Meconium is a newborn foal’s first manure and is composed of intestinal secretions and fluid ingested by the foal while in utero. Meconium can range from firm pellets to pasty consistency and is typically dark brown, black or green in colour looking more like dog poo than horse poo. Meconium is generally passed within the first 3-4 hours of birth. If it is not passed in the first 24 hours of birth it is considered impacted or retained.
Signs of meconium impaction can occur up to 3-4 days after birth. Clinical signs that may indicate a foal has retained meconium include:
Straining to defecate/ “constipated”
tail lifting / tail flagging
increased heart rate
rolling / colicky
lying upside down
abnormal stance, hunched back
The discomfort can lead to foals being depressed and reluctant to nurse. This is a vicious circle as the mare’s milk is a natural laxative and failure to suck leads to the meconium becoming more concreted and difficult to pass.
Meconium impaction can occur in any foal, however is more frequently seen in males due to their smaller pelvis size. Foals may also be predisposed if they are weak or dysmature foals (pre-mature or post-mature). As foals may have not had adequate nursing they are also at risk of failure of passive transfer and it is recommended that an IgG test is performed.
Diagnosis may be made by history of failure to defecate. Meconium may be able to be felt on gentle rectal examination, however radiographs or ultrasound may be required if there is a higher impaction in the large colon.
Treatment for meconium impaction may include manual removal combined with an enema. Fleet enema’s may be routinely given on some farms to reduce the risk of impactions. Care is needed with Fleet enema’s as they may cause rectal irritation and are best warmed before use. Other treatments that you vet may use are soapy water enemas, mucomyst (retention enema), fluids and pain relief. If severe surgical intervention may be required.
If you are concerned that your foal has meconium retention or impaction, please contact your veterinarian immediately.