Yukon News

Experts say risk of sheep transmitting disease ‘very real’

Lori Garrison Friday May 19, 2017

Submitted photo/Government of Yukon

sheep.jpg

Concerns have been raised that domestic sheep and goats can spread disease to Yukon’s thinhorn sheep population.

Rabbitfoot Canyon — that craggy split that divides downtown Whitehorse from Porter Creek — is the last place you would think to look for a wild sheep. But that’s exactly where Philip Merchant said they have turned up in the past.

“They were just standing there, watching the cars go past,” he said.

Merchant was the animal health coordinator with Environment Yukon for 10 years, a position from which he retired in 2011. He is, by his own admission, not a biologist or a veterinarian.

During his career, he said, it wasn’t just Rabbitfoot Canyon where wild sheep turned up unexpectedly but also in the Takhini River area near the sod farm, at Vista Road Tower, and even at the Grey Mountain rifle range, near the sheep silhouette targets.

This could have severe health implications for the species if they were to come in contact with domestic sheep, Merchant said.

“We have as good an idea of where wild sheep are as any jurisdiction, but we don’t know where they want to be,” he said.

As the News recently reported, there have been rising concerns among the conservationists, outfitters, environmentalists and farmers that domestic sheep and goats can spread pathogens to wild sheep. Those pathogens can cause severe — and often fatal — pneumonia.

This has occurred in southern populations of bighorn sheep, to which thinhorn sheep — a group comprised of three species and to which the Yukon’s famous all-white Dall sheep belong — are “very closely genetically related,” according to Environment Yukon ungulate biologist Troy Hegel.

An analogy might be grizzly bears and black bears, or mule deer and whitetails, Hegel said, referring to separate but closely-related species, which are often susceptible to the same infections.

Whereas domestic sheep can carry the bacteria with few or no health consequences, wild sheep have extremely limited resistance because they have never been exposed, said Hegel. Infected sheep either die, or, if they recover, have lingering health issues. Those that recover become “shedders” Hegel said, continuing to harbour the pathogen and infecting healthy members of the herd.

Although cross-species infection is well documented in bighorn sheep, there have been no documented cases of thinhorn sheep becoming infected from contact with domestic sheep. Merchant said there are “reams of data” that this is possible, and that infection has occurred in laboratory settings.

“The guy who was doing the experiment (on thinhorns) stopped his work because he said he was sick of killing sheep,” said Merchant. “You should never confuse the absence of evidence with evidence of absence.”

Hegel agrees the risk of infection to thinhorns is real.

“It’s a real risk — the probable outcome of the disease entering the wild population … there’s no doubt it would have a drastic effect on a population that’s been exposed,” he said.

People have been bringing sheep and goats into the Yukon for much longer than Environment Yukon has been around to do public awareness campaigns, however. This begs the question: If the disease is so contagious and dangerous, why haven’t there been infections — and die-offs — documented before?

“We don’t know this hasn’t occurred (already),” said Hegel. “If it happened 150 years ago, we might not even know.”

Thinhorn sheep have “high fidelity to range,” said Merchant, meaning that they often use the same grazing areas year after year, but we only understand their range “as we define it,” he said.

Animals may come down from the mountain in search of mineral licks, said Hegel, although these are usually routes which are well known to the animals. Small numbers of animals, particularly younger ones, may go “on a walkabout,” he said, where they wander off from their herd and either wind up back with their original population or assimilate into a new one.

These movements are a “key transmission risk,” said Hegel. If one of these wanderers were to come in contact with a domestic sheep carrying pneumonia-causing pathogens and become infected, it could spread the disease into the wild population when it returns to its range, Hegel said.

“They aren’t stuck on a mountain top their entire lives — there’s animals that are moving around,” he said. “These are the ones we are concerned with.”

This wandering behaviour explains the recent and much-talked-about incident of a young thinhorn ram who hopped a fence in Dawson City to visit some domestic sheep.

The ram paid for this casual encounter with its life.

“If a wild sheep comes in contact with a domestic sheep, the policy is to destroy it so that it can’t return to its native population,” said Hegel.

“All the reports have come in, and they’ve all said the same thing — do not let these animals mix in any way,” Merchant said. “That (ram is) the canary in the coal mine.”

“All the pieces of disease outbreak are here, they just haven’t come together yet. But they always do, given enough time.”

These concerns for wild populations have lead to discussions between agricultural and environmental officials and farmers, some of who feel unfairly pressured to meet recommendations to prevent interactions. These recommendations include double fencing, or adding electric fencing, a process which is expensive and labour-intensive.

There have been some calls to ban sheep and goats from the Yukon entirely, which is the way the Northwest Territories is going, said Merchant.

Hegel said that would be a “pretty significant, non-trivial” step for the Yukon.

Merchant said most people who own sheep and goats do not make their living from them, and that the number of sheep and goats in the Yukon is relatively small.

A 2015 flyer from the Animal Health Program entitled Preventing Pneumonia in Wild Sheep, recommends farmers “consider livestock other than sheep to raise fiber, milk and meat.”

“It’s a hobby — does somebody’s hobby have the right to threaten the public interest in conservation?” Merchant said. “Without the sheep, the mountains are just mountains — so I think that anything that could threaten them needs to be looked at.”

Shelia Alexandrovich of Wheaton River Garden said the idea that the eight sheep she raises are “just a hobby” is not a true. Alexandrovich has sheep for meat and milk, as well as for fibre, which she uses to make art and sells as part of her income.

“If I took away my ‘hobby,’ I would starve,” she said. “It provides 80 per cent of my food and 50 per cent of my income.”

“(Merchant) may see me as a hobby farm, but it’s what I do full time — I’m paid in food.”

Alexandrovich has lived in the Annie Lake area — thought to be some of the best wild sheep territory in the Yukon — for 37 years and has never once seen a wild sheep on her property, she said.

Hegel said this was possible, as there might might be other factors in the environment which discourage or prohibit the movement of the sheep onto the farm.

Merchant said the farm is “within one kilometre of where I would expect to see wild sheep.”

“If I thought I’d infect wild sheep, I’d double-fence in a minute — but I’ve never seen a wild sheep here,” Alexandrovich said. “If (the government) wants their concerns addressed — and it’s a legitimate concern — consult with farmers and give them the money to do (what’s been recommended).”

Alexandrovich said she didn’t feel the recommendations took into account the importance of small-scale farming and local food security.

“How on earth do you start (a farming industry) up here?” she said. “The little fellows trying to make inroads into local food … it isn’t easy.”

All in all, Hegel likens the recommendations to seatbelts.

“You can say ‘I never wear a seatbelt, I’ve been driving for 30 years, and I’ve never been in an accident,’” he said. “And then, suddenly, you’re in an accident and you really wish you’d been wearing a seatbelt.”

Contact Lori Garrison at .(JavaScript must be enabled to view this email address)

14 Comments

bb wrote:
7:03pm Friday May 26, 2017

Sheep and goat owners:  contain your animals securely.  No roaming in the hills like they do in Scotland, Ireland, NZ, Australia etc.  that is for sure.

I don’t think this is the right place for sheep… I could be wrong, but it doesn’t seem necessary.  There are other animals that you could raise to kill for food, or go shoot a bison.  Or how about poultry?  That seems to work well for people up here.

Glad people are thinking about these issues before we have a problem.

Darrin Sinclair wrote:
6:49pm Friday May 26, 2017

“there is a lot more use of powerful medicines at play in today’s domestic herds keeping diseases of these animals at bay.”

So Jackson, you are saying essentially that sheep of today are healthier and more disease-free or disease-suppressed than a hundred years ago? Awesome, thanks for helping my argument. Even if I have no idea what powerful medicines you are talking about. Although I think I may know what powerful medicine you’ve been smoking.

Darrin Sinclair wrote:
6:44pm Friday May 26, 2017

I just love when people say “stick to the facts” and then make some outlandish claim that is based on something other than the facts.

There have been a couple of claims that are being used to advance the anti-domestic sheep argument, and I’m not sure if the people saying them are outright lying or just ignorant of the reality.

1. A disease introduction of pneumonia into the wild sheep population will run thru the wild sheep population, leaving a path of devastation in its wake and seemingly stopping only at the ocean.

2. We don’t know there hasn’t been a massive die-off previously because….we just don’t know.

3. A pneumonia outbreak will kill more sheep than resident and non-resident hunters do/will

I’m not going to tackle myths 1 and 2, because I’m going let the Yukon Environment and the science-based research they’ve collected do that for me. It’s called a source, which is what people should provide when they make a claim that what they’re saying is fact

“Again using horn shavings, another researcher examined nuclear DNA to try to understand how modern thinhorn groups are divided up and how they are related to each other. She was able to assign sheep to eight different populations, based on genetics. Sheep tend to stick to their ranges in the mountains and avoid the forests that separate mountain ranges, so there’s very little mixing between populations. Most thinhorns appear to spend their lives within the traditional ranges their ancestors staked out. The researcher also looked for evidence that thinhorn sheep have undergone massive disease-related die-offs, but found none.”

Source: Yukon Thinhorn Sheep; horn growth, genetics and climate change. 2014

I’ll handle myth no. 3 - you have literally no way to substantiate that claim. I can say, conclusively, that introduced disease from domestic sheep have not killed a single thinhorn. How many sheep are legally shot each year?

Jackson wrote:
8:37am Friday May 26, 2017

I doubt very much that today’s domestic sheep and goats are in any way similar to the ones that passed through during the gold rush, there is a lot more use of powerful medicines at play in today’s domestic herds keeping diseases of these animals at bay.

As far as Sinclair’s statements about rich folks hunting up here…a disease transmitted to wild sheep will kill way more sheep (regardless of what population it gets into) than guided or resident hunters do and the disease will not be selecting mature rams near the end or past their breeding cycle.

The idea that the government should pay people to properly fence their land to reduce wildlife conflicts is an incredibly selfish and entitled stance.  The issue of proper fencing doesn’t just apply to disease prevention in sheep either. Looking at the news, bears also suffer from haphazard fencing. People who wish to keep livestock should be prepared to take on the burden of fencing properly (whether that’s financial or just good old elbow grease). I think this whole handout equation should be flipped, if your crummy fencing is allowing wildlife in you should be tasked with the financial burden of having the CO’s running around dealing with the problems that your want of lifestyle created.

BnR wrote:
10:45am Thursday May 25, 2017

Yukon gov has been trying to push for Sheep quotas on yukon big game outfitters, who are currently not on any Sheep quotas (with the exception of the few PHA sub zones in GM7).  This has to go through Yukon Fish and Wildlife Management Board, who have been pushing back on this, which is not surprising given their pro-outfitter bias.
Curious where YWSF stands on outfitter quotas?  Its all well and good to state publicly the lack of “official” affiliation, but yukoners know which interest group drives the YWSF.

Clint Walker wrote:
12:27pm Wednesday May 24, 2017

Proscience Greenie:  Minutes are I tended to capture comments and discussion from all people in attendence at the AGM.  It is the responsibility of the YWSF Board to reach out to all interested parties and members when developing a position and formulating a policy statement on any issue.  Only once this research has been completed, will a position be adopted or a policy be developed.  Rest assured that when it is, it will be in the best interest of the YWSF, our membership and Yukon’s wild sheep.

Please note, the YWSF will never be a lobby group for any other organization or special interest, other than that of the YWSF.  There will be times where we may work with other organizations to accomplish common goals.  Our Board is made up of individuals from a broad spectrum and that is by no accident.  You can take a look at the list of Board Members on our website at http://www.yukonwsf.com.

Thank you for your interest and support on issues you are able to.

eat moose wrote:
10:00am Wednesday May 24, 2017

Sheep should be left in Scotland. No place for them or goats in Yukon.

ProScience Greenie wrote:
9:46am Wednesday May 24, 2017

From the 2017 YWSF AGM post online…
-had a discussion with Ken Taylor and reached out to him to come to our next board meeting to hear TOYA’s stance.
-YWSF would like to form a committee for policy statement with ORV use and will look to work with TOYA and Yukon Fish and Game in creating YWSF stance/policy statement on ORV use.
-suggests that YWSF doesn’t need to start from scratch on a policy statement for YWSF – can draw from TOYA and Yukon Fish and Game.

Note I said ‘flirting’. I do not like TOYA at all and neither do many other Yukoners, hence my concern. I support a lot of what your group does but will draw the line at supporting TOYA or if there is lobbying done on behave of the outfitting industry, an industry that I lately have issues with as many members do not get that the wilds of the Yukon are to be shared by all. Carry on the good work Clint Walker but don’t be surprised if there is criticism if certain lines are crossed.

Clint Walker wrote:
9:54pm Tuesday May 23, 2017

Proscience Greenie:  “Looks like YWSF Is flirting with TOYA in trying to ban or severely restrict ORV usage”????
Wow, really? I am very interested to learn where you learned this from?  That is news to me and my Board. .. As the President of the Yukon Wild Sheep Foundation, I would have thought I would have been one of the first to know this, if it were true…  Hmmm….  Perhaps, keeping the discussion restricted to facts might be better than fear mongering, by way of propaganda.  wink

ProScience Greenie wrote:
2:55pm Tuesday May 23, 2017

Good points Darrin Sinclair, especially the Gold Rush perspective.

Looks like YWSF is flirting with TOYA in trying to ban or severely restrict ORV usage. That really sucks for regular everyday Yukoners but no surprise that it would be good for YWSF’s outfitting industry pals that are all about making good cash doing the trophy hunting thing for rich Outsiders (of any race or gender). Not hard to follow the money on this one. 

Clint Walker wrote:
12:34pm Tuesday May 23, 2017

Mr. Sinclair,

I had written you a lengthy response here, but it was somehow lost here before it posted.  You can reach me through our website at http://www.yukonwsf.com and our email at .(JavaScript must be enabled to view this email address).

Darrin Sinclair wrote:
9:51am Tuesday May 23, 2017

I’m not against hunting, I’m against one special interest group, especially one from outside my country, driving the agenda in the Yukon.

In conclusion Mr. Walker, maybe we can sit down for a beer and figure out a solution that works for everyone.

Darrin Sinclair wrote:
9:49am Tuesday May 23, 2017

The fact that pneumonia, specifically mycoplasma ovipenumoniae, can be transmitted from domestic sheep to wild sheep is indisputable. But some of your facts need straightening out. The transmission from domestic to Dall sheep in the TO zoo was a DIRECT transmission. Not near contact. Read all of Black et al. 1986. The whole scientific paper is important, not just the parts you like. In fact, in nearly 25 papers I’ve read so far, transmission has been thru DIRECT NOSE TO NOSE contact. Why this is important is that it shows that this transmission risk can be mitigated.

Clint, your organization has not contacted Yukon sheep and goat owners to help with a solution. Instead your rich, white, American money-backed organization is seeking to ban sheep and goats because a small risk that can be managed. If the risk was even half as bad as you want us all to believe, we’d already have no wild sheep. Jack Dalton had a toll fee for goats and sheep on the Dalton Trail during the Gold Rush. These animals were driven during the fall/winter ie the mating season of wild sheep. There were no massive die-offs. Yukon Govt papers show that research on mitochondrial rna of wild sheep indicate that populations of sheep are remarkably static on their chosen range. There goes your argument of a wildfire spread of pneumonia throughout the North.

I’m not saying this issue isn’t important. What I am saying is some perspective is needed. Yukoners should be able to have a little piece of land where they can produce their own food and maybe some extra for their neighbors. It’s been possible for that to happen for a hundred years with no problem. But now some American money from an American organization run by rich white people is going to dictate that we can’t raise our own food so that they can fly in, shoot Yukon sheep, then fly out with their head and horns for their wall.

Clint Walker wrote:
3:14pm Friday May 19, 2017

A point of clarification; there has in fact been a documented case of Dall’s sheep becoming infected with Mycoplasma Ovipneumoniae (M. Ovi) and dying as a result of near contact with domestic sheep within the Toronto Zoo in 1986. 
Further to that, a report co-authored by R. Demarchi in December of 2004 for the BC Govt (Status of Thinhorn Sheep in British Columbia) reads: “Experimental infections of Dall’s sheep have illustrated that they are as susceptible to domestic animal bacteria as bighorns.  In fact, Dall’s sheep neutrophils may be more sensitive”“than neutrophils of bighorns.”
Folks, we experienced a die-off of bighorn sheep that left over 98% of the population in North America, dead.  (From 2,000,000 to 25,000 animals in just 150 years).  Let’s not have to learn the same lesson over again, with thinhorn sheep…. 
Once it enters the system, disease moves through bands of sheep, living in a contiguous range, like a grass fire.  If it were to start in the Yukon, it will move north, south, east and west; as we are located at the very heart of thinhorn range, meaning it will take far less than 150 years to decimate the thinhorn population. 
The risk is very real, and the stakes are prohibitively high.  Simply put, there is no business interest, nor any personal livelihood or hobby, which can possibly justify causing the death of +20,000 wild sheep on Yukon mountain sides….  We have no right to do that… 
We need to bring all parties involved together and come up with an effective solution which will not just reduce, but eliminate the risk of this disease transmission between the imported domestic sheep and goats brought into the territory, and the wild sheep, who have been here for over 120,000 years.

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