Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Sep 24;16(1):354.
doi: 10.1186/s12917-020-02577-z.

Low and very low birth weight in puppies: definitions, risk factors and survival in a large-scale population

Amélie Mugnier  1 , Sylvie Chastant-Maillard  1 , Hanna Mila  1 , Faouzi Lyazrhi  2 , Florine Guiraud  1 , Achraf Adib-Lesaux  3 , Virginie Gaillard  3 , Claude Saegerman  4 , Aurélien Grellet  5
Affiliations

Low and very low birth weight in puppies: definitions, risk factors and survival in a large-scale population

Amélie Mugnier et al. BMC Vet Res. .

Abstract

Background: Neonatal mortality (over the first three weeks of life) is a major concern in canine breeding facilities as an economic and welfare issue. Since low birth weight (LBW) dramatically increases the risk of neonatal death, the risk factors of occurrence need to be identified together with the chances and determinants of survival of newborns at-risk.

Results: Data from 4971 puppies from 10 breeds were analysed. Two birth weight thresholds regarding the risk of neonatal mortality were identified by breed, using respectively Receiver Operating Characteristics and Classification and Regression Tree method. Puppies were qualified as LBW and very low birth weight (VLBW) when their birth weight value was respectively between the two thresholds and lower than the two thresholds. Mortality rates were 4.2, 8.8 and 55.3%, in the normal, LBW and VLBW groups, accounting for 48.7, 47.9 and 3.4% of the included puppies, respectively. A separate binary logistic regression approach allowed to identify breed, gender and litter size as determinants of LBW. The increase in litter size and being a female were associated with a higher risk for LBW. Survival for LBW puppies was reduced in litters with at least one stillborn, compared to litters with no stillborn, and was also reduced when the dam was more than 6 years old. Concerning VLBW puppies, occurrence and survival were influenced by litter size. Surprisingly, the decrease in litter size was a risk factor for VLBW and also reduced their survival. The results of this study suggest that VLBW and LBW puppies are two distinct populations. Moreover, it indicates that events and factors affecting intrauterine growth (leading to birth weight reduction) also affect their ability to adapt to extrauterine life.

Conclusion: These findings could help veterinarians and breeders to improve the management of their facility and more specifically of LBW puppies. Possible recommendations would be to only select for reproduction dams of optimal age and to pay particular attention to LBW puppies born in small litters. Further studies are required to understand the origin of LBW in dogs.

Keywords: Birth weight; Canine; Epidemiology; Litter size; Neonatal mortality; Puppy; Risk factor.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Flow diagram describing the data selection process
Fig. 2
Fig. 2
Distribution of puppies by birth weight category according to litter size quartiles. Q1 – puppies from litters with the lowest 25% of registered litter size values for the breed, Q2 and Q3–25% below and above the median, Q4 – puppies from litters with the highest 25% of registered values. NBW: normal birth weight; LBW: low birth weight; VLBW: very low birth weight
Fig. 3
Fig. 3
Repartition of the deaths between early and late neonatal periods by birth weight category. NBW: normal birth weight; LBW: low birth weight; VLBW: very low birth weight
See this image and copyright information in PMC

References

    1. Chastant-Maillard S, Guillemot C, Feugier A, Mariani C, Grellet A, Mila H. Reproductive performance and pre-weaning mortality: preliminary analysis of 27,221 purebred female dogs and 204,537 puppies in France. Reprod Domest Anim. 2017;52:158–162. doi: 10.1111/rda.12845. - DOI - PubMed
    1. Indrebø A, Trangerud C, Moe L. Canine neonatal mortality in four large dog breeds. Acta Vet Scand. 2007;49:S1–S2. doi: 10.1186/1751-0147-49-S1-S2. - DOI - PubMed
    1. Gill MA. Perinatal and late neonatal mortality in the dog. Doctoral dissertation. University of Sydney; 2001.
    1. Groppetti D, Ravasio G, Bronzo V, Pecile A. The role of birth weight on litter size and mortality within 24h of life in purebred dogs: what aspects are involved? Anim Reprod Sci. 2015;163:112–119. doi: 10.1016/j.anireprosci.2015.10.005. - DOI - PubMed
    1. Mila H, Grellet A, Feugier A, Chastant-Maillard S. Differential impact of birth weight and early growth on neonatal mortality in puppies. J Anim Sci. 2015;93:4436–4442. doi: 10.2527/jas.2015-8971. - DOI - PubMed