Disorders and complications of pregnancy and neonatal conditions Flashcards
Physiological pregnancy length in dogs
61-63d from the time of ovulation
56-58d from the onset of cytological dioestrus
58-72d from the first breeding
Any confirmed pregnancy >65d with no signs of parturition warrants investigation, but not panic
Prediction of due date in cats
induced ovulation and numerous matings make prediction of the parturition day far more difficult (52-74d from the 1st mating or 65-66d from the last mating
Warning signs of dystocia in dogs and cats
○ Prolonged gestation when ovulation is known
○ Pregnant bitch >72 days breeding
○ Pregnant queen >71 days post breeding
Alarm bells for dystocia in dogs and cats
Bitch strains for 1hr continuously before the delivery of any puppy
Green or black vaginal discharge prior to delivery of first puppy
The bitch rests 3 or more hours between puppies
The delivery of stillborn puppies
The dam is ill or distressed
Foetal factors in dystocia of dogs and cats
Malpresentation
Malformation
Foetal oversize
Foetal death
Maternal factors in dystocia of dogs and cats
Uterine inertia (primary or secondary)
Anatomical changes of birth canal (often fractures in queens, or intrapelvic masses)
Uterine torsion
Hydrallantois
Vaginal septae and bands
Vaginal stricture
Predisposing factors to dystocia in dogs and cats
Size of the litter, smaller more likely to cause uterine inertia
Breed, brachycephalics or miniature breeds bred at 1st heat
Management of primary uterine inertia
Establish the condition of the dam, number and viability of pups/kittens and when labour started
Small litter size and early onset:
- administration of oxytocin may have some effect and may be combined with calcium gluconate
Numerous pups and exhausted dam: unlikely that the parturition will be completed even if initial uterine contractions can be stimulated. C-section recommended.
Dead foetuses -> c-section.
Oxytocin in support of labour
Currently recommended doses are 0.5-2iu to increase the frequency and quality of uterine contractions
Initial dose - 0.1-0.25iu/kg recommended
The dosage may be repeated in 30 mins
Repeated administration or excessive dose can lead to uterine spasm and tetanic contractions which further compromise the foetuses
Absolutely contraindicated in cases of obstructive dystocia
Calcium in support of labour
Usually given before oxytocin to improve the contractions strength before increasing the frequency
Calcium gluconate is available as several salts and is administered as 10% calcium gluconate at 0.2 mL/kg IV or 22mg/kg per dog SC (give it slowly and keep an eye on the heart rate!)
If S/C you must dilute the volume with 1:1 saline, as calcium salts may be irritating
Do not give more frequently than every 4-6 hours
More commonly used in dogs
In cats, reports of very strong uterine contractions induced by calcium administration discourage most vets
Management of obstructive dystocia in cats and dogs
Determine if there is a realistic chance for manual correction
§ Cause of obstruction
§ Number of foetuses ‘waiting’ and their viability
§ How much space do you have ‘inside’?
Will resolution of this particular obstacle give high chances for timely and safe completion of parturition?
§ If no or not sure then caesarean section
Be delicate and protect the birth canal
Always use as much lubricant as possible
Act in line with the uterine contractions not against them, retract between contractions, pull during them
In small and slim females, you can fix the uterus with the obstructing foetus using a hand applied to lower abdomen
Remember - the best way to reposition/rearrange the foetus is to first push it back a bit to gain space in the birth canal
Once the foetus is in the vagina pull downwards not upwards
Caesarean section in dogs and cats
Usually the easiest and safest way to solve difficult parturition in dogs and cats
Additionally - if the pregnancy was unplanned and the female is not/no longer intended for breeding, ovariohysterectomy can be done at the same time
Plan the anaesthesia for the operated dam carefully, bearing in mind the possible influence on foetuses
Ensure that resuscitation tools and medication are in place if the neonates are expected to be alive
Important surgical aspects:
○ Gravid uterus is heavy and delicate so care should be taken when lifting from the abdominal cavity to avoid ruptures
○ It is helpful to make initial incision in the uterine wall with a scalpel and then widen it with scissors to avoid injury to the foetuses
○ While pulling out foetuses with their foetal membranes some fluid may escape and should be sucked away
○ Move along the whole uterus until you have reached both ovaries and the cervix and are sure all foetuses are removed
Post partum complications in dogs and cats
Placental retention
Sub-involution of placental sites (SIPS)
Eclampsia/puerperal tetany in bitches
Placental retention in dogs and cats
Far less frequent than in livestock
<24h pp -> oxytocin
<48h pp -> pretty serious -> surgery
Sun-involution of placental sites (SIPS)
Specific to dogs
Persistence of sanguineous vulval discharge beyond 16 weeks pp.
Mild cases - spontaneous resolution.
Severe cases - Ovariohysterectomy.
