Sow mortality and welfare euthanasia


While alarming, sow mortality is generally sporadic with little pattern being evident.



Ideally less than 3% of sows should die on the farm

An additional 3% could be euthanased on farm for welfare reasons.

A sow should not go to slaughter if she cannot place all four feet

A sow should not go to slaughter if she is below a condition score of 2

Sudden death in large numbers of sows – more than 3 sows die in a day should always be investigated by the  veterinarian

Swine Fevers – Classical Swine Fever (Hog Cholera) and African Swine Fever

Generally additional clinical signs in other stock.  High temperatures, skin discoloration, abortions and increase in returns.

Postmortem findings: hemorrhages throughout.


When dysentery enters a naοve herd, the adult stock may also become infected and present with similar signs to finishing pigs, including sudden death


The pig, which dies suddenly with erysipelas, may be present with no skin diamonds.  Gross postmortem changes may absent – enlargement of the spleen.


Death generally with no clinical signs

Clostridial Hepatopathy

Sow presents with no clinical signs.  She swells rapidly and decomposes within hours of death.

Diagnosis can be difficult  as changes  resemble normal post-mortem changes


Generally does not kill the sow, but if they do die, may present with laryngeal swelling.


The picture shows a sow which was tested for Anthrax but the cause of mortality was associated with a thyroid tumor

Intestinal disasters-


Any area of the intestinal tract may undergo torsion – the stomach, spleen, liver, small and large bowel.  The distribution of the intestines in the abdomen allows a diagnosis if the twist is not obvious

Splenic stomach torsion

Torsion of a lobe of the liver


for example:




Warfarin – but generally pigs are resistant

Presents with sudden death in a group of sows.  Investigate the dead sows very carefully.  Hydrogen sulfide when odorless is lethal. Poorly maintained electrics are  common on farms.

Hemorrhagic bowl


The etiology is still unsure.

Whey feeding may be associated with a bloat and sudden death. The condition appears as an allergic response with hemorrhage into the intestines.

Heat stress


If the ventilation system fails, pigs will rapidly die from heat stress and suffocation.

Internal hemorrhage

May occur for a number of reasons for example gastric rupture associated with a gastric ulcer.  Can be associated with trauma.

Mating injuries

Boars and sows may be found dead shortly after mating associated with stress and heat stress.  Occasionally the boar can tear the neck of the bladder and the sow bleeds to death

Environ-mental injury

Poorly maintained environments may result in damage to the pigs.  For example, poorly maintained floors - the sows can fall through and drown.  Sows can strangulate themselves under gating if improperly fitted.  Metal cladding can come away forming very sharp points.  Sow can be injured on drinkers in the mating arena.

Salt poisoning

If the sow has no water for 3-4 days, she is likely to die of salt poisoning.  If she has had, repeated problems with her water supplies she may have damaged her kidneys and succumb rapidly to restriction in her water supply.


Heart valve lesions of endocardiosis may be associated with streptococci or erysipelas and may result in heart failure.

Retained piglets

Retained piglets may result in an acute metritis, toxemia and septicemia which can rapidly kill the sow.  Even retained placenta at times will result in a fatal septicemia.   However, it is  also not uncommon to find retained piglets as an incidental finding at post-mortem


Death with few clinical signs – which may be missed

Cystitis and pyelonephritis

Cystitis will not kill the sow; however, if the infection spreads to the kidney, a fatal pyelonephritis may result. On several farms, this is a major cause of death.  A review of the watering system is urgently required.

Gastric Ulceration

Gastric ulcers can result in anemia severe enough to kill the sow.  The ulcer may also erode into a large blood vessel in the submucosa resulting in hemorrhage into the stomach and death of the sow.


Prolapse of the bladder (arrow)

Prolapse of the uterus (arrow)

A variety of prolapses around farrowing may result in the death of the sow, even if surgical intervention is attempted.  The photographs show a prolapsed bladder and prolapsed uterus


stress death

When mixed strange pigs will fight, sometimes to the death.  Young sows can be killed by fighting during oestrus.


Infections after farrowing may result in a severe metritis with resulting death of the sow. There may be few clinical signs excluding septicemia.


If young naive adults are introduced into a normal health herd, an acute meningitis and polyserositis may occur with the resultant death of the gilt or boar.

The picture shows a severe pericarditis in a gilt


Young adults may present as sudden death with the hemorrhagic form of ileitis.  The removal of chronic medication to sows may initiate an outbreak of ileitis.

Pyrexia or septicemia

Sow septic with cyanosis (blueing) of her ears.  Salmonellosis is a possible diagnosis.   Note the purple blotches on her shoulders

PDNS like associated with allergic response

The picture demonstrates the appearance, albeit the photograph is of a weaner similarly afflicted.

Septic focus – pleurisy

The photograph shows a severe unilateral septic pleurisy which resulted in toxemia and death of the sow.  A damaged toe was the source of infection


Lymphosarcoma can affect young adults.

This thymus cancer was found in a sow with a large throat.  

Environment injury - burns

Fortunately, farm fires are uncommon, but it may result in a rapid number of sow deaths.


Sow deaths associated with welfare euthanasia

Broken legs

The X ray shows a broken humerus in gilt.  The foreleg was broken when an oversized boar attempted to mate with the gilt.


The photograph shows a gilt with epiphysiolysis of the femoral head due to a traumatic injury.


If a sow cannot place all four feet on the floor she should not leave the farm.


Sows who do the splits should be euthanased on the farm. It is very unlikely that she will be able to rise let alone start to walk again.


Multiple abscesses are not uncommon in adult pigs.  Sometimes this can be associated with subcutaneous gangrene

Thin sow syndrome

Some sows fail to eat at various stages of production and once a sow becomes condition score 1, it can be very difficult to restore her body condition. Always treat all thin sows as an emergency.


Pigs can present with a variety of bizarre conditions, which may result in their euthanasia.  This old sow (parity 12) suffered a stroke and was unilaterally partially paralyzed and disorientated.