In a recently published study by the University of Giessen, the fertility of bitches after a caesarean section was compared with that after a natural birth. Parameters such as the time of the next heat after the first birth or the caesarean section, which of the following heats was used for another mating attempt, whether this was successful, the number of puppies born and the need for another caesarean section were examined.

The study was based on a survey of patient owners at the university clinic. An online survey was also done. Data were collected from 261 dogs of different breeds, of which 119 bitches belonged to the caesarean birth group and 142 to the natural birth group. The bitches were divided into six breed groups "Bulldogs", "Herding Dogs", "Molossers", "Retrievers", "Sheepdogs" and "Terriers" as well as one group "Others". Interestingly, apart from a single Weimaraner and a single Whippet, no other Gundogs or Sighthounds were included in the sample.

The most common reasons given for caesarean section were uterine inertia (n = 48), malpresentation of the puppy (20), fetomaternal disproportion (n = 15), dead fetus (n=11) and singleton (n=5).
The bulldog breed group had a high proportion of caesarean births. Only 42.11% of Bulldogs had a natural birth as their first birth, and only 31% delivered their pups naturally thereafter. Similarly, only 42.86% (n = 12) of the Terriers had given birth naturally, while among Herding Dogs, Molossiers and Retrievers, 63.16% (n = 24), 60.98% (n = 25) and 56.67% (n = 34) gave birth naturally, respectively.
Overall, 93% of bitches after caesarean section and 91.12% of those after natural delivery became pregnant at the first mating attempt. There was no significant effect on breed group or whether the bitch had a previous caesarean section. Bitches that had already had a caesarean section were more likely to have had further caesarean sections. However, neither breed group nor whether the bitch had had a caesarean section nor the number of previous births had any effect on the number of pups born.

Thus, a previous caesarean section does not seem to have a negative effect on fertility and the number of puppies born in the subsequent breeding. Nevertheless, breeders must be aware that the risk of a second caesarean section is high in the case of a new breeding. They should therefore carefully consider whether to breed to dogs that have previously had a caesarean section, as they are at high risk of having repeat birth problems.

Click here for the complete publication: https://www.frontiersin.org/articles/10.3389/fvets.2022.886691/full