Bacteriological findings in the canine uterus during

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Received: 7 December 2017    Accepted: 9 February 2018 DOI: 10.1111/rda.13181

ORIGINAL ARTICLE

Bacteriological findings in the canine uterus during Caesarean section performed due to dystocia and their correlation to puppy mortality at the time of parturition S Goericke-Pesch1,2

 | V Fux2 | E Prenger-Berninghoff3 | A Wehrend2

1

Department of Veterinary Clinical Sciences, Section for Veterinary Reproduction and Obstetrics, University of Copenhagen, Frederiksberg C, Denmark

2

Department of Veterinary Clinical Sciences, Clinic for Obstetrics, Gynecology and Andrology of Large and Small Animals, Justus-Liebig University, Giessen, Germany

Contents Canine intrauterine bacteriological flora during dystocia is unknown. Thus, frequency (bacterial growth (not) detected), quality (species and number of different bacterial isolates) and quantity (colony-­forming units) of intrauterine bacteria in relation to in utero foetal death in 50 bitches undergoing emergency Caesarean section were investigated. Bacterial growth was quantified from single colonies, (+) (0.5), to strong

Institute for Hygiene and Infectious Diseases of Animals, Justus-Liebig University, Giessen, Germany

growth, +++ (3) and was observed in 34 bitches (68%), with Staph. epidermidis (n = 12),

Correspondence Sandra Goericke-Pesch, Reproductive Unit of the Clinic - Small Animal Clinic, University of Veterinary Medicine, Foundation, Hannover, Germany. Email: Sandra.Goericke-Pesch@ tiho-hannover.de

teria per sample. Regarding the quantity, most often (n = 46) low growth was

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Staph. intermedius-group (n = 7), β-­haemolytic streptococci (n = 6), Staph. aureus, α-­ and γ-­haemolytic streptococci (n = 4 each) being most common and one to four bacidentified. In bitches with living pups only (group I), mean number of isolates was 0.78 ± 0.83 compared to 1.60 ± 1.10 (living + stillborn pups, group II) and 1.0 ± 1.15 (stillborn pups only, group III) and mean bacterial growth in groups I/II/III was + (1.0, quantity), + (1.4) and ++ (1.6). Taking just positive samples into consideration, mean number of bacterial isolates was significantly higher in group II compared to I (p = .0088). We concluded that the canine uterus cannot be considered free of bacteria during dystocia. Mean numbers of different bacterial isolates and quantity of bacterial growth are higher in bitches with in utero foetal death.

1 |  I NTRO D U C TI O N

(Watts, Wright, & Whithear, 1996; Watts, Wright, Lee, & Whithear, 1997; Watts, Wright, & Lee, 1998; Schultheiss, Jones, Kesel, & Olson,

The physiological vaginal flora in the bitch harbours several apatho-

1999). Similarly, reports about the frequency of bacterial isolation

genic and facultative pathogenic bacteria like staphylococci, strep-

depending on the stage of cycle are contentious: whereas Watts

tococci and Escherichia (E.) coli, but also Haemophilus species (spp.),

et al., (1996), (1997), (1998) predominantly isolated bacteria in oes-

Moraxella spp., Flavobacterium spp., Pseudomonas spp., Proteus spp.,

trus and rather infrequently in other stages of the cycle, Schultheiss

Corynebacterium spp., Enterobacter spp., Bacillus spp., Klebsiella spp.,

et al., (1999) and Maksimović, Maksimović, Filipović, Beširović, &

Neisseria spp., Pasteurella spp., Ureaplasmataceae, Bacteroides spp.,

Rifatbegović, (2012) described the highest isolation rate in dioestrus,

Peptostreptococcus spp., lactobacilli and Mycoplasma spp. (Bruchim,

and Olson & Mather, (1978) as well as Baba et al., (1983) did not find

Lutsky, & Rosendal, 1978; Baba, Hata, Fukata, & Arakawa, 1983; van

any significant difference during various stages of the oestrus cycle.

Duijkeren, 1992; Root Kustritz, 2006; Groppetti, Pecile, Barbero, &

Data about bacteriological findings from the canine uterus are

Martino, 2012). Although it is generally accepted that the vaginal

rare and in case of parturition restricted to four cases where samples

microbiota almost represents the bacterial micro-­organisms resid-

were obtained during Caesarean section (Olson & Mather, 1978; also

ing in the uterine in prooestrus and oestrus, data about the uterine

mentioned in Schultheiss et al., 1999). In all these studies, there was

microbiota are controversial with some authors reporting bacterial

no bacterial growth in either of the canine uteri (Schultheiss et al.,

findings only rarely (Olson & Mather, 1978) and others frequently

1999). Another study recently collected samples of one bitch each at

Reprod Dom Anim. 2018;1–6.

wileyonlinelibrary.com/journal/rda   © 2018 Blackwell Verlag GmbH |  1

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GOERICKE-­PESCH et al.

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different time points after natural vaginal parturition, namely 7, 21,

broth containing 10% bovine serum for enrichment. After 24 hr of

28, 35, 42, 56, 70 and 84 days post-­partum, and uterine microbiota

incubation at 37°C, further processing was as described (Goericke-­

was assessed (Orfanou et al., 2009). Bacteria were only isolated in

Pesch et al., 2011; ). Examination of the plates was performed after

two samples, D7 and D21, and all other uterine samples revealed no

24 and 48 hr of aerobic incubation at 37°C. Briefly, colonies were

bacterial growth. However, to our best knowledge studies on a large

counted to estimate bacterial growth. Growth of single colonies,

collective on the uterine microbiota during parturition or dystocia

(+), was regarded as approximately one to five colony-­forming units

are missing.

(CFU), low bacterial growth, +, as six to 50 CFU, moderate bacte-

The aim of this study was to investigate the uterine microbiota in

rial growth, ++, as 51–200 CFU and strong bacterial growth, +++,

samples obtained during Caesarean section due to dystocia and to

>200 CFU. Bacterial colonies detected after broth enrichment only

correlate the results with puppy survival. Data should also improve

were assigned to the low growth rate group, +. Standard bacterio-

our current knowledge on the necessity of antibiotic treatment fol-

logical procedures were used for bacterial species identification as

lowing Caesarean section.

described previously (Goericke-­Pesch et al., 2011). For β-­haemolytic streptococci, slide agglutination tests were performed and they

2 |  M ATE R I A L S A N D M E TH O DS 2.1 | Animals and general procedure Samples were obtained from 50 privately owned dogs dur-

were identified to be serogroup G (Streptococcus canis) according to Lancefield.

2.3 | Statistical analysis

ing Caesarean sections performed at the Clinic for Obstetrics,

Individual numbers of bacterial isolates per dog were summed up

Gynecology and Andrology of Large and Small Animals, Justus-­

within one group to calculate the mean and standard deviation (SD)

Liebig University in Giessen, Germany. There were no elective

per group. For calculation of the mean quantity of bacterial growth,

surgeries performed, but only Caesarean sections necessary for

all samples of one group were added up using the following factors:

obstetrical management purposes (dystocia). All owners were in-

0.5 for (+), 1 for +, 2 for ++ and 3 for +++, and mean and stand-

formed about sampling, processing and data handling and agreed

ard deviation were calculated using Microsoft Excel (Windows XP;

on participation. All institutional ethical guidelines were followed.

Microsoft, Redmond, WA, USA). To test for significant differences

Dystocia was due to obstruction (including single pup pregnancy,

regarding the number of bacterial isolates per samples, only groups

or uterine inertia. Consequently, the cervix was dilated in all cases

I and II were compared due to similar group size. Due to the small

included, and either foetal fluids only (n = 30) or one or more pup-

group size of group III, this group was not included in statistical

pies (n = 20) had passed the birth canal before surgery. Caesarean

analysis. The statistical software program, GRAPHPAD3 (GraphPad

section was performed according to standard procedures (Johnston,

Software, Inc., San Diego, CA, USA), was used for the comparison of

Root Kustritz, & Olson, 2001; Wehrend, 2010). Immediately after

groups I and II. Values were considered to be statistically significant

delivery of all puppies and foetal membranes, a sterile swab was

at p