Changes

This condition results from increased red blood cell destruction, overwhelming the capacity of the [[Liver - Anatomy & Physiology|liver]] to conjugate and excrete the bilirubin which is released into the plasma.  The majority of the bilirubin is therefore unconjugated and, unlike the conjugated form, this cannot be excreted by the [[Urinary System Overview - Anatomy & Physiology|kidney]].  Possible causes of haemolysis and prehepatic jaundice include:

This condition results from increased red blood cell destruction, overwhelming the capacity of the [[Liver - Anatomy & Physiology|liver]] to conjugate and excrete the bilirubin which is released into the plasma.  The majority of the bilirubin is therefore unconjugated and, unlike the conjugated form, this cannot be excreted by the [[Urinary System Overview - Anatomy & Physiology|kidney]].  Possible causes of haemolysis and prehepatic jaundice include:

*'''Haemolytic bacteria''', including ''[[Clostridium haemolyticum]]'' in cattle and [[Leptospira|'''Leptospires''']] in various species.

*'''Haemolytic bacteria''', including ''[[Clostridium haemolyticum]]'' in cattle and [[Leptospira|'''Leptospires''']] in various species.

*'''Haemolytic parasites''', including '''[[Babesia|Babesiosis]]''' in cattle and dogs and ''[[Mycoplasma haemofelis]]'' in cats.

*'''Haemolytic parasites''', including '''[[Babesia|Babesiosis]]''' in cattle and dogs and ''[[Feline Infectious Anaemia|Mycoplasma haemofelis]]'' in cats.

*'''Immune reactions''' to red blood cells, including:

*'''Immune reactions''' to red blood cells, including:

**'''Neonatal isoerthryolysis''', resulting from the production of antibodies by the dam which are ingested by the neonate in colostrum and subsequently cause destruction of red blood cells.  Bilirubin is able to cross the immature blood brain barrier and cause direct damage to the neurones of the brain, a phenomenon called '''kernicterus'''.

**'''Neonatal isoerthryolysis''', resulting from the production of antibodies by the dam which are ingested by the neonate in colostrum and subsequently cause destruction of red blood cells.  Bilirubin is able to cross the immature blood brain barrier and cause direct damage to the neurones of the brain, a phenomenon called '''kernicterus'''.