Biosecurity and Goat Husbandry: What You Should Know About M. ovipneumoniae

National Forests Fight the Pack Goat Practice for Fear of Pneumonia in Goats

Biosecurity and Goat Husbandry: What You Should Know About M. ovipneumoniae

 By Karen Kopf – At Kopf Canyon Ranch, just outside of Moscow, Idaho, we raise Kiko goats for meat and breeding stock. Our goat husbandry practice is to run a clean, tested herd. Recently, pack goat enthusiasts have approached us for packing prospects: male goats that might show a packing disposition. This potential market opened us up to expansion to include a few dairy does for experimental pack goat breed crosses, a brand new world of adventure, excitement — and M.ovi.

 

What is M.ovi?

M.ovi (pronounced “Movee”) is the slang term for a bacterium, Mycoplasma ovipneumoniae, that may be carried in the nasal passages of animals in the subfamily Caprinae. This subfamily consists of musk oxen as well as wild and domestic goats and sheep. Not all do, and some people say it is infrequently or even rarely found in the passages of domestic goats. Furthermore, most carrier goats show no symptoms of respiratory illness and are unaffected.

There are numerous mycoplasma bacteria present in our environment. For bacteria to result in a disease state, such as pneumonia, the host must be vulnerable—for instance, compromised by stress, crowding, shipping, malnutrition, poor air quality, or parasites.

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A herd of bighorn ewes that frequently breach the fence and comingle with a domestic herd of goats. Photo credit: B. Jaeger

Why Should We Test for M. Ovipneumoniae?

It is thought that M. ovipneumoniae transmission from domestic herds/flocks to wild populations—specifically bighorn sheep in the Western United States/Canada, and Dall (thinhorn) Sheep in Alaska/Canada—will result in pneumonia outbreaks in wild populations. For most domestic herdsmen, the geographic possibility of encountering wild sheep is slim to none. So, one might assume that this “doesn’t affect me or my herd.” But it does.

In November of 2017, the Wild Sheep Foundation approached the Alaska Board of Game with a revised version of an earlier proposition to remove domestic goats and sheep from the “clean animal list” though, to date, Alaska has not reported this type of disease outbreak in wild herds. Proposition 90 would restrict goat and sheep ownership to those issued permits, and prohibit them from areas within fifteen air miles of wild sheep habitat—which essentially overlaps the majority of Alaska’s domestic goat producers. (Update: bacteria is now confirmed in Alaska’s wild sheep population, though it has not been determined that the bacteria was transmitted by domestics. http://www.adfg.alaska.gov/index.cfm?adfg=pressreleases.pr&release=2018_03_13)

After hearing testimony, the Board of Game decided unanimously to take “No Action,” but set forth requirements that both groups—producers and the Wild Sheep Foundation—return to the table in Spring 2019 with reports. An interim proposal is to close Alaska borders to untested/positive animals. There is precedent for this. While typical bioscreens (CAE/CL/Johnes) are not required for interstate transport, there are states that have closed borders to other risks, such as brucellosis.

Still, Alaska is geographically isolated. How does this apply to goat husbandry in the lower 48?

Alaska is not the only state that has taken legal action out of fear of M. ovipneumoniae transmission from domestic small ruminants to wild sheep. They are one of seventeen western and midwestern states to do so.

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Outside of Alaska, there have been no proposed bans in the states identified in red, but access to portions of these states has been closed or restricted to small ruminants. Notorious are the reduction in grazing permits for sheep and goats. As an example, the Bureau of Land Management progressively closed 70 percent of the domestic grazing allotments (70,000 acres) in Idaho’s Payette National Forest, a decision that was contested and upheld based on a court-ordered analysis under the National Environmental Protection Act. That analysis determined that best management practices are not sufficient to prevent contact. Furthermore, there are suits in multiple states to restrict access for pack goats to national forests.

If Alaska is successful in legislating stricter policy for interstate transport, it is possible that other states will follow suit. Since animal movement cannot be controlled or monitored within a state, it is possible that impacted states would adopt the Alaska proposal of an M. ovipneumoniae-free state. The broader implication for all producers is a narrow market, effectively eliminating the western states for small ruminant transport—unless animals are tested M. ovipneumoniae-free—or, one step further, come from M. ovipneumoniae-free premises.

The North American Pack Goat Association, a non-profit organization, has been the most active advocate of the domestic goat producer, while being cognizant and proactive about the potential threat to wild sheep. They have spearheaded and participated in the largest sampling to date, and implemented “Best Practice Guidelines” for their pack goats, who would be the most likely to encounter wild populations, to mitigate the threat of bacteria transmission between pack goats and wild sheep. Among the tenets of their guidelines for goat husbandry are testing, using only negative-tested animals, and isolation of negative-tested animals from non-tested animals, as well as carrying copies of the negative results while packing.

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M.ovi status is now appearing in advertisements. Permission to reproduce granted by Kody Crapo.

While there are pack goat breeders breeding specifically for packing, it has been common practice for many dairy goat breeders to offer wethers as “pack goat prospects” as a means of culling males not intended for breeding. Respecting NAPGA’s guidelines, producers marketing pack goat prospects, in light of the M.ovi concern, bear the responsibility of maintaining clean status for any goat types sold, or interacting with those destined for the pack market.

What Has Happened in the Wild Sheep Populations?

In Alaska, to date, M. ovipneumoniae has not been reported in wild sheep or goats in the limited testing of the wild population. In the lower 48, published studies exist on comingled herds of goats and bighorn sheep. Introduction of M. ovipneumoniae into the herd did not result in fatal incidence of pneumonia. The test subjects showed symptoms, but began to improve before they were euthanized by the researcher. Bronchopneumonia was not diagnosed in any of the animals. (Exposure of bighorn sheep to domestic goats colonized with Mycoplasma ovipneumoniae induces sub-lethal pneumonia. Besser TE, et al. PLoS One. 2017)

Infection with M. ovipneumoniae in wild sheep doesn’t mean this disease will occur, as there are healthy populations that carry this bacterium. What has been determined is that in many cases of pneumonia in wild sheep, M. ovipneumoniae is present, and pneumonia can cause significant die-offs in wild sheep.

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Wild sheep (Mt. Hull herd) intermingling with domestic goats in the goat’s enclosure on the Washington/Canada border. Methods of fencing to exclude contact was explored but proved challenging. Fish & Wildlife asked for consent to test the goats for M. ovipneumoniae, which was granted by the producer. The tests results were negative.
Photo credit: B. Jaeger

Can We Prevent Domestic/Wild Encounters?

It is the nature of wild sheep to leave the herd and wander—called foraying—and then return to the herd. Forays exceeding 50 km are documented (Intermountain Region BHS/Domestic Sheep Management Framework—Bighorn Sheep Risk Assessment for Region 4 National Forests 11-20-15). A sheep that forays is considered “rogue.” It is the policy of most, if not all, states to euthanize rogue wild sheep because of the possibility of domestic encounters that might result in transmission of M. ovipneumoniae to the rogue animal and then to the wild sheep when the animal returns to the its herd.

Fencing does not always prevent interaction. Goats are known for their uncanny ability to escape. In the case of the Washington/Canada event, however, the Mt. Hull bighorn regularly breached the fence, not for a lack of food or reproductive drive, but social interaction. In this isolated case, the bighorn were not euthanized because the domestic herd tested negative, and the number of wild sheep involved was too high. It would have compromised the population of a herd that otherwise has had no health issues. Numbers are not always a limiting factor, however. In some wild sheep pneumonia outbreaks, entire herds are exterminated—healthy and symptomatic alike—to prevent the spread of disease, making it difficult to answer the question of natural immunity developing. (http://www.ndow.org/Bighorn-Sheep-Disease-Event-Montana-Mountains/)

How Do We Test for M. Ovipneumoniae?

The Washington Animal Disease Diagnostic Laboratory, or WADDL, has a serology (blood) test that can determine whether a flock/herd or individual animal has been exposed—but does not indicate an individual animal’s current infection/shedding status. It is validated for use in testing sheep, and validation for use in domestic goats is underway. Determining the shedding status of an individual animal requires collection and testing of a nasal swab, and a positive result on any one swab means M. ovipneumoniae is/was present on the premises and that the animal was shedding at that point in time. (For more information about testing: https://waddl.vetmed.wsu.edu/animal-disease-faq/mycoplasma-ovipneumoniae-diagnostics-in-domestic-and-wild-sheep-and-goats or contact Dr. Maggie Highland with the USDA-ARS-ADRU: Maggie.Highland@ars.usda.gov.)

 

To date, two large sample studies have been done on domestic goats. In 2016 collaborative efforts of NAPGA, 83 pack goat owners, the USDA-ARS-Animal Disease Research Unit funded project, with extensive help from APHIS personnel, sampled 576 domestic pack goats from 83 premises that had strictly pack goats or pack goats and other domestic goats present, located in 13 states in the lower 48. The animals were swabbed at intervals, for a series of three swabs. In the pack goat study, prevalence was 5 percent overall, with a positive result on repeat sampling in five of the 83 premises (six percent of premises). 90 percent of the goats with M. ovipneumoniae detected on the nasal swab (shedding bacteria) were less than one year old, 77 percent were less than six months old. (The manuscript of this study is being prepared for release, but information has been publicly presented https://dec.alaska.gov/eh/pdf/vet/movi-presentation- highland-201708.pdf.) The USDA-ARS Animals Disease Research Unit is currently collaborating with the Alaskan State Veterinarian, Dr. Robert Gerlach to determine prevalence of M. ovipneumoniae and sheep disease in Alaska’s small ruminant herds/flocks. This study is ongoing; completion and final reporting is expected in 2018. (Information about the Alaska study can be found at: https://dec.alaska.gov/eh/vet/Movi.html.) It appears that this issue presents differently in goats and sheep, and for this reason, would indicate that a single management protocol for small ruminants would not be the most effective way to address the concerns.

Currently, if a producer is not affiliated with a study, the cost associated with testing a swab through WADDL is $45/WA State and $67.50/out of state. For a series of three this translates to $202.50 per animal.

Questions That Beg Answers

Is a minimum of a series of three swabs plus serology testing enough to confirm that a flock/herd is truly negative? If so, what is the optimal spacing between swab samples being collected? How frequently should a herd be tested to confirm maintenance of negative status? If a positive is found within a herd, what is the follow-up testing protocol? Is there an incubation period? If it is so contagious, and transmitted by nose-to-nose contact, why is the prevalence (at least detection of the bacterium) in positive goat herds so low? What should management protocols be for producers that want to eliminate M. ovipneumoniae from their herds? Should kids under one year of age with positive test results be culled? Or should they be retested as adults? Do positive kids continue to shed as adults, do they clear the infection, or do they remain a carrier but not shed at a detectable level? Once a premise is determined to be positive, is culling the carriers enough to achieve negative status? How many swab samples should be tested to confirm that an animal is a true carrier/shedder as opposed to the possibility of being an intermittent carrier (not the true chronic carrier in the pen)? The bacterium is thought to be host-dependent, but whether it can survive outside of the host has not yet been well studied. To answer these questions, more studies are needed, specific to goats.

Nasal swab samples ready for submission. Photo credit: K. Kopf
Nasal swab samples ready for submission. Photo credit: K. Kopf

What Does This Mean to Domestic Goat Herdsmen and Goat Husbandry
Practices?

To keep markets open, protect land access, and steward our herds responsibly, hobbyists and commercial producers nationwide need to be aware of the regulatory initiatives—not just in our own backyards. It is entirely appropriate to request awareness, education and advocacy from our agricultural and breed associations. Above all, we must support research efforts to determine the risk and management protocol for domestic goat husbandry regarding this new concern.

Karen and her husband Dale own Kopf Canyon Ranch in Moscow, Idaho. They enjoy “goating” together and helping others goat. They raise Kikos primarily, but are experimenting with crosses for their new favorite goating experience: pack goats! You can learn more about them at Kopf Canyon Ranch on Facebook or www.kikogoats.org.

 

NAPGA Statement:

“Goat Packing really started in the early 70s when a young wildlife biologist turned to the pack goat in desperation for the perfect pack animal to carry his equipment into the backcountry while doing research on bighorn sheep. The pack goat community, consisting mostly of hunters, hikers, fisherman, researchers and outdoor enthusiasts, have been using pack goats on the landscape for over forty years.

“There has never been a disease transmission occurrence or die-off because of a ‘pack goat’ meeting or coming into contact with bighorn sheep or mountain goats and we want to keep it that way. As strong advocates for the safety of all wildlife and as good stewards of the land, I believe that the testing for M.ovi and other diseases of concern for our pack goats should be considered a mandatory step in goat husbandry. It’s the right thing to do. The North American Pack Goat Association is strongly committed to the use of Best Management Practices and only the use of M.ovi-negative pack stock. We want to make recreational goat packing bulletproof. There is still so much that we don’t know about M.ovi and taking precautions is critical. It’s our responsibility to be educated and aware of M.ovi and the issues of concern. We take that responsibility very seriously.

“I strongly believe that education and awareness are the critical keys to developing Best Management Practices that will pilot absolutely bullet proof recreational goat packing anywhere wild sheep or goats are present. We can do this and we will.”

Curtis King

President, North American Pack Goat Association.

Originally published in the March/April 2018 issue of Goat Journal and regularly vetted for accuracy.

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