West Nile Virus found in a horse near Medicine Hat

By Leah Murray
August 16, 2018 - 5:30pm Updated: August 17, 2018 - 11:09am


MEDICINE HAT, AB – Blue Sky Veterinary Clinic said it found West Nile Virus in a horse near Medicine Hat.

A post on the organization’s Facebook page indicates there have been other cases in the Brooks and Jenner area.

August is the prime month for West Nile Virus (WNV) to appear. It’s carried by a certain type of mosquito, the Culex tarsalis.

WNV is a mosquito-borne virus that can cause swelling and inflammation of the brain and spinal cord in horses, birds and humans. It was first detected in Alberta in 2003.

According to Alberta Agriculture most horses bitten by an infected mosquito will not develop clinical disease, as they’re able to fight off the virus. But, around 35 per cent of those who do develop symptoms may die or have to be euthanized because of complications.

For those who do get sick they can exhibit several symptoms.

“listlessness, a change in demeanour becoming less active and isolated, reduced appetite, inability to swallow, drooping lips, muscle twitching, a lack of co-ordination, weakness in the limbs, partial paralysis or an inability to get up,” listed the Agriculture and forestry website. “A fever is not always present.”

Officials say infected horses should be examined by a veterinarian because the signs are similar to those caused by Western Equine Encephalitis, Eastern Equine Encephalitis and Rabies.

Some horses that recover from WNV may suffer from permanent neurological issues.

Last year there were seven cases of WNV confirmed in humans in Alberta.

Alberta Health Services said of the seven cases, four of those were in the south health zone that stretches from Medicine Hat to Lethbridge.

No cases have been reported so far this year but AHS says August is the peak season for cases of WNV to appear.

“There are some people who start feeling like a viral illness because it is a virus, you get a fever, headaches, body aches that usually happens within a couple days to a couple weeks of getting bitten,” said Dr. Lizette Elumir, medical officer of health. “On the rare occasion it can turn into a neurological disease or a serious disease.”

While WNV can have serious and even deadly consequences, Dr. Elumir said many people may not even realize they've contracted it.

“Whether we have cases or not, that doesn't mean we shouldn't be protecting ourselves,” she explained. “Keep in mind a lot of West Nile is a-symptomatic, so if you do end up getting West Nile Virus, a large number, like 80 per cent of them, you have no symptoms at all.”

There is a vaccine for horses to help prevent them from contracting West Nile Virus along with other equine diseases stemming from mosquito bites, but there is no such vaccine for people.

AHS says people should protect themselves against the disease by using insect repellent and wearing protective clothing to prevent bug bites.

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