Brucellosis

[Wapiti Warrior]

I was wondering why elk all over Montana are not getting the heat like the Gardiner elk? I mean most of the elk in Montana were transplanted from Yellowstone in the early 1900's, so why don't they have Brucellosis?

John

 

[RobG]

I was wondering why elk all over Montana are not getting the heat like the Gardiner elk? I mean most of the elk in Montana were transplanted from Yellowstone in the early 1900's, so why don't they have Brucellosis?

John

Kat's the expert on this... but a summary. Many years ago the cattlemen introduced Brucellosis into the Yellowstone bison. The bison then transferred it to the Yellowstone elk. It has only become a problem relatively recently. Right now the infected elk herd is limited to the Yellowstone area - say within a 50 miles radius (look up elk brucellosis designated surveillance area). However, it is expected to keep expanding since the elk migrate a lot. For example, one cow was tagged in the Madison and wound up at the Wyoming feed grounds.

 

[katqanna]

Sorry, saw this earlier but have been on the phone all days with agencies about the bloody brucellosis study.

Not an expert, always a student.

Okay, heres the overview. Cattle brought Brucella abortus to the elk and bison populations with the settlers west. Brucellosis was first detected in wild bison herds in the early 1900's, elk following in 1930's (they werent studying the elk before that but elk probably had it at the same time). With the near extinction of many elk and bison populations for a variety of reasons, you didnt see much spread of the disease or wildlife to/from domestic interaction.

A small percentage of elk carry and transmit brucellosis. They estimate that about 2-3% of the populations in the GYA area - except around the Wyoming elk feedgrounds where that number can rise 10-30%. While bison are genetically more susceptible to contracting brucellosis than elk, they are not the major transmitters (never been a documented case of wild bison to cattle ever). Yet, elk, while not as susceptible to succumbing to brucellosis (better immune system for fighting off the bacteria) are more capable of transmitting back to the cattle which originated this particular type of Brucella - abortus. Other varieties are dominant in other species, like Brucella suis in swine or melitensis in goats.

So around the elk feed grounds brucellosis in elk is about 30% due to unnaturally congregating elk during the high risk time of abortions and feeding near abortions, which is how this is transmitted - ingestion/inhalation of infected materials. But we dont have an elk feedground here in Montana, so our numbers should be lower like they used to be. Collared elk have proven to move long ways into Montana and have contact with the Wyoming elk feed grounds. But, due to APHIS and DOL's agenda of trying to wipe out bison here in Montana, with slaughters coming out of the YNP and such, it has created a Wyoming feedground type situation which is increasing the seroprevalence around the YNP in elk, as well as bison. Exposing an infected females sexual organs or birthing materials to other bison or elk, where curiosity causes them to inhale, lick, ingest any infected materials is spreading brucellosis in the northern part of the YNP, into Montana.

Just because an animal becomes infected, does not mean it remains infected. Just like our getting chicken pox as a child, they can show antibodies in their blood for exposure - antibodies (seropositive) yet not remain infected or infectious to others.

There may be some elk that are in other parts of Montana that have these positive antibodies to exposure, but no disease. The farther away from YNP, the smaller the percentage of seroprevalence in elk. Since elk giving birth are more secluded and any possible abortions dropped from a naturally uncongregated elk, scavengers are quick to clear that aborted material up. The only way to test for the actual disease is to kill the animal and culture it from their organs. They do not know for certainty how many of the elk near Gardiner are actually infectious because they would have to kill them to determine that.

Part of the reason for the elk "heat" around Gardiner is political. This is part of the danger of this last elk brucellosis work plan that the FWP commission just approved (Tourtlotte did not vote for it). The 2015 work plan allows for these actions against the elk to be taken not just within the Designated Surveillance Area, but in any area of Montana where the elk are known to come in contact with the DSA elk.