Coccidiosis of Piglets


Causal agent

Isospora suis.  This is a coccidia a parasite

Age group

Occurs between 8 and 15 days of age.  Chronic cases can be seen post-weaning

Clinical signs


Coccidiosis scour

Scour tends to occur in individual pigs from approximately 6 days of age, but most of the litter scour at 8-10 days.  At the start of diarrhoea, vomiting may be seen

Diarrhoea ranges from white to pasty cream faeces through to a yellowy watery diarrhoea

Piglets tend to be in poor condition, hairy and growing more slowly than other piglets within the litter

Mortality rates reach 20% in acute cases

The scour is not responsive to antibiotic therapy -excluding sulph medicines

Piglets which survive often become unthrifty finishers when exposed to high pathogen concentrations, as they have little passive immunity and an immature gut

Failure to recognise the disease leads to increased farrowing house mortality, poorer weaning weights and increased post-weaning problems


Most farms will have Coccidiosis at a low level affecting piglet performance


The coccidial egg, or oocyst infects young piglets by mouth, and relatively heavy infections are needed to cause disease.  After ingestion, the organisms move down to the small intestines, where they invade the gut wall.  In successive stages of a complex life cycle, they emerge from the wall at 5-9 days and again at 11-14 days after infection, and it is this emergence which causes diarrhoea.


For clinically significant disease to occur, piglets need to be infected with relatively high numbers of oocysts

Oocysts survive well in farrowing house environments.  They are resistant to drying and most disinfectants

Infection from the sow plays only a small part in disease development.  Sows excrete a different coccidia called Eimeria

Most piglets are infected by oocysts carried over from previous litters

Once the piglet starts scouring, the intestinal wall is damaged, and treatment will not work effectively

Failure to recognise the disease leads to increased farrowing house mortality, poorer weaning weights and increased post-weaning problems

Incubation period

The incubation period is 5 days


Post-mortem Lesions

There may be very few postmortem findings – steatorrhea (increase of fat in faeces).  Some times there is a generalised enteritis.  Scrapes from the intestinal wall may reveal the coccidial parasite.  Histological examination are also used, however, note coccidia are also very common (normal?)


Can be very difficult.  Coccidial oocysts are only excreted in the faeces long after the clinical disease has passed

Response to treatement with Baycox (toltrazuril) Europe or Marquis (15% ponazuril) US- not licenced for pigs.  Dose 7mg/kg.  For Marquis use one tube (127g) into 4 litres of water and administer 4 ml orally per 4 to 10 day old piglet.

Coccidia Isospora suis drawingIsospora suis

Isospora suis oocyst only has two merozoites within the egg

Coccidia Eimeria drawing

Emeria (from the sow) has four merozoites within the egg, allowing easy differentiation


Give electrolytes

Give extra bedding.   Stop creep feeding.  Increase heat to piglets

Treat with Toltrazuril an oral preparation given at 4 and 10 days of age. Note this can make the pigs vomit.  Sulpha-antibiotic medicines may also be used as treatment


Prevent carry over of oocysts from previous litters.

Clean the farrowing house with an occide disinfectant such as Oocide (Antec International)

Control of rapid multiplication in infected piglets can be achieved by early and sometimes repeated treatment

Reduce/cease cross-fostering after 2-3 days of age

Use as a preventive measure Toltrazuril oral doser.  Pigs should be dosed at 4 and 10 days of age.  Note some piglets vomit after being treated

Sows should be washed/disinfected before entering the farrowing house

Do not enter pens

Use separate brushes, forks, shovels in each farrowing room

Control flies

Reduce draughts and other environmental stress factors

Common differentials

Other causes of preweaning diarrhoea.   Stress induced diarrhoea


Non Specific Colitis


Causal agent

None identified. Diarrhoea of weaned pigs of any age from weaning to slaughter.  Diarrhoea can occur within hours of consuming a new batch of pelleted feed and they can dramatically cease within hours of the removal of the suspect feed.  Considered important factors are nutrition, infectious agents, and draughts

Age group

Weaning to slaughter pigs, most common between 25-30 kg pigs

Clinical signs

Diarrhoea weaner

Softening of faeces with/without mucus and/or blood

Diarrhoea can develop

Decreased growth rate.   Feed conversion increases

Most common between 8-10 weeks of age

More commonly seen in fast growing pigs on high density diets


Agent not recognised, but can appear to spread around and between farms

The syndrome classically occurs with a particular feed and when this is changed the ‘disease’ disappears.  Nutritional factors known to affect digestion are:

Presence of trypsin inhibitors in peas, beans and soya

Poor quality fat

Post-mortem Lesions

Colitis large bowel PM

The colon and small intestine may demonstrate areas of inflammation both acute and chronic.  The spiral colon contains abundant watery green or yellow mucoid and frothy contents.  In some cases there may be no gross lesions.


The photograph shows raised rugae in the inside of the large bowl but few other lesions


Based on the clinical signs and absence of other specific organisms


Air smoking room draughts

Improve the environment, remove draughts and ensure that the stocking rate is correct – photo shows a growing shed being examined for draughts

Do not place pigs into buildings which are damp and cold

Check and clean the water supply

Ensure the correct pig is placed in the building

Change the feed to a meal

Establish an all-in/all-out programme

Common differentials

Other causes of post-weaning diarrhoea