Difference between revisions of "Uterine Inertia"

Latest revision as of 17:24, 2 November 2022

Introduction

Uterine inertia describes the failure of the uterus to expel a foetus normally and is a common cause of canine and feline dystocia.

Uterine inertia can be primary or secondary.

Primary Uterine Inertia

This describes the total or partial absence of contractions to expel a normal foetus through an unobstructed birth canal.

Several causes have been found:

Breed predisposition

Large litter overstretching the uterus

Small litter not stimulating the uterus enough. Small foetuses cannot apply enough pressure on the uterine wall and cervix to set up the Fergusson reflex.

Systemic disease: Obesity and lack of exercise, hypocalcaemia, septicaemia.

Complete primary uterine inertia occurs if 2nd stage labour does not begin. Partial inertia occurs if the 2nd stage begins but contractions soon fail.

Secondary Uterine Inertia

Uterine muscles become exhausted after prolonged contraction against an obstructing or oversized foetus or during birth of a large litter. There is usually subclinical hypocalcaemia and/or hypoglycaemia.

This can occur in the sow, bitch and guinea pig.

Diagnosis

Physical examination may help identify foetuses in the birth canal. Digital examination of the vagina will also enable the uterine and vaginal tone to be assessed.

Lack of a response to pressure per vaginum indicates a lack of the Ferguson reflex which indicates uterine intertia.

Radiography can be taken to assess the number and size of foetuses.

Ultrasound can help assess foetal viability.

Treatment

If the bitch is in good condition with normal sized puppies and no obstruction, medical treatment can be attempted.

Oxytocin can be administered intramuscularly, repeated at 30 minutes for a maximum of 3 injections.

Calcium gluconate or dextrose solution can also be administered if a suspicion of hypocalcaemia or hypoglycaemia exists.

A caesarean section is indicated if there is no response to the oxytocin, or if the foetuses are too large for a vaginal birth.

Uterine Inertia Learning Resources
Flashcards Test your knowledge using flashcard type questions	Small Animal Soft Tissue Surgery Q&A 12

References

Pasquini, C. (1999) Tschauner's Guide to Small Animal Clinics Sudz Publishing

Slatter, D. (2002) Textbook of small animal surgery Elsevier Health Sciences

Noakes, D. (2001) Arthur's Veterinary Reproduction and Obstetrics Elsevier Health Sciences

Webinars

Failed to load RSS feed from https://www.thewebinarvet.com/urogenital-and-reproduction/webinars/feed: Error parsing XML for RSS

@@ Line 1: / Line 1: @@
-* Protracted birth due to weak or absent uterine contractions.
+{{OpenPagesTop}}
+==Introduction==
+Uterine inertia describes the '''failure of the uterus''' to expel a foetus normally and is a common cause of [[Dystocia - Dog & Cat|'''canine and feline dystocia''']].
+Uterine inertia can be '''primary or secondary'''.
-=== Primary Uterine Inertia ===
+== Primary Uterine Inertia ==
+This describes the '''total or partial absence of contractions''' to expel a normal foetus through an unobstructed birth canal.
-* Lack of Oxytocin Receptors
+Several causes have been found:
-* Lack or failure of Oxytocin release
+:'''Breed predisposition'''
-* Lack or failure in Prostaglandin release
+:'''Large litter''' overstretching the uterus
-* Obesity and lack of excercise in bitches.  The small foetus cannot apply enough pressure on the uterine wall and cervix to set up the [[Parturition_-_Endocrine_Control_of_Parturition_- Anatomy & Physiology|Fergusson reflex]].
+:'''Small litter''' not stimulating the uterus enough. Small foetuses cannot apply enough pressure on the uterine wall and cervix to set up the [[Parturition Endocrine Control - Anatomy & Physiology#Ferguson Reflex|Fergusson reflex]].
-* Foetus is too small, or not entering cervix.
+:'''Systemic disease''': Obesity and lack of exercise, [[hypocalcaemia]], septicaemia.
+Complete primary uterine inertia occurs if '''2nd stage labour''' does not begin. Partial inertia occurs if the 2nd stage begins but contractions soon fail.
-=== Secondary Uterine Inertia ===
+== Secondary Uterine Inertia ==
+Uterine muscles become '''exhausted after prolonged contraction''' against an obstructing or oversized foetus or during birth of a large litter. There is usually subclinical '''hypocalcaemia and/or hypoglycaemia'''.
-* Dystocia with subsequent muscle failure
+This can occur in the sow, bitch and guinea pig.
-* Large number or size of offspring causes the uterine muscle to become stretched and fatigued.
-* Common in sow, bitch and guinea pig
-[[Category:Reproductive Disorders]][[Category:Parturition]]
+==Diagnosis==
+'''Physical examination''' may help identify foetuses in the birth canal. Digital examination of the vagina will also enable the uterine and vaginal tone to be assessed.
+Lack of a response to pressure per vaginum indicates a '''lack of the [[Parturition Endocrine Control - Anatomy & Physiology#Ferguson Reflex|Ferguson reflex]]''' which indicates uterine intertia.
+'''Radiography''' can be taken to assess the number and size of foetuses.
+'''Ultrasound''' can help assess foetal viability.
+==Treatment==
+If the bitch is in good condition with normal sized puppies and no obstruction, '''medical treatment''' can be attempted.
+'''Oxytocin''' can be administered intramuscularly, repeated at 30 minutes for a maximum of 3 injections.
+'''Calcium gluconate''' or dextrose solution can also be administered if a suspicion of hypocalcaemia or hypoglycaemia exists.
+A '''caesarean section''' is indicated if there is no response to the oxytocin, or if the foetuses are too large for a vaginal birth.
+<big>'''See also: [[Dystocia - Dog & Cat#Clinical approach to dystocia in small animals|Clinical Approach to Dystocia in the Dog and Cat]]'''</big>
+{{Learning
+|flashcards = [[Small Animal Soft Tissue Surgery Q&A 12]]
+}}
+==References==
+Pasquini, C. (1999) '''Tschauner's Guide to Small Animal Clinics''' ''Sudz Publishing''
+Slatter, D. (2002) '''Textbook of small animal surgery''' ''Elsevier Health Sciences''
+Noakes, D. (2001) '''Arthur's Veterinary Reproduction and Obstetrics''' ''Elsevier Health Sciences''
+{{review}}
+==Webinars==
+<rss max="10" highlight="none">https://www.thewebinarvet.com/urogenital-and-reproduction/webinars/feed</rss>
+[[Category:Expert Review - Small Animal]]
+[[Category:Reproductive Disorders]][[Category:Parturition]][[Category:Reproductive Diseases - Dog]]