The impact of an overweight body condition on pregnancy, parturition, and physical activity in the bitch
- 1Virginia-Maryland College of Veterinary Medicine, Blacksburg, Virginia, USA
- 2Department of Small Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Blacksburg, Virginia, USA
- 3Department of Population Health Sciences, Virginia-Maryland College of Veterinary Medicine, Blacksburg, Virginia, USA
Abstract
The aim of this study was to determine how an overweight body condition affects pregnancy success in the bitch. Fifteen client-owned medium-to-large breed bitches were enrolled for 16 pregnancies from breeding to 4 weeks postpartum and grouped as lean (LE; body condition score, BCS: 4–5/9; n = 10) or overweight (OW; BCS: 6–7/9; n = 6). A triaxial accelerometer (FitBark 2) was used to monitor physical activity, quantified as ‘BarkPoints’. Serum progesterone (P4) and C-reactive protein (CRP) were measured alongside ultrasonographic conceptus growth using inner chorionic cavity diameter (ICCD) and biparietal diameter (BPD). Parturition duration was recorded. Placental microvascular density was quantified through CD31 immunolabeling of the endothelium. Data analysis included t-test, Fisher’s exact test, linear mixed-effects models, or generalized estimating equations; significance was set at P < 0.05. LE bitches had significantly higher baseline BarkPoints, which gradually decreased until parturition. BarkPoints of OW bitches did not change throughout pregnancy but increased during lactation. All bitches had an increase in BarkPoints during the last 4–6 h prepartum. OW bitches had clinically notable increases in embryonic resorption rate and duration from the first visible abdominal contraction to the first puppy expulsion, although these were not statistically significant. No differences were seen between maternal BCS groups in conceptus growth, parturition duration parameters, placental microvascular density, serum P4, or CRP. In conclusion, an overweight maternal body condition may have clinically important, albeit not statistically significant, associations with reproductive parameters in this small cohort. Both body condition and reproductive stage (i.e. pregnancy and lactation) appear to affect habitual physical activity level in broodbitches.
Lay summary: Excessive body fat is suspected to negatively affect reproductive success in dogs, similar to other species. Thus, we aimed to determine whether overweight dogs had negative pregnancy outcomes. Six overweight and ten lean female dogs were monitored throughout pregnancy until the first 4 weeks of lactation. Lean dogs had higher baseline activity levels at home than overweight dogs. During pregnancy, lean dogs had a gradual decline in their activity that remained low throughout lactation. Overweight dogs maintained their baseline activity levels throughout gestation but increased them during lactation. No differences were found between the two groups in embryonic growth rate, duration of labor, placental vasculature, or selected blood biomarker concentrations. We noted a potential clinically relevant increase in early pregnancy loss and slower labor progression until the birth of the first puppy in overweight bitches, although this was not statistically significant. Although a relatively small number of dogs were included, the results point toward potential negative effects of obesity on canine reproductive performance.
Related
- Iron promotes M1 polarization of decidual macrophages during parturition via increased TfR1 and TLR4 expression
- Exercise, Physical Activity and Breast Cancer: The Role of Tumor-Associated Macrophages
- Effects of exercise and physical activity on circulating inflammaging- and immunosenescence-related biomarkers in older adults and adults with chronic diseases: an umbrella review
- Hox gene activity directs physical forces to differentially shape chick small and large intestinal epithelia
- Antidepressant medication use and objectively measured physical activity and sedentary behaviors in adults: A cross-sectional analysis of a nationally representative sample of Canadian adults
BibTeX
@article{mccarter2026impact,
title = {{The impact of an overweight body condition on pregnancy, parturition, and physical activity in the bitch}},
author = {Samantha J McCarter and Julie T Cecere and Stephen R Werre and Megan Shepherd and Andrea Jones and Orsolya Balogh},
journal = {Reproduction \& Fertility},
year = {2026},
month = oct,
doi = {10.1530/raf-26-0093},
url = {https://doi.org/10.1530/raf-26-0093},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - The impact of an overweight body condition on pregnancy, parturition, and physical activity in the bitch
AU - Samantha J McCarter
AU - Julie T Cecere
AU - Stephen R Werre
AU - Megan Shepherd
AU - Andrea Jones
AU - Orsolya Balogh
PY - 2026
DA - 2026/10/26
JO - Reproduction & Fertility
DO - 10.1530/raf-26-0093
UR - https://doi.org/10.1530/raf-26-0093
AB - The aim of this study was to determine how an overweight body condition affects pregnancy success in the bitch. Fifteen client-owned medium-to-large breed bitches were enrolled for 16 pregnancies from breeding to 4 weeks postpartum and grouped as lean (LE; body condition score, BCS: 4–5/9; n = 10) or overweight (OW; BCS: 6–7/9; n = 6). A triaxial accelerometer (FitBark 2) was used to monitor physical activity, quantified as ‘BarkPoints’. Serum progesterone (P4) and C-reactive protein (CRP) were measured alongside ultrasonographic conceptus growth using inner chorionic cavity diameter (ICCD) and biparietal diameter (BPD). Parturition duration was recorded. Placental microvascular density was quantified through CD31 immunolabeling of the endothelium. Data analysis included t-test, Fisher’s exact test, linear mixed-effects models, or generalized estimating equations; significance was set at P < 0.05. LE bitches had significantly higher baseline BarkPoints, which gradually decreased until parturition. BarkPoints of OW bitches did not change throughout pregnancy but increased during lactation. All bitches had an increase in BarkPoints during the last 4–6 h prepartum. OW bitches had clinically notable increases in embryonic resorption rate and duration from the first visible abdominal contraction to the first puppy expulsion, although these were not statistically significant. No differences were seen between maternal BCS groups in conceptus growth, parturition duration parameters, placental microvascular density, serum P4, or CRP. In conclusion, an overweight maternal body condition may have clinically important, albeit not statistically significant, associations with reproductive parameters in this small cohort. Both body condition and reproductive stage (i.e. pregnancy and lactation) appear to affect habitual physical activity level in broodbitches. Lay summary: Excessive body fat is suspected to negatively affect reproductive success in dogs, similar to other species. Thus, we aimed to determine whether overweight dogs had negative pregnancy outcomes. Six overweight and ten lean female dogs were monitored throughout pregnancy until the first 4 weeks of lactation. Lean dogs had higher baseline activity levels at home than overweight dogs. During pregnancy, lean dogs had a gradual decline in their activity that remained low throughout lactation. Overweight dogs maintained their baseline activity levels throughout gestation but increased them during lactation. No differences were found between the two groups in embryonic growth rate, duration of labor, placental vasculature, or selected blood biomarker concentrations. We noted a potential clinically relevant increase in early pregnancy loss and slower labor progression until the birth of the first puppy in overweight bitches, although this was not statistically significant. Although a relatively small number of dogs were included, the results point toward potential negative effects of obesity on canine reproductive performance.
SN - 2633-8386
ER -