Neonates Flashcards
what type of placentation do bovine have? small ruminants?
cotyledonary, epitheliochorial (synepitheliochorial)
are Ig’s transferred across the placenta?
no
what are some of the stressful things that occur from a fetus/neonate point of view?
decreased O2 physical - squeezed thru the birth canal temperature - cold outside!! sounds light
How do neonates adapt to stress/new life on earth?
epinephrine and cortisol increase
How do you explain neonates that “were doing really well” for the first little while, and then “all of a sudden crashed”?
the increases in cortisol and epinephrine can mask problems that the animal was having while in-utero
which body systems of the neonate need to change and begin functioning right away after birth?
cardiovascular, respiratory (immediately), acid-base balance, energy metabolism, temperature regulation
describe the changes that occur in the circulatory system of the neonate
Separation of the umbilicus -> anoxia -> (also compression of the chest helps to expel fluids out of the lungs) reflex gasping -> lungs are aerated -> surfactant keeps them open (surface tension)
Pulmonary vascular resistance is DECREASED -> allows for increased alveolar ventilation -> more blood flow to lungs
Increased venous return to LA (from lungs) -> increased pressure in LA -> reversal of the R-L shunt of the FO, FO closes
chemoreceptors on aorta sense increased O2, stimulate closure of the DA
what are the three physiologic things that help initiate respiration in the neonate? (besides physical compression)
Loss of immersion reflex (the immersion reflex inhibits breathing in the womb)
Breathing centers are stimulated by cold, light, touch, limb movement.
O2, CO2, pH receptors maximally stimulated.
a fetus may be [HYPER/HYPO] active if it becomes hypoxic inutero
hyper!
obviously hypo if deadmeat
what are some ways you can stimulate breathing?
remove fetal membranes
clear fluids from resp tract
stimulate those breathing centers!! (massage, move legs, poke their nasal philtrum)
if necessary, ventilator
Keep them in sternal recumbency and bring back legs forward underneath them
hypothermic neonates are failing to adapt. what are the sequelae of decreased body temp?
hypothermia -> CNS depression -> do not nurse -> hypoglycemia
heat production due to brown fat metabolism is maximized at ___ after birth
3 hr
factors affecting thermo regulation
Enviromental: temperature, moisture, wind
Individaul differences:
body mass: surface area ratio
brown fat (determined by nutrition of the dam during pregnancy)
Critical temperature for calves = 55F. If ambient temp is <55, calf will need to increase dietary intake in order to maintain body temp
Maternal behaviors
Energy/activity of the calf
What are the ways a calf can produce heat?
Brown fat metabolism
Shivering - requires metabolism of glucose and liver glycogen stores (from colostrum, milk, liver)
When are a neonate’s brown fat stores typically depleted?
within 1-5 days. depends on the amount they had to start with, which depends on the dam’s nutrition during pregnancy
when are a neonate’s liver glycogen stores typically depleted (if not replenished by nursing)?
4-6 hours
when you suspect hypothermia, what are three things you should check for?
Low body temp
Absent-decreased suckle reflex
No shivering
general causes of hypothermia
cold, wet, windy environment; lack of energy (not nursing); disease
treatment for hypothermia
Dry them off!
put them in a warm air (calf dryer etc.), hot water bath, warm oral fluids, blanket, straw, warm dry bedding in barn, etc.
which body systems are slower to develop/adapt to extra-uterine life?
GIT, renal, nervous, musculoskeletal, immune
Small intestine is able to absorb ____ for the first 24 hrs of life
large particles including proteins, bacteria, maternal cells.
What effect does sickness, stress, or debilitation have on the metabolism of neonates and what does it mean for treatment?
higher metabolic demands, need to provide extra nutrition!
T/F: kidneys are functionally mature at birth
true!
T/F: dilute urine indicates poor renal function in the neoneate
False! Milk has a lot of water -> dilute urine!
The nervous system of neonates is prone to ___ and ___
trauma and asphyxia
How can trauma to the musculoskeletal system lead to other problems?
Rib trauma –> tracheal/esophageal problems
legs –> unable to nurse –> hypoglycemia, hypothermia, etc -> anaerobic metabolism –> acidosis
clinical findings of dystocia
meconium staining poor thermoregulation crazy blood glucose nervous system issues hypoxia - dummy facial edema (will lead to difficulty nursing)
dystocia calves are potentially more prone to disease later in life due to___
metabolic and organ system derangements
T/F: you should worry about little things like decreased vigor, other subtle non-specific things happening with a neonate?
true! subtle things like lack of vigor, slow to rise and nurse (within 2 hr), disinterest in dam, decreased suckle, lack of curiosity can be early signs of more severe impending disease
the chances of having successful treatment/management of disease are best if ___
they are initiated early and aggressively! do not advise “wait and see” approach
definition of successful passive transfer of immunity
TIMELY ingestion and absorption of an adequate MASS of IgG (and other factors) by the neonate
failure of PT is indicated if serum IgG concentration___ (bovineSR and camelid)
<1000 mg/dL at 48 hr old
<800 mg/dL @ 36-48 hr (camelid)
Why is PTI important?
Calves with FPT have increased risk of death within first 3 mos. of life (increased risk of septicemia, diarrhea, enteritis, omphalitis, resp dz…).
Also experience decreased weight gain, milk production, and decreased survival past 1st lactation.
what are the mechanisms of protection that colostral Ig’s offer? (3)
Lactogenic - bind and neutralize pathogens in the gut
Systemic - absorbed into circulation -> neutralize antigens in the blood
Enteric - IgG that was absorbed is secreted back into the gut -> neutralize antigens
how do Ig’s get from the maternal serum into colostrum?
4-6 weeks pre-partum, IgG, M, A, binds to receptors on Basement Membrane of mammary glands -> transport vesicles -> apical membrane -> secreted into milk
how do Ig’s get from calf gut to ECF?
non-selective, non-receptor mediated transport across gut wall
