This condition is more formally known as neonatal hypoxic ischaemic encephalopathy (HIE) and is seen as abnormal behaviour during the first few days of life. Other common names for the disease are ‘wanderer foals’ and ‘barker foals’.
The exact cause of the condition is unknown but appears to involve asphyxia (lack of oxygen) and ischemia (poor blood supply) to the brain or other organs during late gestation, delivery or the early neonatal period.
Some of the common causes are:
- Foaling problems such as red bag deliveries, dystocias, caesarean sections, foals that need to be resuscitated at birth and induction of labour
- Placental abnormalities such as placentitis and premature placental separation
- Maternal problems include anaemia, endotoxaemia secondary to colic, cardiovascular disease or hypotension (low blood pressure)
- Thoracic trauma such as fractured ribs or prolonged thoracic compression during difficult delivery has also been implicated.
There are two major types of this condition:
1. The foal appears normal at birth and has often suckled normally. These foals deteriorate within 6-24 hours with rapid progression of the condition over the first 24 hours.
2. The foal is abnormal from the outset and is often clumsy and confused. These foals don’t have a suck reflex and are disinterested in feeding.
Neurological signs are the most evident clinical signs including poor teat seeking behaviour, tongue hanging out, head pressing, loss of suck reflex, ‘barking’, hyperesthesia on handling, seizures, weakness and abnormal posture.
Respiratory signs are also seen including dyspnoea, abnormal breathing patterns, shallow breathing and breath holding.
These foals are far more susceptible to secondary conditions such as septicaemia.
This can be difficult in the early stages as the signs are often subtle unless the history indicates towards a foal at a high risk of developing this disease. Concurrent disease processes in other body organs and generalised depression can obscure clinical signs of HIE.
The placenta can be useful in the diagnosis and early recognition of a high risk foal. If there is any indication of placentitis, thickening of the placenta or premature placental separation these foals need to be monitored closely for development of this condition.
Often in the early stages it is difficult to differentiate this condition with septicaemia and it is therefore common practice to provide combined treatment in all cases. Even if these foals don’t start off with septicaemia, they are at a far higher risk of developing it than normal healthy foals.
The treatment is often very intensive and can become very expensive.
Treatment is aimed at:
- Reducing any cerebral oedema (brain swelling)
- Improving cerebral perfusion and oxygenation
- Controlling any seizures if present
- Preventing /controlling/treating concurrent sepsis with necessary antibiotics
- Ensuring adequate transfer of immunity, it is very important to check all foals IgG levels.
1. Regular turning of the foal to prevent trauma and bed sores.
2. Feeding via a naso-gastric tube. Some foals require total or partial parental nutrition if they have concurrent diarrhoea, gastric ulcers or colic.
3. If the foal is born with HIE ensure it gets adequate good quality colostrum.
Foals that develop HIE after birth have a much better prognosis and complete recovery is possible provided they get the appropriate treatment. Those foals that are born with HIE have a poor prognosis for survival without intensive and expensive treatment. Concurrent sepsis (or other complicating disorders) reduces the prognosis to almost hopeless.
The rate at which the foal improves is also important. If there is no improvement after 4 days of treatment the prognosis becomes far poorer.
Bosch Hoek Equine Hospital is a state of the art Equine hospital situated in the beautiful Kwa-Zulu Natal Midlands of South Africa. Our primary goal is to offer clients and their horses world class care and expertise for both surgical and medical conditions with a rehabilitation centre to match.
If you require our services or would like to discuss anything please call one of us on the numbers below:
Dr Helen Tiffin 082 966 9324
Dr Jenny Lawrence 082 836 9897
Dr Anna Bowker 082 849 3456
Dr John Hodsdon 072 165 7122
|Dr Jenny Lawrence
Equine Veterinarian BVSc
Jenny qualified in 2005 after which she worked as a small animal veterinarian in the United Kingdom for 3 years. In 2008 she returned to South Africa to begin equine work with the late Dr Dave Mullins before joining the Bosch Hoek Equine Hospital where she has become an important part of our team and has a special interest in foal medicine. Jenny recently returned to the UK for a short period where she worked with renowned breeding expert, Dr Jonothan Pycock as well as spending time at various equine hospitals and AI centres in the UK.