TheHorse_Logo_color (1) (1)_full-white

Beasts of Burden

Targeting disease in Africa’s
working donkeys and horses

Sounds of the Debre Zeit, Ethiopia, evening rush hour—low-tech traffic noises of passing hoofbeats and car-tire buggies on the main road—fill the alley where a man carefully harnesses his small gray horse for the drive home. He buckles, ties, and readjusts pieces and parts cobbled together out of saddlery and found items—leather, burlap, rope, twine, wire, and yellow bits of weathered plastic with edges wrapped in duct tape. Quickly, the equipment conceals the horse’s weathered, ribby frame. Still visible on his lower limbs are the orange splotches of iodine and the purple stains of salve covering the oozing sores on his shoulders, forearms, and lower limbs.

An owner harnesses his horse, which suffers from a fungal disease.

This horse is a lucky one—his driver has made a special trip to the Society for the Protection of Animals Abroad (SPANA) veterinary clinic on a nonclinic day so that 36 equine veterinarians, researchers, and others from around the world can take a close look at cases very different than those they see back home. The group has gathered in Addis Ababa, Ethiopia, at the First International Havemeyer Foundation Workshop on Infectious Diseases of Working Horses and Donkeys with a goal of learning how global collaborations can help this very large and important segment of the equine world.

A Crucial But Complex Role

At least 112 million domesticated equids live across the world, the great majority of which are working animals, says Professor Alan Guthrie, director of the University of Pretoria’s Equine Research Centre, in South Africa: 60 million horses, 42 million donkeys, and 10 million mules. About 13 million of those donkeys live in Africa alone, and about 75% of those are in the sub-Saharan region, which includes Ethiopia.

Alan Guthrie, BVSc, MedVet, PhD

Director of the University of Pretoria’s Equine Research Centre, in South Africa.

Richard Newton, BVSc, MSc, PhD, FRCVS

Head of Epidemiology and Disease Surveillance at the Animal Health Trust, in Newmarket, U.K.

Karen Reed, BVetMed, MSc, MRCVS

The London-based head of animal welfare for The Brooke, an international animal welfare organization dedicated to improving the lives of working horses, donkeys, and mules in some of the world's poorest communities. The Brooke provides treatment, training, and animal health and well-being programs across Africa, Asia, and Latin America.

One might expect widespread replacement of this “horse power” with horsepower. After all, it’s the 21st century. But the U.N.’s Food and Agriculture Organization (FAO) reported in 2011 that even in countries where the number of working animals is falling, there are many pockets in remote or rural poor communities where these animals make crucial contributions to livelihoods. In fact, in many parts of Africa the number of working horses and donkeys is increasing.

As for alternatives, “tractors and other things are expensive and not particularly green,” says Professor Richard Newton, head of Epidemiology and Disease Surveillance at the Animal Health Trust, in Newmarket, U.K. “Working equids are not going away anytime soon and, in fact, may well become more important.”

West Africa in particular has seen growth in working donkey populations. Karen Reed, head of animal welfare for The Brooke, an international equine charity that assists working equids and their owners in developing countries, reports, “They’ve increased in numbers from 4.5 to 6 million in the past decade, with the ‘donkey line’ moving southward” in this region. She says these animals often represent a vital stepping-stone for families out of poverty.

Indeed, “Our powerhouses of equestrian sport contribute to just about 10% of the domestic horse population,” Guthrie observes. “The rest of the world has a lot of other important roles for them.”

Globally, those roles support 300-600 million people, says Reed, 158 million in Africa alone. The job descriptions in Africa run the gamut, with equids involved in:


Plowing, tilling, weeding, transporting inputs (water, fertilizers, etc.), harvesting;


Moving fodder, moving whole families;


Urban and rural transport to schools, hospitals, shopping, etc.;




Moving building materials, from bricks to steel beams; and


Nigatu Aklilu, DVM, MSc

Country director of The Society for the Protection of Animals Abroad (SPANA) Ethiopia Project, based in Debre Zeit. SPANA is an international working animal welfare organization that provides training and education, along with clinics for donkeys, horses, mules, camels, and livestock across Africa and the Middle East.

Dr. Nigatu Aklilu, country director of SPANA’s Ethiopia Project, points out that most agricultural products bought in African cities are transported at least once on the backs of donkeys and horses on their journey to the consumer.

Many of these animals have second jobs: In Senegal (West Africa), for instance, horses used for agriculture double as taxis.

But for all their year-round importance, their lives aren’t always so great. “Donkeys are seen as very low status,” explains Reed. Therefore, it can be difficult to get to the people who can make a difference in their lives—for example, owners of brick kilns, where donkeys commonly bear incredible burdens, are offsite and do not see the animals’ condition day in and day out. “What you have is a lot of undernoticed animals.”

Also, owners often rent their horses or donkeys out for day-use to drivers who might not treat them with the same care as they would their own animals.

Left: Stephanie L. Church/The Horse; Right: Courtesy The Donkey Sanctuary

Compounding these problems is the invisibility of working equids to governments and international institutions; historically, they have paid little attention to improving these animals’ health and welfare, says Reed, though the FAO, OIE (effectively the “World Health Organization” for animals, present at this workshop), and European Union are showing increased interest.

Sustainable Change with Harnessing and Farriery

Roly Owers, MRCVS, is the chief executive of World Horse Welfare, an international horse charity aiming to improve horses’ lives around the world through education, campaigning, and hands-on care.

Finally, the very rise of working equid use in some areas—even in the hands of people grateful for new means of income—comes with its own complications. “The current expansion of donkey ownership may be to areas where equine management is not part of the traditional culture,” says Reed. So veterinarians and other individuals working on behalf of nongovernmental organizations (NGOs), such as SPANA, The Brooke, The Donkey Sanctuary, and World Horse Welfare, are seeing first-generation horse owners who supremely value their horses and donkeys but simply don’t know how to care for them.

These NGOs have been at work providing education, care, and low-cost humane equipment for these owners.

Working Equid Realities

Wrangling Wounds & Microbes

While our sources have gathered for the purpose of discussing working equid diseases, Aklilu and several others point out that diseases can’t be talked about without discussing the overall welfare problems.

Aklilu says the traditional beliefs and attitudes described, along with a variety of other factors, lead to these problems.

  • Overworked, overloaded, and used at high speeds on rough roads (“They fall and are affected by many injuries,” and, “many donkeys carry five times their body weight.”);
  • Managed poorly with low-quality and/or inadequate feed, water, housing, and hygiene;
  • Deprived of proper health care, including foot and dental care;
  • Subjected to inhumane hobbling, tethering, and bitting, along with incorrect harness materials (rough, synthetic, poor design, and improper usage);
  • Harmed through traditional practices such as faulty drenching (deworming), branding, castration, and wolf tooth removal, and through use of substances such as battery acid, burnt oil, cattle dung, etc., for wound treatment;
  • Pregnant, sick, very young, or very old;
  • Used in drought and very hot and cold conditions;
  • Not prioritized for funding in areas of health care and welfare;
  • Not legally protected by any animal welfare legislation; and
  • Impacted by poverty (Even if owners are educated and aware, Aklilu says, they don’t always have access to or cannot afford the resources they need.).

Wounds and compromised immunity caused by items in that laundry list can be open invitations for diseases. But it’s important to note that whether a community is educated or whether it’s developed or developing, disease happens. “The diseases that we’re working with don’t know whether that horse is an A-grade show jumper, a world-class racehorse, or a working horse,” says Guthrie.

Here are the top six infections working equids in Africa face, in no particular order. You’ll recognize a couple of them from your annual core vaccination lineup:

Histoplasma capsulatum var. farciminosum yeast: the causative agent of epizootic lymphangitis Courtesy Dr. Claire Scantlebury
Equine lung pulmonary edema and hemorrhage caused by African horse sickness Creative Commons/Dr. Richard Jakowski
Clostridium tetani Courtesy CDC
Rabies Courtesy CDC
Babesia caballi Wikimedia Commons
Trypanosomes Courtesy CDC

Epizootic Lymphangitis (EZL) is a fungal infection that causes illness, loss of use, and abandonment in horses. Affected animals, like the ones shown throughout this story, develop large areas of weeping wounds and swollen, filled legs. Veterinarians say the fungus probably gains access to the horse’s lymph system via sores from ill-fitting harnesses. Biting insects could also play a role, as could close contact between infected horses. Treatment is time-intensive and often impractical.

African Horse Sickness (AHS) is a viral disease spread by Culicoides midges. Affected animals can show clinical signs ranging from pulmonary distress to heart failure, and the disease is often fatal. Vaccination can prevent infection.

Tetanus, often referred to as lockjaw, is caused by toxins produced by Clostridium tetani, a spore-forming bacterium that infects contaminated wounds. Vaccination can prevent infection; treatment generally requires intensive care.

Rabies is a viral infection of the nervous system and salivary glands that can spread quickly to other mammals and is preventable through vaccination. But as equine vaccination can be impractical in some poor regions, control efforts have been focused on canine vaccination.

Piroplasmosis is caused by Theileria equi and/or Babesia caballi, protozoan parasites transmitted from one infected equid to another by ticks or other arthropods. These microbes cause the body’s immune system to attack and kill its own red blood cells, often leading to death. Although treatment is possible, the drugs are not always available in these countries.

Trypanosomiasis is caused by protozoa called trypanosomes that are spread by tsetse flies. Infected animals lose weight, become anemic, develop swelling underneath their bellies and neurologic signs such as ataxia (incoordination), and, finally, die if untreated.

African equine owners also report cases of generalized respiratory illness on a regular basis. University of Liverpool (U.K.) researchers are currently examining horses with respiratory signs in towns near Addis Ababa and hoping to determine the cause so they can recommend effective prevention and treatment measures.

As NGO veterinarians help owners manage disease, they take the opportunity to teach hygiene and preventive techniques. “Most of the time, when we get the animals (to be treated), we first teach the owners about particular problems,” says Aklilu. “For example, if we teach them about EZL, we teach them about how to prevent it, by decreasing all kinds of wounds. We also teach them about good harnessing: how they can make good bits and good harness materials. And on preventive aspects—we give a dewormer, ivermectin orally, and vaccination before the outbreak times.

“Most of the time we focus on preventive aspects, but once problems occur … we teach them how to make the recovery faster,” he says. “We have to work continually with the owners and drivers. There is change, but it’s not sufficient.”

Epizootic Lymphangitis: A Working Equid Disease

Epizootic Lymphangitis Up Close

Dr. Nigatu Aklilu describes treating cases to veterinarians at the SPANA clinic.

Equine researchers in the U.K. hope to define better the transmission methods of epizootic lymphangitis (EZL), which causes painful skin and eye lesions and leads to lameness and loss of use in working horses and donkeys throughout the developing world.

Dr. Gina Pinchbeck, senior lecturer in veterinary epidemiology at the University of Liverpool, in the U.K., and her colleagues are currently studying EZL.

Gina Pinchbeck, BVSc, Cert. ES, PhD, Dipl. ECVPH, MRCVS

Senior lecturer in veterinary epidemiology at the University of Liverpool, in the U.K.

There are three forms of the disease, which is caused by a fungus called Histoplasma capsulatum var. farciminosum—cutaneous (skin), ocular, and respiratory. She explained that a cutaneous EZL case starts as a single nodule that erupts. The infection travels though the lymphatics, causing swelling of the limbs and nodules elsewhere on the body.

“The horse can become debilitated and develop secondary infections … sometimes with joint involvement,” she says. “Quite often they’re abandoned at this point and seen by the road. The theory is that they want to stand where there are less flies,” likely because of air currents from the passing traffic.

Veterinarians see the ocular form less frequently. Cases start as a persistent conjunctivitis and swelling, and sometimes the infection spreads into the facial tissues, seen as small nodules. If cases go untreated, secondary infections and severe ocular disease can occur.

Cutaneous lesions are also seen in the respiratory form of the disease but are accompanied by nasal discharge and severe coughing. Post-mortem examinations indicate these horses have damage throughout their respiratory system.

Photo credit: Stephanie L. Church/The Horse

Veterinarians have reported cases of EZL in Ethiopia, Sudan, The Gambia, Senegal, Egypt, Nigeria, Iraq, India, and China, among other countries. Occurrence could be dependent on altitude or rainfall, said Pinchbeck.

The disease ranks high among working equid owners as a major problem; when Pinchbeck and her graduate students conducted participatory studies to prioritize diseases of African working equids, 11 out of 17 groups and 14 out of 16 groups ranked EZL as the most important disease.

“There’s a big desire to find a solution for the disease,” she says. “It’s a serious welfare issue because it’s difficult to treat and causes abandonment.” That makes the problem a socioeconomic one, as well. “Many owners acknowledge the disease has a direct economic impact due to its chronic and debilitating effect. They will continue to work the horse as long as possible but ultimately they become so affected they can no longer work.”

The fungus is sensitive to treatment with antifungals, but these medications simply are not affordable. Currently, control is quite difficult, says Pinchbeck: Veterinarians lance all of the nodules and infuse them with a 4% tincture of iodine. Resolution using this method can take up to two months and is only successful if treated early.

Until they determine the exact route of transmission and effective preventive techniques—which will only come about with more funded research—all veterinarians can do is advise owners to seek treatment early and prevent wounds, Pinchbeck says.

Pile of Problems: Where to Begin?

Indeed, even with the teaching and treating, there are still many barriers to improving the welfare of working horses, donkeys, and mules. The factors Aklilu described weigh heavily, as does a vast collection of other impediments.

So where does a roomful of equine researchers and clinicians —with a variety of backgrounds and a desire to help—begin to solve these problems? Our sources say you can’t just pick a disease and start throwing darts (or dollars) at solving it; you must go about it in a deliberate, planned way that makes funding go further and changes sustainable, with the understanding that African countries face logistical challenges much different than our own.

Stuart Reid, BVMS, PhD, DVM, Dipl. ECVPH, FSB, FRSE, MRCVS

Principal at the Royal Veterinary College, in Hatfield, U.K., current president of the Royal College of Veterinary Surgeons, and chair of the trustees of The Donkey Sanctuary, a U.K.-based international animal welfare charity that works to protect and care for donkeys and mules.

Professor Stuart Reid, principal at the University of London’s Royal Veterinary College and chair of the trustees of The Donkey Sanctuary, pointed out that to be successful in making change, you must have technical solutions, behavioral acceptance, and institutional buy-in.

Let’s look at tetanus. At a very basic level, a technical impediment to reducing cases might be the logistical difficulty of refrigerating equine tetanus vaccines until they can be administered. A social one might be that the owners don’t perceive tetanus as a problem in the first place, or they don’t believe they can take a day off work to get the animal vaccinated—even if the vaccine is free. An institutional impediment could be the low status of horses and donkeys on the government’s list of priorities, with an infrastructure that might not support vaccine distribution at all.

Courtesy SPANA

So, our sources for this article and the other delegates took the list of diseases described and defined impediments for each, and started brainstorming strategies for reducing cases—for the diseases that aren’t already being tackled.

“The basis of any intervention has to be understanding the problem in the first instance,” says Reid. “And the wonderful thing about getting this group of people together has been working with the people who are on the ground here, understanding the problem, and then working together to try to identify some sensible way forward … not necessarily solutions in the first instance, but a sensible way forward.”

He emphasizes that one key to making progress is involving social scientists and economists in future discussions to help determine directions for aid.

Offering Hope

Meanwhile, back in the first world, where a lot of horses live better than many humans do worldwide, the welfare issues of the millions of working equids can seem distant and a bit perplexing to solve.

Paul Lunn, BVSc, MS, PhD, MRCVS, Dipl. ACVIM

Dean of the College of Veterinary Medicine at North Carolina State University, in Raleigh.

Dr. Paul Lunn, dean of the College of Veterinary Medicine at North Carolina State University and member of the workshop’s organizing committee, says, “Our role is to get behind the people who live and work in these countries and the scientists focused on these problems. We need to provide them with the resources; sometimes those are intellectual, sometimes they’re technological, sometimes they’re advocacy, and often they are funding.

“We’re ignoring most of the horses on earth right now,” he adds. “Those of us who work in privileged nations have the opportunity to form partnerships with our counterparts in low-income countries that can have a huge impact, be it on infectious diseases or other problems.”

That need for impact is clearly evident as the little gray, now fully harnessed and ready to go, stands gingerly in the dirt lane beside the SPANA clinic. There’s no rig parked nearby to take the uncomfortable animal home, as there would be at the veterinary hospitals we’re accustomed to.

But this horse is able to go home—his EZL treatment regimen is ongoing; one of his fellow cart horses, awash in EZL sores that haven’t healed, remains behind at the courtyard to be euthanized.

Heading Home

The gray’s driver finishes a cell phone call, packs away the bottle of iodine tincture for treating the harnessed horse’s lesions and those of his other horses, and he and three other adults assemble quickly on the cart and trot away. They’ve done what they can to care for the animal, but now they need to get home to attend to their families and, for now, that’s another chore for the little gray horse.

“It’s important to understand that families share their horses … these social bonds are important to community structures,” Reed reminds us, and she quotes Ganesh Pande of Shramik Bharti, a Brooke India partner organization in Kanpur, India: “We know that for the whole world it might be only a donkey, mule, or horse, but for the marginalized poor owner it is the whole world.”