Canine Pregnancy Flashcards
Lifespan of chilled semen AI
<4 days in normal dogs
Advantage of surgical AI
Comparable pregnancy rates/litter size can be achieved with 10% of the sperm numbers inseminated vaginally
Obligatory diestrus
Always occurs, following estrus
- regardless of pregnancy status, then P4 is high regardless
How is pseudo-pregnancy a misnomer?
An intact bitch always has a luteal phase (obligatory diestrus) with high progesterone and most resolve without treatment
Psuedopregnancy
Due to elevated prolactin levels in the face of falling progesterone
- mammary development
- behavioral changes, nesting, agitation
- increased appetite and enlarged abdomen
Why would you treat a pseudopregnancy?
Increased risk of mammary tumors
- give prolactin inhibitiors
Pregnancy diagnosis
- palpation at 20-40 days
- ultrasound at 20 days
- relaxin assay at 25 days
- radiographs after 42 days
At ______ days you can feel separate bulges
30 days
You can get a fetal heart rate at ______
55-58 days
Placentas are described by
- shape
- origin
- degree of invasiveness
- structure of fetal placental vasculature
- degree of intimacy of attachment
Canine placentation
- zonary
- chorioallantoic
- endotheliochorial invasiveness
- structure of fetal placental vasculature: labyrinthine
- degree of intimacy of attachment to endometrium: deciduate
Length of pregnancy
- 64-66 days from LH surge (P4 of 2-2.9 corresponds to LH surge)
- 57 days from onset of cytological diestrus
- apparent length of 57-67 days from breeding
Parturition
Sharp decline in progesterone with resultant decline in body temperature
- P4 is thermotrophic
- prolactin increase and peak before with short decline, followed by increase when pups suckle
Normal canine delivery
- stage 1: 6-12 hours
- stage 2: 3-12 hours
- stage 3: follows with each fetus w/n 15 minutes
- expulsion of 1st fetus takes the longest
- interval b/w pups can be 5 min to 2 hrs
Management before parturition
- proactive measures: 57 days from diestrus, 64-66 days from LH surge
- approx 24 hrs after final drop in progesterone: less than 2 ng/ml, drop in body temp
Diagnosing stage 2 labor
- passage of fetal fluids
- visible abdominal straining
- rectal temp returning to normal after abrupt drop
Clinical signs of dystocia
- greenish brown (uteroverdin) discharge without delivery of first pup in 2-4 hrs
- strong straining for >20-30 min without progression
- more than 2-3 hrs between pups
- dam in 2nd stage labor for >12 hrs
Dystocia
Inability to expel fetus out of the birth canal without assistance
- incidence in dogs is around 5%
- risk factors: brachycephalic, toy breeds, singleton litters
Dystocia etiology
75% maternal and 25% fetal
Maternal causes of dystocia
Primary uterine inertia (number one cause of dystocia)
- secondary uterine inertia due to low calcium
Fetal causes of dystocia
- malpresentation
- fetal oversize
- malformations and fetal death
Clinical exam of parturition
- vaginal exam: fetus in birth canal
- mammary chain: presence of milk
- palpate abdomen
- fetal heartrate less than 150 indicates stress
Obstruction
- torsion
- malposition
- narrow birth canal or more often vaginal stricture
- fetal anasarca
- some pups delivered vaginally with gentle traction and lubrication
Medical management of uterine inertia
- oxytocin
- calcium gluconate
C section
- ventral midline incision
- exteriorize uterus
- uterotomy incision
- delivery pups after breaking down fetal membranes
- double clamp umbilicus
- deliver to assistant
- inverting pattern in uterus
- routine abdominal closure
Anesthesia
- minimize anesthesia time
- propofol induction
- iso or sevo inhalant
- lidocaine line block on abdomen
- fluids
- pre oxygenate for 5 min
- avoid alpha 2 agonists!
Neonatal care
- reverse any drugs
- get dry, warm
- suction mouth and nose
- assure pups are nursing
- rotate pups to assure adequate milk ingestion
- colostrum ingestion
