Abstract: is a protozoan parasite that causes the sexually transmitted disease known as "dourine" in horses. This chronic illness is directly spread from one animal to another during mating. Doflein proposed the name in 1901. Despite being distributed worldwide, the broad use of artificial insemination technology over the past three decades has resulted in only a few cases being documented. The condition is typically fatal and is characterized by gradual emaciation, nervous system involvement, and edematous lesions of the genitals. The incubation period between exposure and the onset of clinical symptoms varies widely, ranging from a few weeks to several years. The diagnosis of dourine can be challenging because of factors such as a lack of knowledge about the parasite and host-parasite interactions following infection. However, in reality, the diagnosis is based on clinical evidence backed by molecular and serological testing. Coital exanthema, surra, infectious anemia in horses, viral arthritis in horses, and purulent endometritis cause such infectious equine metritis are examples of differential diagnosis. Coital exanthema, surra, equine infectious anemia, viral arthritis, and purulent endometritis are examples of conditions that should be considered in the differential diagnosis of infectious equine metritis. Dourine is the only trypanosomiasis that is not spread by an insect vector. Treatment is generally not advised in dourine-free areas due to the possibility of asymptomatic carrier animals and the concern that treated animals may continue to spread the disease. Dourine vaccination does not yet exist. Thus, preventing dourine is dependent on achieving an infection-free status, which is accomplished by checking the blood for antibodies.
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Overview
Dourine is a sexually transmitted disease in horses caused by the protozoan parasite Trypanosoma equiperdum.
The disease leads to severe symptoms including emaciation, nervous system issues, and genital swelling, and is usually fatal.
Diagnosis is difficult but relies on clinical signs supported by molecular and serological testing.
There is no vaccine or recommended treatment, making prevention through testing and controlling animal movement crucial.
Introduction to Dourine
Dourine is caused by the parasite Trypanosoma equiperdum, which is unique among trypanosomes because it is transmitted directly between horses during mating rather than through insect vectors.
The disease was first named by Doflein in 1901 and is known to have a worldwide distribution, though reported cases have decreased due to artificial insemination decreasing direct sexual transmission.
The disease primarily affects horses and is chronic and progressive in nature.
Clinical Manifestations
Symptoms include gradual weight loss (emaciation), involvement of the nervous system leading to neurological signs, and edematous (swollen) lesions in the genital areas.
The incubation period can vary dramatically from a few weeks up to several years, complicating timely identification.
Diagnosis Challenges and Methods
Diagnosing dourine can be difficult because of limited knowledge about the parasite’s biology and its interaction with the horse host after infection.
Diagnosis primarily depends on clinical symptoms combined with molecular (e.g., PCR) and serological (antibody detection) tests to confirm infection.
Other diseases with somewhat similar symptoms that must be differentiated from dourine include:
Coital exanthema (a herpesvirus infection)
Surra (another trypanosome transmitted by insects)
Equine infectious anemia (a viral disease)
Viral arthritis in horses
Purulent endometritis and other infectious causes of equine reproductive disorders
Treatment and Control
There is currently no vaccine available against dourine.
Treatment is generally not recommended, especially in regions where the disease is not present, because:
Treated animals can become asymptomatic carriers, continuing to spread the parasite unnoticed.
Prevention relies heavily on maintaining infection-free status by:
Regular blood testing for antibodies against the parasite before allowing animals to breed.
Using artificial insemination as a safer reproductive method to reduce transmission risk.
Significance and Implications
Dourine remains a hidden but serious threat to equine health due to its chronic nature and potentially fatal outcome.
The disease’s unique transmission route necessitates strict control measures based on testing and breeding management rather than vector control strategies used for other trypanosomiases.
Increased awareness, diagnostic capabilities, and preventive protocols are essential to protect horse populations worldwide.
Cite This Article
APA
Rimayanti R, Khairullah AR, Mustofa I, Utomo B, Lestari TD, Utama S, Akintunde AO, Mulyati S, Hernawati T, Dawood AQ, Riady G, Khan IU, Rasad SD, Moses IB.
(2025).
Hidden menace: Understanding the devastating consequences of dourine disease in horses.
Open Vet J, 15(9), 3931-3942.
https://doi.org/10.5455/OVJ.2025.v15.i9.2
Division of Veterinary Reproduction, Faculty of Veterinary Medicine, Universitas Airlangga, Surabaya, Indonesia.
Khairullah, Aswin Rafif
Research Center for Veterinary Science, National Research and Innovation Agency (BRIN), Bogor, Indonesia.
Mustofa, Imam
Division of Veterinary Reproduction, Faculty of Veterinary Medicine, Universitas Airlangga, Surabaya, Indonesia.
Utomo, Budi
Division of Veterinary Reproduction, Faculty of Veterinary Medicine, Universitas Airlangga, Surabaya, Indonesia.
Lestari, Tita Damayanti
Division of Veterinary Reproduction, Faculty of Veterinary Medicine, Universitas Airlangga, Surabaya, Indonesia.
Utama, Suzanita
Division of Veterinary Reproduction, Faculty of Veterinary Medicine, Universitas Airlangga, Surabaya, Indonesia.
Akintunde, Adeyinka Oye
Department of Agriculture and Industrial Technology, Babcock University, Ilishan Remo, Nigeria.
Mulyati, Sri
Division of Veterinary Reproduction, Faculty of Veterinary Medicine, Universitas Airlangga, Surabaya, Indonesia.
Hernawati, Tatik
Division of Veterinary Reproduction, Faculty of Veterinary Medicine, Universitas Airlangga, Surabaya, Indonesia.
Dawood, Ahmed Qasim
Department of Veterinary Preclinical Sciences, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Malaysia.
Department of Physiology, Pharmacology, and Chemistry, Faculty of Veterinary Medicine, Al Shatra University, Al Shatra, Iraq.
Riady, Ginta
Reproduction Laboratory, Faculty of Veterinary Medicine, Universitas Syiah Kuala, Banda Aceh, Indonesia.
Khan, Imdad Ullah
Faculty of Veterinary and Animal Sciences, Gomal University, DI Khan, Pakistan.
Rasad, Siti Darodjah
Faculty of Animal Husbandry, Universitas Padjadjaran, Sumedang, Indonesia.
Moses, Ikechukwu Benjamin
Department of Applied Microbiology, Faculty of Science, Ebonyi State University, Abakaliki, Nigeria.
MeSH Terms
Animals
Horses
Horse Diseases / parasitology
Horse Diseases / diagnosis
Trypanosoma / physiology
Dourine / parasitology
Dourine / diagnosis
Female
Male
Conflict of Interest Statement
The authors declare no conflict of interest.
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