Prevalence of reproductive disorders in bitches with special emphasis on mismating

Introduction

The domestic dog (Canis lupus familiaris) is one of the earliest domesticated animal species and remains an important companion animal worldwide. Dogs are maintained for various purposes including companionship, security, hunting, sporting activities and assistance to elderly or disabled individuals (Costa et al., 2019) [1] . Reproductive disorders constitute a significant proportion of clinical cases presented in female dogs to veterinary hospitals (Beaudu-Lange et al., 2021) [2] . Common conditions include vaginal disorders, uterine infections such as pyometra, gestational abnormalities including early embryonic death, fetal maceration and dystocia, lactational disturbances and neoplastic conditions affecting the genital tract and mammary glands (Gupta et al., 2020; Fielding et al., 2021) [3,4] . Hormonal fluctuations during the estrous cycle, particularly variations in progesterone and estradiol, also influence reproductive physiology and predispose bitches to several reproductive pathologies (Maya et al., 2017) [5] . Misamting incidents may occur due to accidental exposure to stray male dogs or mating with an undesirable male or a dog of a different breed. Even a single mating during the fertile period may result in pregnancy (Romagnoli, 2015) [6] . When future breeding potential needs to be preserved, medical management is often preferred over surgical sterilization to prevent or terminate unwanted pregnancy (Sridevi, 2015) [7] . However, treatment is recommended only after confirmation of pregnancy since many bitches presented for mismating may not conceive (Wanke et al., 2002) [8] . Therefore, trans-abdominal ultrasonography is advised prior to administration of abortifacient drugs to avoid unnecessary exposure of non-pregnant animals to potential systemic side effects (Srinivas et al., 2008) [9] . Considering the clinical importance of this condition, the present study was undertaken to evaluate the occurrence of mismating among dogs presented with reproductive complaints and to document their clinical characteristics and management practices.

Materials and Methods

The present study was conducted at the Super Speciality Veterinary Hospital (SSVH), Visakhapatnam, Andhra Pradesh. A retrospective epidemiological analysis was carried out to evaluate the occurrence of reproductive disorders in dogs presented to the hospital, with particular emphasis on mismating cases. Clinical records of dogs presented with reproductive complaints between June 2025 and February 2026 were reviewed. During the study period, a total of 9,720 dogs were recorded with various reproductive conditions including pyometra, pregnancy diagnosis, pseudopregnancy, anoestrus, dystocia, canine transmissible venereal tumour and mismating.For each mismating case, relevant data were obtained from clinical records and owner history.The collected data was compiled and categorized to assess the occurrence pattern of mismating cases and associated epidemiological factors.

. Distribution of Physiological and Pathological Reproductive Conditions

During the present investigation, a total of 9,720 dogs were presented with reproductive complaints. Among these, physiological reproductive conditions accounted for 45.89 per cent (4,461 cases), whereas reproductive tract disorders constituted 54.11 per cent (5,259 cases) (Table 1). The slightly higher proportion of pathological conditions indicates that reproductive disorders continue to represent a major component of clinical cases in canine practice. Among the physiological conditions, pregnancy diagnosis (24.03%) and estrus detection (21.86%) were the most frequently recorded. The proportion of pregnancy diagnosis observed in the present study was higher than the 16.25 per cent reported by Gupta et al. (2020) [3] but comparable with (Sethi 2019) [10] (21.14%) and (Nagar et al., 2008) [11] (25%). A slightly higher value of 29.09 per cent was reported by (Kumar et al., 2011) [12] , whereas (Oluwatoyin and Fayemi 2011) [13] documented a lower incidence of 8.1 per cent. Estrus detection accounted for 21.86 per cent of the cases, which closely agrees with (Gupta et al., 2020) [3] (21.81%), while (Oluwatoyin and Fayemi 2011) [13] reported 6.1 per cent. The higher proportion of these physiological conditions likely reflects increased owner awareness regarding breeding management and reproductive monitoring.

Occurrence of Major Reproductive Disorders

Among the reproductive disorders, pyometra was the most frequently encountered condition (21.20%), highlighting its continued clinical importance in intact bitches. This observation was comparable with (Raju, 2017) [14] (20.3%), although higher incidences were reported by (Gupta et al., 2020) [3] (23.25%), (Nagar et al., 2008) [11] (31.77%), (Honparkhe et al., 2010) [15] (40%) and (Singh et al., 2013) [16] (40%). In contrast, lower incidences were reported by (Gibson et al., 2013) [17] (2.2%), (Sathiamoorthy and Raja, 2011) [18] (3%), (Fukuda, 2001) [19] (15.2%) and (Jena et al., 2013) [20] (16.72%). The variation among studies may be attributed to differences in population demographics, reproductive management practices and accessibility of veterinary care. Dystocia constituted 13.43 per cent of the reproductive cases, emphasizing its clinical importance in canine obstetrics. Earlier reports indicate that dystocia occurs in approximately 5-7 per cent of canine births (Purohit et al., 2004) [21] , while (Nagar et al., 2008) [11] reported incidences between 11.58 and 12 per cent. The occurrence of transmissible venereal tumour (TVT) was 8.48 per cent, which was higher than (Sathiamoorthy and Raja, 2011) [18] (1.4-3.27%) and (Joseph et al., 2005) [22] , but lower than (Kumar et al., 2011) [12] (10.30%), (Nagar et al., 2008) [11] (10.36%), (Singh et al., 2013) [16] (30%) and (Honparkhe et al., 2010) [15] (31%).

Occurrence of Other Reproductive Conditions

Other reproductive disorders recorded included pseudopregnancy (3.53%), vaginal hyperplasia (2.47%), vaginitis (1.41%), fetal resorption (1.06%), sub-involution of placental sites (0.71%) and anoestrus (0.35%) (Table 1; Fig. 1). The incidence of pseudopregnancy observed in the present study was comparable with (Honparkhe et al., 2010) [15] (4%), (Kumar et al., 2011) [12] (4.24%) and (Singh et al., 2013) [16] (5%), whereas (Nagar et al., 2008) [11] reported a higher value of 11.58 per cent. The relatively low occurrence of anoestrus compared with (Kumar et al., 2011) [12] (6.06%) and (Nagar et al., 2008) [11] (6.09%) may be related to variations in breed distribution, nutritional management and endocrine factors influencing reproductive cyclicity (Concannon, 2011) [23] .

Age-wise Distribution of Reproductive Complaints

Age-wise evaluation revealed that the highest proportion of reproductive complaints occurred in dogs aged 1-5 years (44.50%), followed by 5-10 years (36.00%), while the lowest occurrence was observed in animals aged 10-15 years (19.50%) (Table 1). A similar age-related trend was reported by (Gupta et al., 2020) [3] . The higher incidence in younger animals may be associated with increased breeding activity and the onset of reproductive life during this age period.

Incidence of Mismating

Out of the total reproductive cases examined, 142 dogs (1.46%) had a history of mismating. (Table 1). This proportion was lower than the 2.67 per cent reported by (Gupta et al., 2020) [3] and 3.63 per cent reported by (Kumar et al., 2011) [12] , but slightly higher than (Dabhi,2005) [24] (1.14%), indicating that accidental mating continues to represent an important reproductive management issue in dogs.

Distribution of Mismating Cases According to Breed, Age and Parity 3.2.1. Breed-wise Distribution

Detailed evaluation of mismating cases (n = 88) revealed variations according to breed. Shih Tzu dogs constituted the highest proportion (20.45%), followed by Labrador Retriever (15.91%) and non-descript dogs (13.64%). Other breeds included Lhasa Apso (10.23%), Pug (9.09%), German Shepherd (9.09%), Maltese (7.95%), Beagle (6.82%) and Husky (6.82%) (Table 2). Similar breed-related patterns have been reported by (Gupta et al., 2013) [25] and (Ajala et al., 2011) [26] , possibly reflecting the popularity of these breeds as companion animals.

Age and Parity-wise Distribution of Mismating Cases

Age-wise analysis revealed that the highest proportion of mismating cases occurred in bitches aged 1.5-4 years (38.64%), followed by 4-6 years (29.55%), >6 years (20.45%) and less than one year (11.36%). Parity-wise evaluation indicated that nulliparous bitches constituted the highest proportion (45.45%), followed by primiparous (34.09%) and multiparous animals (20.45%). The higher incidence in young, sexually mature and nulliparous bitches may be attributed to increased estrous activity combined with inadequate owner awareness and insufficient breeding management during early reproductive cycles. Additionally, inexperience in detecting behavioral signs of estrus and failure to implement timely preventive measures may predispose these animals to unintended mating. These findings are in accordance with earlier reports of (Johnston et al., 2001) [27] and (Root Kustritz,2012) [28] , who emphasized the importance of proper estrus monitoring and controlled breeding practices in reducing mismating incidents. Evaluation of owner-related factors revealed that accidental mating with a non-descript male dog was the most frequently reported reason for seeking prevention of pregnancy (25.00%), followed by suspected exposure to stray male dogs during proestrus (20.45%) and undesired cross-breeding with a different breed (15.91%) (Table 3). Other reasons included management constraints (13.64%), perception that the female was too young for breeding (10.23%), advanced age of the bitch (6.82%), and consanguineous mating with offspring (4.55%) or between siblings (3.41%). Similar observations have been reported by (Johnston et al., 2001) [27] .

Interval Between Mating and Clinical Presentation

With respect to the interval between mating and presentation, the majority of animals were presented within 3-7 days of mating (38.64%), followed by presentation within one month (27.27%), 1-2 days (18.18%) and within 24 hours (15.91%) (Table 3). Early presentation is considered crucial for improving the effectiveness of therapeutic interventions aimed at preventing pregnancy.

Treatment Preference of Owners

Regarding treatment preference, 71.59 per cent of owners opted for medical management, whereas 28.41 per cent preferred surgical sterilization (Table 3). The higher preference for medical therapy may reflect the owners' intention to preserve the future breeding potential of their animals, similar to observations reported by (Root Kustritz, 2012) [28] .

Conclusion

The present study highlights the occurrence pattern of reproductive conditions in dogs presented to SSVH, Visakhapatnam. Pyometra emerged as the most common reproductive disorder, while pregnancy diagnosis and estrus detection constituted a substantial proportion of physiological presentations. Although mismating accounted for a relatively small percentage of cases, it remains a clinically relevant issue, primarily associated with exposure of estrous bitches to free-roaming male dogs. The findings highlight the importance of improving owner awareness regarding estrous management and responsible breeding practices to minimize unintended mating and ensure timely veterinary intervention.

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