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Potential Donkey Health Challenges

A donkey grazing in a grassy field.

June 15, 2020

Unfortunately for the humans looking out for them, donkeys don’t tend to show any signs that they’re sick until it can’t be hidden any longer, usually resulting in much more intensive treatment than an early diagnosis would have led to. If you want to ensure early disease recognition, you’ll have to spend a lot of time with the donkeys in your care, so slight changes and symptoms are more apparent to you. By conducting regular full body health examinations, you’ll be able to know what healthy looks and feels (and smells!) like, and when you should be concerned.

If you are new to caring for donkeys, you may think they are like small horses and act similarly. However, you would be mistaken. Donkeys are generally more stoic in nature, and may only exhibit the smallest behavioral changes in response to an uncomfortable or painful feeling. So keep a close eye on them!

Animal Healthcare Disclaimer

This is not an exhaustive list of everything that can happen to a donkey, but can help you get a sense of what challenges a resident under your care may face in their lifetime. If you believe a resident is facing a health issue, always discuss with a qualified veterinarian as soon as possible. Reading about health issues does not qualify you to diagnose your residents!

Issues By Body System

Circulatory: Equine Infectious Anemia (“Swamp Fever”)

Gastrointestinal: Anthrax, Colic, Diarrhea, Gastric ulcers, Internal Parasites – Large Strongyles, Small Strongyles, Roundworms, Pinworms, and Tapeworms

Metabolic: Equine Cushing’s Disease, Equine Metabolic Syndrome

Musculoskeletal System: Arthritis, Club Foot, Hoof Abscesses, Hoof Avulsion, Hoof Cracks, Hoof Overgrowth, Laminitis, Pigeon Fever, Thrush, White Line Disease (‘Seedy Toe’)

Neurological: Equine Encephalomyelitis, Equine Protozoal Myeloencephalitis, Tetanus (‘LockJaw’)West Nile Virus, Rabies

Reproductive System: Cryptorchidism

Respiratory:  Anthrax, Equine Herpes Virus, Equine Influenza, Lungworms, Strangles

Skin And Hair:  Abscesses, Anthrax, Brucellosis, Dermatophilosis (‘Rain Scald’), External Parasites ( Lice, Mites, and Ticks), Insect Hypersensitivity (‘Sweet Itch’), Pastern And Heel Dermatitis (‘Mud Fever’), Pigeon Fever, Sarcoids

Urinary System: Cystitis and Pyelonephritis

Vision: Cataracts, Conjunctivitis

Weight and Diet:  Hyperlipaemia, Laminitis, Obesity

Abscesses

An abscess can be caused when an infection or foreign body stimulates the accumulation of white blood cells. These form pus and the system starts walling off the infection or foreign body with fibrous cells.

Abscesses can occur anywhere in a donkey’s body, including the internal organs. More often, accesses form in the hoof or under the skin where the pressure often builds up, rupturing the abscess. This rupturing can expel surprising amounts of pus, depending on the size of the abscess. After an abscess ruptures, the wound may continue to leak pus and become a chronic sore. Abscesses of the hoof are commonly caused by the puncturing of the hoof by something sharp that stays lodged within the hoof. In these case, the infection can grow into the deep tissues. The donkey will exhibit signs of lameness.

An example of accesses of the internal organs is Strangles, an infection caused by Streptococcus equi that causes abscesses in the lymph nodes below the ear and under the throat, as well as in the internal organs.

If you suspect an abscess, call a veterinarian to diagnose it. They make apply a poultice to draw out the abscess to the surface. They may also lance the abscess and irrigate the wound (any abscess on the face or neck should be treated by a veterinarian to minimize risk of major bleeding). Ask them to take a sample of the pus to discover the type of bacteria causing the infection and dictate the type of antibiotics, if any, are required. This will also help you know if you need to isolate the donkey to prevent the herd from becoming infected.

In the event that you do not have access to a veterinarian, lancing an abscess is a relatively simple process, though this technique should be taught by an expert or veterinarian prior to attempting! You can start by applying a poultice – heated, moist cloth to the site of the abscess. Then trim the hair around the abscess, disinfect the surface with an antiseptic, and make a low, small, vertical incision with a sharp and sterilized knife. Using sterile gloves, carefully squeeze out the excess pus and flush the wound with disinfectant. Discard or sterilize anything that comes into contact with the pus and monitor the wound for up to a month. You may want to isolate the donkey depending on the abscess size or location for this time period. Certain diseases will require additional care and treatment of the abscessed donkey. (Back to the top)

Anthrax

Anthrax is caused by Bacillus anthracis spores, which can lie dormant in soil across the world for many years. The bacteria can activate and contaminate soil and grass in certain weather conditions, especially wet and cool weather followed by hot and dry weather. Animals that graze are susceptible to the disease after eating contaminated grass. Symptoms include depression, incoordination, staggering, trembling, convulsions, excitement, bleeding, and unfortunately, typically death. If you suspect a donkey is suffering from anthrax, you must contact your veterinarian immediately. Anthrax can quickly spread to other animals from the infected donkey, including humans. Confirmations of anthrax must be reported to government officials. If it is treated very early on with antibiotics, it is possible for donkeys to survive. There is also a vaccine available for anthrax. (Back to the top)

Arthritis

Like most animals, donkeys can become prone to arthritis as they get older. Arthritis can also be caused by injury, infection, malnutrition, and a lack of space to move freely. Symptoms include less motion, laying down more often, weight loss, shabby coat, strange gait, and swollen joints. Treatment for arthritis differs depending on the root cause, so if you believe that a donkey is suffering from arthritis, it’s important to consult with your veterinarian. Make extra sure that their environment is as arthritis-friendly as can be, minimizing steep grades or long walks to food or water if you can! (Back to the top)

Brucellosis

Brucellosis in equines is characterized by two conditions, namely Poll evil and fistulous withers:

A horse’s poll is the area at the top of the head between the ears and running down the back of the neck. Poll evil is a disease where the area is injured or becomes inflamed and swells, and eventually the infection leads to devitalized tissue.

Fistulous withers is a condition found in horses and donkeys where the supraspinous bursa (located near the withers) becomes inflamed. This condition can be caused by traumatic injuries or infectious agents. When an infectious agent is involved it is most often caused by Brucella abortus.  Common signs of fistulous withers are swelling, pain, and heat, but can also include fever, lethargy and stiffness. Over time, the bursa may rupture and have an infectious looking discharge. This may heal over, leaving a scab, or it may continue to drain for many days. If left untreated, the problem can heal and then show up again some time later. In almost all cases, the area surrounding the bursa becomes thickened with scar tissue and inflammation.

If the bursa is un-ruptured and not draining, treatment with antibiotics and anti-inflammatory agents is recommended. When the bursa is fistulated or draining, most treatments include removing any involved tissues and flushing the area with dilute betadine or other solutions. Antibiotics are also often given to help prevent additional infections. Affected donkeys typically do not give this disease to other animals or humans, but it can be spread by cows, goats, wild pigs, sheep, deer, and related animals to horses, donkeys, and humans. Keep donkeys away from infected cows, sheep or goats and keep infected donkeys with openly draining fistulous withers separate from other residents. (Back to the top)

Cataracts

A cataract is an increased density or opacity of an eye’s lens, reducing the transmission of light to the retina. Some cataracts are congenital, while others are acquired. Acquired causes of cataracts can be caused by trauma or ocular disease, UV light, toxin ingestion, and ionizing radiation. Aging donkeys may also develop senile cataracts. Cataracts may appear as an initial grayness, or bubbles or cracks in the lens. These progress to white or grey opacity, preventing light from being reflected from the retina. This obscures the structures behind the lens. It is important to treat the underlying conditions and associated symptoms. Unfortunately, cataracts are irreversible once formed. Only specialized surgery can potentially fix the issue. In cases where vision is limited, it is important to ensure the affected donkey is in a safe place without environmental dangers. (Back to the top)

Conjunctivitis

Conjunctivitis is a non-specific symptom or response of the eye to injury. The conjunctiva includes the inner eyelid and surrounding membrane. There are many cause of conjunctivitis, ranging from viral disease to fungal infections. Infections that cause conjunctivitis can be also known as Pink Eye. Often conjunctivitis is caused by an irritant in the eye, such as dust, flies, or a foreign body. Bacterial infections and trauma to the eye can also cause conjunctivitis. Symptoms of conjunctivitis include a reddened, inflamed membrane, and watery/mucousy discharge.

Washing the eye to remove dirt or a foreign object is a good first step. It’s important to identify the cause before further treatment, as it will alter the course of treatment. Call a veterinarian to discuss the symptoms and proper course of treatment. (Back to the top)

Cystitis And Pyelonephritis

Cystitis or urinary tract infections (UTI) are common in equines. They are often associated with disorders that disrupt urinary flow. When a UTI has spread to the kidneys it is called pyelonephritis. Common organisms involved in these issues are E. coli, Enterococcus app., and Streptococcus app. You may notice a donkey frequently attempting to urinate or notice blood in their urine. Other symptoms include dribbling or scalding of the perineum and legs. Donkeys with pyelonephritis may appear depressed and anorexic. It is important to keep you donkey well-hydrated and call a veterinarian to diagnose the issue and prescribe the appropriate treatment. (Back to the top)

Club Foot

An abnormally shaped upright foot can be caused by congenital or acquired deformities of the deep digital flexor tendon. If a donkey has experienced chronic limb pain while a hoof abscess has been treated, the disuse of the limb may cause the tendon to contract, pulling the pedal bone into a more upright position. It is important to identify the cause, removing the source of pain where applicable. NSAIDs can be used to encourage relaxation of the tendons. If the club foot is chronic, trim the hoof regularly and keep the foot balanced. Do not try to return it to the ‘correct’ shape, as this could cause lameness. Toe abscesses are common, so protect the donkey’s toe region from over wear. (Back to the top)

Colic

Colic refers to the symptom of abdominal pain, rather than a specific disease.  It is similar to the condition in horses but the distribution of common causes and signs can be somewhat different. Various types of colic may present differently, and they are often assessed on the basis of history, pain, heart rate, respiratory rate, gut sounds, and other clinical exam findings. Signs of dehydration are not always obvious as donkeys tend to cope better with dehydration than horses due to their adaptation to arid climates. The heart rate of a donkey with colic is often increased above their average normal of about 44 beats-per-minute. Their normal respiratory rate is 16-20 breaths-per-minute, and this may also increase with colic, depending on the cause.

Causes:

  • Impactions or blockages with partially digested food,
  • Muscle cramps (spasmodic colic)
  • Gas colic (flatulent colic)
  • Tumors in the abdomen, particularly in older donkeys
  • Obstructions with ‘foreign bodies’ such as plastic bags
  • Twisted guts (torsion)
  • Stomach ulcers
  • Worms – tapeworms or roundworms
  • Pancreatitis – very serious inflammation of the pancreas.

The “stoic” nature of a donkey may mean the only signs of colic you observe are “dullness” and an unwillingness to eat. You might see a donkey stretch themselves out in a standing position if they are extremely uncomfortable. It is important to take small changes in behavior very seriously with donkeys.

Symptoms:

  • Dullness – most commonly the first sign
  • Lack of appetite or refusing to eat
  • Rolling and pawing at the ground (rare in donkeys, if seen indicates very serious problems)
  • standing with the body stretched out
  • Fast breathing, raised heart rate
  • Excessive sweating
  • Color of gums or inside eyelid – brick red color is a poor sign
  • Lack of, or a reduction in the normal quantity of droppings

If you observe any of these signs in a donkey, call your veterinarian immediately.

While you wait for the veterinarian to arrive, continue monitoring the unwell donkey for further signs of discomfort. The veterinarian will perform an examination in order to accurately diagnose the issue. Depending on the findings of the examination, the veterinarian may decide to introduce fluids into the donkey’s stomach via a tube inserted into a nostril. They may also put the donkey onto a ‘drip’ (fluid introduction via the large vein in the neck) and prescribe pain-killers and antibiotics when appropriate. Sometimes hospitalization and/or surgery may be required. Unfortunately, there are scenarios where euthanasia may be the most compassionate option in grievous cases.

Possible Causes And Management:

  • Feed – sudden changes to diet, poor quality food, too much grass, feeding cereals:
    • Make any dietary changes gradually over at least a week, ideally 2-4 weeks. Feed good quality forage and donkey specific proprietary foods. Avoid moldy food
    • Always soak sugar beet to the manufacturer’s recommendations
    • Ensure regular feeding: small amounts and often, especially if the animal is supposed to be eating extra calories
    • Avoid access to too much rich spring grass, which can lead to problems with laminitis and colic
    • Avoid access to grain and other rich food. Rich food, particularly those that are high in starch and sugar, can cause laminitis and colic
  • Inadequate/dirty water supply:
    • Check troughs at least daily: Self-fill auto-waterers can become blocked, water supply can fail
    • Clean any contaminated water containers, as donkeys will not drink dirty water
    • Check that water is not frozen or too cold. Many donkeys will not drink very cold water; take the chill off the water in cold weather
    • Consider offering several sources of water
  • Eating non-food items such as plastic bags, rope or bedding:
    • Ensure donkeys cannot access such material
    • Watch out for donkeys eating their bedding, eg when box-rested under veterinary instruction
    • Consider changing the bedding to something less palatable, such as wood shavings
    • Cardboard or paper bedding is not recommended for donkeys
  • Ingestion of poisonous plants:
    • Know about the poisonous plants and trees that could be present at your sanctuary and prevent your residents from accessing them
    • Check pasture and boundary fences and hedgerows frequently and remove them or fence off the problem area
    • Fence off trees during fruiting to prevent overeating
  • Sandy soil: Avoid grazing on sandy soil pasture if possible
  • Dental disease – failure to chew food adequately resulting in a blockage of the gut:
    • Ensure donkeys’ teeth are checked at least annually by a qualified equine dental technician or veterinarian following a dental care program
    • Dental disease is more common in older donkeys. Suspect teeth problems if donkeys are ‘quidding’ (dropping partially-chewed food) or drooling saliva
  • Worms – migrating worm larvae or large numbers of worms causing an obstruction:
    • Ensure regular fecal worm egg counts are carried out to determine if donkeys require treating for worms. Consult your veterinarian for advice
    • Pick up manure from the paddock a minimum of twice per week
  • Stomach ulcers:
    • Reduce stress and ensure you ‘trickle feed’ the donkey

(Back to the top)

Cryptorchidism

Cryptorchidism is a condition where one or both testes fails to descend from the abdomen into the scrotal sac. Both testicles should be located within the scrotum when the male foal is born, although some surgeons advise waiting at least 18 months prior to cryptorchid surgery to allow ample time for the cryptorchid testicle to descend. A single testicle should never be removed if the other cannot be located; the animal may remain fertile and this could lead to serious welfare implications if mares and jennies are impregnated. (Back to the top)

Cushing’s Disease

Cushing’s disease is a hormonal disorder that arises when the nerve supply to the pituitary gland becomes damaged. This ultimately causes increased quantities of hormones to be released from the gland. The disease is more correctly termed ‘Pituitary Pars Intermedia Dysfunction (PPID).’

the severity does seem to increase with age. There is also a possibility that obesity predisposes to PPID, but this has not been confirmed.

While is is common to see signs of Cushing’s disease in horses in the form of long, hairy coats, and excessive urinating and drinking, it is harder to see these signs in donkeys.

Unfortunately, the first indication that a donkey may have PPID is a severe attack of laminitis, or if a donkey suffers from recurrent bouts of laminitis. Due to the stoical behavior commonly exhibited by donkeys, it is important to be aware of any behavioral changes or intermittent lameness in a donkey that might be related to underlying laminitis. If a donkey has recurrent infections and parasites, you should consider calling your veterinarian. Because PPID also affect body fat and muscle, a donkey may present with a “potbelly” and lethargy.

If a donkey is found to have PPID, there are long-term treatment options available. Daily medication and bi-annual blood test are required for maintenance. The treatment used is a drug called Pergolide.

Pergolide may interfere with a donkey’s appetite in the first few weeks. Be sure to closely monitor their appetite and communicate with your veterinarian if they are not eating. (Back to the top)

Diarrhea

Diarrhea is never pleasant and can even be caused by a serious underlying medical disorder. Identifying the underlying cause and treating it is the best course of action. Here are some common causes of diarrhea:

  • Salmonella infection (infectious)
  • Intestinal parasites
  • Sudden changes in diet, such as access to lush grass, or ingesting a large amount of concentrates
  • Antibiotics
  • Internal tumors
  • Sand colic
  • Liver disease or heart failure
  • Hyperlipaemia
  • Inflammatory bowel disease
  • Reaction to medications

Ensure the donkey receives plenty of fluids and call a veterinarian in order to diagnose and administer proper treatment to the donkey resident. (Back to the top)

EncephalomyelitisEEE (Eastern equine encephalomyelitis), WEE (Western equine encephalomyelitis) and VEE (Venezuelan equine encephalomyelitis)”

Equine Encephalomyelitis viruses are transmitted through mosquito bites and affect the nervous system. They can cause inflammation of the brain in both equines and humans. Affected animals may display circling or head-pressing behaviors and show signs of impaired vision, muscle twitches, inability to swallow, paralysis, convulsions, and fever. There are annual or semi-annual vaccinations available against EEE and WEE. Vaccinate against VEE as recommended by your veterinarian. (Back to the top)

Equine Herpes Virus

There are five distinct strains of the herpesvirus that can affect equines. Equine herpesvirus 1 (EHV-1) and equine herpesvirus 4 (EHV-4) both cause respiratory disease when first contracted. Fever, nasal discharge, and coughing are all symptoms of the disease and can be hard to distinguish from Equine Influenza. Treatment involves rest and careful observation to prevent secondary infections. Contact your veterinarian for a diagnosis and possible treatment options. Isolate any sick donkeys or horses. (Back to the top)

Equine Infectious Anemia “Swamp Fever”

Equine infectious anemia, or EIA, is a blood-borne viral disease transmitted primarily through insects, particularly horse flies, deer flies, and mosquitos. It can infect any equid, and some donkeys may not show any symptoms but can still be a source of infection for other animals. Those that do display symptoms may have a fever or anemia.

Infection is spread primarily through insect bites, but can also be transmitted through contaminated needles and other instruments, or passed on from mare to foal during pregnancy. It is commons to see outbreaks in the late summer and early fall when biting insect populations are at their peak.

There is a 7-45 day incubation period before signs of the disease are observed. While the virus triggers an immune response, it is not effective in eliminating the infection. Sadly, there is currently no cure. There is no vaccination either. However, the Coggins test can help diagnose and control the disease. (Back to the top)

Equine Influenza

Equine Flu is a contagious viral respiratory disease caused by various strains of the Influenza virus. It affects the upper and lower respiratory tract of horses, donkeys and mules. Just like with humans, this flu is very contagious and spreads rapidly. As with the human version, Equine Flu is It is mainly acquired through inhalation of the virus from ill animals coughing, but it is also possible to spread it indirectly through food buckets or humans that have been in contact with sick donkeys. There is a possibility that it can also be spread to canines too.

Symptoms:

  • Very high temperature, which lasts for 1-3 days
  • Frequent harsh, dry coughing that can last for several weeks
  • Clear, watery nasal discharge that may become thick and yellow or green
  • Enlarged glands under the lower jaw
  • Clear discharge from the eyes and redness around eyes
  • Depression and loss of appetite
  • Filling of the lower limbs

It is important to seek veterinary treatment if a donkey resident has Equine Flu as it weakens their immune system, making them vulnerable to secondary infections. It could also develop into a more serious respiratory disorder if left untreated.

Vaccinate donkeys routinely based on your veterinarian’s recommendations. Prevention is best! (Back to the top)

Equine Metabolic Syndrome

Equine Metabolic Syndrome is most associated with insulin resistance, obesity, and an increased risk of developing laminitis. Donkeys are more prone to EMS than horses. Obesity may present itself in specific areas of the body, specifically the crest of the neck, the trunk, and the fatty pads over the rump.

Laminitis may develop gradually, with the only sign being laminitis rings on the hooves, or it could be associated with seasonal turnout to pasture, and present as severe recurrent painful laminitis. If you suspect a donkey resident may have EMS, call your veterinarian. They will likely perform a complete physical examination and bloodwork. If the insulin level tests high, your veterinarian may confirm the diagnosis with a Combined Glucose-Insulin Test.

If a donkey resident does have EMS, you will want to limit sugars and starches in their diet. You may have to consider a grazing muzzle if they have access to a grassy pasture, as too much high-sugar grass can cause a problem. Low sugar grass hay (NSC content of 12% or less) should be the basis of their diet. They may also need a multi-vitamin/mineral supplement, on a veterinarian’s recommendation. Be sure to change diets gradually, as immediate changes can cause other health issues to arise.

In addition to a low carb and sugar diet, donkeys with EMS will need daily exercise. Hand walking or otherwise encouraging the donkey to walk is important. However, if they are showing signs of laminitis, only exercise them on the advice of your veterinarian. (Back to the top)

Equine Protozoal Myeloencephalitis

Equine protozoal myeloencephalitis is a neurological condition affecting donkeys and other equines. It is caused by the protozoa Sarcocystis neurona and occurs most commonly in the United States. It has also been reported in southern Canada, Mexico, and several countries in Central and South America.

Symptoms can include stumbling, falling, weakness, muscle stiffness and tightness, muscle atrophy, and localized sweating. Treatment includes the use of anti-coccidial agents, such as ponazuril, and NSAIDs. However, corticosteroids are likely to worsen the symptoms. (Back to the top)

External Parasites

There are a number of pesky parasites that can irritate your resident donkeys. The most common include lice, mites, and ticks, though there are certainly more.  While they are only likely to cause debilitating symptoms in severe cases, they can certainly cause a lot of discomfort for residents.

Lice infections are very common, and there are a number of donkey-safe treatments for lice, but it’s important to begin treatment early on to prevent infestations before they get out of control. Signs of lice include itching and hair loss. Although it may be difficult to see them, lice are visible. Adult lice are very small and grayish-yellow in color.

Mites, on the other hand, burrow under the skin and cannot be seen. There are several species of mites that affect donkeys, Signs of mite infestations are severe itching, possibly causing the donkey to rub against objects, stamp their feet, or bite at themselves. They will also have lesions with greasy, scaly skin and hair loss. In severe cases, you may observe poor appetite and weakness.

Ticks are another parasite affecting donkeys. They tend to latch on around the groins, ears, and behind leg joints. Be sure to check for these three parasites every time you conduct a donkey health checkup! (Back to the top)

Gastric Ulcers

Gastric ulcers are lesions on the lining of the stomach, duodenum, or esophagus. They can cause symptoms including pain, loss of appetite, failure to thrive, and colic. There are many factors that might cause ulcers to develop, including age, sex, temperament, exercise intensity, intermittent versus continuous feeding, stall confinement, high concentrate diets, non-steroidal anti-inflammatory agents, parasites (Gasterophilus sp., Habronema muscae), Helicobacter spp., and other bacteria. Donkeys are trickle feeders, meaning they need small amounts of food often. Some studies show a correlation between donkeys eating extra cereal grain and developing ulcers. Feeding donkeys a couple large meals a day may increase the likelihood of them developing ulcers. (Back to the top)

Hoof Avulsion

Hoof avulsions happen when the hoof wall becomes partially or fully detached from the foot. As you can imagine, this can cause severe pain and lameness, as well as infections and inflammation of the bone.

Causes:

  • Trauma
  • Severe febrile diseases (diseases causing prolonged, high fevers)
  • Laminitis
  • Administering corticosteroids to a laminitic patient (iatrogenic)

It is possible to treat a small separation by flushing and bandaging the area, and administering antibiotics and NSAIDs. Complete hoof avulsions have a poor prognosis. (Back to the top)

Hoof Cracks “Grass/Sand Cracks”

It isn’t uncommon to see hoof cracks in donkeys, especially those that were used for work or who were neglected. Hoof cracks can be categorized as grass or sand cracks. Grass cracks start at the bottom of the hoof and crack upwards, while sand cracks start at the coronary band and crack downwards. On occasion, a crack may run the full length of the hoof.

Causes:

  • Dehydrated and brittle hoof horn
  • Damage from shoe removal
  • Excessively overgrown feet
  • ‘Seedy toe’ or White Line Disease
  • Abnormal foot shape or poor shoe placement
  • Damage to the coronary band

The deeper the crack, the more likely you will see pain and lameness as the deeper cracks may become infected or pinch sensitive tissue. You may also observe swelling, heat, and pain at the coronary band if there is an infection. Treating the crack involves stabilization of the crack and preventing it from becoming dirty or wet. Dirt will only push the crack further apart. Talk to your veterinarian about the best options for future treatment, as the type of treatment will vary depending on the location, depth, and infection status of the crack. (Back to the top)

Hoof Overgrowth

Unfortunately, hoof overgrowth is a fairly common occurrence in rescued populations. Many have suffered from neglect before arriving at a sanctuary, and their hooves are proof of that. Overgrowth can occur when donkeys are kept on soft ground, or when shoes have been left on for too long, in donkeys with injuries or poor conformation, if lameness is present, or if the weight is not distributed evenly over the whole hoof. In these cases, improper hoof trimming can also result in overgrown hooves.

If you take in a donkey with severely overgrown hooves, you should get a radiograph to ascertain whether bone changes have occurred within the hoof. A veterinarian may prescribe pain medicine and give recommendations for trimming the hoof. (Back to the top)

Hyperlipaemia

Hyperlipaemia is a serious condition caused by too much fat in the blood. Donkeys are particularly susceptible to this condition. Hyperlipemia results from a negative energy balance when fat reserves are mobilized and sent to the liver to be converted to glucose for energy. Donkeys are not able to efficiently regulate the issue, leading to increased fat levels in the blood, potentially leading to liver and kidney degeneration and failure. Hyperlipaemia is a potentially life-threatening condition that is not uncommon in donkeys.

This condition can present subtly at first, including behavior changes such as dullness and decreased appetite. It is therefore important to pay close attention, and alert a veterinarian early to any abnormal signs. 

Risk Factors:

  • Obesity
  • Age and Sex: Older jennies (female donkeys) are more at-risk
  • Late pregnancy/Early lactation
  • Cushing’s Disease
  • Laminitis
  • Stress, such as from concurrent diseases & surgery
  • Loss of a companion
  • Relationships between pasture mates

It can be hard to detect early signs of Hyperlipaemia in donkeys. It’s important to be familiar with the behaviors of each resident donkey so you can quickly notice when something doesn’t seem right.

Symptoms:

  • Dullness
  • Reduced Appetite
  • Halitosis
  • Mucous-covered dung or reduced dung production
  • Excessive fluid buildup in the tissues
  • Head-pressing, circling
  • Loss of muscle control
  • Collapse
  • Seizures

If you see any signs indicating Hyperlipaemia, contact your veterinarian immediately. (Back to the top)

Insect Hypersensitivity ‘Sweet Itch’

As if biting insects weren’t troublesome enough for donkeys, it is possible that donkey residents may have a hypersensitivity or “sweet itch” to insect bites. Sweet Itch is predominantly caused by midges. Most reactions are an immediate hypersensitivity (Type I) but also include a delayed hypersensitivity reaction (Type IV).

Symptoms:

  • Multiple swellings
  • Hair loss/rubbed hair
  • Itching and “picking at” the skin
  • Hives

For some donkeys, the hives or bumps will resolve themselves over a day or two. Steroid treatment can help alleviate itching and inflammation. (Back to the top)

Internal Parasites

There are a number of internal parasites that can affect a donkey’s quality of life, and unfortunately a number of internal parasites that are resistant to common treatments. Common internal parasites donkey residents are susceptible to include:

  • Lungworms
    • Lungworms are an internal parasite that commonly affect donkeys. Horses who live with donkeys can also contract lungworms and develop respiratory issues, such as bronchitis, but are unlikely to pass the infection to another horse. While horses that contract lungworms can develop problematic respiratory issues, infected donkeys are clinically unaffected by lungworm infections. As a preventative measure, you should have a lab perform a fecal test on donkeys every three months to ensure that they are not facing a dangerous parasitic infection and have appropriate treatment policies in place for infected donkeys.
  • Tapeworms
  • Small Strongyles
  • Large Strongyles
  • Roundworms
  • Pinworms

Symptoms:

  • Lethargy
  • Diarrhea
  • Clumped stools
  • Weight Loss
  • Anemia
  • Colic

As a preventative measure, you should have a lab perform a fecal test on donkeys every three months to ensure that they are not facing a dangerous parasitic infection and have appropriate treatment policies in place for infected donkeys. (Back to the top)

Laminitis

Laminitis is a serious and sadly common disease affecting donkeys. It can be very painful. It affects the sensitive and insensitive tissues in the foot that support the pedal bone. When these tissues lose blood flow,  become inflamed, or break down, the result is a painful condition that can be debilitating and sometimes fatal.

Causes:

  • An sudden change in diet
  • Overload of lush grasses or cereals and fruits
  • Excess weight
  • Infections in the body
  • Cushing’s Disease
  • Equine Metabolic Syndrome
  • Trauma

Donkeys are at an increased risk of developing laminitis. There are two types of laminitis: acute and chronic.

Symptoms Of Acute Laminitis:

  • Lameness, especially when a donkey is turning in circles; shifting lameness when standing
  • Heat in the feet
  • Increased digital pulse in the feet (most easily palpable over either sesamoid bone at the level of the fetlock)
  • Pain in the toe region when pressure is applied with hoof testers
  • Reluctant or hesitant gait (“walking on eggshells”)
  • A “sawhorse stance,” with the front feet stretched out in front to alleviate pressure on the toes and the hind feet positioned under them to support the weight that their front feet cannot

Symptoms of Chronic Laminitis:

  • Rings in hoof wall that become wider as they are followed from toe to heel
  • Bruised soles or “stone bruises”
  • Widened white line, commonly called “seedy toe,” with occurrence of seromas (blood pockets) and/or abscesses
  • Dropped soles or flat feet
  • Thick, “cresty” neck
  • Dished hooves, which are the result of unequal rates of hoof growth (the heels grow at a faster rate than the rest of the hoof, resulting in an “Aladdin-slipper” appearance)

It is important to begin treatment as soon as possible. Contact your veterinarian for the best course of action. In the meantime, feed only hay grass until your veterinarian advises differently and move the afflicted donkey onto soft ground. (Back to the top)

Obesity

Because donkeys evolved in arid, inhospitable environments, their bodies are able to thrive on highly fibrous, poor quality food. As such, they have different nutrient requirements with significantly lower energy and protein needs when compared with horses. Dietary management of donkeys is especially important as they are prone to obesity and related disorders. Diets high in concentrates, fruits, and lush grass can cause issues. (Back to the top)

Pastern And Heel Dermatitis (‘Mud Fever’)

Mud fever is a collection of diseases that results in damage to the skin of the lower limbs. As a result, there can be a number of causes. Wet, muddy conditions can exacerbate these issues and is a risk factor.

Causes:

  • Bacterial infection 
  • Rain-scald 
  • Ringworm
  • Contact with irritant chemicals
  • Photosensitisation/Sunburn associated with liver disease or certain plants 
  • Immune-mediated disease of the blood vessels

Symptoms:

  • Flaky, greasy skin
  • Thickening and scaling of the skin
  • Loss of hair or reddening of the skin
  • Swelling
  • Itching, resulting in self-trauma and bleeding
  • Purulent discharge (yellow, thick and often foul-smelling)
  • Development of nodules (“grapes”) of inflamed tissue in particularly severe and chronic cases

Treatment depends on the underlying cause. Please contact your veterinarian for advice on how to administer appropriate treatment. (Back to the top)

Pigeon Fever (Dryland Heaves or Dryland Strangles)

Pigeon fever is an infectious disease affecting donkeys and horses. It can be spread through open wounds, mucous membranes by other equids and possibly by house, horn, and stable flies. The disease originated in the western United States, but has since spread through the rest of the country, and even some parts of Mexico. It may present with external abscesses, limb infections, or internal infections.

Symptoms

  • Swollen breast
  • Abscesses, sores, and/or draining pus along the midline
  • Decreased appetite
  • Fever
  • Lethargy
  • Weight Loss
  • Signs of respiratory or abdominal pain
  • Swollen limbs
  • Internal infection
  • Lameness

Contact your veterinarian if you suspect Pigeon Fever. Isolate any sick donkeys or horses and disinfect their environment. Make sure you dispose of any material that comes into contact with them as hazardous material. After handling infected animals, wash your hands, clean and disinfect your boots, and change clothes. (Back to the top)

Rabies

Rabies is a zoonotic disease affecting the brain. It is most commonly spread by animal bites, but can also be spread from contact with the saliva of an infected animal through a break in the skin, or by touching eyes, nose, or mouth after touching saliva.

Symptoms:

  • Confrontational/combative behavior
  • Sensitivity to touch and sound
  • Lethargy
  • Weakness in limbs
  • Throat and neck paralysis

There are annual rabies vaccinations to protect donkey residents from this disease. (Back to the top)

Rain Scald

Rain scald is a common skin condition in donkeys and horses.  It is caused by a bacteria spread by other animals. It thrives in wet and muddy environments and is spread by carrier animals. Abrasions are an easy way for this bacteria to enter the skin. Rain scald appears as small, crusty lumps, causing hair to stand up. While rain scald can affect the flanks and face, it is particularly common on the caudal pastern if donkeys are in a muddy environment. If a donkey or horse remains in a rainy environment, the dorsal (back) surfaces may become soaked with rain, increasing the likelihood of contracting rain scald.

Minimizing exposure to wet and muddy environments can help prevent and treat rain scald. To treat, shave or clip the affected area, apply diluted antiseptic, and leave the afflicted area open to the air to dry. Remove loose scabs and dispose of them to prevent further infections. Be sure to wear gloves and dispose of these as well, and wash up thoroughly before coming into contact with other donkeys or horses. Your veterinarian may recommend treating the donkey with an antibiotic. (Back to the top)

Sarcoids

Sarcoids are common skin tumors and can be problematic to treat. Definitely get advice from a veterinarian on the best course of action and in the meantime, try to leave them them alone. Sarcoids can be found on any part of the body but they are most common around the head, eyes, groin, midline, and, axilla (underarms). Although sarcoids are benign, they can can grow and become infected. Some are crusty and wart-like and cause hair-loss and thickened skin around the lesion. Others are soft nodules under the skin, and some start off as alopecia with a crust surface. A biopsy can trigger further growth and should be avoided when a sarcoid is suspected. (Back to the top)

Strangles (Distemper)

Strangles is a highly contagious upper respiratory infection caused by Streptococcus equi bacteria. It is so infectious that pastures housing the infected donkeys will remain contaminated for months. Healthy donkeys usually survive the infection. Special care should be taken with older, younger or ill donkeys.

Symptoms:

  • Coughing
  • Yellow “snotty nose”
  • Swollen throat
  • Glands with pus draining

There is an annual vaccination for donkeys. Be sure to wash your hands, clean and disinfect your boots, wear latex or plastic gloves, and change clothes between handling quarantined donkeys and other donkey residents. (Back to the top)

Tetanus “LockJaw”

If a donkey has any open wound and has not been vaccinated for Tetanus, they could become seriously ill or die if that bacteria enters the bloodstream. A donkey that has tetanus or lockjaw will die unless it receives an antitoxin injections within 24 hours of the injury.

Symptoms:

  • Rigidity
  • Muscle spasm
  • Third eyelid moving – leading to vision issues.
  • Paralysis of respiratory system and jaw

Tetanus can be prevented by annual vaccinations. (Back to the top)

Thrush

Thrush is a fungal infection caused by Spherophorus neaophorus. It eats away at the tissues of the frog of the hoof and leaves a black slime. There is a distinctive foul odor associated with the infection. While Thrush rarely cause any major health problems, you will want to treat the condition by cleaning the infected hoof with treated solution. Thrush is prevented by keeping a donkey’s feet clean and dry as much as possible. (Back to the top)

West Nile Virus

West Nile Virus is a zoonotic disease that affects the brain. It is passed by mosquitos from birds to equines or other animals. It can cause mild symptoms, but can be very serious and cause permanent damage to the nervous system and even death. 30% of clinically affected equines die from it.

Symptoms:

  • Difficulty walking, stumbling, weakness of limbs
  • Convulsions
  • Muscle twitching
  • Head tilt or drooling
  • Hypersensitivity

Luckily, there is an annual vaccination that can prevent WNV. (Back to the top)

White Line Disease “Seedy Toe”

White Line Disease is when a fungus attacks the white line of tissue that attaches the sole to the hoof. It is more common in wet environments. The white line area can become crumbly. Luckily, lesions are rarely painful, but care must be taken to ensure the hoof stays free of foreign objects and organisms. If that happens, it may cause pain or infections. The treatment is to remove all dead and discolored material so new healthy horn can grow down. Exposure is necessary to minimize the chance of infection. In severe cases, your farrier should work with a veterinarian to make sure that the work does not cause any instability to the hoof. The healing donkey should be kept on clean, dry ground until fully recovered. (Back to the top)

SOURCES:

Endocrine Disorders In Donkeys | The Donkey Sanctuary

Gastric Ulcers In Donkeys  | The Donkey Sanctuary

Colic In Donkeys | The Donkey Sanctuary

Sarcoids In Donkeys | The Donkey Sanctuary

Mud Fever | Liphook Equine Hospital

The Working Equid Veterinary Manual | The Brooke

Abscess In Horses | Pet MD

Equine Influenza | Merck Veterinary Manual

Three Forms Of Pigeon Fever | American Association Of Equine Practitioners 

15 Facts On Donkey Health | The Horse.com (Non-Compassionate Source)

Lungworms In Donkeys And Horses | Stable Management (Non-Compassionate Source)

Equine Infectious Anemia: What to Know | NC State Veterinary Medicine (Non-Compassionate Source)

Diseases That Affect Horses, Ponies, Mules, And Donkeys | National Center For Foreign Animal And Zoonotic Disease Defense (Non-Compassionate Source)

Equine Brucellosis: Review On Epidemiology, Pathogenesis, Clinical Signs, Prevention And Control | Journal Of Experimental Biology And Agricultural Sciences (Non-Compassionate Source)

Gastric Ulcer Syndrome In Donkeys | Revue De Medecine Veterinaire (Non-Compassionate Source)

West Nile Virus And Horses | Mosquito Control (Non-Compassionate Source)

Non-Compassionate Source?

If a source includes the (Non-Compassionate Source) tag, it means that we do not endorse that particular source’s views about animals, even if some of their insights are valuable from a care perspective. See a more detailed explanation here.

Updated on September 16, 2020

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