- Nephritis is a term used to describe damaged kidneys seen at the abattoir.
- Kidney damage may be active or old and localised or generalised; nephritis is a general term for kidney inflammation.
- Prolonged damage causes kidneys to be shrunken, irregular and scarred. Recent damage causes swollen, discoloured or spotty kidneys (also referred to as ‘white spotted kidney’).
- Long-term, nephritis reduces growth rate/weight loss, and this can lead to sudden death or chronic ill-health and subsequent death (weeks to months).
- Kidneys are condemned at the abattoir depending on the extent and spread of damage.
- Kidney damage may follow infections or toxin exposure. Toxins may come from poisonous plants or chemical exposures icluding some drenches.
- Infections can come from wounds or rumenitis or direct infections of the kidney (e.g. leptospirosis)
- Toxins typically derive from poisonous plant exposure e.g. soursobs; or from chemical exposure (e.g. some antibiotics, fertilisers, heavy metals etc.).
- Some animals may be mildly affected and show no signs of illness.
- Animals with chronic kidney damage may suffer from ill-thrift, pale gums, increased urination and sporadic deaths.
- Sheep can appear normal with 25% (or more) kidney function; disease is only seen when kidneys become severely degraded.
- Significant damage leads to decreased production, growth and/or death. Affected animals are often unresponsive to treatment.
- Finding the cause of the nephritis is the first step. This may require investigation by a veterinarian.
- Will vary depending on the cause and if it is sudden or chronic.
- Stock should immediately but slowly, be moved from known toxic areas.
- Use sharp and clean marking equipment disinfected regularly, with a chlorhexidine-based disinfectant e.g. Hibitane.
- Avoid wet conditions, overcrowding, prolonged holding and unnecessary separation of lambs and ewes.
- Choose a balanced ration introduced over 2 or more weeks.
- Prevent weeds by quarantining new sheep for 7 days and using weed deterrents and provide adequate hay in weedy paddocks.
- Measure drench and antibiotic dosage rates accurately and use faecal egg counts to determine if drenching is required.
- Consider vaccination against leptospirosis.