- Jaundice is the yellowing of body tissues like gums and conjunctiva due to liver malfunction or excessive breakdown of red blood cells, leading to an accumulation of the yellow pigment (bilirubin) in the body.
- Jaundice typically results from serious liver damage, where the liver cannot process the excess bilirubin and allow its removal from the body.
- Liver malfunction can be caused by a variety of toxic plants.
- Cirrhosis occurs when liver cells are so damaged, they die and are replaced by scar tissue. Cirrhosis is a sign of chronic liver disease.
- Liver damage, producing jaundice and cirrhosis, also results in reduced growth rate/weight loss, death, and extra costs due to management/treatment.
- Jaundiced animals can be prone to sunburn. This is because the liver also processes the light-sensitive chemical chlorophyll that plants use to capture sunlight; a damaged liver may not remove all active chlorophyll from the circulation thereby leaving the skin hypersensitive to sunlight.
- At the abattoir severely affected (yellow) carcases or livers may be condemned.
- Liver damage is often caused by exposure to toxins, and can lead to jaundice. Jaundice can also occur without liver damage if there is damage to red blood cells,
- Mycotoxins produced by fungus and commonly found in lupins (Lupinosis) and spoiled or mouldy feed (Aflatoxicosis).
- A variety of toxic plants (e.g. Lantana, St John’s Wort, heliotrope) can cause liver damage, jaundice and light sensitivity.
- Mycoplasma ovis (formerly Eperythrozoon ovis), an infectious bacterium affecting the red blood cells that can cause carrier animals to relapse under stress.
- Leptospirosis can also produce jaundice due to haemolytic anaemia.
- Copper toxicity can occur due to stresses like poor nutrition, yarding, transport and bad weather.
- Heliotrope toxicity causes death (weeks to years after toxin ingestion), depression and jaundice for 1-2 days before death.
- Lupinosis causes reduced appetite, condition loss, disorientation, depression, lethargy, stiff gait/hunched back, jaundice and death within 3 days.
- Copper toxicity causes pale gums, jaundice, lethargy and death in 3-5 days.
- Mycoplasma oviscauses ill thrift, pale gums, jaundice and death (especially after a stressful event).
- Photosensitive animals develop crusty lesions on less well-covered parts of the body, such as on the ear flaps, face and nose.
- Veterinarians assist in diagnosis and management of jaundice in live animals.
- The first step is to identify the cause of jaundice; is it due to rupture of red blood cells (haemolysis) or liver damage?
- Immediately remove animals from the source of toxicity.
- Provide animals with access to shade if showing signs of photosensitisation.
- Feed oats and cereal hay and prevent access to green pick for 6 weeks to prevent photosensitisation.
- Minimise stress and avoid yarding.
- Reduce bacterial infections by using sharp marking equipment, disinfected regularly by a chlorhexidine-based disinfectant e.g. Hibitane.
- Prevent weed introduction, use seeds and grain from known uninfested sources, maintain pastures, use weed deterrents and provide hay in weedy paddocks.
- Lupinosis can be prevented by limiting and managing lupin stubbles and avoiding grazing heavily pregnant ewes or weaners on lupin stubble.