5. Neonatology Flashcards
why is neonatology important?
More and more owners are leaving dogs intact
-more mismatings and thus neoante exposure in practice
-more purposeful breedings
-appears to be some discomfort in this this area for many veterinarians
rate of neonatal mortality and top reasons. When do most deaths occur?
The rate of neonatal deaths ranges from 17-30%
The 1st week of life is when most neonatal deaths occur
Most neonatal deaths caused by:
◦ Poor husbandry practices
◦ Suboptimal management
◦ Poor mothering
**Most are preventable!
lungs are filled with what in utero?
fluid
right side of the heart in utero is essentially what type of pressure system? what occurs as a result?
◦ Right side of the heart (to the lungs) = essentially high pressure system
◦ Causes blood to shunt from R side of the heart to the L
adaptations of the fetal heart to make circulation bypass the lungs
◦ Ductus arteriosus: blood goes from pulmonary artery to aorta
◦ Foramen ovale: blood goes from right atrium to left atrium
when the lungs fill with air upon birth, the right side of the heart is now what type of pressure system? what occurs as a result?
◦ Right side of the heart = low pressure system
◦ No longer any shunting from R to L
> pressure on L side is actually greater than the R side
◦ Ductus arteriosus closes
◦ Foramen ovale closes
At birth
◦ ⬆ oxygen tension> ductus arteriosus narrows & pulmonary vessels dilate
◦ ⬆ left-sided pressure >closure of foramen ovale
is there a lot of blood flow to the neonatal lungs?
no, bloodflow to lungs is sparse
how do neonates get O2?
placenta
what happens to neonatal lungs just before birth? what about upon birth?
◦ Just before birth: adrenal glands > cortisol > stimulates production of surfactant
◦ When umbilical cord blood supply is cut = hypoxia + ⬆ in vascular resistance > dyspnea = reflex contraction of the chest
◦ Negative pressure in airways = suction into lungs
what is the most common prenatal condition? what are some factors that may contribute?
fetal hypoxia (maternal stress, compromise, dystocia, etc.)
inability to inflate lungs for newborns leads to
hypoxia
Neonates cannot compensate well for what 3 conditions? why?
-hemorrhage
-hyperthermia
-acid/base imbalances
This is due to poor myocardial contractility
-Have incomplete autonomic innervation of heart and vasculature > not good blood pressure control
why are neonates more sensitive to temperature fluctuations?
◦ They cannot shiver
◦ They cannot vasoconstrict
◦ They have ⬆ surface area:body mass ratio
◦ Have little body fat
◦ Have poor blood flow to extremities
◦ Have high water composition
◦ Are unable to pant
why are neonates more sensitive to temperature fluctuations?
◦ They cannot shiver
◦ They cannot vasoconstrict
◦ They have ⬆ surface area:body mass ratio
◦ Have little body fat
◦ Have poor blood flow to extremities
◦ Have high water composition
◦ Are unable to pant
how does neonatal stomach pH compare to that of adults and what does this mean?
higher stomach pH
>more susceptible to bacterial infections
what is the neonatal microflora at birth? how does it evolve?
Born with sterile GI
> make up their own flora based on mom, environment & diet
Colostrum is both a source of
nutrients & immunoglobulins
what is colostrum and when is it delivered?
-Is the 1st mammary secretion produced after delivery
-transition to milk at day 2-3 post partum
what % of antibodies are passed through placenta in dogs? cats?
<5% of antibodies are passed through placenta in dogs; 25% in kittens
◦ Almost have no immunoglobulins @ birth
how does gut permeability evolve after birth?
Gut permeability starts to ⬇ 8hrs after birth; virtually none by 24hrs
what antibodies are present in colostrum? what most of all?
3 classes of immunoglobulins are present in colostrum (IgG, IgM, IgA)
◦ 60-75% is IgG
what time immunity does colostrum confer to neonate?
Colostral intake = acquisition of passive immunity
Risk of neonatal mortality depends on 2 factors:
◦ Quality of the transfer of passive immunity
◦ Growth of the puppy between birth & 2 days of age
when should we use colostrum replacement? how do we do it?
To be used in cases of failure of passive transfer
Administer plasma or serum from vaccinated adult
◦ Oral if <12hrs old
◦ Subcutaneously if >12hrs old – achieve higher levels when given subQ
If you can, its good to get pooled serum from multiple vaccinated adults of same household
Can give as 3 boluses (birth, 12 & 24hrs) or all at once
Should NOT be used as a substitute for colostrum
>colostrum is always better if available
how often should new pups be weighed?
at least once daily, 2x is better
-make a chart/graph
how does weight of newborns normally change in the first 24 hours? how should body weight change after this, up to 10 days?
Normal for weight to decrease in 1st 24hrs (if c- section, less so if natural whelping)
◦ Should then gain 5-10% of their body weight daily
◦ Should double their weight within 7-10 days of age
what does newborn weight loss after the first 24 hours indicate?
something is wrong
>can precede other signs by 16h
important considerations for neonatal drug selection
◦ Decreased renal clearance
> Do not have normal glomerular filtration rate until 6 weeks of age
◦ Decreased hepatic metabolism
why are newborns predisposed to hypoglycemia?
◦ Are born with limited glycogen stores
◦ Have poor gluconeogenesis capability
◦ Glucose – neonates have an:
> Increased demand for it
> Increased loss of it
> And a decreased ability to synthesize it
what is APGAR scoring? how do we perform it and what do different scores mean?
Appearance
Pulse
Grimace
Activity
Respiration
Consists of assigning a score (0-2) in each category:
◦ Heart Rate
◦ Spontaneous breathing
◦ Response to an irritating stimulus
◦ Muscle tone
◦ Color of mucous membranes
Scores close to 10 > associated with neonatal viability
Scores 6 or lower > associated with neonatal mortality & should receive supportive care
A lot of variation of this scoring method exists. Some also add other parameters
common causes of neonatal dehydration
Can lead to hypovolemia quickly
> lack of compensatory mechanisms
How do we assess dehydration in neonates?
◦ Skin tent is not reliable
◦ Mucous membranes – should be deep pink, can be misleading if just nursed
◦ Urine color: should be dilute yellow if well hydrated
how should we administer fluids to a dehydrated neonate?
◦ Oral (if GI is working) ok
◦ Subcutaneous
◦ IV or IO (intraosseous)
causes of neonatal hypoglycaemia? how quickly can a neonate become hypoglycemic if not nursing
◦ Diarrhea
◦ Vomiting
◦ Infection
◦ Decreased intake
Can become hypoglycemic in 24hrs if not nursing
clinical signs of hypoglycemia in neonate?
◦ Weakness, anorexia, tremors, crying, coma, seizures
at what point is a puppy considered hypothermic? how should they be warmed?
Should not be less than 35oC
should not be warmed up more than 1oC/hr
how can we prevent hypothermia in puppies?
Should be kept warm in environment (heat lamps, warm towels)
Temperature should be taken regularly
how can we treat hypothermia in neonates?
Can give warm fluids as tx
GI issue caused by hypothermia in neonates? what does this mean for caregiver?
Causes gut to slow down > ileus
◦ Previously ingested food ferments > gas > bloat
Do NOT feed a cold puppy
some common causes for sepsis in neonates:
◦ 2nd to wounds (tail docking, ear crops, umbilicus)
◦ Respiratory or GI infections
◦ In utero acquired infection (less common)
clinical signs of neonate sepsis
◦ Can be subtle
◦ Hypovolemia
◦ Vocalizing
◦ Reluctance to nurse
◦ Decreased urine output
◦ Increased lactate
◦ Cold extremities
◦ Loss of hair or sloughing of extremities (tail tip, ear tips)
Dx of neonate sepsis
Culture of organisms from blood or affected tissues
Tx of neonate sepsis
◦ Warm fluids
◦ Fresh or fresh frozen plasma from well vaccinated adult
◦ Broad spectrum antibiotics
signs of neonatal response to therapy for sepsis
◦ Less pale MM
◦ Stronger pulse
◦ Warmer extremities
◦ Lower lactate levels
3 potential causes of fading puppy syndrome
◦ Infectious agents > sepsis = most common
◦ Environment
◦ Genetics
2 manifestations of fading puppy syndrome
Sick at birth, born weak & small or with birth defects
>unable to nurse
>dehydration, hypothermia, hypoglycemia
>death within 1st few days of life
◦ Caused by perinatal bacterial infections & respiratory distress
◦ Neonates initially appear healthy but become weak in 1st few weeks of life
>become depressed, anorexic
>enter fatal cycle of dehydration & hypothermia
Dx of fading puppy syndrome
◦ Can be difficult
◦ Based on history & physical exam findings
◦ Culture & sensitivity of tissues
◦ If neonate can’t be saved, post mortem exam is recommended
where is canine herpes virus found?
Ubiquitous in environment
result of canine herpes virus for neonates
Causes necrotizing disease in neonates
pathognomonic signs for canine herpes virus in neonates
Petechial + ecchymotic hemorrhage on major organs
what pups are most likely to be affected by canine herpes virus?
Pups under 3 weeks of age = most likely to be affected
◦ Typical to have the quickest growing pup affected
what are the clinical signs of canine herpes virus
◦ Acute
◦ Stop nursing
◦ Vocalize continuously
◦ Death in 1-3 days
is canine herpes virus easy to diagnose and treat?
no, difficult for both
how can we prevent canine herpes virus?
Prevention = keep warm neonatal environment
what is neonatal isoerythrolysis? when does it occur?
◦ Hemolytic disease of newborn kittens
◦ Related to colostrum ingestion & blood types
Occurs when kittens with type A blood have a dam who’s type B blood
◦ Queen has strong anti-A antibodies in her colostrum
◦ Kittens ingest these anti-A antibodies
◦ Attacks their own type A blood
A, B & AB are the blood types in cats
>Type A cats have weak anti-B antibodies
>Type B cats have strong anti-A antibodies
Neonatal Isoerythrolysis clinical signs
◦ Anemia, icterus
◦ Tail tip necrosis ◦ Weakness
◦ Tachypnea
◦ Tachycardia
◦ Hemoglobinuria
◦ Sudden death
◦ Mortality rate is high even with prompt intervention
how to treat Neonatal Isoerythrolysis
Kitten should be removed from the dam and transfused if necessary
◦ Can use washed type B blood or cross-match blood
how can we prevent neonatal isoerythrolysis
- Avoid mating type B queens to type A toms
- All breeding cats should be blood typed and bred to their own blood type
- Blood type kitten before allowing it to nurse
If drug insert says never been tested in pregnancy, assume what?
Assume that its not safe!!
Excessive vitamin A causes what neonatal disorder?
midline defects
Lack of vitamin D causes what neonatal defects?
tooth & bone abnormalities
Feline parvovirus causes what neonatal defects?
cerebellar hypoplasia
Corticosteroids cause what congental disorder?
cleft palate when given at certain stage of gestation
Nutrition for neonates is important if
◦ There’s a need to supplement (large litter)
◦ Have to wean early (maternal illness)
◦ In orphaned or neonates that needs additional support (runt of the litter, not gaining well)
methods of manual food delivery to neonates
◦ Can do bottle feeding, sponge feeding or tube feeding
commercial milk replacer vs homemade - which to use for neonatal nutrition if needed?
Commercial milk replacer is recommended over home-made
how often do newborn dogs need to be fed? what temp should food be?
◦ Newborns need to be fed 6-8x daily (once every 2hrs)
◦ Once they are a couple weeks old, can increase
intervals
◦ Food should be warmed to 38.6C
average stomach capacity of neonateal dog
4tsp per lb
most important parameter to assess fetal viability
steady weight gain
Estrogen has many effects on the bitch. List 2 effects of estrogen on the bitch
- Edema of the vulva, vaginal epithelium
- Cornification of superficial cells
List 3 reasons why bitches are unique in their estrous cycles
- They ovulate immature eggs
- Their progesterone levels rise prior to ovulation
- They have extreme variability in the length of most
stages of their estrous cycles
Select the MOST correct statement regarding pregnancy diagnosis in bitches:
a) Ultrasound is most useful to determine fetal numbers and can be done as early as 19
days of gestation
b) Radiographs are a great way to determine fetal viability and to confirm due dates
c) Ultrasound is most useful to confirm due dates and to assess fetal viability
c) Ultrasound is most useful to confirm due dates and to assess fetal viability
List 3 reasons for which veterinary intervention would be required during whelping
- Overdue based on due date from ovulation
timing - Pup in the canal with straining for >15 minutes
- Presence of green/black vaginal discharge and no
signs of labor - More than 3 hrs between puppies
Select the most correct answer regarding neonates:
a) Neonatal mortality is preventable, and most neonatal deaths occur before 3 weeks of
age.
b) Neonatal Isoerythrolysis occurs when type B queens have type A kittens.
c) Neonates should not be fed when they are cold. They should be warmed up rapidly
prior to feeding them
b) Neonatal Isoerythrolysis occurs when type B queens have type A kittens.
What are the 3 biggest threats to neonates?
- Hypoglycemia
- Hypothermia
- Dehydration
