Which pathogen pair is associated with both respiratory disease and abortion in horses?

Which pathogen pair is associated with both respiratory disease and abortion in horses?

• A. Equine influenza and EVA
• B. Equine viral arteritis and EVA
• C. Equine viral arteritis and equine herpesvirus 1
• D. Hendra and EHV-1

Answer: (C)

The key idea is that some horse viruses can cause both respiratory illness and abortion, so the best pair includes two agents each known to produce both problems. Equine viral arteritis virus (the disease equine viral arteritis) can cause abortion in pregnant mares and also presents with respiratory signs during outbreaks. Equine herpesvirus 1 (EHV-1) is a major cause of respiratory disease as well as abortion in pregnant mares. Together, these two pathogens cover the two clinical features—respiratory disease and abortion—making them the correct pairing. Equine viral arteritis can spread via inhalation and can also be shed in semen by carrier stallions, leading to abortions in late gestation alongside respiratory signs like fever and nasal discharge. Equine herpesvirus 1 commonly causes contagious respiratory disease in horses and, in pregnant mares, can trigger abortion, especially in late gestation. The other options don’t fit both features for each pathogen: one pair includes a pathogen that mainly causes respiratory disease without abortion, or the two pathogens are not distinct, or a virus not typically associated with abortion in horses.

The key idea is that some horse viruses can cause both respiratory illness and abortion, so the best pair includes two agents each known to produce both problems. Equine viral arteritis virus (the disease equine viral arteritis) can cause abortion in pregnant mares and also presents with respiratory signs during outbreaks. Equine herpesvirus 1 (EHV-1) is a major cause of respiratory disease as well as abortion in pregnant mares. Together, these two pathogens cover the two clinical features—respiratory disease and abortion—making them the correct pairing.

Equine viral arteritis can spread via inhalation and can also be shed in semen by carrier stallions, leading to abortions in late gestation alongside respiratory signs like fever and nasal discharge. Equine herpesvirus 1 commonly causes contagious respiratory disease in horses and, in pregnant mares, can trigger abortion, especially in late gestation. The other options don’t fit both features for each pathogen: one pair includes a pathogen that mainly causes respiratory disease without abortion, or the two pathogens are not distinct, or a virus not typically associated with abortion in horses.