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Cystitis and Pyelonephritis

Cystitis is inflammation of the bladder and nephritis is inflammation of the kidney. The bacteria causing cystitis are usually Actinobaculum suis (originally called Corynebacterium suis or Eubacterium suis) or sometimes E. coli. It is impossible to eradicate these organisms. They are present in every herd.

This disease is an important cause of mortality in all ages of dry sows. Occasionally it may be seen in gilts, even maiden gilts, although this is uncommon unless there has been gross and prolonged faecal contamination of the vulva. In badly affected herds sow mortality can exceed 12% per annum.

Sows die rapidly or respond poorly to treatment remaining chronically diseased. Disease can be so acute that death is the only sign. It is more common in the first 21 days post mating because the urine of the sow becomes alkaline and both A.suis and E.coli will survive and multiply in alkaline urine.

Reproductive failure is not associated with this disease specifically unless the sow is ill and as a consequence either dies or aborts. High mortality affects overall sow mortality and therefore pregnancy survival.


  • None
Weaners & Growers
  • Uncommon
  • Appear ill.
  • Not eating.
  • Thin sows.
  • Red rimmed eyes - membranes red.
  • The area around the vulva is wet and soiled with evidence of blood and pus in the urine.
  • Death - high mortality
  • Abortion
  • Chalky mineral deposits.
  • Pigs show pain / discomfort.
  • May grind teeth.
When cystitis occurs alone:
  • The disease may be prolonged and not fatal.
  • Appetite and the general condition of the sow can be normal.
  • Pus in the urine or a slight discharge clinging to the vulva may be seen.
  • This should be distinguished from inflammation of the womb or vagina.

Causes / Contributing factors

  • Low water intake.
  • Infrequent urination.
  • Faulty drinkers.
  • Badly drained boar and sow pens increase the risk of infection
  • The disease is more common in herds that have high numbers of old sows.
  • Squeezing the prepucial sac at mating increases the bacterial load transmitted to the vagina, (which may also result in increased returns to service).
  • Sows that are too big for the stalls often adopt a dog sitting position with the vulva becoming heavily contaminated, allowing excessive bacterial multiplication.
  • Contamination of the vulva with faeces particularly from weaning to 21 days post mating. This occurs in stalls when solid back boards drop down to the ground level.
  • Stress at farrowing can occasionally activate disease.


By post-mortem examination. Examinations should be carried out on all sows that have died without obvious cause.

In the live animal, diagnosis is based upon clinical signs and evidence of blood and pus in the urine. Urine can be tested for the presence of blood, protein and the pH (acidity or alkalinity) by using paper strip tests. Urine can be collected in clean receptacles, especially if sows are made to stand up 2-3 hours after feeding when they tend to urinate. Affected animals show evidence of blood and protein in the urine and a pH of 7 or more. (Normal urine is slightly acid, that is, less than the pH7.) Sows showing a pH of 8 or more may die in their next pregnancy.

Further Reading

Click on the links below to find out more about this disease, including treatment, management control and prevention information. The top link is the main article on this disease.