The obtunded foal Flashcards
What is the difference between obtunded and stuporous foals?
Obtunded - Responsive to tactile, visual and auditory stimuli
Stuporous - Only responsive to painful stimulus
What are signs of an obtunded foal?
- Lack of Suck
- Increased Recumbency
- Obtundedness
What can cause a foal to become obtunded?
- Sepsis/SIRS
- Enteritis
- Pneumonia
- Uroabdomen
- Neonatal Encephalopathy (Maladjustment)
- Prematurity/dysmaturity
- Neonatal Isoerythrolysis
- Trauma
- Musculoskeletal issues
What are maternal, placental and foal risk factors for obtundedness in the foal?
Maternal
* Dystocia
* Concurrent illness in dam
* Gestation (Prematurity)
* Bonding
* Parity
Placental
* Placentitis
* Placental insufficiency
Foal
* Failure of passive transfer
* Sepsis
* Encephalopathy (Maladjustment syndrome)
* Omphalitis
* Congenital defects
* Trauma
When would you test for passive transfer of antibodies in the foal?
At 24 h and if the foal has nursed
Why would you test glucose levels in foals? What are clinical signs of hypoglycaemia?
- Hypoglycaemia common in sick neonates
- Some degree in normal foals in first 1-2h
- Profound hypoglycaemia in sick neonates that have not nursed
- Can quickly deteriorate
- Premature and dysmature foals are more prone
Clinical signs of hypoglycaemia
* Obtunded
* +/- Seizures
What do you need to remember when measuring lactate in the foal? Why would you measure it?
Remember normal neonates have mildly increased lactate in the first 24h (sometimes for up to 3 days)
* Clearance perhaps more important?
* Increases despite fluid therapy associated with non survival
Increases suggest severe disease process
What is normal neonate USG?
Normal neonate with normal renal function is hyposthenturic!!
i.e. <1.008
BUT
First urination should be concentrated (hypersthenuric, >1.030)
Colt: 8-10h
Filly: 10-12h
Why would you do haematology and biochem in the foal?
White Blood Cell Count (Neutrophils)
* Common to see a Leukopenia and neutropenia
* Increased band neutrophils
* Sepsis
* Sometimes leucocytosis
Biochemistry
* Don’t forget creatinine clearance
* Moderate increase in creatinine can be normal up to 36h
* Organ function
What inflammatory markers can you test for in the foal? What do they indicate?
Serum Amyloid A
- Acute inflammation (<12h)
Fibrinogen
* Inflammation 2-5 days ago
* Great for in utero infection/inflammation
What are the systemic inflammatory response syndrome criteria in the foal? How are they interpreted?
At least 3 abnormal parameters including abnormal temp or leukocyte count
What additional tests would be run for obtunded foals in referral centres?
- Arterial blood gas
- Blood Culture
- Glucose support +/- Total parenteral nutrition
What is neonatal encephalopaty also known as? What is it? How is it managed?
- Neonatal maladjustment Syndrome
- Broad term - Neonate with neurological signs
- Many have concurrent diseases
- Don’t forget sepsis
- Intensive care
- Others need a helping hand
- Colostrum via NGT
- Feeding tube placement
- Antimicrobials
When is a foal considered premature? How is that different to dysmature? What are the characteristics?
- Premature <320 days
- Dysmature full term but characteristics of premature
Important characteristics (all don’t have to be present)
* Small body size (low birth weight)
* Rounded forehead
* Silky hair coat
* Entropian
* Floppy ears
- Flexor and periarticular laxity
- Carpal and or fetlock contracture
- Incomplete ossification of cuboidal bones in carpus and tarsus
- crush injury when standing
Other characteristics
* Generalised weakness and difficulty standing
* Abnormal glucose metabolism
* Impaired thermoregulation
* Respiratory dysfunction (surfactant)
* Endocrine dysfunction
* Insulin insensitivity
* + other dysfunctions
* Most need intervention and supportive care to survive!
What is the prognosis of prematurity and dysmaturity?
- Can be good with appropriate care!
- Can catch up to age matched peers
- Born <300 days have a worse prognosis
- Don’t tend to catch up
- Cost of supportive care ££££
- complications
- Crush injury (athlete? QOL?)
- Sepsis
- complications
What is neonatal isoerythrolysis? What are the conditions in which it occurs?
- Foals red blood cells are destroyed
- Preformed maternal anti-red blood cell antibodies ingested in the colostrum
- Multiparous mares
- (can have maiden mare with previous blood product administration)
Pathophysiology
* Mare needs to be negative for the antigen (most commonly Aa -ve and Qa -ve)
* Mare must become sensitised to and produce antibodies against the offending antigen. E.g.
* Previous foals
* Previous blood product administration (e.g transfusion)
* The foal must have inherited from the sire the antigen to which the mare has been sensitised
* If these conditions are met, most likely antibody’s will be produced and passed in colostrum –> loss of RBCs
What is the clinical presentation of a NI foal? How is it diagnosed? How is it treated? How can it be prevented?
Presentation
* Initially pale mucous membranes
* Develop icterus
* Weakness
* Obtundation
* Tachycardia
* Tachypnoea and or dyspnoea
* Seizures
* Pigmenturia
Diagnosis
- History + clinical exam
* Declining PCV 10-20%
* Definitive diagnosis
* Agglutination or lytic tests
* Majority of the times not needed
Treatment
* Depends on severity and age
* Can deteriorate rapidly (declining PCV)
* Refer?
* Whole blood transfusion required
* Minimise stress
* If <24h old
* Withhold from nursing (antibodies!)
* IgG from another mares colostrum or plasma
* Supportive care
Prevention
* Do not use that mare and sire combination again
* If you do, withhold colostrum completely (24h)
* Other IgG sources
Where can we get blood for a blood transfusion in a NI foal?
- The Mare
- Washed RBCs would be suitable but time consuming
- The Stallion - NO!
- A Blood Donor Horse - Yes
- AaQa negative ‘Universal Donor’
