Movi in Alaskan Dall Sheep?

Could it be true? The Alaska Department of Fish & Game just recently announced that Movi has been found in Alaskan Dall sheep and mountain goats in several mountain ranges across the state.

If true, this could be the beginning of the end. 

Chugach Dall Sheep

The pathogen Mycoplasma ovipneumoniae or Movi for short is a dangerous respiratory bacteria linked to devastating outbreaks of pneumonia in bighorn sheep populations across the western states. 

There are many strains of Movi, but the vast majority have proven fatal to bighorn sheep among other species of Caprinae, namely mountain goats and muskoxen. 

Here in the north, the Alaska Wild Sheep Foundation embarked on a historic effort in late 2016 to begin raising awareness about Movi and the potential impact it could have on Alaskan Dall sheep.

The history of Movi likely dates back centuries, but it was in the early 1970s when it was first described in the scientific literature as a pneumonia causing pathogen in domestic sheep. Since then, hundreds of strains of Movi have been isolated from the nasal cavities of domestic sheep and goats across the world. Movi has been found on every continent except Antarctica. 

Given the widespread occurrence of Movi, it's no surprise that bighorn sheep from Washington to Texas have been exposed to Movi over the years through chance interactions with domestic sheep and pack goats. It only takes one close encounter for the respiratory pathogen to pass between animals. Incubation may take weeks to months, leading to delayed respiratory problems.

Discovering the source of individual transmissions has been difficult, but with genotyping now available for the bacteria, many such transmissions have been documented. Given the relatively few number of strains of Movi found in bighorn sheep, scientists are now more confident than ever the pathogen was not endemic in wild sheep herds in North America prior to the arrival of domesticated Caprinae.

Many domestic sheep and goats are carriers of this pathogen, though show no outward signs of illness. This is what makes it so dangerous to our naive Caprinae. I have yet to meet an owner of a domestic sheep or goat that doesn't care about our wild sheep and goat populations, but it's the bridge they must cross that's causing such consternation on this issue. 

Here are the facts. Domestic sheep and goats carry Movi. In Alaska, roughly 4-6% of domestics are believed to carry it. With less than 2000 domestic sheep and goats in the state, this is a relatively small number, but it's important to recognize that it's here. As of yet, we don't know what strains are present in Alaskan domestics.

As for our wild populations, until this year, analysis of hundreds of Dall sheep nasal swab and blood samples have all been clean of Movi - no sign of the pathogen or any past exposure to the pathogen. All these samples have been run at credible diagnostic labs familiar with Movi. 

Now we have results from a new lab, a USDA Agricultural Research Services lab, showing that Movi is present in several populations across our state. They have yet to confirm their findings through any experienced diagnostic lab, and they have yet to show any back up data from blood serology tests - which would show some evidence of past exposure to the pathogen. 

With no reported pneumonia outbreaks, and no all-age die-offs in our Dall sheep populations, where does this leave us?

It leaves us seriously questioning the results. 

We know that most strains of this pathogen that have been introduced to wild Caprinae have been scientifically documented to cause pneumonia, individual deaths, and long term recruitment problems for these populations. Should a virulent strain of Movi find its way into our wild Caprinae populations here in Alaska, we would expect large scale pneumonia, die-offs and persistent recruitment problems for years. Movi would likely spread like wildfire across our connected mountain ranges impacting thousands of Dall sheep and mountain goats alike.

It would be a nightmare for the future conservation of our wild Caprinae. 

If indeed Alaskan Dall sheep and mountain goats are carrying Movi, then one of three things is happening. Either our animals have super powers that other wild caprinae across the globe do not have, the strain they have is relatively benign, or this pathogen the USDA lab found is not really Movi. 

It is our responsibility as good stewards of our natural resources to question that which doesn't seem right and seek to truth, no matter the cost.

In this case, we seriously question the validity of these results and we're left wondering just what is this pathogen that has been found in our wild Caprinae. It's important to understand the biology and history of Movi in this instance. To date, Movi has never been documented and confirmed to be present in any other animal than the sub-family Caprinae. Biologists in Nevada, among others have been looking for it for years in other big game species - it's never been found. It's a host specific pathogen like most other Mycoplasmas, and most biologists agree it's unlikely it can thrive in any other species long enough to be carried or transmitted.

So back to the findings. Considering this particular research lab has also reportedly found Movi in other species such as deer and bison, this further raises our concern for the validity of their Alaska Movi results. 

Until there's confirmation of these results or a peer reviewed publication of the data, we will continue to question what seems a little off. 

Science evolves. Scientists don't always get it right. This is part of the scientific method. Failure is the best way to move forward in science and in life.

Clearly we must remain vigilant on this topic. We must push for the best available science and confirmation of anything that seems out of place. Movi is out of place in Alaskan Dall sheep and mountain goats.

Let's work to keep learning and improving our knowledge base. If we do have Movi, the science says that other more virulent strains can still severely impact our wild populations. If we find through further confirmation testing that this bug isn't Movi, then consider a bullet dodged.

Regardless, our Alaskan Dall sheep and mountain goat populations are some of the most valuable natural resources in the world. With roughly $40 million coming into Alaska annually because of these species, one could say this is the most significant Alaskan conservation issue of the century.

Did you know that the continuous Wrangell Mountains connect Alaska, the Yukon, and British Columbia? Consider how a pathogen in the Wrangell Mountains could find it's way to the only Stone Sheep population in the world? Yes it could easily happen.

This is real, and this is worth getting involved.

Somehow we must work together to find a solution to keep our wild Caprinae safe. If you would like to get involved, please join the Alaska Wild Sheep Foundation and do what it takes to keep our wild Caprinae clean and safe!