USE OF ULTRASOUND TO LOCATE RETAINED TESTES IN DOGS AND CATS

Ultrasound-Based Technologies for the Evaluation of Testicles in the Dog: Keystones and Breakthroughs

Ultrasonography is a valuable diagnostic tool extensively used in the andrology of human and domestic animals, including dogs. This review aims to provide an overview of various technologies based on ultrasound, from the basic B-Mode ultrasonography to the more recent advancements, such as contrast-enhanced ultrasonography (CEUS) and ultrasound elastography (UEl), all of which are utilized in the evaluation of canine testicles. The review outlines the principles behind each of these technologies and discusses their application in assessing normal and abnormal testicular conditions. B-mode canine testicular ultrasonography primarily focuses on detecting focal lesions but has limitations in terms of objectivity. Other technologies, including Doppler ultrasonography, B-Flow, and CEUS, allow for the characterization of vascular patterns, which could be further measured using specific applications like spectral Doppler or quantitative CEUS. Additionally, ultrasound elastography enables the assessment of parenchyma stiffness both qualitatively and quantitatively. These ultrasound-based technologies play a crucial role in andrology by providing valuable information for evaluating testicular function and integrity, aiding in the identification of pathological conditions that may impact the health and quality of life of male dogs.

Anti-Müllerian hormone levels in serum and testes of male dogs: relations with neuter status and bilateral abdominal cryptorchidism

Anti-Müllerian hormone (AMH) analysis has contributed to new information in the reproductive endocrinology of domestic animals, due to clinically available diagnostic tools. An accurate and rapid diagnostic method to distinguish between neutered and bilateral abdominal cryptorchid dogs is needed in veterinary practice. Therefore, this study uses an enzyme-linked immunosorbent assay to evaluate the clinical relevance of AMH analysis in peripheral blood as a diagnostic tool for dogs with suspected bilateral abdominal cryptorchidism. The possible alteration of the AMH localization in testicular tissue caused by this pathologic condition was also investigated using immunohistochemistry. Male dogs were divided into three groups of healthy intact (n = 14), healthy castrated (n = 14), and bilateral abdominal cryptorchid (n = 14) dogs. The results demonstrated a higher level of serum AMH in the cryptorchid group compared to the intact group (P < 0.01), while serum AMH levels of all castrated dogs were below the limit of detection (<0.05 ng/mL). Moreover, the percentage of positive AMH immunostaining of the intact group was less than that of the cryptorchid group (P < 0.01). A significantly positive correlation was found between serum AMH concentration and localization in testicular tissues (r = 0.93, P < 0.01). Our findings suggest that AMH levels in the peripheral blood could be used as an alternative and rapid screening method for detecting dogs with abdominal cryptorchidism.

[Diagnostic utility of the anti-Mullerian hormone in companion animals]

The anti-Mullerian hormone is a glycoprotein secreted by Sertoli cells in males and granulosa cells in females. The initial identification of this hormone in canine and feline serum was achieved in 2011. Meanwhile, a variety of studies have demonstrated its clinical significance as a tool in the endocrine diagnosis. This review summarizes the current knowledge about anti-Mullerian hormone in small animal reproduction and describes future opportunities for its diagnostic usage.

A Retrospective Study of Laparoscopic Cryptorchidectomy in 19 Cats with Intra-Abdominal Testes

Cryptorchidism is heritable in cats, and due to the pathological risk of testicular torsion, and the development of testicular neoplasia, cryptorchidectomy is the treatment of choice. For the intra-abdominal testes, a laparotomic approach is generally recommended; however, laparoscopic cryptorchidectomy in cats has been documented in a few clinical case reports. The aim of the study was to report the short-term clinical outcomes for 19 cryptorchid cats with intra-abdominal testes that underwent cryptorchidectomy with laparoscopic techniques. Medical records of client-owned sexually intact male cats that underwent laparoscopic cryptorchidectomy in different veterinary hospitals or ambulatory surgical services were reviewed. The procedure was performed in 19 cats. The average time (mean ± standard deviation, SD) for all procedures was 23 ± 6 min (range 15-35 min). The time for laparoscopic removal of a single abdominal testis was 22 ± 6 min, with 30 min for the bilateral abdominal testes. The time until hospital discharge varied depending on the surgeon's criteria, with a mean of 6 h (range 3-24 hrs). None of the cases analyzed showed any surgical complications. The results of this study suggest that laparoscopic cryptorchidectomy is an appropriate surgical procedure to treat cryptorchid cats with intra-abdominal testes, all with benefits of minimal invasion surgery.

Polyorchidism in a cat

A 9-mo-old, male domestic shorthair cat was presented for castration because of mounting behavior observed by the owner. On physical examination, the cat was bilaterally cryptorchid, but had penile spines. Abdominal exploration through a midline laparotomy revealed 2 pairs of masses. All 4 masses had gross features of testes, and ranged from 7 × 5 × 5 mm to 12 × 6 × 7 mm, with associated epididymal tissue. Histologically, each mass contained seminiferous tubules consistent with testicular tissue, and epididymal tubules, confirming a diagnosis of polyorchidism; deferent ducts were not found. There was no evidence of neoplastic, infectious, or inflammatory disease. Mounting behavior ceased 4 wk post-surgery. Histologic confirmation of more than 2 testes is needed to establish a diagnosis of polyorchidism, a rare congenital anomaly that has been reported infrequently in the veterinary literature; reports have been of animals with triorchidism, with the exception of 1 cat with 4 intraabdominal testes. Our report emphasizes that, although rare, polyorchidism should be considered in cryptorchid cats, or whenever penile spines are present in a previously castrated cat. Our case also highlights the value of checking for penile spines in a bilaterally cryptorchid cat if abdominal ultrasound is not an option to aid in surgical planning.

The Use of Abdominal Ultrasound to Improve the Cryptorchidectomy of Pigs

Simple Summary

Cryptorchidism is the failure of one or both the testes to descend in the scrotum. In pigs, the incidence of cryptorchidism varies from 4% to 12%, and the most frequent localisation of retained testes is the abdominal region. In other species, transabdominal ultrasound is the most reliable diagnostic tool to localize the retained testis. This study aimed to evaluate the value of ultrasound in correctly identifying the location of retained testes, to improve the cryptorchidectomy in pigs. The ultrasound examination reduced the duration of anaesthesia, surgery, and postoperative pain. Indeed, the technique used is safe, effective, and rapid. To locate the testis, it should recognise the echo structure of the testicle and the mediastinum is well always recognisable for its hyperechogenicity. The routine use of the ultrasound examination is considered a useful alternative before the cryptorchidectomy in the pig because it allows the exact location of the retained testicle, ensuring reduced manipulation of the viscera.

Abstract

This study aimed to describe a technique to locate retained testes in pigs by means of ultrasound examination and thereafter proceed with cryptorchidectomy. Fifty-two monolateral cryptorchid pigs were enrolled. After anaesthesia, 42 pigs (Group U) underwent ultrasound examination before cryptorchidectomy, and 10 pigs (Group C) were used as control group without ultrasonography. The total duration of anaesthesia, ultrasound examination, and surgery was evaluated. In 10 pigs of Group U and 10 pigs of Group C, the heart rate (HR), respiratory rate (RR), and body temperature (T) were monitored to assess intraoperative pain response. An operator used the Piglet Grimace Scale (PGS) to assess postoperative pain. In Group U, the total time required for anaesthesia and surgery was less than Group C. No intra- or postoperative complications were reported in both groups. For HR, RR, and T, no statistically significant differences were observed. During the postoperative pain assessment, the highest pain scores were recorded at T6 (6 h after surgery). Ultrasound examination was found to be a valid technique for locating the retained testis in the abdomen in cryptorchid pigs and to reduce the duration of the surgery.

Successful laparoscope-assisted orchiectomy in three cryptorchid sheep

Three adult Corriedale cryptorchid sheep were subjected to laparoscope-assisted orchiectomy of the retained testicles. One (n = 2) or both (n = 1) the testicles were missing in their scrotal sac and inguinal regions. Ultrasonography was used to locate the retained testicles and their distance from the abdominal surface. The animals were restrained in dorsal recumbency and Trendlenburg posture under lumbosacral epidural anaesthesia using 2% lignocaine hydrochloride. Two laparoscopic ports were created in the caudal abdomen adjacent to the retained testicles. They were identified by their ovoid shape, white glistening surface (Tunica albuginea) and typical vasculature. Laparoscope-assisted exteriorization of the testicles after enlarging the ports, ligation of their blood supply and resection of the spermatic cord was performed successfully. The scrotal testes in two rams were then subjected to routine Burdizzoo castration. The laparoscopic port sites healed without complications and all the animals continued to do well subsequently. From this case report, it is concluded that in sheep the laparoscopy; a minimally invasive procedure can confirm abdominal retention of testicle/s and may also be used for their retrieval in a single sitting. Although total laparoscopic procedure is expected to reduce the incision size further but requires advanced laparoscopic instruments and expertise.

Imaging of the male reproductive tract: Not so easy as it looks like

Diagnostic imaging is one of the most important tools in the breeding soundness evaluation of dogs and cats with reproduction problems. In recent years several imaging techniques have been developed, trying to aid the diagnosis and to differentiate between abnormal findings. This review presents the current knowledge on the imaging of normal and abnormal testes, spermatic cord, excurrent duct system, scrotum, accessory sex glands, penis and muscles for protrusion, erection and ejaculation of the dog and of cat. It also highlights the weak points and disadvantages of each imaging technique.

Can testicular artery Doppler velocimetry values change according to the measured region in dogs?

Testicular tissue maintenance is performed by the testicular artery, and the hemodynamics of this artery can be evaluated using Doppler ultrasonography. The aim of this study was to characterize the peak systolic velocity (PSV), end diastolic velocity (EDV), pulsatility index (PI) and resistivity index (RI) of five regions of the testicular artery in dogs, including two proposed regions and three that have been previously described. Twenty-two dogs were used, and the PSV, EDV, PI and RI of the testicular artery were measured in five regions: proximal, medial and distal supratesticular; marginal; and intratesticular. The median values for PSV (cm/s), EDV (cm/s), PI and RI in the five regions were as follows: proximal supratesticular (23.1, 3.7, 2.1 and 0.8); medial supratesticular (17.2, 4.5, 1.5, and 0.7); distal supratesticular (12.2, 5.7, 0.8, and 0.5); marginal (11.3, 6.5, 0.5, and 0.4); and intratesticular (5.7, 3.5, 0.5, and 0.4). There was a difference between the PSV of the medial and distal supratesticular regions. There were differences in the PSV, EDV, PI and RI among the distal supratesticular, marginal and intratesticular regions. Measurements of PSV, EDV, PI and RI of the testicular artery in dogs at the proposed regions showed different results due to the hemodynamic and morphological differences of the artery during its course in the spermatic cord and to the testicles. It is necessary to identify the region in testicular artery Doppler velocimetric evaluations of dogs, given that there is a difference according to the region measured.

Canine cryptorchidism: An update

This review article is aimed at providing an update on canine cryptorchidism based on the research studies published in this area over the last 26 years. Although a majority of these research studies were directed at investigating the genetic and molecular basis of cryptorchidism, the mechanisms underlying this problem in dogs are still not clear. Future studies using advanced genomic and molecular approaches and including a larger number of dogs of multiple breeds are required to further our understanding of canine cryptorchidism. Diagnosis and treatment of cryptorchidism in dogs have not received much attention. Research advancements include investigation of ultrasonography and anti-Müllerian hormone assay as potential diagnostic methods. Advancements in treatment include the use of laparoscopic-assisted cryptorchidectomy. Based on the available literature, this method appears to be the best for removal of abdominal cryptorchid testes from dogs. However, future studies that compare laparoscopic-assisted cryptorchidectomy with the traditional approaches are required for a more conclusive determination of the best method for cryptorchidectomy in dogs.

Computed Tomographic Features in a Case of Bilateral Neoplastic Cryptorchidism with Suspected Torsion in a Dog

An 11-year-old male German Shepherd dog presented for inappetence and weight loss. Physical examination and initial bloodwork revealed palpable abdominal masses, mild non-regenerative anemia, and thrombocytopenia. Survey radiography and abdominal ultrasonography confirmed the presence of bilateral abdominal masses and lymphadenopathy. Contrast-enhanced computed tomography (CT) was performed in order to further investigate the origin of the intraabdominal masses, confirming two enlarged cryptorchid testes, one of which had an associated CT “whirl sign.” Histopathology of the testes and lymph nodes revealed bilateral malignant Sertoli cell tumors and seminomas with lymph node metastasis of both neoplasms. The purpose of this case report is to discuss the benefits of CT in the diagnosis of cryptorchid testes and describe an additional organ that may display CT “whirl sign.”

Emergency laparoscopic cryptorchidectomy for acute abdomen due to testicular torsion in a dog

A 7-year-old male Siberian husky was presented with signs of acute abdomen. Based on the history and diagnostic imaging findings, torsion of an undescended abdominal testis was presumed. Emergency exploratory laparoscopy was performed and confirmed spermatic cord torsion in a non-neoplastic testis. The testis was enlarged and local peritonitis was evident. Laparoscopic cryptorchidectomy was performed and the dog recovered uneventfully. Histopathology confirmed thrombosis and necrosis. Laparoscopy is not only the method of choice for elective cryptorchidectomy, but can also be used in patients with acute abdomen from testicular torsion of an undescended testis.

Laparoscopic-assisted cryptorchidectomy in a cat

A 21-month-old male castrated domestic short hair cat was presented due to suspected unilateral abdominal cryptorchidism. Unilateral abdominal cryptorchidism was confirmed with ultrasonography and laparoscopic-assisted cryptorchidectomy was performed. Laparoscopic-assisted cryptorchidectomy is a simple, fast and safe method for the treatment of abdominal cryptorchidism in dogs and cats, offering the benefits of minimal invasive surgery, which is still underreported in the veterinary literature.

Laparoscopic Treatment of Testicular Torsion in a Puppy

A 6 mo old male puppy was presented as an emergency for an acute onset of lethargy, ptyalism, and vomiting. On physical examination, the dog was painful on abdominal palpation. A torsed intra-abdominal testis was diagnosed via abdominal ultrasonography and radiography. Laparoscopy was used to identify and remove the torsed testis. The dog recovered uneventfully and was described as doing well by the owners at the 6 mo follow-up telephone contact. This is the first report of an abdominal testicular torsion treated with laparoscopy.