Neonatal Maladjustment Syndrome

Description

Neonatal Maladjustment Syndrome is also known as convulsive foal syndrome, dummy foal syndrome, barker or wanderer foal. The descriptive name of the condition is based on the actions and responses of the foal.

Some researchers and veterinarians prefer to call the condition Perinatal Asphyxia Syndrome, while others separate the condition into at least two categories, the neurological signs and the dysfunction of multiple organ systems, under such names as Hypoxic Ischemic Encephalopathy (HIE) for the neurologic component, and Perinatal Hypoxic-Ischemic Disease for the multiorgan component.    

Extensive research has found that the conditions in a foal afflicted with behavioral abnormalities, the accompanying neurologic signs and the effects on organs make this syndrome much more complex than originally thought.

Symptoms

• Loss of sucking reflex
• Seizures or convulsions
• Emitting of strange, unusual whinnies or barking sounds 
• Lack of coordination
• Weakness
• Respiratory distress
• Circulatory stress
• Recumbency
• Coma
• Signs of blindness
• Erratic movements and behavior

Typically, a foal appears normal after an uncomplicated delivery, but within a short time loses its sucking reflex and begins to exhibit abnormal behavior. Seizures, with jerking movements of the head and body, spasms of the neck, limbs, tail and thrashing of legs are common.

Convulsions are accompanied by obvious respiratory distress, and the foal often makes strange sounds, sometimes sounding like a barking dog.

Afflicted foals may lack the ability to make coordinated movements and may not be able to turn over or stand unaided.

In many cases, the foal becomes inert and recumbent, does not respond to stimuli, may appear blind and loses affinity for its dam. This is often referred to as the "dummy stage."

Later, the foal may become very active, wander aimlessly, bump into objects and may endanger itself if not properly contained.

Essentially, the foal's behavior is abnormal and is often accompanied by dysfunction of multiple organ systems. As a result of convulsions, the foal may develop brain swelling and thermoregulatory, respiratory and circulatory failure. This leads to death in about half of the cases.

Foals that survive the convulsive phase have a favorable prognosis. Reflexes, including the sucking reflex, return gradually over a two- to three-day period. If the foal doesn't develop septicemia, and is able to stand and suckle within four days of birth, the prognosis is very favorable, provided no residual neurological deficit exists.

Causes

The syndrome is believed to be caused by central nervous system asphyxia (lack of oxygen) before, during or after delivery. Mares with placental infections, hydrops, or those that have a red bag delivery, where the placenta separates from the uterus, sometimes produce foals with the abnormalities of this syndrome. Premature foals are also susceptible.

Prevention

The best prevention is careful selection of mares for breeding and making sure that the mare is well cared for during pregnancy and parturition. This includes careful attention to nutrition, exercise and general health.

Treatment

First, and foremost, any newborn foal should be carefully observed for several days after birth for any signs of unusual behavioral traits or physical abnormalities.

If a foal shows any signs of seizures, it is important that a veterinarian assess the situation since control of seizures is important for both the neurological and physical health of the foal. Sometimes, turning the foal onto its sternum or helping the foal to stand is helpful.

Diazepam, Valium or an anti-epileptic drug may be given by intravenous injection for emergency control of seizures, but if continuing seizures occur, phenobarbital may be prescribed and used repeatedly until seizures are controlled. If phenobarbital doesn't work, phenytoin is sometimes prescribed.

Nasal oxygen can be of value and DMSO may be given to reduce brain swelling.

During seizures, it is important to protect the foal from injury by cushioning the area and making sure that it can't harm itself by knocking into hard, stationary objects. A clean, well-padded surface for the foal to lie on should be provided and all hay and straw should be removed.

During cool weather, prevent hypothermia by covering the foal with a warm blanket and raising the temperature in the stall or area where the foal is kept.

Foals that are not able to suckle should be given two quarts of mare's colostrum by nasopharyngeal catheter within 18 hours of birth.

Nutrition and water balance should be maintained by feeding the mare's milk or a warm milk replacer via nasopharyngeal catheter every hour at the rate of 20 percent of body weight per day, or as prescribed by a veterinarian.

The mare should be milked to obtain milk and to prevent her from drying up.

Since gastric ulcers are common in convulsive foals, preventative anti-ulcer treatment is usually prescribed.

Once the foal begins recovery, it will need training as it learns to walk, nurse and follow its mother.