equine influenza
Tens of thousands of working equids in Western Africa have died in a sweeping equine influenza (EI) outbreak.

Official disease notification from Senegal and Nigeria to the World Organization for Animal Health (OIE) indicate more than 40,000 cases have resulted in more than 3,000 equid deaths since mid-December. However, other reports indicate case numbers in other countries, which haven’t submitted official notifications, could be skyrocketing even higher.

“We have received unofficial statistics of 62,000 deaths in Niger alone in donkeys and some horses presenting with symptoms like those we’ve seen in our country, which were confirmed cases of equine influenza,” said Mactar Seck, DVM, program manager at Brooke West Africa, in Dakkar, Senegal. Brooke West Africa is part of Brooke, a U.K.-based international animal welfare charity focusing on improving health and welfare for working horses, donkeys and mules.

As of May 2, Senegal, which has a working equid population of about 1 million, had reported 37,000 cases and 2,700 deaths to the OIE, but it has since recognized thousands more cases and the death toll has risen to more than 6,000, Seck said. The first equine influenza case in that country was reported only six weeks ago, on March 26.

In Nigeria, with 1.4 million equids, more than 3,000 cases led to nearly 300 deaths, mostly within a six-week period leading up to early February, official reports say.

In Niger, Mali, and Burkina Faso, local veterinarians and charity groups have recognized an equid disease outbreak, but it appears no official testing has yet been carried out, said Seck. Death estimates in those countries are running into the tens of thousands.

The vast majority of equids dying in the outbreak are donkeys. “In Senegal, only 150 of the deaths have been horses,” said Seck.

Human Impact and Equine Welfare

Meanwhile, equids aren’t the only ones suffering during the disease outbreak.

“Many of these families that rely on their working equids for their livelihood will lack the resources to buy a new animal, and this disease outbreak will have increased the already rising price of donkeys,” said Roly Owers, MRCVS, CEO of World Horse Welfare, in Norfolk, U.K, which also has a project in the Rufisque area just outside Dakar. “It is clearly too early to tell the full level of impact at this time.”

As for equine welfare, there will “certainly be a major impact,” he said. “The effect on individual animals varies hugely, with the disease being subclinical (showing no clinical signs) in some to causing severe signs and death.”

Many of the affected equids will also not have the chance to benefit from proper care—even something as simple as rest, Owers added. “Rest is a crucial element of disease treatment, and many owners will not have been able to rest their animal due to their situation,” he said. “In many cases, this will have made the infection worse.”

Disease Treatment and Control Measures

Many owners—mainly farmers and merchants who use equids to work fields and transport goods—treat their sick animals with home remedies, Seck said.

“It’s a very common practice,” he said. “The first reflex is to automedicate with traditional medicines and only call the veterinarian when, a few days later, the animal’s condition has significantly deteriorated. So that complicates our efforts to manage and contain the epidemic.”

Where disease has been reported to the OIE, government officials have enacted movement control inside the country; surveillance outside containment and protection zones; official disposal of carcasses, by-products, and waste; disinfection; ante- and post-mortem inspections; and treatment of affected animals (i.e., symptomatic treatment with antibiotics), according to the OIE. Strong winds and dust likely increased spread and susceptibility, Senegalese authorities added.

“Equine influenza is not a simple disease; like all influenza viruses it mutates and periodically can present a very severe strain,” Owers said. “It is likely that there are significant secondary complications (such as strangles as a secondary infection), as well, here. The virus lowers an animal’s immune status making it more prone to secondary infections.”

Seck added, “At first we thought it was strangles, which is what we’re more used to seeing in our region. But as the outbreak progressed we realized it was something different, and so we tested for equine influenza and found positive results. This is the first time equine influenza has been diagnosed in Senegal.”

Influenza vaccines are essentially nonexistent in the country, he added; however, “a vaccination campaign would be impractical and expensive for our population, who would be unlikely to comply,” he added.

The outbreak’s origin is currently unknown, but illegal importation of animals could be a critical factor, according to the OIE and Brooke International, and Seck concurs.

“We’re not sure yet, but we think it’s related to animals being moved across countries and even continents, including the importation of racehorses from Europe,” he said.

The current epizootic outbreak is “being taken very seriously both at government and international level,” Owers said. “Through the OIE, the International Coalition for Working Equids (which includes Brooke, World Horse Welfare, The Donkey Sanctuary, and SPANA [the Society for the Protection of Animals Abroad]) has been promoting practical biosecurity guidance through national government for donkey owners,” he said.

Now, the epidemic appears to be resolving, with no new cases reported within the last week, said Seck.