Plus-Hex CLINICAL
Point-of-care laboratory analysis
Foals are born with low glycogen stores , resulting in blood glucose levels falling just a couple of hours after birth . Following the ingestion of colostrum , they must have frequent milk feeds to keep glucose levels adequate for energy metabolism .
Blood glucose tests are frequently carried out on newborn foals . There are a number of handheld point-of-care laboratory analysers available , such as the Accutrend Plus system ( Roche Diagnostics ), which give instantaneous results without the carer needing to leave the foal unit ( Figure 6 ). Normal glucose levels should be maintained within the range 5 – 10 mmol / l , with intervention required if levels consistently fall below 4 mmol / l . Glucose levels will stay relatively elevated in foals receiving total parenteral nutrition ( TPN ). should be used in isolation ; if one or more results raise a concern , a complete haematology and biochemistry analysis may have to follow .
Critical care monitoring
The frequency of monitoring is dictated by the medical state of the neonate . The condition of a neonate can deteriorate more quickly than that of an adult horse . Therefore , a recumbent foal receiving parenteral support and oxygen therapy should be monitored at least every 2 hours , due to the potential for the parameters to rapidly change from their normal ranges ( Table 2 ).
Table 1 . Normal ranges for vital signs in equine neonates [ 3 ] .
Parameter
Normal range
Body temperature
Heart rate ( beats per minute )
Respiration rate ( breaths per minute )
Mucous membrane colour Capillary refill time
Indirect mean arterial blood pressure
37 – 39 ° C 90 – 120
20 – 40
moist and pale pink < 2 seconds > 60 mmHg
Critical care monitoring must be systematic and thorough , and should cover all body systems , as outlined in the following sections .
Mentation
Note mentation without human interference , preferably before entering the stable , and observe the foal ' s behaviour – does it react to people in the room , is it easily awakened when stimulated and is it exhibiting any neurological signs ? Try not to stress the foal for the remainder of the examination , but be aware of any adverse changes that may arise .
Figure 6 . Point-of-care analyser for measuring glucose , lactate and triglycerides .
Plasma lactate concentrations are now being assessed more widely in sick neonates , with raised levels indicating a severity of disease that needs urgent treatment . Hyperlactataemia has also proved to be a reliable prognostic indicator . Manual packed cell volume and total plasma protein tests are useful and inexpensive to run , with abnormal results relating to hydration status and anaemia . No blood test result
Respiration
Assess the foal ' s resting respiratory rate before entering the stable . Observe any changes in the rate and effort over a few minutes . Approximately 12 hours after birth , the respiratory rate of a healthy foal will decrease to 20 – 40 breaths per minute . With a stethoscope , auscultate bilaterally in the dorsal and ventral regions for abnormal sounds and note whether they are accompanied by laboured breathing . Neonates will have louder lung sounds than those of adults , due to their thinner chest wall .
Volume 39 ( 2 ) • April 2024
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