Equine Viral Arteritis in Donkeys: Respiratory and Systemic Signs

Quick Answer
  • Equine viral arteritis, or EVA, is a contagious viral disease of equids, including donkeys, caused by equine arteritis virus.
  • Many infected donkeys may have mild signs or no obvious signs, but some develop fever, nasal discharge, conjunctivitis, limb or belly swelling, and marked tiredness.
  • The virus spreads through respiratory secretions during acute infection and through semen from persistently infected breeding males.
  • Pregnant jennies may be at risk for reproductive loss, and breeding males can become long-term carriers, so herd-level management matters.
  • Diagnosis usually requires lab testing such as RT-PCR on nasal swabs or blood, plus serology; supportive care is the main treatment because there is no antiviral cure.
Estimated cost: $250–$1,500

What Is Equine Viral Arteritis in Donkeys?

Equine viral arteritis (EVA) is a contagious infection caused by equine arteritis virus, a virus that affects equids such as horses, donkeys, mules, and zebras. The disease can involve the respiratory tract and blood vessels, which is why affected animals may show both cold-like signs and whole-body signs such as swelling, fever, and depression.

In donkeys, the disease may be overlooked because some infected animals have very mild illness or appear normal. Even so, infected donkeys can still matter in herd health planning, especially if they live with breeding animals or move between farms, shows, or sales. In breeding males, one of the biggest concerns is the possibility of a persistent carrier state, where virus continues to be shed in semen after the acute illness has passed.

For pet parents, the practical takeaway is that EVA is not a condition you can confirm by appearance alone. Several equine diseases can look similar. If your donkey has fever, nasal discharge, eye inflammation, unusual swelling, or sudden lethargy, your vet may recommend testing and temporary isolation while results are pending.

Symptoms of Equine Viral Arteritis in Donkeys

  • Fever
  • Clear nasal discharge
  • Conjunctivitis and tearing
  • Swelling around the eyes
  • Limb, belly, sheath, udder, or ventral swelling
  • Depression and reduced appetite
  • Cough
  • Hives or skin rash
  • Abortion or reproductive problems
  • Severe illness in young foals

Call your vet promptly if your donkey has fever, eye inflammation, nasal discharge, new swelling, or sudden lethargy, especially if there has been recent travel, breeding activity, or contact with unfamiliar equids. See your vet immediately for breathing difficulty, collapse, abortion, or illness in a foal. Because EVA can resemble influenza, herpesvirus infection, strangles, purpura, or other infectious conditions, early testing and isolation guidance from your vet are important.

What Causes Equine Viral Arteritis in Donkeys?

EVA is caused by equine arteritis virus (EAV). During acute infection, the virus is commonly spread through respiratory secretions, so close nose-to-nose contact, shared airspace, and contaminated hands or equipment can all contribute to spread within a group. The incubation period is often short after respiratory exposure, commonly about 2 to 3 days, though it can be longer after venereal exposure.

Breeding transmission is also important. Persistently infected breeding males can shed virus in semen for long periods, sometimes for years. That means natural breeding and artificial insemination can both spread infection. In mixed equid settings, this matters for donkeys as well as horses.

Not every exposed donkey becomes obviously sick. Disease severity depends on the strain, dose, immune status, age, and overall health of the animal. Some donkeys may stay subclinical or show only mild respiratory signs, while others develop more noticeable systemic illness with fever, swelling, and marked malaise.

How Is Equine Viral Arteritis in Donkeys Diagnosed?

Your vet usually cannot diagnose EVA from signs alone. The clinical picture overlaps with several other equine infectious diseases, so laboratory confirmation is the key step. Testing may include RT-PCR to look for viral genetic material in nasal or nasopharyngeal swabs, blood, semen, or tissues, depending on the case.

Serology is also used, especially paired samples taken during the acute and recovery phases to look for a rising antibody response. In breeding males, semen testing may be part of the workup if there is concern for a carrier state. If a foal dies or a pregnancy is lost, your vet may recommend submitting tissues and fluids for PCR, virus isolation, and pathology.

Because timing matters, samples are most useful when collected early after fever or the first signs of illness. While waiting for results, your vet may advise temporary isolation, movement restrictions, and careful record review of recent breeding, transport, and herd contacts.

Treatment Options for Equine Viral Arteritis in Donkeys

Spectrum of Care means you have options. Here are treatment tiers at different price points.

Budget-Conscious Care

$250–$600
Best for: Mild, stable cases where the donkey is eating, breathing comfortably, and can be safely monitored with close veterinary follow-up
  • Farm call or clinic exam
  • Basic isolation plan at home
  • Temperature monitoring and daily observation
  • Supportive care directed by your vet, such as rest, hydration support, and anti-inflammatory medication if appropriate
  • Targeted PCR or limited initial testing based on the donkey's signs and herd risk
Expected outcome: Often good in uncomplicated adult cases, though recovery time and herd risk vary. This approach does not address every possible complication.
Consider: Lower upfront cost range, but less complete testing may leave unanswered questions about herd exposure, breeding risk, or carrier status.
Most Common

Recommended Standard Treatment

$600–$1,500
Best for: Most donkeys with suspected EVA, especially when there are multiple signs, herd exposure concerns, pregnancy risk, or breeding animals on the property
  • Complete veterinary exam and isolation guidance
  • RT-PCR and/or paired serology
  • CBC and chemistry as indicated
  • Supportive medications and fluid planning based on hydration, fever, and appetite
  • Recheck exam and herd biosecurity recommendations
  • Breeding-risk discussion, including semen testing if relevant
Expected outcome: Good for many adult donkeys with timely supportive care, but reproductive losses and management complications can still occur.
Consider: Higher cost range than conservative care, but gives clearer answers for diagnosis, monitoring, and prevention of spread.

Advanced / Critical Care

$1,500–$4,000
Best for: Foals, severely ill donkeys, outbreak situations, pregnant animals, or breeding males where carrier-state decisions affect the whole herd
  • Hospitalization or intensive on-farm management
  • IV fluids and more frequent monitoring
  • Expanded diagnostics for severe respiratory or systemic illness
  • Ultrasound or additional imaging if complications are suspected
  • Foal or reproductive case management
  • Specialized breeding evaluation for persistent shedding in males
Expected outcome: Variable. Many adults recover, but foals and reproductive cases can be more serious, and persistent semen shedding in males can create long-term management issues.
Consider: Most intensive and highest cost range. It offers broader monitoring and herd-level decision support, but may exceed what every farm needs.

Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.

Questions to Ask Your Vet About Equine Viral Arteritis in Donkeys

Bring these questions to your vet appointment to get the most out of your visit.

  1. Which signs in my donkey make EVA more or less likely than influenza, herpesvirus, or strangles?
  2. What samples should we collect today, and how soon after fever do they give the best chance of diagnosis?
  3. Does my donkey need PCR, serology, or both?
  4. Should this donkey be isolated, and for how long while we wait for results?
  5. Are any other donkeys, horses, or mules on the property at risk right now?
  6. If this is a breeding male, do we need semen testing to look for persistent shedding?
  7. What supportive care can safely be done at home, and what changes would mean I should call back right away?
  8. What is the expected cost range for testing, follow-up, and herd biosecurity planning in this case?

How to Prevent Equine Viral Arteritis in Donkeys

Prevention starts with biosecurity. New arrivals should be separated from resident equids for a period recommended by your vet, especially if they recently traveled, bred, or came from a sale or event. Avoid shared waterers, nose-to-nose contact, and shared tack or handling equipment until health status is clearer. If illness appears, early isolation and prompt testing help limit spread.

Breeding management is especially important because semen can carry the virus. Carrier breeding males should be identified and managed separately. Mares or jennies being bred to a known carrier or with infective semen may need testing, vaccination planning where appropriate, and temporary separation after breeding. Your vet can help tailor this plan to the animals on your property.

Vaccination is part of prevention in some equine settings, but it should be discussed carefully with your vet because recommendations depend on species, breeding role, pregnancy status, and local regulations or farm goals. In horses, modified live and inactivated vaccine strategies are used in some regions, with timing rules around breeding and pregnancy. For donkeys, herd-level prevention still relies heavily on testing, movement control, breeding oversight, and practical biosecurity.

Find a Vet Near You