Piroplasmosis is a blood-borne parasitic disease that affects all equines and usually causes fever, anemia, yellowing of the membranes of the eyes and mouth, and urine that is tinged dark brown to red.  The disease is unusual in that some horses can die while others never even get sick.  However, the ones that never get sick are still carriers and can be a source of infection to other horses.  Because of this, horses that test positive must be quarantined or euthanized to prevent spread to other horses. 

Piroplasmosis is spread by anything that transfers blood from one horse to another and ticks are the most common method of transmission.  However, the disease can also be transmitted by using the same needle on different horses when giving injectable medication.  Even dental equipment like teeth floats can transmit the disease if not cleaned and disinfected well between horses as could tattoo or surgical instruments.   To protect your horse, the USDA has developed some recommendations to help protect your horse from piroplasmosis.  Always use a new sterile needle and syringe for injections whether the injection is in the vein or muscle.  And never use anything but a sterile needle and syringe to draw medication out of a multidose vial.  Always disinfect all equipment used on a horse after a procedure, including teeth floats and other dental equipment, tattoo instruments, and surgical instruments.