Smith 3 - Neonate / Foals Flashcards
What regulates contractile properties of the uterine myometrium?
estrogens
When does equine fetal HR peak?
3 months gestation, 196bpm
What is the fetal response to hypoxia?
bradycardia and decreased movement
CTUP
combined thickness of utero-placental unit
should be 8-15mm
Most common cause of placentitis in the horse?
ascending infection via a relaxing cervix
strep zoo, e coli, enterobacter, kleb, pseudomonas
CS of placentitis
vaginal discharge, premature udder development, precocious lactation
fever NOT common
Tx of placentitis
Kpen/gent or TMS or ceftiofur pentoxy flunixin altrenogest DMSO
Foal CPR
breaths - 10/min
compressions - 100-120/min
epi - .5-1ml (1mg/mL)
PAS / HIE / NE effects
most affected = nervous
second most = renal
Necrotizing Enterocolitis
intestinal coagulative necrosis, bacterial overgrowth, pneumatosis intestinalis, marked inflammatory response
birth hypoxia + clostridial infection?
Foal ADG
1.5kg/day
Foal incisor eruption
6d / 6wks / 6mos
PDA
continuous machinery murmur with a point of max intensity over the L heart base, 3rd ICS
- systolic component often remains as it starts to close
- disappear by day 3-4
BRIX
1) 0-15%, 0-28gm/L IgG = POOR
2) 15-20%, 28-50gm/L = borderline
3) 20-30%, 50-80 = adequate
4) >30%, >80 = V GOOD
Replacement K (mEq)
0.4 X BW kg x K deficit in mEq
Bicarb deficit (mEq)
0.6 X BW kg X Base deficit (mEq)
Drug effects in neonates
- better absorption from GI
- less plasma protein binding
- increased distribution in ECF
- increased BBB permeability
- longer half life / slow elimination
Foal E requirement
125-150 kcal/kg/day
Sepsis due to ascending infection
Foals have accelerated maturity, so they are more likely to be septic but also to survive
S type osteomyelitis
synovial
bacterial infection of the synovial membrane with no radiographic changes
- joint effusion and ST swelling
- first 2 weeks of life
- carpus, stifle, hock
E type osteomyelitis
epiphyseal
infection extends to subchondral bone
- 3-4 weeks of age
- femoral condyles, distal radius, distal tibia, or patella
P type osteomyelitis
physeal
physis on the metaphyseal side of the growth plate
- 1-12 weeks of age
- distal radius/tibia, distal metacarpi/tarsi
T type osteomelitis
tarsal - cuboidal bones of tarsus or carpus
Common joint pathogens in foals
e coli, salmonella, actinobacillus, klebsiella, strep, rhodococcus
Causes of seizures in foals
NE
bacterial meningitis, viral encephalitis, …
Incidence of NE
1-2% of all births
HI Insult: Primary Phase
increased extracellular glutamate, membrane depolarization, increased intracellular calcium, intracellular sodium influx
HIE Insult: Secondary Phase
acute inflammation, excitotoxicity, increased intracellular calcium, increased reactive oxygen and nitrogen species
Hypoxia and glutamate
impairs normal function of astroglial glutamate transporters in the synaptic cleft –> accumulation instead of reuptake –> opening of ion channels, excess calcium influx = excitotixicity, apoptosis and necrosis
Why is the neonatal brain prone to oxidative injury
high concentrations of unsaturated fatty acids
high rate of oxygen consumption
low concentration of antioxidants
Tx for bacterial meningitis in foals
3rd gen cephalosporins - cefotaxime, ceftriaxone
excellent CNS penetration
Benign Juvenile Epilepsy
arabian foals
- 2d-6mos
- seizures, obtundation and transient blindness
- normal between episodes
- cessation by 12 months
Kernicterus
NI complication where bilirubin-IXa is deposited in the brain.
CS: icteric MMs, seizures difficult to control, altered mentation
dysmaturity
there has been intrauterine growth retardation
-low birth weight
prematurity
gestational period shorter than usual
-low weight, small body size, short shiny hair coat, rounded head, droopy ears, laxity
fescue toxicity
neotyphodium coenophialum
prolonged gestation, perinatal mortality, agalactia
11B-hydroxysteroid dehydrogenase
converts excess biologically active cortisol into inactive cortisone in the placenta to reduce exposure to the fetus
Bloodwork with HPA axis maturity
normal or elevated neutrophil count, N:L ratio, or WBCC = positive indicators of survival
– neutropenia ddx sepsis
Inadequate HPA axis maturation: CS
after 12-18 hours, onset of weakness, depression, seizures, resp failure, feed intolerance, cardiovascular collapse, lactate elevation, mixed metabolic and respiratory acidosis
Low dose dopamine
.5-5ug/kg/min
agonises dopaminergic receptors
renotubular effects, vasodilation of coronary and intestinal vasculature
Moderate dose dopamine
4-10ug/kg/min
stimulate B1-adrenergic receptors, chronotropy
High dose dopamine
> 10ug/kg/min
agonism of a1-adrenergic receptors, widespread vasoconstriction
Dobutamine
3-20ug/kg/min
acts on B1 adrenoceptors to improve myocardial contractility without vasoconstriction
ABG site in foals
dorsal metatarsal artery
Causes of laryngeal paralysis in foals
nutritional myodegeneration, HYPP, botulism
Tracheal Collapse
miniatures - develop signs as adults
honking cough, stridor, dyspnea with mild exercise
dynamic DV collapse during inspiration
Ideal TX for bacterial pneumonia
3rd gen cephalosporins have superior lung penetration, minimum 1 month tx
Neonatal EHV-1 pneumonia
fatal
leukopenia, myeloid cell depletion on BM, dilated retinal vessels, red discolored optic disc
Histoplasma capsulatum
in utero placentitis, abortion, or birth of infected foal
multiple organ disease including granulomatous pneumonia
dx: yeasts on airway cytology
Common bacterial diarrhea in foals
C perf type C C perf type A C diff bacteriodes fragilis r equi salmonella NOT E COLI
classical intestinal clostridosis of foals
C perf type C - produces a and b toxins, and enterotoxin
colic, rapid dehydration, cardiovascular collapse, hemorrhagic diarrhea
<10 days old - often <36hrs
high mortality
c. perf type A
produces alpha toxin and enterotoxin
lower mortality, better response to tx
c diff
Toxin A = enterotoxin
Toxin B = cytotoxin
clostridial enterocolitis tx
metro + penicillin IV crystalloids plasma biosponge lactase enzymes
Most common cause of infectious diarrhea in foals
rotavirus
Group A serotype G3
Rotavirus mechansims
- replicates in intesine, invades lining, causes cell death
- loss of absorptive capacity
- decreased lactase production
- crypt cell proliferation = increased secretion
- enterotoxin
- cytotoxin NSP4, a noncompetitive inhibitor of Na-glucose symporter, enhances intestinal chloride secretion
meconium impactions
occur in the distal segments (SC or rectum), lead to colonic gas distention
most common cause of newborn colic
meconium impaction
uroperitoneum causes
congenital - failure of the dorsal bladder wall to close
acquired - ruptured bladder
labs in uroperitoneum
elevated CK and BUN hyperK hypoNa hypoCl metabolic acidosis
