By Roger Dixon BVM&S Cert AVP(ESM) MRCVS Ashbrook Equine Hospital
The Normal Foal
The normal newborn foal will attempt to right itself within the first few seconds following birth and should stand by 1 hour. The foal will then start to search for the udder and should suck from the mare by 2 hours. The normal foal will nurse 5-7 times an hour and often lie down between feeds. When a human enters the stable, the foal’s normal response is to jump up and search for the udder. It is normal for newborn foals to have a wide-based stance, follow the mare and avoid contact with humans. It is very important that the mare/foal bond is allowed to develop, so observation from a distance is recommended provided no problems are evident. Colt foals generally urinate by 6 hours and fillies should urinate by 10-12 hours.
The Importance of Colostrum
Foals are born with an immune system which is said to be immunocompetent but immunonaieve – this is because they are born without any antibodies in their bloodstream and therefore have a very limited ability to fight infections. Colostrum is the first secretion produced by the mare’s udder. It contains antibodies and other important factors and is an excellent energy source.
The normal foal will ingest 1.5-2 litres of colostrum in the first few hours of life. Specialised cells in the foal’s small intestine are able to absorb antibody very well for the first 12 hours when the gut is said to be ‘open’. However, antibody absorption declines after 12 hours and by 24 hours the gut is said to be ‘closed’. It is therefore essential that the foal ingests sufficient good quality colostrum within 12-18 hours of birth to reduce the chances of serious infections developing. If insufficient colostrum is ingested/absorbed, then this is likely to lead to a condition known as Failure of Passive Transfer.
Failure of Passive Transfer
It is generally recommended that newborn foals are examined by a vet within the 12-36 hours of birth; earlier if there is a problem. As part of the examination, your vet is likely to take a blood sample to measure the level of antibody in the bloodstream to ensure an adequate level of protection against disease. If insufficient antibodies are detected, this is know as Failure of Passive Transfer (FPT). There are different levels of FPT, depending of the antibody level detected, as shown below:
Risk Factors for FPT
Any factor that interferes with the foal ingesting/absorbing good quality colostrum is considered a risk factor for FPT. Common risk factors include:
– Running milk:
- Especially common in older mares, or mares which have had several foals.
- The udder contains a finite amount of colostrum. If the mare has ‘run milk’ for several days before birth and lost the colostrum onto the stable floor, then she may be producing normal milk by the time the foal attempts to nurse.
– Maiden mare:
- May have low quantity/quality colostrum.
- May be very nervous with a first foal and unwilling to let the foal suck.
- Some maiden mares need sedation in order to allow nursing.
– Sick foal:
- If the foal is lying down, depressed or distracted (e.g. from straining to defaecate) then the colostral intake will be reduced.
- Inspection of the mare’s udder is a good way to detect whether the foal has nursed; a very full, distended udder is a sign that the foal may not have nursed and FPT is possible.
– Sick mare:
- Colostrum/milk production is likely to be reduced if the mare is sick.
- If the mare is lying down, the foal will not be able to access the udder.
Treatment of Failure of Passive Transfer
If diagnosed before 18 hours the gut is still ‘open’ and colostrum may be administered by bottle or stomach tube. There are several options:
- Use colostrum from the dam, provided the quality is adequate.
- Use colostrum from another mare:
– On studfarms it is common practice to freeze 250ml batches of good quality colostrum for emergency use.
- Use commercially available colostrum-replacement powder:
– These are derived from a bovine source.
– Although a good energy source and ‘better than nothing’, they often contain relatively low concentrations of antibody.
If diagnosed after 18 hours the gut is ‘closed’ and antibody cannot be absorbed.
- A plasma transfusion is often the best option and is a relatively simple procedure.
- Most equine vets stock commercially available quality-controlled hyperimmune plasma. It is administered via a catheter in the jugular vein over 60 minutes. This delivers antibody directly into the foal’s bloodstream.
- It is the preferred option for complete FPT.
If Left Untreated……..
If the antibody level remains low, the foal is susceptible to infection over the following days/weeks. During the first 18 hours when the gut is ‘open’, bacteria from the environment are likely to be ingested as the foal searches for the udder and nuzzles around the often-contaminated hind legs. These bacteria are then translocated across the gut wall in the same way as antibody and into the bloodstream (bacteraemia). This may result in sepsis; a severe disease.
Sepsis accounts for approximately 30% of foal mortality. It typically affects foals less than 7 days old. FPT is the major risk factor, but it is possible for foals with a normal antibody level to be affected; this depends on the type and challenge dose of invading pathogen. Common bacteria involved include E.coli, Actinobacillus, Salmonella and Enterococcus. The bacteria can localise to specific regions, including the liver, lungs, kidneys and joints where they cause damage/disease.
Signs of Sepsis
As a prey species, foals are very much a ‘flight’ animal. As such, any sign of lethargy or unwillingness to suck may be extremely significant and an early warning of developing sepsis (or other condition). Other signs may include:
- Diarrhoea (40% of cases).
- Breathing difficulties (50% cases).
- Lameness and/or or swollen joints.
- Cloudy eyes.
- Haemorrhages on the gums.
- Umbilical infections.
Treatment of Sepsis
Sepsis may be extremely difficult to treat. Affected foals usually require hospitalisation and intensive nursing in order to survive. Treatment is usually expensive (£1000-£3000) and may include i.v. antibiotics, i.v. plasma, treatment of shock, joint lavages under general anaesthetic, intra-nasal oxygen and specialist nutrition. Prevention is therefore better than cure; this emphasises the need for clean foaling conditions and a blood test to detect FPT.
Meconium is the first faeces the foal produces. It is a mixture of ingested amniotic fluid, mucus and bile. It is usually dark in colour and may be expelled as pellets or a sticky mass. It is normally passed within 3-4 hours of birth, followed by yellow-brown ‘milk faeces’.
Approximately 3% of foals will develop a meconium impaction. There are several predisposing factors including prematurity, trauma at birth, low birth weight and dehydration. Colostrum actually has a laxative effect, so a meconium impaction can actually be a ‘red flag’ warning that insufficient colostrum has been ingested and that FPT may also be present. Colt foals reportedly have a higher incidence of meconium impaction because they have a narrower pelvic canal.
Clinical signs include:
- Progressive straining and tail-lifting/swishing.
- Rolling and stretching (colic).
- Adopting bizzare postures e.g. lying on back.
- Refusal to suck.
Meconium impactions are treated by your vet administering an enema. They are usually easier to treat if the impaction is detected earlier. Some studfarms give an routine preventative enema particularly to colt foals soon after birth to help clear the meconium.
It is very important that the umbilical stump is treated soon after birth. Historically, many chemical/solutions have been applied to encourage the umbilicus to dry up and prevent infection (‘navel ill’). We generally recommend:
– Dilute ‘hibiscrub’ (chlorhexidine 0.5%), with or without the addition of surgical spirit to aid dessication. Ideally treated twice daily for 3 days.
– Dilute iodine (pevidine). However, this has several disadvantages to hibiscrub:
- iodine is inactivated by organic material, e.g. faeces.
- iodine is irritant is applied too concentrated.
- iodine has been shown to encourage adhesion (sticking) of bacteria.
It is very important to monitor the umbilicus for signs of infection during the first few days. These will include heat, pain, swelling and wetness of the stump. By 48 hours after birth, the umbilicus should have shrivelled up and become small, dry and non-painful.
‘Dummy foal’ is a vague term used to describe foals which exhibit a particular set of symptoms within 72 hours of birth. It has many other names in the veterinary literature, including ‘neonatal maladjustment syndrome’, ‘ischaemic encephalopathy’, ‘perinatal asphyxia syndrome’ and ‘neonatal encephalopathy’.
Signs develop within 72 hours of birth and may include:
- Loss of awareness of environment.
- Loss of affinity for mare and failure to suck.
- Inability to stand.
- Blindness, struggling randomly and seizures.
Signs often last 1 day in cases which are treated early but may persist for up to 5 days in some cases.
Many different causes have been proposed. Some clinicians think that a lack of oxygen at birth due to premature placental separation or dystocia (difficult birth) causes a form of brain damage. However, recently American researchers at the University of California have proposed that some cases are due to a very rapid stage 2 labour and delivery of the foal. Their hypothesis is as follows:
- During gestation, the developing foetus is maintained in a partially-sedated state by chemicals in the uterine environment. Hence foals ‘do not gallop in the uterus’.
- The main signal that turns off these chemicals and therefore ‘wakes up’ the foal is a period of squeezing as the foal passes through the mare’s pelvic canal.
- If the foal is born is born too rapidly, the necessary squeezing does not occur and the chemicals are not completely turned off. The foal then reverts to ‘foetal cortical status’ and becomes a dummy foal.
The same researchers have developed the technique of ‘The Foal Squeeze’. This involves squeezing the thorax of the dummy foal with a specific rope technique for about 20 minutes. The foal lies down and appears heavily sedated; just as if he/she was back in the uterus. When the thoracic pressure is removed, the foal effectively ‘wakes up’ as if it has been reborn! This procedure has had excellent results in suitable cases. An interesting video of the technique is available to view on You Tube; google Madigan Foal Squeeze to find the link!
Don’t Ignore the Mare!
Finally, it is also important to pay attention to the mare. At a post-foaling check, your vet will examine the placenta to ensure it has all been expelled. The vulval region will be examined for tears/excessive haemorrhage etc. The udder will also be examined to confirm the foal has sucked and that the mare is not suffering from undue discomfort.
Take Home Message…….
In a nutshell, the main points to remember after foaling are:
- Observe the foal’s demeanor; he/she should be active and shadow the mare.
- Observe the foal drink; make sure he/she is properly latched onto the teat and not just nuzzling around the udder making drinking noises!
- Treat the umbilicus from as early as possible and continue treatment for 2 days.
- Ensure meconium is passed and watch for signs of unproductive straining.
- Call your vet to arrange a blood test to measure antibody levels and inspect both the mare and the foal.