CVC Highlight: My approach to canine dystocia - Veterinary Medicine
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CVC Highlight: My approach to canine dystocia
This emergency and critical care specialist, who has additional insight on breeding dogs, provides pointers on identifying dystocia as well as the treatment options he uses to achieve an optimal outcome for the bitch, puppies, and breeder.


VETERINARY MEDICINE


TREATMENT TACTICS

With dystocia, you need to ascertain what clients want and what they can afford. How important are live pups to them? Cesarean section is a tool for producing live pups, and if clients want live pups, you should not delay in doing it. But if they can't afford it, you can try other techniques such as oxytocin and fetal manipulation.

Oxytocin

You have several options for managing dystocia. Oxytocin can be used as the first line of treatment for primary uterine inertia, but most bitches will not respond to it. You will generally have to do a cesarean section to address primary uterine inertia. Secondary inertia without fetal malposition or fetal distress can be hard to sort out. The bitch could be taking a break, but if it's been more than four hours since the birth of the last puppy, it's probably uterine inertia.

If oxytocin administration isn't contraindicated after I've performed a vaginal exam and radiography (e.g. no narrowed birth canal or fetal malpositioning), then I administer up to two doses, 20 minutes apart. I use small doses because it decreases blood flow to the fetus (e.g. 0.5 units for a Chihuahua and 2 to 3 units for a Newfoundland subcutaneously or intramuscularly). The uterus becomes refractory to oxytocin after a few doses, so you need to do a cesarean section for larger litters (or if two doses don't produce contractions and a puppy).

Fetal manipulation

If there is absolute fetal oversize or inadequate pelvic diameter, do a cesarean section. If there is only one large pup in the canal, you can try to manipulate it. If you detect fetal malposition, use gentle manipulation with your fingers around the pup's neck or shoulders (you need long fingers for this). And use lots of lubricant. You may be able to push them from behind by using abdominal palpation or use one finger rectally and one vaginally. Use slow steady traction, and warn anyone in the room that fetal dismemberment could occur despite your care. Above all, don't waste time. Each puppy is valuable to the breeder.

Cesarean section

Cesarean section is indicated if you detect fetal distress on ultrasonography, uterine inertia does not respond to oxytocin, or fetal oversize or malposition or vaginal obstruction exists. If you do a cesarean section, plan ahead. You need to limit the time the bitch spends in dorsal recumbency so she experiences no further decrease in ventilation. And limit the time from anesthetic induction to pup removal. Don't induce anesthesia before you're scrubbed and ready to do surgery. Have all your equipment ready and adequate staffing on hand.

Administer intravenous fluids to the bitch. I give atropine as a premedication to support the maternal and fetal heart rate. For anesthesia, propofol and isoflurane (or sevoflurane) are best. You can also do a line block with bupivacaine. You can give the bitch an opioid once the pups are removed (oxymorphone, hydromorphone, or morphine).

Delivery and postoperative care

Vigorous stimulation and oxygen administration are the best techniques to revive the puppies once they're removed. You can suction the oropharynx to remove fluid, but don't swing the puppies; it can cause brain damage, and you could throw them. If the puppies aren't breathing and the bitch has been given opioids, administer one drop of naloxone and doxapram sublingually. Be patient; you should try to revive them for 15 to 20 minutes before you give up. For postoperative pain, prescribe tramadol for the bitch.

PROSPECTIVE PREGNANCIES

For subsequent pregnancies, a vaginal delivery can be attempted, especially if the problem was due to big pups. In this situation, advise the breeder not to overfeed the bitch so the pups aren't so big. Patients with secondary uterine inertia tend to have it again. And if the bitch experienced primary uterine inertia, she'll most likely need a cesarean section for subsequent deliveries.

Scott Shaw, DVM, DACVECC
Department of Clinical Sciences
Cummings School of Veterinary Medicine
Tufts University
North Grafton, MA 01536


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Source: VETERINARY MEDICINE,
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