Foals Flashcards
What do you need to be careful of when dosing foals
Dosages need to change as the foal grows ~1kg a day
Differences between neonates and adults dosing
Dynamic dosages
Increased oral bioavailability
Volume distribution (increased %water)
Decreased plasma proteins
Decreased metabolic and excretory activity
What should you assume in sick foals
Septic till proven otherwise
Treatment for foal sepsis
Antimicrobials
Hemodynamic support
Supportive care
Examples of low sepsis risk
Unobserved foaling/meconium impaction
Example of moderate sepsis risk
Umbilical infection
Example of high sepsis risk
Dystocia
Neonatal encephalopathy
Examples of septic foals
Neonatal encephalopathy+ septic joint
Enterocolitis
Treatment for low/medium sepsis risks
Oral TMPS (trimethoprim sulphadiazine) 30mg/kg BID
Treatment for high risk sepsis/septic foals (normal renal function)
IV sodium penicillin 22mg/kg every 6h
IV gentamicin 12mg/kg every 36h
Treatment for high risk sepsis/septic foals (abnormal renal function)
IV centiofur 5mg/kg every 12 h
What should you be careful of with oxytetracycline in foals
Kidney damage
Causes tendon laxity
What should be avoided in sedating a foal
Alpha 2 agonists - bradycardic
Should you use nsaids in foals?
Only if very necessary. Side effects much worse than in adults
What other therapeutics should be used in a hospitalized foal
Sucralfate +/- PPIs
What should be used for a dehydrated/hypovolemic foal
20ml/kg Hartmann’s (repeat up to 3x)
Treatment for mild obtundation/not nursing
250-500ml good quality colostrum via NGT
Treatment for FPT
Plasma 20ml/kg -/+ further 20-40 ml/kg based on IgG post transfusion
Transfuse SLOWLY watch for reactions
Best sedation for foals
Diazepam+/- butorphanol
Normal heart rate for a foal at birth
60-80
Normal heart rate for a foal at 1h
120-150
Normal heart rate for a foal 1-5 days old
80-100
Respiratory rate for foal at birth
60-80
Respiratory rate for a foal from 1hour old
~30
When should crackles not being present on lung auscultation
24 hours onwards
When is a patent ductus arteriosus normal in a foal
Under 96 hours
Normal temperature for a foal
Under 38.9°C
Normal timings for a foal
Sternal 5mins
Standing 1h
Suck reflex 30m-2h
Nursing 2h
Urinating 4h
Defecating 4h
What should you advise the owner to do with a newborn foal
Save placenta
Treat umbilicus within 4 hours (0.5% chlorhexidine or 2%iodine
Check nursing,urination and defecation
What should be checked at a newborn foal check
umbilicus (hernia/treatment)
Nursing (latching/milk return)
Palate (over/undershot jaw, cleft palate)
Anus (is there one/meconium)
Eyes (entropion/haemorrhage)
Chest (heart/lungs/ribs)
Limbs (flexural/angular deformities)
IgG if 24hours upwards
What actions/treatments can you support a newborn foal with
IgG test
Enema (more needed in colts)
Tetanus antitoxin
What care should be taken examining a foal
Wear clean gloves
Always restrain in vision of mard
Always put one arm around chest and one under belly
Where should you avoid giving IM injections in the foal
Neck - pain prevents nursing
What size needle should you use for IV in the foal
20G 1inch
What looks like a alien on ultrasound
Urachal remnant
(Eyes are left and right umbilical arteries)
How often should a foal feed
5-6 times an hour
How big is a foals stomach capacity
1l in 50kg
How much of bodyweight should be consumed per 24 hour period
20% (10l in 20kg)
Why should you use milk replacer at 3/4 strength
Decreased risk of constipation
Maternal risk factors for an obtunded foal
Dystocia
Concurrent illness
Gestation (short)
Bonding
Parity
Placental risk factors for an obtunded foal
Placentitis
Placental insufficiency
Foal factors for the obtunded foal
FPT
Sepsis
Encephalopathy
Omphalitis
Congenital defects
Trauma
Cut off values for IgG tests
> 800mg/dL normal
400-800mg/dL partial failure
<400mg/dL complete failure
Clinical signs of hypoglycemia in the foal
Obtunded
+/- seizures
What should the first urination be
Hypersthenuric >1.030
Within 8-10 hours in coly and 10-12 in filly it should be hyposthenuria <1.008
What is common to see on haematology
Leukopenia and neutropenia with increased band neutrophils
What does increased fibrinogen at birth show
In uterine infection/inflammation
At what temperature is a foal classified as having a fever
> 39.2
At what temperature is a foal classified as hypothermic
<37.2
Broad causes of obtundedness
Sepsis/SIRS
Neonatal encephalopathy
Prematurity/dysmaturity
Common name for neonatal encephalopathy
Neonatal maladjustment syndrome
What defines premature vs dysmature
Premature <320 days
Dysmature full term but acts premature
Characteristics of a premature foal
Small in size
Rounded forehead
Silly hair coat
Entropian
Floppy ears
Flexor/periarticular laxity
Carpal/fetlock contracture
Incomplete ossification of cuboidal bones
Prognosis of premature
Good with right care if born >300 days can catch up to peers
What is neonatal isoerythrolysis
Destruction of red blood cells due to pre-formed anti red blood cells antigens ingested in colostrum
How does neonatal isoerythrolysis occur
Mare becomes sensitized to an antigen (often via stallion from previous foals or blood transfusion)
Antibodies absorbed in the colostrum then attack the foals own blood cells
Clinical signs of neonatal isoerythrolysis
Pale MM
Weakness
Obtundation
Tachycardia
Tachypnea and or dyspnea
Seizures
Pigmenturia
Diagnosis of neonatal isoerythrolysis
History/clinical exam
-marked anaemia 10-20%
Declining PCV (good evidence)
Definite - agglutination/lytic tests
Treatment of neonatal isoerythrolysis
If under 24h withhold from nursing
Can deteriorate rapidly - refer/whole blood transfusion - must be from universal donor AaQq negative horse
Supportive care
What is classes as tachycardia (under and over 3 days)
Under 3 days - 115bpm
Over 3 days - 120
What classes as tachypnoea
> 56bpm
Normal venous blood lactate foal
<5 under 3 days
<2.5 over 3-14 days
Causes of meconium impaction
Enterocolitis
Dysmotility
SI strangulation
Congenital abnormalities
Intussusecption
Hernias
Gastric ulceration
Lactose intolerance
Signs of meconium impaction
No meconium
Colic
Tail flagging
Signs of enterocolitis
D+
Colic
Tail flagging
Sepsis
Signs of dysmotility
Colic
Tail flagging
Sepsis
Signs of SI strangulation
Colic
Sepsis
Signs of congenital abnormalities (gi/foal)
Colic
Lock of faeces
Signs of intussusecption
Colic
Refux
Sepsis
Signs of hernias
Colic
Nothing if not strangulating
Signs of gastric/duodenal ulceration
Colic
Reflux
Tail flagging
Signs of lactose intolerance
D+
Signs of uroabdomen
Tail flagging,
posturing
Stranguria
Dysuria
Signs of urinary congenital abnormalities
Dysuria
Stranguria
Urinary incontinence
Signs of Umbilical infection
Colic
tail flagging
Sepsis
First line of treatment for meconium impaction
Phosphate enema
(Max 2 in 24h)
What do you see in ultrasound of meconium impaction
Hypo/anechoic speckled appearance with intestine contracted around meconium
How is acetyl cysteine enema administered
Foal sedated in lateral with lifted hindend
Foley catheter inserted into rectum and gently cuffed
150-200ml 4% acetyl cysteine gravity flowed into rectum.
Clamp closed and catheter left in place for 45 mins
What are the 3 types of enema
Phosphate
Soapy water
Acetyl cysteine
Where does the bladder most commonly rupture
Dorsal wall
Diagnosis of uroabdomen
Ultrasound - free fluid in abdomen
Abdominocentesis
Increased serum creatinine
Hyperkalemia
Metabolic acidosis
Hyponatremia and hypochloremia
Treatment for uroabdomen
Refer for surgical repair
Clinical signs of uroabdomen
Depression
weakness
Hypovolemia
Stranguria/anuria
Bradycardia
Diagnosis of umbilical infection
Thickening/abcessation of umbilicus
Inflammatory markers increased
Treatment of umbilical infection
Broad spectrum antimicrobials
Surgery if poor response to medical
Risk factors for respiratory disease in the foal
Systemic sepsis
Congenital abnormalities
Meconium aspiration
Milk aspiration
Birth trauma
Causes of acute respiratory distress immediately following bitth
Extrapulmonary disorders causes obstruction
- bilateral choamal atresia
Stenosis of the nares
Severe laryngeal odema/collapse
DDSP
Sub epiglottic cysts
Severe pulmonary abnormalities
Congenital cardiac abnormalities
What is treatment for acute respiratory distress syndrome
Intranasal oxygen
Ventilation
Anti-inflammatories (corticosteroids)
Broad spectrum antimicrobials
What causes atelectasis
Failure of surfactant production
What can meconium aspiration lead to
Mechanical airway obstruction
Regional air trapping
Surfactant inactivation and displacement
Chemical pneumonitis and alveolitis
Persistent pulmonary hypertension
Treatment for meconium aspiration syndrome
Aspiration of material from nasal passages and pharynx
Nasal intubation with careful suction
Intranasal oxygenation
Anti inflammatories
Pentoxyfyllone (benefits against SIRS)
Treatment of secondary pneumonia
What can cause milk aspiration
Generalized weakness
Poor suckle
Dysphagia
Congenital abnormalities
Bottle feeding
How do you treat milk aspiration
Correct the cause
Nasoeosophageal feeding tube
Broad spectrum antimicrobials
How can you diagnose broken ribs in foals
Physical exam - crepitus and auscultation
Ultrasonography
Radiography
Clinical signs of EHV in foals
Typically fatal - similar to neonatal sepsis
Cardiovascular and respiratory insufficiency
Congested MM
Leukopenia, neutropenia and lymphopenia
Treatment of EHV in foals
Anti-virals
Supportive therapy
Parasitic pneumonia cause and treatment in foals
Parascaris
Fenbendazole or Pyrantel
When is bacterial pneumonia most common in foals
1-6 months
Most common cause of bacterial pneumonia in foals
E.coli
What do all isolates of rhodococcus capable of causes disease in foals have
Plasmid encoding Virulence associated protein (VapA)
Rhodococcus clinical disease
Insidious
Lower URT infection.
Fever
Lethargy
Coughing
Tachypnea
Dyspnoea
Extrapulmonary disorders
Treatment of rhodococcus infectiob
Oxygen
Nsaids
Keep cool
Antimicrobials - macrolide and rifampin
(Azithromycin and clarithromycin)
Prevent with hyperimmune plasma
What is congenital hyperextension
Flaccidity of flexor muscles after birth
Often resolve after a few weeks
Can need protective bandaging/corrective shoeing
What can occur with congenital hyperflexion
May cause dystocia
May prevent standing
How does oxytetracycline work for tendon contracture
Large dose within a few days of both
Prevents the traction of collagen fibrils making them more susceptible to elongation during weight bearing
When does the distal radius growth plate close
24 months
When does the distal metacarpal growth plate close
6-9 months
When does the proximal phalanx growth plate close
6-12 months
When does the distal tibial growth plate close
17-24 months
When does the distal metatarsal growth plate close
9-12 months
What is physitis
Inflammation of the physis/ growth complex
Clinical signs of physitis
Heat
Pain
Lameness
Swelling
Often around carpus/fetlock
What can trigger physitis
Sudden feed/feed energy increase
Abrupt increase in exercise
Direct trauma to physis
Yearling - at distal radius
Diagnosis/treatment of physitis
Diagnosis - radiographs and physical exam
Treatment - restrict exercise, pain relief, cause correction, potential sepsis
Salter Harris fractures
Occur at distal physis of MC/MTIII
Treated with cast coaptation <6 weeks or surgery feasible (not first line if extensive fund not available)
Classification of salter Harris fractures
S - straight across growth plate - type one
A - type 2 - above growth plate
L - type 3 - lower than growth plate
T - type 4 - through growth plate
Where is incomplete ossification likely to occur
Cuboidal bones of carpi and tarsi
When does ossification of cuboidal bones occur
Last 2-3 months of gestation
What foals are at risk for incomplete ossification
Premature and dysmature
What should you do if you suspect a foal is premature/dysmature
X-ray cuboidal bones
Definition of angular limb deformity
Deviation from the long axis of the limb in the frontal plane
Treatment for incomplete ossification of cuboidal bones
Box rest
What are the 2 types of angular limb deformity
Varus and valgus
What level of carpal valgus is tolerated
2-5°
Aetiologies of angular limb deformity
Incomplete ossification - dysmature, premature , Placentitis in gestation, mare colic/heavy parasite burden in gestation
Peri-articular laxity
Acquired or congenital
Evaluation of angular limb deformity
Radiography - compare limbs with orthogonal views, essential for premature or dysmature
Measure origin of deviation
Angular limb deformity conservative treatment
Box rest and controlled exercise (must have normal ossification
Box rest only with incomplete ossification
Trimming/rasping of foot
- valgus trim lateral wall
- varus trim medial wall
Hoof extensions
- valgus medial extension
- varus lateral extension
When should you leave angular limb deformity
When there is peri-articular laxity
What radiograph should you initially take of a foal with angular limb deformity
DP and lateral
Where should you colimate on angular limb deformity radiographs
Mid tibia-mid Tarsus for measurements
When is conservative treatment okay
When entire limb is facing one way
Surgical treatment of angular limb deformity
One joint in a different direction
When should you treat surgically for angular limb deformity
In the rapid growth period
What do you need to be careful of with screws of angular limb deformity
Monitor and remove appropriately
Correction will continue for a while after the screw is removed
