National Farm and Facility Level Biosecurity User Guide for the Equine Sector
Annex 2: Important infectious diseases of horses in Canada

Selected Horse Diseases: The following table provides a list of important equine diseases that are a potential risk to the health of the Canadian equine herd. Many of the disease pathogens are already present in Canada, while others pose a risk through the importation of horses, semen, embryos, contaminated equipment or through international travel to equestrian events. Legend B (bacterial), F (fungal), P (parasite), V (viral). This is not a complete list and does not include internal parasites (Refer to Annex 12).

Important infectious diseases of horses in Canada
Name Pathogen Type Horses can infect people Route of transmission Direct (contact) Route of transmission Indirect (fomite) Route of transmission Aerosol/airborne Route of transmission Vector Route of transmission Ingestion Other Comment
Anthrax Bacillus anthracis B Yes X X X X
Aspergillosis Aspergillus spp F No X X X
Botulism Clostridium botulinum B No X
Brucellosis Brucella spp B Yes X X X Reproductive
Clostridium difficile infection Clostridium difficile B Maybe X
Coccidioidomycosis Coccidioides immitis and C. posadasi F Yes Contact with soil. Not horse-to-horse
Contagious Equine Metritis (CEM) Taylorella equigenitalis B No Reproductive Not currently present in Canada
Coronavirus Equine coronavirus V No X
Cryptococcosis Cryptococcus neoformans, C, gattii F No Environmental. Not horse-to-horse.
Cryptosporidiosis Cryptosporidium parvum P Yes X
Dourine Trypanosoma equiperdum P No Reproductive Not currently identified in Canada
EEE Eastern equine encephalomyelitis virus V No Mosquito
Equine granulocytic anaplasmosis Anaplasma phagocytophilum B No Ixodes ticks
Equine herpesvirus type 1 abortion Equine herpesvirus type 1 (EHV-1) V No X X X X
Equine herpesvirus type 1 neurological disease (myeloencephalopathy) EHV-1 V No X X X X
Equine herpesvirus type IV EHV-4 V No X X X
Equine infectious anemia Equine infectious anemia virus V No Biting flies Cross-contamination of blood. Aerosolized blood.
Equine protozoal myeloencephalitis (EPM) Sarcocystis neurona P No X Associated with exposure to feces from opossums and some the other small mammals
Equine viral arteritis (EVA) Equine viral arteritis virus V No X X Reproductive
Influenza Equine influenza virus V No X X X
Glanders Burkholderia mallei B Yes X X X
Leptospirosis Leptospira interrogans B Maybe X X Contaminated water major source
Lice (pediculosis) Haematopinus asini, Bovicola equi P No X X
Lyme disease Borrelia burgdorferi B No Ticks (Ixodes spp)
Mange Chorioptes equi, Sarcoptes scabiei, Demodex equi P Yes for Sarcoptes X X
MRSA Methicillin-resistant Staphylococcus aureus B Yes X X
Piroplasmosis Babesia caballi, Theileria equi P No Certain ticks Blood
Potomac horse fever Neorickettsia risticii B No Aquatic insects Ingestion. Mainly from surface water
Rain scald/rain rot Dermatophilus congolensis B No X X
Rhinovirus Equine rhinovirus V No X X
Rhodococcus equi pneumonia Rhodococcus equi B Rarely X
Ringworm Trichophyton equinum, Microsporum canis F Yes X X
Salmonellosis Salmonella sp B Yes X
Strangles Streptococcus equi equi B No X X
Venezuelan equine encephalitis (VEE) Venezuelan equine encephalitis virus V Yes Mosquitoes Not currently identified in Canada
Vesicular stomatitis Vesicular stomatitis virus V No X Insects. Mainly sandflies and black flies. Not currently identified in Canada
Western equine encephalitis (WEE) Western equine encephalitis virus V No Mosquitoes
West Nile encephalitis West Nile virus V No Mosquitoes
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