Stillbirths occur worldwide. A rate higher than 7% of piglets born dead is significant.
- Causes of Stillbirths >
- Effects of Stillbirths >
- Diagnosis of Stillbirths >
- Treatment & Control of Stillbirths >
Causes of Stillbirths
Stillbirth is the term given to the birth of a piglet which is found dead within the membranes after farrowing is complete. The piglet may have died prior to farrowing, died during the process of birth, or died after birth but without clearing the membranes.
Piglets removed at hysterectomy all survive, but some of those born naturally are born dead.
Disease may cause the piglet to die shortly before farrowing, during the process and before clearing the membranes. The diseases responsible include:
- enterovirus,
- eperythrozoonosis,
- leptospirosis,
- mycotoxicosis (especially zearalenone),
- parvovirus,
- PRRS
- and toxoplasmosis.
Carbon monoxide poisoning may also increase stillbirth rates dramatically. Many of the stillbirths which occur in normal litters result from delays in farrowing. These may result from the presence of a dead piglet or a mummy in front of the piglet concerned and the delay caused can deprive it of oxygen and kill it.
Similarly, destruction of the placenta before or during farrowing can lead to loss of oxygen and death unless the piglet is farrowed very fast. Oversized foetuses may delay parturition and are often born dead and uterine inertia may occur in older pigs, calcium deficient sows or those which have just passed a difficult piglet.
Effects of Stillbirths
Stillborn pigs are found dead in the membranes behind the sow or delivered dead as a result of assistance at farrowing or following uterine inertia during prolonged farrowing.
Diagnosis of Stillbirths
- Piglets found dead in the membranes behind a sow may be stillborn, but the point of death should be confirmed by post-mortem examination.
- Pigs which have died in the membranes have a fleshy cord, membrane on the skin and cartilaginous curled up tips to the toes. Many of these piglets have not breathed and their lungs are plum coloured and sink in water.
- Some piglets which have died in the membranes have partially expanded lungs which float in water.
- Piglets which have died in the course of farrowing appear mature and fresh.
- In those which died before farrowing, the membranes may already be discoloured, the skin yellowish not pink and the eyes may be beginning to sink in.
- Signs of immaturity such as closed eyes or lack or hair may be noted.
- A history of uterine inertia or assistance at farrowing may explain the stillbirths.
- Piglets of older sows or those with large litters are most likely to be born dead, as other products of parturition, such as mummies frequently cause mortality in piglets which follow them.
- The cause of death may be congenital and the piglet may be malformed or so small as to be non-viable.
- Culture or demonstration of infectious agents may suggest a cause. Animals which have died from carbon monoxide poisoning are often cherry red.
Treatment & Control of Stillbirths
Where uterine inertia is occurring (if no piglet has been born for 2 hours), remove foetuses manually as soon as possible until normal farrowing continues.
Compromised piglets may be resuscitated by clearing the membranes from the mouth, using a sucker to clear airways, massaging the chest and swinging the piglet by the hind legs to stimulate breathing.
If calcium deficiency in the sow is suspected, give calcium borogluconate into the ear vein and treat any other illness in the sow.
Where farrowing cannot be attended, confirm that the vulva of the sow is not pressed against the back of the farrowing crate and that there is a heat lamp at the tail of the sow to prevent chilling of the piglets.
Prevention of stillbirths requires attendance at farrowing, careful attention to those sows known to have a high stillbirth rate, prompt intervention when uterine inertia occurs and culling of sows after the seventh litter.
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