A rare case of Polyorchidism (Triorchidism) in a dog: Surgical intervention and outcome

Introduction

Polyorchidism is a rare developmental congenital anomaly characterized by the presence of supernumerary testes. While cases have been documented in various species including humans, horses, and cattle, it is considered uncommon in canines (Tamminen et al., 2012) [1] . This condition is often asymptomatic and may be discovered incidentally during routine physical examination, surgical procedures, or post-mortem examination. Polyorchidism can be categorized based on the number of testes (triorchidism, tetraorchidism). Triorchidism is more prevalent in such cases and the location of supranumerary testis maybe scrotal, inguinal or abdominal (Haddock and Burns 1987) [2] . Polyorchidism can be associated with pathologies, like cryptorchidism, inguinal hernia, testicular torsion, or tumour (Hancock and Hodgins 1984) [3] . This case report describes a unique presentation of triorchidism in a Shih-Tzu dog complicated by severe scrotal necrosis and orchitis, requiring immediate surgical management.

Case History and Observations

A two-and-a-half-year-old intact male Shih-Tzu dog presented to the clinic with a two-day history of lethargy, inappetence and severe pain associated with a swollen scrotum. The owner reported a progressive increase in the size of the scrotum, which had become dark and was leaking a serosanguinous discharge fluid. On physical examination, the scrotum was severely enlarged, firm and exhibited extensive necrosis of the skin (Fig: 1A) with active fluid seepage. The scrotal swelling extended cranially into the inguinal region. The dog's temperature was 103.5°F (39.7°C). Blood work revealed a significant leukocytosis with a left shift, indicative of a severe inflammatory or infectious process. Abdominal ultrasonography was not performed due to the dog's painful demeanor and the clear diagnosis of severe scrotal pathology. A presumptive diagnosis of severe orchitis with scrotal necrosis was made, antibiotic, analgesic and anti-inflammatory drugs were prescribed as the primary course of action for three day. On follow up after 3 days, no significant recovery was noticed as per history and physical examination. Therefore, surgical intervention was recommended.

Surgical Procedure and Findings

The dog was pre-medicated with atropine sulphate (Zespin® at 0.04 mg/kg b.wt) followed by induction with xylazine (Xylaxin® at 1.2 mg/kg b.wt) as pre-anesthetic and ketamine (Ketaset® at 7 mg/kg b.wt) as an anesthetic, and maintenance with combination of ketamine and diazepam in 2:1 (v/v) ratio. A standard surgical preparation of the caudal abdomen and perineum was performed. A prescrotal to caudal scrotal lateral incision was made to expose the affected tissues. The superficial layers of the scrotum were found to be necrotic and sloughing. Upon entering the scrotal sac, left testicle found to be mildly inflamed (Fig: 2A), surrounded by necrotic tissue. The right testicle was somewhat normal (Fig: 3A).

As the dissection proceeded to remove the inflamed tissues, an unexpected finding was made. A separate, encapsulated mass was discovered attached to the deep subcutaneous tissue, caudal and left-lateral to the base of the penis. Upon careful dissection, a third testis was found. This third testis was not connected to the main scrotal sac or the other two testes. All three testes (Fig: 4A, 4B, 4C), inflammatory tissue (Fig: 4D) and the entire affected scrotal and perineal skin (Fig: 4E) were removed by the procedure consisting castration and scrotal ablation. The spermatic cords of the two main testes were ligated and transected as per a standard castration procedure. The third testis was removed with its surrounding capsule and tissue upon ligation of its independent spermatic cord. The surgical site was thoroughly lavaged, and a multilayered closure was performed.

Discussion

Polyorchidism is a rare condition in canines, and the majority of reported cases are incidental findings in other animals as in horses (Davies 2010) [4] and also in humans (Savas et al. 2010) [5] . The reason behind the polyorchidism is not known (Tamminen et al., 2012) [1] . The development of extra testis is suggested to occur during embryogenesis by genital ridge duplication or longitudinal/transversal division (Leung 1988) [6] . Polyorchidism have been classified into two types mainly: type A with ductus deferens and type B without ductus deferens (Bergholz et al. 2007) [7] . The unique presentation in this Shih-Tzu, with painful scrotal swelling, necrosis, and orchitis, highlights that supernumerary testes can be a site of significant pathology. The exact cause of the severe inflammation is speculative, but it is plausible that the condition was a complication of the patient's polyorchidism and possibly a form of cryptorchidism affecting the third testis. In this the third testis was found on left side that show the similarity with previous finding (Leung 1988) [6] . The ectopic location of the third testis, combined with its lack of a direct connection to the main scrotal sacs, may have predisposed it to an inflammatory event or even torsion, which subsequently spread to the other two testes and the surrounding scrotal tissue. The management of this case involved radical surgical excision, which was critical for a favorable outcome. The successful resolution of the dog's symptoms and the confirmed diagnosis of triorchidism underscore the importance of thorough surgical exploration in cases of complex scrotal and testicular pathology.

Conclusion

This case report describes a rare and clinically significant presentation of triorchidism in a two-and-a-half-year-old Shih-Tzu dog. The polyorchidism was complicated by severe orchitis and scrotal necrosis, which required castration and scrotal ablation. The findings highlight the importance of considering polyorchidism as a differential diagnosis in cases of canine testicular pathology and the need for thorough surgical exploration to identify all affected structures.

Acknowledgement

AcknowledgementAuthors thank the, College of Animal and Veterinary Sciences, Sardar Vallabhbhai Patel University Agriculture & Technology, Meerut -250110, Dean College of Veterinary Science and Animal Sciences, Uttar Pradesh, India and Head, Department of Veterinary Clinical Complex for providing necessary facilities to carried out this case study. Contribution by AuthorsAll the authors contributed equally to writing the manuscript. The final manuscript was read by all the authors and consented to publication.

References

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