Zion bighorn sheep lambs showing no signs of deadly pneumonia after outbreak

ST. GEORGE — After an outbreak of deadly pneumonia in the bighorn sheep in Zion National Park last year, wildlife biologists report that so far there have been no deaths related to the disease in the park.

Bighorn sheep on a cliff in Zion National Park, Utah, May 16, 2019 | Photo by Mikayla Shoup, St. George News

Park biologists were concerned for the herd after testing revealed that the deadly bacteria causing the pneumonia has, in other herds, wiped out anywhere from 20% to 100% of the population.

Read more: Zion park officials concerned for bighorn sheep herd after outbreak of deadly pneumonia

“We were all pretty devastated when we found it last year because it can be really destructive, it can kill a whole herd,” wildlife technician Brianna Johnson said. “But we still haven’t definitively observed any mortality from that disease.”

Park officials first observed a sheep with symptoms of the disease July 20, 2018. After testing, they discovered that the pneumonia was caused by a bacteria called Mycoplasma ovipneumoniae, otherwise known as Movi, which is highly contagious and oftentimes deadly since there is no vaccine or cure for it.

Read more: Zion biologist advises livestock owners how to keep deadly pneumonia from spreading

Depending on the severity of the strain, many adult sheep can live with the bacteria with few to no complications. Lambs, however, have a harder time surviving the disease, and their deaths can cause a decline in the population.

A bighorn sheep ewe and lambs in Zion National Park, Utah, May 16, 2019 | Photo by Mikayla Shoup, St. George News

In Zion, however, no symptoms of pneumonia have been observed in this year’s lambs, and none of the 800 bighorns in the area have been killed by the disease.

“Right now, to date, with the collared sheep that we have, we have not seen any die off as adults, and we’re currently monitoring the newborn lambs and still seeing good survival on them also,” Jason Nicholes, a wildlife biologist with the Utah Division of Wildlife Resources, said.

Not only have none of the sheep died from Movi, but some of them are testing negative for it altogether.

The last testing that the park performed was in January, where they tested several sheep that had died of natural causes, and none tested positive for Movi, leaving park biologists baffled.

“It was really surprising. We expected to see somewhere between 50% and 80% of them to be positive but they weren’t,” Nicholes said.

It’s possible that the Zion herds simply contracted a less aggressive strain of Movi and have been able to live with it easily, he said. Another factor could be that they live in an area with plenty of food and water, and aren’t experiencing much stress.

Wildlife technician Brianna Johnson searching for bighorn sheep in Zion National Park, Utah, May 16, 2019 | Photo by Mikayla Shoup, St. George News

The park also transported 50 sheep from the park in 2017 to reduce the herd density, which could be a contributing factor to their health as well.

“It’s hard to say anything for sure except that they’re not dying of pneumonia right now, which is awesome,” Johnson said.

Because the entire herd was showing symptoms of pneumonia last year, it’s possible that the sheep that are testing negative for Movi simply have such a low level of the bacteria that they are unable to detect it, Nicholes said.

Even though this strain of Movi appears to be mild, the park will no longer be transplanting sheep from their population to boost other herds. Many times, the reason the bacteria is deadly is because the sheep contract yet another type of bacteria in addition to Movi, which can have devastating effects. And so far, the sheep in Zion have not tested positive for any bacterias other than Movi.

“I’m glad I didn’t have to watch that happen here,” Johnson said.

Email: mshoup@stgnews.com

Twitter: @STGnews | @MikaylaShoup

Copyright St. George News, SaintGeorgeUtah.com LLC, 2019, all rights reserved.

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