Detection and residence time of bisphosphonates in bone of horses

Bisphosphonates are potent anti-resorptive agents that have the potential to adversely affect bone healing in equine athletes, and normal bone adaption in young racehorses. A concern exists that bisphosphonate inhibition of normal bone metabolism could lead to increased bone fractures during high-intensity exercise. We found only a single report describing concentrations of tiludronate in the bone of horses, and no studies describing clodronate. Knowledge of the residence time in bone could allow for a better understanding of the long-term effects of these compounds. Our objectives were to develop a method for detection of bisphosphonates in bone and add to the limited information available regarding the disposition of these drugs in the bone of horses. Two horses received clodronate and 2 tiludronate disodium. Postmortem collection of bones and teeth occurred either 4 or 30 d post drug administration. Additionally, postmortem blood, synovial fluid, aqueous humor, and bone samples from racehorses with various histories of bisphosphonate administration were collected, and concentrations determined using the developed LC-MS/MS method. Bisphosphonates were detected in bones and teeth tested at 4 and 30 d. In a postmortem sample, clodronate was detected in bone from a horse with reported administration 18 mo prior; clodronate was not detected in other sample types collected from this horse. Bisphosphonates reside in bone for extended periods of time, which could lead to potential long-term effects, increasing the potential for bone fractures in young and/or athletic horses.

Persistent infection and pancytopenia associated with ferret systemic coronaviral disease in a domestic ferret

Ferret systemic coronaviral disease (FSCD) is a well-established cause of mortality in domestic ferrets. We describe herein novel findings in a case of FSCD that was diagnosed and medically managed following virus detection by immunohistochemical (IHC) staining of surgical biopsy samples. Hematologic changes in this ferret suggested spread of the virus to the bone marrow, which was confirmed by IHC staining of a postmortem sample. Genotyping of the virus indicated that the virus grouped with alphacoronaviruses and was most closely related to ferret enteric coronavirus (FRECV) MSU-2. Our clinical case demonstrates that a FRECV MSU-2–like ferret coronavirus associated previously with the enteric pathotype may cause systemic disease, including bone marrow involvement causing persistent pancytopenia.