Nursing care in neonatal large animals requires a combined approach of the entire veterinary team. The survival rates of critically ill neonates can be dramatically improved with sophisticated diagnostic techniques and cutting edge therapeutics. However, one of the major factors for the successful outcome of the critically ill neonate is the diligent nursing care. Recognizing the early signs of deterioration allows a more rapid intervention and stabilization of the patient.
A physical examination of the large animal neonate begins with observation from a distance.1 Changes in the medical status of a critical neonate occur rapidly; therefore frequent and careful observations are important. Very subtle or vague signs may be overlooked; therefore an understanding of normal neonate behavior is essential. Most neonates are precocious and are very active soon after birth. The healthy neonate should be keenly aware of people and often return to their dam when approached (flight response). During the first week of life, the newborn foal will stay within a few feet of the dam due to the very close bond that was established shortly after birth. Foals that fail to follow the mare, wander away or appear depressed should be evaluated for an underlying problem.
Normal foal activity centers on periods of eating, sleeping and playing. Normal newborn foals will nurse every 30 minutes at a minimum, therefore a foal that remains recumbent for extended periods of time and fails to rise and nurse should raise suspicion of a problem. Additionally, foals may spend time nosing, bunting and mouthing the udder without actually nursing. Closer observation may be necessary to confirm that actual milk consumption is occurring. Palpation of the mare's udder for engorgement is useful to ensure that the foal is nursing appropriately. Foals that do not nurse when under the mare's udder may have milk staining on the nose and face as it streams from the teats. Conversely, if the mare is not producing enough milk and the foal is not receiving adequate nutrition, the foal may display repeatedly attempt to nurse and display agitation or frustration. Foals that demonstrate milk regurgitation from the nose after nursing may have dysphagia or esophageal dysfunction. This may suggest an upper respiratory problem such as a cleft palate.
Normal foals will spend periods of time frolicking and playing after eating. Lethargy, lack of response to external stimuli and overall decreased activity are subtle observations that should be investigated further. Neonatal foals that are lame or reluctant to rise should immediately be evaluated for musculoskeletal problem such as septic arthritis and / or osteomyelitis. As a general rule, foals will urinate shortly after nursing; therefore this is a good opportunity to observe the location of the urine stream. A patent urachus is diagnosed by observing urine streaming from the umbilicus rather than the genital structures. Neonatal meconium is dark brown and either pasty or firm little fecal balls; whereas milk feces are yellow and pasty. Defecation, in contrast to urination, is observed infrequently; therefore foals that develop frequent and /or liquid feces may be developing enterocolitis. Bruxism, rolling or thrashing, assuming dorsal recumbency, straining with frequent posturing and tail flagging are quite obvious signs of discomfort in foals. However more subtle signs that can often be missed include increased time in recumbency, frequent adjustment of recumbent position, twisting of the head and neck and stretching. Abdominal distension may also be observed in foals that are developing gastrointestinal disease or a ruptured urinary bladder.
Observation of respiratory effort should be done prior to entering the stall. With handling and excitement, the respiratory pattern can change. A respiratory rate can be taken at a distance since tachypnea may also develop with handling and the stress of capture. Increased respiratory effort may be observed when the rib cage moves with excessive motion or the abdominal cavity contributes to the respiratory movements. In many cases, respiratory effort may appear worse when the foals are recumbent for prolonged periods of time. Foals with respiratory muscle fatigue may have an asynchronous motion of the thorax and abdominal cavity.
Neurologic examination in neonatal foals may be challenging, because of the neurologic immaturity of foals. The gait may appear awkward in a normal neonate since coordination is developed with time and exercise. The normal stance may be rather base-wide and they may also respond to external stimuli with exaggerated movements, such as head and neck jerking and hypermetria. However more concerning signs of neurologic disease can include blindness, facial paralysis, strabismus, poor tongue tone, loss of suckle, nystagmus, head tilt, head pressing, propulsive circling, proprioceptive deficits, intention tremors, seizures, and coma. Again, one of the first subtle neurologic signs that may be observed is loss of interest in the mare, inability to find the udder and loss of suckle reflex.
After having observed the foal at a distance, the physical examination can be completed. Some mares are very cooperative and trusting of people, and will not resent handling of the foal. Other mares are very protective and may become distressed when the foal is retrained. In these situations, personnel should restrain the mare and ensure that she has visual contact with the foals so that the examination can continue. After the foal is caught, the handler should carefully restrain the foal with one arm around the front of the chest and the other around the hindquarters or grasp the base of the tail. Foals may become cataplectic or collapse with excessive restrain, therefore light control is preferable. Grasping the foal around the rib cage or abdomen should be avoided, since incorrect handling may result in rib fractures or worse.
The normal rectal temperature in the neonatal foal ranges from 99°F to 102°F (37°C to 39°C). The normal heart rate is 60 to 80 beats/minute at birth, increasing up to 150 beats/ minute within the first hour, then stabilizing at 80 to 100 beats /minute. A heart rate of up to 130 beats / min or higher can be recorded with exertion or excitement, but should return to normal range after a few minutes. Peripheral pulses can be palpated at the facial artery (located beneath the ramus of the mandible), the brachial artery (located at the medial aspect of the elbow), the great metatarsal artery (found on the lateral aspect of the third metatarsal bone) and coccygeal artery (at the base of the tail). The distal limbs should feel warm to the touch. Cold limbs can indicate poor peripheral perfusion due to septic shock as blood is directed away from the extremities to other important tissues. Cardiac auscultation of the newborn foal usually reveals a loud machinery or holosystolic murmur at the left heart base that should abate within the first 72 hours of life. This murmur is suspected to originate from a patent ductus arteriosus or from physiologic causes, respectively. These murmurs can, on rare occasion, persist up to 60 days after parturition. Bilaterally audible murmurs are most often pathologic and require closer examination. Peripheral perfusion can be assessed by examining mucous membranes of the mouth, nares, eyes and vulva. Mucous membranes should be pale pink and moist with a capillary refill time of 1 to 2 seconds. Mucous membrane with petechiation, hyperemia, icterus and cyanosis are abnormal It is important to know that membrane color does not provide an adequate assessment for peripheral oxygenation in the foal. Adequate oxygenation can only be assessed by means of an arterial blood gas analysis. . The sclera and inner pinnae should also be closely examined for petechiation and ecchymoses. On white hooves, hyperemic coronary bands (coronitis) may be present with septicemia. The respiratory rate after birth ranges from 40-60 breaths/min, but will decrease to 30-40 breaths/min within the first 24 hours. The auscultable lung boundaries extend from the 17th intercostals space at the tuber coxae to the area above the tube coxae. A thorough complete auscultation of the lung fields should always be performed. The lung sounds of a foal are normally harsh; therefore it can be difficult to identify lung pathology. An increased respiratory rate associated with exacerbated harsh lung sounds may be present with many other systemic diseases that do not specifically affect the lungs. Particular attention needs to be addressed to abnormal sounds including crackles and wheezes, which always indicate lung pathology. A careful palpation of the chest should be included in the examination to identify possible rib fractures. Auscultation of the neonatal abdomen should be done bilaterally in four quadrants: both the flanks and the ventral abdomen. Normally, borborygmi can be heard every 10 seconds or so. Intestinal sounds can be categorized as normal, increased, decreased or absent. Abdominal "pings" (high-pitched tympanic sounds) or 'watery" sounds should be considered abnormal. Hydration status is a subjective evaluation, but can be assessed by estimating skin turgor, mucous membrane texture, and corneal quality. Skin turgor can be difficult to interpret when tented on the neck; therefore evaluating skin tent on the upper eyelid may be more reproducible. Prolonged skin tent, mucous membrane dryness, corneal dryness and sunken eyes are indicators of advanced dehydration. Subtle dehydration may be difficult to determine. To complicate matters, critically ill foals may have normal hydration but the fluid can be suffering from hypoperfusion and hypovolemia.2 Diagnostic tests such as blood pressure measurement and bloodwork can also be useful in establishing the cardiovascular status.
The musculoskeletal system should be examined by careful palpation of all the joints and growth plates (physis) of the limbs. Joint effusion may be easier to detect on the carpi, fetlocks, tarsi and stifles. Detection of effusion in the hip, shoulder and elbow may be more challenging; however, by simultaneously palpating both sides, differences may be detected. The examiner should also evaluate the tendons for evidence of tendon laxity or contracture. Foals with severe contracture or laxity may have difficulty standing without assistance. The skin should be carefully examined daily especially in the recumbent foal. Decubital ulcers or pressure sores can occur over bony prominences such as the elbows, hocks, stifles and hips. Foals with septicemia may have linear dermal necrosis in the crevices of the hocks. A body condition score should be assigned as part of the examination and may be a useful tool to assess the adequacy of the foal nutrition. Henneke established a body condition score system, using a scale of 1 (emaciation) to 5 (normal).3
The urogenital system also requires intense examination. As mentioned previously, the neonatal foal urinates fairly frequently. Although indwelling urinary catheters are necessary to accurately determine urine output, a subjective assessment may be made by close observation. The umbilical remnant should be palpated daily and inspected for signs of infection, increase in size, and moistness which is suggestive of patency. Because the predominant part of the umbilical structures lies within the abdomen, ultrasonographic examination is required to perform a thorough examination. Examination of the urogenital system also includes palpation of the umbilical, inguinal and scrotal areas for hernias and distention. Progressive abdominal distention and depression of the equine neonate may indicate patency of the urinary tract within the abdomen (e.g., rupture of the urinary bladder or a rent in the urachus).
The ophthalmologic exam represents an integral part of the physical examination. Foals normally don't have a menace reflex during the first two weeks of life. The pupillary light reflex may be considerably slower if the foal is excited. The presence of an entropion or an ectropion should be noted during the exam because they may provide information about the patient's hydration status and maturity. The eyes must also be thoroughly examined for corneal abrasions and ulcers. Other conditions that occur in foals include uveitis, hyphema (blood in the anterior chamber), hypopyon (purulent exudate in the anterior chamber), and congenital cataracts.
Managing the Recumbent Foal
Foals may be recumbent from various conditions such as septicemia, neonatal encephalopathy, prematurity, dysmaturity or noninfectious musculoskeletal disorders. Careful attention must be paid to sanitation when caring for critical neonatal foals. Stalls should be cleaned frequently to remove urine and fecal contaminated bedding. Before handling the critical foal, hands should be washed or latex gloves should be worn. Strict aseptic techniques should be used when handling IV catheter ports to administer injections or replace fluid bags. Strict protocols for cleanliness should be adhered to when handling indwelling feeding tubes as well.
Nursing care for the recumbent neonatal foals produces multiple challenges. Some recumbent foals struggle repeatedly and require constant attention to prevent self-trauma and to avoid tangling the IV fluid and oxygen lines. To protect the foal from self-trauma, the foal should be kept on a padded foal bed. These can be obtained commercially or made by placing a water-proof barrier over an infant mattress. One of the main advantages of the commercial made padding is that it can easily be disinfected between uses. A thick layer of blankets or fleece is placed on top of the pad to provide warmth and reduce friction. If padding is not available, then an 8-10 inch thick layer of straw is an option. It is important to keep the recumbent foal sterna as often as possible. This helps to prevent lung atelectasis and improves oxygenation, which is especially important in foals with pneumonia. Foals can be maintained in sterna recumbency with the assistance of multiple pillows, wedge pads and rolled towels. A specially designed V-shaped pad is commercially available to help keep the foal upright. Additional padding of the eyes may be necessary since recumbent foals are prone to ophthalmic problems such as entropion which can lead to corneal ulceration. Soft helmets can be placed to provide protection. Alternately, eye protection can be provided by making soft "eye-donuts" with brown gauze rolls shaped into a circle using white tape. These "eye donuts" seem to be more tolerated than the soft helmet by some foals. A soft padded bra (wireless) can also be applied to the head to provide protection of the eyes, especially in foals with corneal ulceration. Dehydrated foals may have a poor tear film, and foals with septicemia may have incomplete eyelid closure and develop exposure keratitis. To protect the eyes, a long acting eye lubricant can be applied to the eyes. Ultimately, however, to prevent self trauma a full time foal-sitter may be necessary.
Many critical foals have difficulty with thermoregulation. It is important to provide external warmth to prevent and treat hypothermia. Again, the use of a multiple layers of blankets will help insulate and retain body heat. A forced hot air blanket (Bair Hugger), is a safe way to provide external warming. The inflated blanket is placed on top of the foal, then a towel or light blanket is placed on top. Heat lamps provide concentrated warmth to the general area, and are helpful in un-heated facilities. However care should be taken to avoid touching the lamp since they can cause burns. The foal's legs have a large surface area that can allow heat loss. Applying soft leg wraps (not tight) may help to warm the hypothermic foal. Makeshift hot water bottles can be made by filling latex gloves with tepid (not hot) water and tying off the cuff. These can be place along the trunk of the foal to help provide warmth. Electric blankets and heating pads should be avoided since they may overheat and cause thermal burns.
It is important to keep the foal as dry as possible. Urine, exudates and other fluids could harm the skin and may prevent effective warming of the foal. Absorbent padding ("wee-wee" pads), diapers and towels placed under the genitalia will help to soak up urine and feces. These should be checked and changed very frequently. In some circumstances, the veterinarian will place an indwelling catheter and a closed collection system. These are useful to record urine output. Feces (especially diarrhea) and urine can cause dermatitis and scalding. Keeping the foal clean helps prevent these unwanted complications. The area should be washed using a soft material, such as sheet cotton, and gentle soap. The area should be thoroughly dried and a light coating of protective emollient such as petroleum jelly or vitamin A&D ointment should be applied to the perineum. In some cases, a moisture barrier such as a diaper rash preparation containing zinc oxide and balsam may be chosen.
Frequent turning the recumbent foal is important to allow aeration of both lung field and to help prevent bed sores on the down side. Turning should be done every 2 hours. With large foals, this task can require two people. To turn the foal safely, tuck the legs under the foal's body. One person should gently cradle the shoulders/head, while the other cradles the hindquarters. The foal is then moved upright and over to the other side. The foal should not be flipped onto his back.
Nursing care of the critical neonate begins with a thorough physical examination, which is repeated often to re-assess the status of the patient. Managing the recumbent patient can be labor intensive and costly, however the vigilant nursing care can dramatically affect the outcome of these critically ill neonates.
1. Hoskins JD, Bolt DM, Chapman A. Neonatal care of puppy, kitten and foal. In: Clinical textbook for veterinary technicians. 6th edition. DM McCurnin and JM Bassert (eds). Elsevier Saunders, 2006.
2. Palmer JE. Recognition and resuscitation of the critically ill foal. In: Equine neonatal medicine: a case-based approach. RM Pardis (ed). Elsevier Saunders, Philadelphia, PA, 2006.
3. Henneke DR. A condition score pyslen for horses. Equine Pract 7:13-15, 1985.