Changes

Also known as: '''''Equine Piroplasmosis — Biliary fever

Also known as: '''''Equine Piroplasmosis — Biliary fever

==Description==

==Introduction==

Equine babesiosis is a tick-borne protozoal infection of donkeys, mules, horses and zebra characterised by acute haemolytic anaemia. The disease is caused by the intraerythrocytic protozoa ''Theileria equi'' (formerly ''Babesia equi'') and ''Babesia caballi'' and is transmitted primarly by ixodid ticks. Equine babesiosis is present in most tropical and sub-tropical regions of the world where tick vectors are present. Only the United States, Canada, Australia, Japan, England and Ireland are not considered to be endemic areas. The disease is associated with high economic losses relating to treatment costs, loss of performance, abortion and death.

Equine babesiosis is a tick-borne protozoal infection of donkeys, mules, horses and zebra characterised by acute haemolytic [[Anaemia - Introduction|anaemia]]. The disease is caused by the intraerythrocytic protozoa ''Theileria equi'' (formerly ''Babesia equi'') and ''Babesia caballi'' and is transmitted primarly by [[Ixodes spp.|ixodid]] [[:Category:Ticks|ticks]]. Equine babesiosis is present in most tropical and sub-tropical regions of the world where tick vectors are present. Only the United States, Canada, Australia, Japan, England and Ireland are not considered to be endemic areas. The disease is associated with high economic losses relating to treatment costs, loss of performance, abortion and death.

==Aetiology and Pathogenesis==

==Aetiology and Pathogenesis==

''B. caballi'' and ''T. equi'' are transmitted by ticks, which become infected when they ingest parasites in the blood of infected horses. Approximately 15 species of ticks in the genera Dermacentor, Hyalomma and Rhipicephalus can be vectors for these organisms. ''T. equi'' can also be transmitted by ''Boophilus microplus''. Currently, there is no evidence suggesting transmission by other insects. Infected adult ticks host several cycles of replication of Babesia spp and final maturation of the parasite occurs when the tick attaches to a new host. For this reason, the tick must remain attached to the host for a period of time (up to a few days) before infection can occur. Equine babesiosis may also be transmitted via contaminated surgical instruments, blood products or syringes. Following recovery from infection, horses may become lifelong carriers of the disease and represent a potential reservoir of parasites.  

''B. caballi'' and ''T. equi'' are transmitted by ticks, which become infected when they ingest parasites in the blood of infected horses. Approximately 15 species of ticks in the genera [[Dermacentor spp.|Dermacentor]], [[Hyalomma spp.|Hyalomma]] and [[Rhipicephalus spp.|Rhipicephalus]] can be vectors for these organisms. ''T. equi'' can also be transmitted by [[Rhipicephalus spp.|''Boophilus microplus'']]. Currently, there is no evidence suggesting transmission by other insects. Infected adult ticks host several cycles of replication of ''Babesia'' spp. and final maturation of the parasite occurs when the tick attaches to a new host. For this reason, the tick must remain attached to the host for a period of time (up to a few days) before infection can occur. Equine babesiosis may also be transmitted via contaminated surgical instruments, blood products or syringes. Following recovery from infection, horses may become lifelong carriers of the disease and represent a potential reservoir of parasites.  

==Clinical signs==

==Clinical signs==

Clinical signs are generally dependent on the causative parasite. Infection with ''B. caballi'' tends to result in a milder form of disease that is often clincally inapparent whereas ''T. equi'' results in a more serious disease. The clincal presentation of the disease is variable and dependent on the immunological status of the affected animal. In rare cases, the presentation may be peracute with animals found dead within 24-48 hours of the onset of clinical signs. More often cases occur acutely with clinical signs including depression, pyrexia, inappetance, icterus, haemoglobinuria, conjunctival petechial haemorrhages amd anaemia. Small and dry faeces are often reported. Other common clinical signs include tachypnoea, ataxia and oedema of the head.

Clinical signs are generally dependent on the causative parasite. Infection with ''B. caballi'' tends to result in a milder form of disease that is often clinically unapparent whereas ''T. equi'' results in a more serious disease. The clinical presentation of the disease is variable and dependent on the immunological status of the affected animal. In rare cases, the presentation may be peracute with animals found dead within 24-48 hours of the onset of clinical signs. More often cases occur acutely with clinical signs including depression, pyrexia, inappetance, [[icterus]], haemoglobinuria, conjunctival petechial haemorrhages amd [[Anaemia - Introduction|anaemia]]. Small and dry faeces are often reported. Other common clinical signs include tachypnoea, ataxia and oedema of the head.

The subacute form of the disease has a similar but less severe presentation, characterised by intermittent fever, anorexia, weight loss, signs of mild colic and oedema of the distal limbs. Chronic infections are typically accompanied by varying clinical presentations including mild inappetance, weakness, weight loss and mild anaemia.  

The subacute form of the disease has a similar but less severe presentation, characterised by intermittent fever, anorexia, weight loss, signs of mild colic and oedema of the distal limbs. Chronic infections are typically accompanied by varying clinical presentations including mild inappetance, weakness, weight loss and mild anaemia.  

==Control==

==Control==

In non-endemic areas, carrier horses should not be imported. If they are, they should be identified using serological testing, quarantined and treated.  

In non-endemic areas, carrier horses should not be imported. If they are, they should be identified using serological testing, quarantined and treated.  

==References==

==References==