Background and history

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 and streptococci. A. suis is a common inhabitant of the preputial sac in the scrotum of the boar and occasionally the vagina of the sow. It has the ability to adhere specifically to the lining of the bladder and urinary tract and does not get easily flushed out with the flow of urine.

Urine passes from the kidneys down the two tubes (ureters) to the bladder where they enter and continue along the surface for approximately 30 to 40mm as straw like structures called the ureteric valves. As the bladder fills up pressure on them stops the urine being squeezed back towards the kidneys. In diseased sows the ureteric valves are often shortened from their normal length to as little as 10mm and if cystitis is present the bacteria can reflux back to the kidneys producing a very severe reaction. This causes the kidney function to cease (renal shunt) and death results in a matter of a few hours.

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.

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 percent per annum.

If a herd has an annual mortality of more than five percent some sows may be dying from unrecognised cystitis/pyelonephritis. In such herds post-mortem examinations of all sows that have died without apparent cause should be carried out.

It is impossible to eradicate these organisms, and they are present in every herd.

Cystitis can be confused with a vulval discharge which comes from the vagina or the womb and is usually of a salad cream consistency, whereas that from the urine contains pus and blood, and also endometritis and vaginitis.

Clinical signs

In sows, usually seen in the early pregnancy period.

• Appear ill.
• Not eating.
• Poor condition.
• Red rimmed eyes – mucous 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.
• Poor response to treatment.

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.

Diagnosis

• Clinical signs, most notably puss and blood in urine.
• By post-mortem examination. Examinations should be carried out on all sows that have died without obvious cause.
• Remember that a dead piglet in the womb may give similar symptoms.

Urine tests

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 seven or more. (Normal urine is slightly acid, that is, less than the pH7.) Sows showing a pH of eight or more have up to a 30 percent chance of dying in their next pregnancy.

Causes

• Low water intake.
• Infrequent urination.
• Faulty drinkers.
• Badly drained boar and sow pens.
• 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.
• If the stalls or tethers are (as they should be) comfortable, dry and free from draughts, if the ambient temperature is constant day and night, if the sows are fed a satisfying balanced diet once a day and if they are otherwise undisturbed, most will tend to lie down for very long periods. They develop a state of what is termed 'passive withdrawal' or 'self-narcosis', and become too lazy to stand up to drink and urinate.

Prevention

If the disease is present as a herd problem check the points below to identify the problem areas:

• Ensure a good supply of clean fresh water. Check water supply daily.
• Sows may be induced to drink more by increasing the salt in the ration to 0.9 percent.
• Walking a boar in front of the sow stalls daily will encourage them to stand and urinate.
• Feed sows in confinement twice daily to encourage animals to rise and giving water, particularly at the same time.
• If sows are fed in a continuous trough always put a small amount of water in first before the feed to encourage intake.
• Wherever possible use water troughs as drinkers, rather than nipple drinkers, particularly in loose-housed sows.
• Scatter small amounts of feed into the trough at watering time.
• Look carefully behind each sow daily to identify any showing clinical signs of cystitis.
• Check that drinkers are at the correct height and provide easy access. The ideal height for sows is 800mm.
• If using nipple drinkers in loose housing provide one drinker per 10–15 sows with the water flow rate of two litres a minute.
• Provide water troughs with a minimum depth of 100mm.
• Reduce or prevent contamination of the vulva with faeces particularly from weaning to 21 days post mating. There should be a 100mm gap between the bottom of the board and the floor to prevent faeces building up behind the sow.
• Ensure sows have enough space in stalls.
• If group housing is used at weaning make sure the pens are well drained.
• Do not use sawdust for bedding.
• Wash and disinfect pens regularly.
• Do not handle the prepuce at mating. Squeezing the prepucial sac increases the bacterial load transmitted to the vagina.
• Always wear gloves at mating time to prevent the spread of the E. suis infection.
• Treat the boar's prepuces with antibiotic to reduce levels of E. suis.
• Sows could also be medicated from weaning to 21 days post mating during the most susceptible period by top dressing with in-feed supplements. The dose used is based on the assumption that the sow will eat 2.5kg of feed per day during this period and the amounts of top dressing should be calculated on the basis of 600g to the tonne of active antibiotic. In most cases using a 10 percent premix this will be between 15 and 20g of premix powder per day.
• In a herd with major problems the prepuces of all the boars should be swabbed and forwarded to a laboratory to determine the isolation rate of E. suis bacteria and its antibiotic sensitivity. In a normal herd the isolation rate would be less than 30 percent but in a diseased herd this can approach 100 percent. In such cases attention to hygiene and management in the boar pens is required.

Eradication

It is impossible to eradicate the organisms associated with this disease. They are present in every herd.

Treatment

• Once a sow has shown clinical signs of cystitis or pyelonephritis and lactation has ceased it is advisable to cull her.
• Antibiotic treatment is indicated to destroy the incriminating bacteria but it must be excreted in the urine. The dose will vary from 7 to 10mls depending on the body weight of the sow and the strength of the preparation used. The best medicines to use are:
  • trimethoprim/sulpha;
  • amoxycilli;
  • lincomycin;
  • oxytetracycline;
  • penicillin/streptomycin.

• Lincomycin is effective at a dose level of 10mg/kg. This medicine is active against E. suis.
• A more broad-spectrum antibiotic however may be required if coliforms or other bacteria are involved. In such cases either ampicillin or amoxycillin at 10 to 15mg/kg should be given daily for 4 to 5 days.
• On a herd basis, treatment is best carried out using either chlortetracycline (CTC) or oxytetracycline (OTC) at levels of 600g/tonne for a period of 14 days. It may be necessary to repeat this treatment every 4 to 6 weeks.
• An alternate method is to inject the sow at weaning or at mating with a long-acting single injection of penicillin or amoxycillin.
• Antibiotic mastitis tubes or liquid antibiotics can be instilled into the prepuce daily for five days to reduce the weights of infection.