taller grasses are not a solution, because goats search for the newest and most tender sprigs as they are the most nutritious. These new sprigs are closest to the ground, where the blood-sucking stomach worms are waiting to be ingested.

There is much confusion and outright disinformation regarding the level of Resistance, Tolerance, and Susceptibility to worms by different meat-goat breeds. Resistance refers to goats whose immune systems have counteracted the effects of a high worm load and survived, leaving them with fewer worms than their herd mates. True resistance should be genetically set. Dr. James Miller, parasitologist and professor emeritus, Louisiana State University, knows of no scientific documentation proving any breed of goats to be genetically resistant to worms in the USA.

Tolerance describes goats that harbor in their bodies a worm level that kills susceptible animals; they tolerate the worm infection. Goats susceptible to worms need to be culled and slaughtered. Individual goats within a herd may be "worm tolerant." No herd or breed can legitimately make that claim. Select for goats that handle a reasonable worm load and cull the others. I cannot stress enough the importance of culling poor performers, whether they are susceptible to worms or infections or whether they have poor body conformation. Culling never goes out of style, no matter how long you have been raising goats.

IMPORTANT: Goats that are tolerant of worms are not tolerant of every type of worm nor do they automatically carry that tolerance from one location to another. Tolerance is only against the worms that goats have been exposed to in their natural habitat. If that environment changes and different worms are introduced or if the goats are moved onto another property, then the process of acquiring adaptability must occur all over again. See my article on Adaptability on the Articles page at www.tennesseemeatgoats.com. Also, conditions change on the same property from month to month, year to year, and even from pasture to pasture.

Regularly scheduled fecal counts using McMasters slides and counting the number of eggs in the feces are critical to inform you which goats are productive and to keep your herd healthy.

When moved, goats need time (months, not days or weeks, and sometimes longer) to adapt to the bacteria, viruses, worms, cocci, and other organisms that inhabit their new home. This is true of every goat that is moved, whether it is a breeding buck, doe, or kids. Bucks moved into field performance tests need at least six months and sometimes longer, depending upon the time of year they are moved and the differences between their old location and their new one, to adapt to their new environment to develop antibodies that keep them healthy and able to compete on an equal basis. Bucks who have lived in the area in which the field performance test is being conducted have an enormous "home field advantage" because they have already adapted.

Do not ever move pregnant does. Kids born at the new location will have no protection in their mothers' milk from the new organisms because the dam will not have had time to develop antibodies before her kids are born. In 2000, I moved only 125 miles from Buda, Texas to Lohn, Texas, and bred the does within 90 days of arrival. The results were disastrous. An abortion organism acquired at the new location infected many of the does. My first goat acquired in January 1990 and her first-born daughter born in February 1991 died, in addition to other dams and multiple kids. The forty-five (45) weak kids born had to be bottle fed to be saved. It was a tragic and expensive learning experience which could have been avoided had breeding been put off for 12 months while the goats' immune systems adapted to the new location.

Goats, like deer, stress easily when moved. Do not make it more difficult by putting demands upon their immune systems by insisting on immediate breeding.

Management is critical. Too many goats on too small acreage is a recipe for a parasite disaster. The number of goats that can be run on a given piece of land is determined primarily by how well the parasite load can be controlled and not by the amount of plant material available for the goats to eat. You have to figure out this number for your own herd, and you do it by starting with just a few goats and culling heavily.

Understand that if your facilities are overcrowded, too wet, and/or unsanitary, no amount of culling is going to solve your problems, because you will be expecting goats to live in conditions where no goat can survive or thrive. In such situations, culling isn't your solution; you are in the wrong business.

Do not succumb to advertising that a certain breed is resistant to or more tolerant of worms than any other breed. This has not been scientifically proven in the USA. All breeds can be made "wormy" through bad management, overcrowding, and environmental conditions favoring worms.

SUZANNE W. GASPAROTTO, Onion Creek Ranch, Texas 3/1/25