Tests confirm two Mexican gray wolf pups at southern Michigan zoo have died of a rare mosquito-borne virus as health officials work to curb the spread of the virus in people and animals.
Binder Park Zoo in Battle Creek says results received this week confirm the pups that died in early September were killed by Eastern equine encephalitis, which is also known as Triple-E. The two wolves were part of a litter born June 14 to a breeding pair of wolves at the zoo. The one wolf pup who survived appears healthy and is being monitored along with her parents.
According to the zoo's press release, the Mexican gray wolf is the "rarest subspecies of gray wolf." In 2018, only 131 were counted in the wild.
“Although EEE infection in canines is very, very rare, there have been a few cases previously reported in domestic dog puppies. All species considered highly susceptible to EEE infection at the zoo, including domestic and non-domestic equine species and ostriches, are vaccinated on a yearly basis,” Dr. Kim Thompson, staff veterinarian at Binder Park Zoo, said in a press release.
Those highly susceptible species includee domestic and non-domestic equine species and ostriches, but not canines.
”There's not a vaccine labeled for any canine for this disease because it is to extremely, extremely rare that any domestic canine would catch this disease,” Thompson said.
For those worried about their domestic dogs and cats, Michigan Department of Health and Human Services Public Information Officer Lynn Sutfin recommends keeping them indoors.
"EEE is quite rare in dogs and cats, however horses experience severe disease (90% case fatality rate)," she said via email. "A vaccine is available for horses. It is likely that companion animal species other than horses can be infected when they are bitten by an infected mosquito, but they are much less likely to become ill."
Do not used repellents approved for humans on pets and seek information from your veterinarian on how best to keep your animals safe.
The state Department of Health and Human Services reports the virus has been confirmed in humans or animals in at least 12 Michigan counties. Three people in southwestern Michigan have died.
In earlier reporting from Michigan Radio's Paulette Parker, the most recent data for Triple-E infections is as follows:
Human Cases
- 8 cases
- 3 Kalamazoo County (fatality)
- 1 Berrien County
- 1 Barry County
- 1 Cass (fatality)
- 1 Calhoun
- 1 Van Buren (fatality)
Additionally, Triple-E has been identified in 26 animals in Barry, Berrien, Calhoun, Cass, Genesee, Jackson, Kalamazoo, Lapeer, Montcalm, Newaygo, St. Joseph, Kent, and Van Buren.
Updated Sept. 26: 1:51 p.m.: The MDHHS alerted Kent County officials on September 26 that a deer was discovered to have died and tested positive for Triple-E. It is the firest reported case in that county.
People are urged to guard against mosquito bites. The department is encouraging officials in affected counties to consider postponing, rescheduling or cancelling outdoor activities including sports occurring at or after dusk until there's a hard frost. Aerial spraying is being considered.
The MDHHS provides the following as signs and symptoms of the virus and when to seek medical attention:
Signs of EEE include the sudden onset of fever, chills, body and joint aches which can progress to a severe encephalitis, resulting in headache, disorientation, tremors, seizures and paralysis. Permanent brain damage, coma and death may also occur in some cases. Anyone experiencing these symptoms should visit their physician’s office.
To learn more about the virus, visit the state's website.
