Due to the outbreak of equine piroplasmosis in the state of Missouri, the Canadian Food Inspection Agency (CFIA) has asked the United States Department of Agriculture (USDA) to suspend the issuance or endorsement of export certificates for horses and other equines originating from the State of Missouri. 
The imposed restrictions on the import of equidae into Canada from Missouri is effective immediately. The CFIA has confirmed that the import restriction only applies to live horse, donkey or mule imports and not to equine semen or equine embryo imports.
The USDA has also been asked to provide supplementary certification for horses and other equines from other states as follows: “During the previous twenty-one (21) days, the animal(s) in this shipment has/have not been in the State of Missouri.”
The Canadian Border Services Agency will ask all equine transporters crossing the border into Canada the following questions:  
1.      Do the horses  originate from the state of Missouri or have they been in that state within the past 21 days?
2.      Have the horses transited the state of Missouri en route to Canada?

If the horses originate or have been in the State of Missouri within the past 21 days, or have transited through that state, they will be referred to the CFIA. CFIA will determine, based on document verification and inspection, whether the horses should be allowed to enter Canada.
It is strongly recommended that horse owners refrain from travelling to or transiting through Missouri with their horses. It is important to note for horse owners who still want to export their horses to Missouri that they CANNOT bring them back to Canada on the original Canadian export certificate. Instead, it will be necessary that they move their horses to a non-affected state to establish residency in that state for at least 21 days prior to export to Canada. This means that the horses will be returning to Canada on a U.S. health certificate that includes the statement for non residency in Missouri during the last 21 days prior to export to Canada.
Current import requirements for horses entering Canada may be found using the CFIA Automated Import Reference System (AIRS) at http://airs-sari.inspection.gc.ca. To determine specific import requirements for each horse, specific parameters that refer to each horse’s circumstances will need to be entered and customized import requirements will be provided.

Equine piroplasmosis (EP) is caused by two parasitic organisms, Babesia equi and Babesia caballi. It is primarily transmitted to equidae by ticks but this bloodborne disease can be spread mechanically from animal to animal by contaminated needles or surgical instruments.
Once infected, an equine can take 7 to 22 days to show signs of illness. Mild forms of the disease cause equines to appear weak and show lack of appetite. More acute cases can occur where EP is not common and the animals have not built up a resistance to the disease. Signs of the acute phase include fever, anemia, jaundiced mucous membranes, a swollen abdomen, laboured breathing, central nervous system disturbances, roughened-hair coats, constipation, colic, and hemoglobinuria—a condition which gives urine a red color. In some cases, death may occur. Equidae that survive the acute phase of infection may continue to carry the parasites for long periods of time. These animals are potential sources of infection to others through tick-borne transmission or mechanical transfer by needles or surgical instruments.
EP is not endemic to the United States or Canada and some other countries but it is present in the Caribbean, South and Central America, Eastern and Southern Europe, Africa and the Middle East.  The greatest risk for introduction of this disease is through the trading of animals or international equestrian sports where infected and non-infected animals are in contact. If an outbreak of EP occurs in a country such as the USA, the World Organization for Animal Health (OIE) must be notified and made aware of the steps that will be taken to eradicate the disease. (Source: USDA)