Mycoplasma ovipneumoniae (M. ovi) in Alaska Wildlife:
Answers to Frequently Asked Questions
What is M. ovi?
M. ovi is a shorthand name for Mycoplasma ovipneumoniae (pronounced "My-koh-plaz-ma oh-vee nu-moh-nee-ay"). M. ovi is a bacterium that can lead to respiratory disease such as pneumonia in sheep and goats. M. ovi does not affect humans.
Little is known about the status or presence of M. ovi and other bacteria of the Mycoplasma genus in Alaska. Mycoplasmas are simple organisms lacking cell walls; more than 100 known species exist. These species include numerous strains of varying virulence ("virulence" is the ability to infect or damage a host).
Has M. ovi been found in Alaska's wildlife?
M. ovi was detected for the first time in Alaska in Dall's sheep and mountain goats in March, 2018. The respiratory pathogen was documented in caribou and moose in Alaska in June, 2018. For more information about these findings, please see the press releases:
- 03-13-2018: Respiratory Pathogen Confirmed for First Time in Alaska Dall's Sheep and Mountain Goats
- 03-20-2018: New Findings Suggest M. ovi is More Widespread in Alaska's Wild Sheep and Goats
- 06-15-2018: Respiratory Pathogen "M. ovi" Documented in Additional Species in Alaska is Also Implicated in Alaska Caribou Death
Are Alaska's wildlife populations in danger?
The presence of M. ovi does not mean that an animal is diseased. M. ovi has now been detected in healthy Dall's sheep as well as mountain goats, caribou and moose in Alaska with one caribou mortality associated to the bacterium. More research and monitoring is needed to determine if any of the M. ovi strains found in Alaska are similar to those in the Lower 48 that have been associated with high mortality events (so far they have not). More information and analyses are needed to characterize the M. ovi strains and determine how widespread M. ovi and other Mycoplasmas might be in Alaska.
How did M. ovi get into Alaska's wild sheep population?
This is currently unknown. More research is needed to characterize the M. ovi from Alaska's wild sheep and goats and compare them to the strains identified in domestic sheep and goats. Preliminary data suggests there are multiple strains in the wild populations and the partial DNA sequences available don't precisely match those in the U.S. domestic sheep or Bighorn sheep. Published research has shown that domestic sheep and domestic goats in China and the U.S. have genetically different strains of M. ovi.
How does M. ovi affect sheep?
- In wild sheep, M. ovi has been identified as a pathogen in bighorn sheep pneumonia outbreaks in several western states and British Columbia. These M. ovi related outbreaks have resulted in sporadic and, at times, large-scale morbidity and mortality events in bighorn sheep. Some of these have resulted in subpopulation-level events with mortalities of 70 to 90 percent.
- M. ovi paralyzes cilia in the airways (cilia are hair-like structures that help keep the lungs clear of mucus, dust, and pathogens) and prevents them from moving out pneumonia-causing bacteria that are inhaled into the lungs. This can cause respiratory disease, particularly when the animal is affected by other factors such as nutritional or environmental stress.
- In cases where M. ovi results in pneumonia in domestic sheep, lambs usually are more severely affected. Populations of infected bighorn sheep that have survived M. ovi related disease events have shown poor recruitment and low or stagnant population growth rates.
- Domestic sheep and bighorn sheep can be clinically healthy carriers of M. ovi. This means some sheep may have M. ovi, but exhibit no ill effects. These sheep are thought to spread M. ovi to other sheep over prolonged periods of time, increasing the number of sheep exposed as well as the area over which the pathogen is spread.
Has M. ovi been verified in domestic animals in Alaska?
M. ovi has been detected in a small number of flocks of domestic sheep and goats in Alaska. These animals were healthy and not showing any signs of illness.
Did domestic livestock bring M. ovi to Alaska?
This is currently unknown. Studies have shown that some pathogens which may cause disease are spread between domestic livestock and wildlife. It's important to note that populations of domestic sheep and goats in Alaska are relatively small and confined to farms. This is not the case in the Lower 48 where large numbers of free-ranging sheep and goats may use grazing leases on public lands which can be adjacent to habitat of wild sheep. Still, there may be some threat of spreading pathogens between domestic and wild animals in Alaska. Our studies with the Department of Environmental Conservation are intended to assess the risks.
How prevalent is M. ovi currently in domestic animals in Alaska?
The estimated population of domestic sheep and goats is about 1,500 animals. So far, almost 400 animals have been tested and M. ovi has been detected in about 4 percent of domestic sheep and goats.
How long have we known M. ovi to be present in domestic animals in Alaska?
In 2017, a surveillance testing project of domestic sheep and goats was started. This voluntary project collected samples from sheep and goat farms across the state.
Is testing currently being done for M. ovi in domestic animals in Alaska?
Voluntary surveillance testing will continue through 2018 as more farms are participating in the project.
Where can I learn more about M. ovi in Alaska's domestic sheep and goats?
More information can be found on the Department of Environmental Conservation's webpage at http://dec.alaska.gov/eh/vet/movi.aspx
What testing is done and how is M. ovi detected?
Blood and nasal samples are collected from the animal. Tests are run on serum from sheep and goats to look for antibodies that indicate a previous exposure and immune response, but this does not necessarily indicate current illness. A swab is inserted into the nasal cavity and analyzed using polymerase chain reaction (PCR) tests that detect the genetic material of the Mycoplasma bacteria in any species of animal. There are many species of Mycoplasma that can affect animals. The current ADF&G study, conducted in collaboration with the US Department of Agriculture, was screening for all species of mycoplasmas in many species of Alaskan wildlife. It was completely unexpected to detected M. ovi on nasal swabs in Dall's sheep, mountain goats, caribou and moose.
How long has M. ovi been present in Alaska's wildlife?
Prior to 2009, the only tests available for M. ovi were not as specific and likely not as sensitive as the current test methods. Of the 300 Dall's sheep, sera were collected and tested prior to the availability of these newer tests. A few (2-3) samples showed a reaction, but these results could not be confirmed and additional samples could not be collected from these particular animals.
How is M. ovi transmitted in animals?
M. ovi is a respiratory bacterium and is spread when animals exhale, cough, and sneeze the bacteria out through their mouths and noses in tiny particles that can stay suspended in the air. It can also be spread by direct contact, and possibly by exposure to contaminated feed or equipment.
What can be done on a statewide level to prevent the spread of M. ovi in Alaska wildlife?
The best way to prevent the spread of disease is to keep domestic sheep and goats separated from wildlife and avoid comingling or contact. To reduce contact and spread of pathogens that can cause disease, Alaska law prohibits the use of domestic goats and sheep as pack animals when hunting Dall's sheep, mountain goat, or muskoxen.
What is ADF&G doing about this?
The department is continuing to collect and test samples for M. ovi and other mycoplasmas from hooved wildlife in Alaska including: (1) taking samples from hunter harvested animals, (2) investigating dead and/or sick animals, (3) sampling animals captured for radio collar deployment during management or research projects, (4) establishing multi-year intensive monitoring studies of specific sheep and goat populations to assess the impact of M. ovi, and (5) conducting research to improve future surveillance efforts.
How can hunters help?
Participate in hunter harvest sampling — Please click on link to see a complete list of species and areas we are collecting samples from to test for M. ovi as well as actions we are requesting from you (PDF 968 kB).
Report any observations of sick wildlife. If harvested animals have any abnormal lung tissue (lungs should be spongy and uniform pink, except for bloodshot areas) immediately call or text the Wildlife Health and Disease Surveillance Reporting Line at (907) 328-8354 or send an email to firstname.lastname@example.org . Record the location, take photos of the carcass and abnormal tissue, and collect a lung for submittal to your nearest Alaska Department of Fish and Game office.
Are animals showing signs of respiratory disease safe to eat?
In general, yes, however we can't categorically state that wildlife are always safe to eat. More specifically, edibility of the meat should not be affected by respiratory disease. Affected parts identifiable as thick yellow or green pus on the inside of the ribs, or lymph nodes oozing pus, should be trimmed off and meat cooked thoroughly. Hunters should not harvest and consume animals that look ill or sick. Severely diseased animals may be in poor condition, reducing the quality and taste of the meat. It is not recommended to eat sick animals or meat that smells rotten (although the meat still must be salvaged).
For more information on respiratory disease in wildlife, see our webpage: http://www.adfg.alaska.gov/index.cfm?adfg=disease.respiratorydisease