Diseases with Horse-to-Human Transmission

infected but often do not show clinical signs.
Transmission Infected horses can transmit the parasite to humans indirectly through fecal contamination of water or directly through handling or on contaminated surfaces.
Humans Symptoms in humans include diarrhea abdominal cramps bloating and weight loss.
Treatment and prevention The antibiotic metronidazole is commonly used to treat giardiasis in both species.
Leptospirosis
Equine leptospirosis is often the result of infection with the bacteria Leptospira interrogans through contact with infected urine often in contaminated feed or water. The bacteria spreads rapidly to tissues throughout the body via the bloodstream.
Leptospirosis can be associated with equine recurrent uveitis moon blindness
Humans In humans ingestion of the parasite can cause watery diarrhea vomiting stomach cramps and weight loss. Symptoms may last up to two weeks.
Treatment and prevention Symptoms often resolve without treatment in people with healthy immune systems. For those with compromised immune systems or severe infections antiparasitic drugs such as nitazoxanide and antimotility agents such as loperamide can help relieve diarrhea.
Giardiasis
Singlecelled organisms of the genus Giardia most commonly Giardia duodenalis attach to the intestine causing problems with absorption of vitamins and other nutrients often resulting in diarrhea. Contaminated water and soil are the primary sources of infection.
Horses Giardia can cause intermittent diarrhea in some infected horses as well as poor hair coat and weight loss. Foals are frequently infected but often do not show clinical signs.
Transmission Infected horses can transmit the parasite to humans indirectly through fecal contamination of water or directly through handling or on contaminated surfaces.
Humans Symptoms in humans include diarrhea abdominal cramps bloating and weight loss.
Treatment and prevention The antibiotic metronidazole is commonly used to treat giardiasis in both species.
Leptospirosis
Equine leptospirosis is often the result of infection with the bacteria Leptospira interrogans through contact with infected urine often in contaminated feed or water. The bacteria spreads rapidly to tissues throughout the body via the bloodstream.
Horses In horses the disease is associated with abortions stillbirths kidney disease and equine recurrent uveitis moon blindness although some infected horses show no clinical signs.
Transmission Humans can become infected when contaminated water contacts broken skin or mucous membranes eyes nose or mouth.
Humans In humans leptospirosis causes flulike symptoms including abdominal pain high fever chills vomiting and jaundice but neurologic respiratory cardiac and ocular issues can occur.
Treatment and prevention Antibiotics and antiinflammatories are used to treat leptospirosis. There are currently no human vaccines for leptospirosis but one is available for horses.
Rabies
Rabies a highly fatal disease
 found worldwide is caused by the rabies virus. All mammals are susceptible to rabies but it is relatively rare in horses with less than 100 cases reported annually