By Joseph Robertia
Moose never look regal in the spring. They’re scrawny and lean from the long winter without fresh forage and scruffy while shedding their ragged-looking cold-weather coat. But one young cow lingering in Kasilof lately has an even more unappealing presence.
“They’re called infectious cutaneous fibromas,” said John Crouse, a wildlife biologist at the Alaska Department of Fish and Game, in regard to the dry, hairless, apple-sized tumors dangling from the moose’s body.
Actually a virus, fibromas affect nearly all species of the deer family and have been documented in white- and black-tailed deer, mule deer, fallow deer, red deer, roe deer, Sika deer and caribou, in addition to moose.
“The ‘warts’ can be anywhere from golf ball sized up to volleyball sized, and they can have just one or be covered in them,” Crouse said. They may also grow in individual tumors or in large clumps of them.
As a virus, fibromas are spread from moose to moose via direct contact with an infected animal, contact with an object that a moose with a burst wart has rubbed on, or by insect bites.
“It’s not too big a deal for them or their long-term health. Usually it’s the younger animals under 2 years old that get them, and it will clear up after a few months,” Crouse said, although on rare occasions some tumors can develop in sensitive areas, such as around the eyes and nose or in the armspits, and affect the animal’s sight, breathing or movement.
During the time fibromas are showing, the infected moose may look worse than they are due to the unsightly appearance of the tumors and their tendency to burst and weep.
“Some of them can get so big and dangly they’ll actually tear off or open. It usually occurs from moose walking through so much brush. They’re usually so much wider than what they’re walking through, so the warts can get caught or scraped open on branches,” Crouse said.
The wounds can also get infected, or just heal back into a calloused-looking scar until the hair grows back, he said.
Crouse said the condition is somewhat common in Alaska, including on the peninsula.
“We get calls about animals with it every year, and some years more than others,” he said.
The calls usually come in around this time, and are often by residents worried the moose may be suffering and needing to be euthanized, but Crouse explained that euthanasia is not warranted.
“I wouldn’t want to be killed for having a few warts,” he said.
While the animal spotted around Kasilof is a cow, bulls can also be infected. Crouse said that hunters need not worry about harvesting an infected animal should they come across a legal one in hunting season. The disease is not known to affect humans who come in contact with infected moose, such as during skinning or butchering animals with fibromas.
“The warts are only on the skin of the animal. It doesn’t go into the deep tissue, so the meat is fine. It doesn’t affect it at all,” he said.