Changes

The disease can then invade a specific organ system resulting in associated clinical signs:

The disease can then invade a specific organ system resulting in associated clinical signs:

'''Opthalmic''': The initial signs are blephrospasm, increased lacrimation, photophobia and corneal oedema, with progression to retinal detachment, synechia formation, and cataracts. Chronic leptospirosis causes recurrent uvietis, typically signs develop 2-8 months after initial infection. Up to 67% of recurrent uveitis cases are due to leptospirosis. It is not clear whether the recurrent uveitis is immune mediated or due to intraocular bacterial infection. 

'''Opthalmic''': The initial signs are blephrospasm, increased lacrimation, photophobia and corneal oedema, with progression to retinal detachment, synechia formation, and cataracts. Chronic leptospirosis causes recurrent uvietis, typically signs develop 2-8 months after initial infection. Up to 67% of recurrent uveitis cases are due to leptospirosis.  

'''Reproductive''': Leptospirosis can cause placentitis, abortion, still birth or neonatal disease depending on the serovar and the stage of gestation when infected. Approximately 3-4% of equine abortions are caused by Leptospirosis, and are most frequently due to serovar Pomona, or occasionally Harjo. Abortion is usually late term, at 9 months of gestation.

'''Reproductive''': Leptospirosis can cause placentitis, abortion, still birth or neonatal disease depending on the serovar and the stage of gestation when infected. Approximately 3-4% of equine abortions are caused by Leptospirosis, and are most frequently due to serovar Pomona, or occasionally Harjo. Abortion is usually late term, at 9 months of gestation.

'''Renal''': leptospirosis rarely causes urologic signs including polyuria/polydipsia, azotaemia, pyuria and haematuria.

'''Renal''': leptospirosis rarely causes acute renal failure, signs include polyuria/polydipsia, azotaemia, pyuria and haematuria.

'''Hepatic''': Horses with the hepatic form of the disease will bei icteric, pyrexic and lethargic.  

'''Hepatic''': Horses with the hepatic form of the disease will bei icteric, pyrexic and lethargic.  

Culture of Leptospira is challenging but can be attempted from urine, blood and aqueous humour in antemortem diagnosis, or from liver, kidney, fetus or placenta in post mortem diagnosis.  

Culture of Leptospira is challenging but can be attempted from urine, blood and aqueous humour in antemortem diagnosis, or from liver, kidney, fetus or placenta in post mortem diagnosis.  

A MAT or ELISA opn serum is a more sensitive diagnostic method. Paired titres 4 weeks apart are optimal.  

A MAT or ELISA on serum is a more sensitive diagnostic method. Paired titres 4 weeks apart are optimal.  

===Ultrasound===

===Ultrasound===