Surgical management of squamous cell carcinoma of the canine male external genitalia: 15 cases (1994-2020).

Fifteen male dogs with squamous cell carcinoma of the external genitalia were admitted for further investigation and surgical management between 1994 and 2020. The dogs belonged to various breeds. Thirteen dogs were intact and two were castrated with a median age of 8 years and a median weight of 28 kg. Seven dogs were white-coated and eight nonwhite coated. Scrotal ablation and orchiectomy were performed in four dogs, partial penile amputation in two, partial penile amputation plus partial preputial ablation in one, penile amputation, and scrotal urethrostomy in seven, and local preputial excision in one dog. Postoperative complications included hemorrhage in 10 dogs, bruising at the urethrostomy site in seven, and urethrostomy dehiscence in one dog. Tumor recurrence was recorded in six dogs. Dogs with poorly differentiated tumors that had tumor recurrence had shorter survival and worse prognosis compared to those with well and moderately differentiated tumors. The mean survival time was 48.132 months. After a median follow-up of 23 months (range: 8 to 72 months), eight dogs were alive, five were euthanized and two dogs died from unrelated causes. Surgical excision seems to be a treatment option for dogs with squamous cell carcinoma of the external genitalia.

Cutaneous Canine Mast Cell Tumor: The Use of Proliferative Markers (Ki-67 and Ki-67 × AgNOR) in Cytological Samples for Diagnosis and Prognosis.

A cytological grading system for canine mast cell tumors (MCTs) has been developed, but its integration into clinical routine has been hindered due to its diagnostic limitations. The aim of this study was to assess the prognostic value of Ki-67 and argyrophilic nucleolar organizing region (AgNOR) markers in cytological MCT samples and to determine cut-off values for these markers in correlation with histopathological grading. Cytological samples were collected prior to surgical excision, and histopathological samples were obtained postsurgery from 45 dogs diagnosed with cutaneous mast cell tumors (MCTs). The cytological specimens were classified using a two-tier grading system, and their Ki-67 (average immunopositive nuclei per 100 cells) and AgNOR (average AgNOR counts per 100 nuclei) signaling was assessed. Through receiver operating characteristic (ROC) analysis, cut-off values for Ki-67 and Ki-67 × AgNOR were determined to better align with histopathological grading (classified as low or high grade according to Kiupel's scoring system). Without the inclusion of proliferative markers, there was a 73% agreement between cytological and histopathological grading. The prediction of histopathological grade was slightly more accurate when assessing Ki-67 and Ki-67 × AgNOR signaling in cytological specimens (75% and 80%, respectively) compared to the initial cytological grading. The cytological assessment of canine MCTs proves beneficial for the initial evaluation, and the incorporation of the evaluation of Ki-67 and AgNOR markers may assist in identifying diagnostically highly malignant MCTs.

Diagnosis of traumatic urethral stricture in a canine patient with contrast-enhanced voiding urosonography : A case report.

A 5-year-old intact male mixed-breed dog presented with a 3-day history of stranguria and dysuria. Results of physical examination, plain radiographs, and ultrasonography were consistent with a traumatic urethral stricture in the prescrotal urethra just under the previous trauma region, resulting in partial obstruction of urine outflow. Contrast-enhanced voiding urosonography (CE-VUS) was performed, and a urethral stricture was confirmed. The dog underwent surgery. A scrotal urethrostomy was performed. After 3 days of hospitalization, the dog was discharged from the Clinic. Based on an extensive literature review, this is the first report using CE-VUS to evaluate urethral pathology in a canine patient.

Surgical Anatomy of the Gastrointestinal Tract in Cats.

In cats, the gastrointestinal tract is one of the regions in which surgical procedures are most frequently performed by veterinary surgeons; therefore, knowledge of the surgical anatomy of the feline gastrointestinal tract is of high importance. The main surgical procedures performed include gastrotomy, gastrectomy, enterotomy, and enterectomy, as well as procedures in the liver and pancreas. There are also anatomical differences between dogs and cats, increasing the need for deep knowledge of the anatomy treated in the different surgical approaches. The aim of the present review is to describe in detail the anatomy of the gastrointestinal tract in cats highlighting the anatomical regions of significant importance in different surgical procedures.

Τhe Effect of Opioid Administration on Cytologic and Histopathologic Diagnosis of Canine Cutaneous Mast Cell Tumors Treated by Surgical Excision.

Mast cell tumor (MCT) is a frequent cutaneous tumor in dogs, with a variable biological behavior. Studies correlate cytologic and histopathologic features of MCTs with their biological behavior, prognosis, and response to treatment. The use of preoperative opioids is common in canine patients undergoing surgical removal of these tumors. Certain opioids can induce or downregulate mast cell degranulation and influence cancer progression. The aim of the present study was to investigate whether the administration of morphine or butorphanol during surgical excision of canine cutaneous MCTs affects their cytologic and histopathologic appearance, thus influencing cytologic and histopathologic grading. This was a prospective, blinded, randomized, cohort clinical study. Forty-five dogs with cutaneous MCTs were randomly allocated into three groups according to preanaesthetic medication: dexmedetomidine combined with morphine (group M) or butorphanol (group B) or normal saline (group C). Cytologic specimens and histopathologic samples were obtained both prior to and after surgery. Samples were graded according to Kiupel's and Patnaik's systems, examined immunohistochemically for Ki-67 protein (Ki-67) and c-kit proto-oncogene product (KIT) expression, and histochemically for argyrophilic nucleolar organizing regions (AgNORs). Based on both Kiupel's and Patnaik's systems, no statistically significant differences were noted concerning the number of cases with grading discrepancies in grades allocated prior to versus after surgery among the groups. The same applied for cytological grading and immunohistochemical and histochemical evaluation. It seems that administration of morphine or butorphanol as part of the preanesthetic medication for surgical removal of canine cutaneous mast cell tumors does not influence histopathologic and cytologic grading of MCTs.

Influence of age on resistance to distraction after tracheal anastomoses in dogs: An ex vivo study.

OBJECTIVE: To determine the influence of age on the ability of tracheal anastomoses to sustain distraction in dogs. STUDY DESIGN: Ex vivo study. SAMPLE POPULATION: Cadaveric canine tracheae (n = 16). METHODS: Tracheae were harvested from the cadavers of 8 immature and 8 adult dogs. Each trachea underwent end-to-end annular ligament anastomosis with a simple continuous pattern with 2-0 polypropylene on a taper cut needle. The constructs were tested to failure in distraction, with a tensiometer set at a drop head speed of 50 mm/min, as determined by preliminary testing. Failure was defined by tissue pullthrough or suture material failure. The force and elongation at failure were compared between age groups. RESULTS: The median age was 5.5 months (4-7.5 months) in immature dogs and 8.25 years in adult dogs (2-18 years) Tracheal anastomoses failed at lower forces (44.91 ± 59.03 N) but sustained more elongation (39.75 ± 5.45%) in immature dogs than in adult dogs (149.31 ± 45.36 N, P = .007 and 30.57 ± 7.19%, P = .0012, respectively). Tissue apposition was not achieved in 4 specimens each in immature and adult dogs, respectively. CONCLUSIONS: The technique used for tracheal anastomoses in this study failed at lower loads but sustained more elongation when performed in immature dogs. CLINICAL SIGNIFICANCE: Immature dogs may be able to withstand longer tracheal resection than adult dogs but reinforcement techniques seem mandatory to improve resistance to tension. Alternative anastomosis techniques should be considered to improve tissue apposition.

Lymphoplasmacytic Prostatitis Associated With Urethral Obstruction in a Dog; A Case Report.

A 10-year-old, male intact, mixed breed dog was admitted with a history of intermittent lower urinary tract signs of 18-months duration. Dysuria, stranguria, pollakiuria and overflow incontinence developed 2 weeks prior to presentation, while vomiting, polydipsia and anorexia were seen a few days prior to admission. Physical examination revealed prostatomegaly. Biochemistry results were compatible with postrenal azotemia. Abdominal imaging confirmed prostatomegaly with consequent urethral obstruction, and ultrasound-guided fine needle aspiration cytology of the prostate gland was consistent with granulomatous inflammation. The dog was hospitalized, urethral patency was preserved and upon laparotomy a cystostomy tube was placed, and prostatic biopsy was obtained. Orchiectomy was also performed. Urine culture performed 2 days prior to the surgery was negative. Prostatic histopathology revealed mild to moderate lymphoplasmacytic prostatitis. Three months postoperatively, clinical signs had resolved completely and urinations remained normal while the dog is still in good health 3 years after diagnosis. This is the first case of canine lymphoplasmacytic prostatitis in which clinical signs, diagnostic evaluation, management and long-term follow up are available.

A Controlled Trial of Polyglytone 6211 versus Poliglecaprone 25 for Use in Intradermal Suturing in Dogs.

The objective of this work was the comparative evaluation of the healing process after employing 4/0 poliglecaprone 25 and 4/0 polyglytone 6211 in a continuous intradermal suture pattern. Ten Beagle dogs were used, in which skin incisions were created surgically and subsequently were sutured by means of continuous intradermal pattern using polyglytone 6211 or poliglecaprone 25 suture. Cosmetic, clinical, and histologic scores were evaluated. The cosmetic appearance of the wounds was blindly evaluated on days 7, 14, 28, 180, 360, 730, and 1095. On the same days, tissue biopsy was performed for histological evaluation. Clinical evaluation was performed initially daily, then weekly, monthly, and finally yearly, till day 1095. The clinical appearance of the intradermal pattern with both sutures was initially very good, deteriorated in the second post-operative month and thereafter improved. The cosmetic, clinical, and histological differences between the two suture materials were minimal and statistically insignificant. Polyglytone 6211 is sufficient for use in intradermal suturing in dogs. However, its earlier absorption compared to poliglecaprone 25 did not have any beneficial effect on cutaneous wound healing and scar appearance in the experimental animals.

Contrast enhanced computed tomography assessment of superficial inguinal lymph node metastasis in canine mammary gland tumors.

Mammary gland neoplasms are predominant in dogs. However, sentinel lymph node (SLN) status assessment criteria have not been established for these cases. In this retrospective, secondary analysis, diagnostic case control study, CT images of 65 superficial inguinal SLNs were obtained before and 1, 3, 5, and 10 min after intravenous administration of contrast agent (iopamidol 370 mgI/mL). The presence and degree of postcontrast enhancement were assessed, by means of the median absolute density value and the maximum absolute density value at any time point in the center and in the periphery of each SLN measured in Hounsfield units (HU), before and after contrast agent administration. These values were compared with histopathological findings postsurgical excision. Receiver operating characteristic analysis was conducted. The absolute density values ranged widely at each time point and within each group of nodes (negative, positive, control group). At all time points, the median density value in the center and in the periphery was significantly higher in metastatic than in non-metastatic SLNs (P ≤ .014). Among the parameters tested, the median absolute density value measured in the periphery of the SLN 3 min after injection showed the highest sensitivity, specificity, and accuracy (AUC) (87.5%, 82.1%, and 92.1% respectively), with a cutoff value of 50.9 HU. The maximum absolute density value at any time point in the center and periphery of the SLNs was also significantly higher in metastatic SLNs compared to non-metastatic (P ≤ .001). With a cutoff value of 59.5 HU, the maximum absolute density value in the periphery of the SLN displayed high sensitivity and specificity (87.5% and 89.3%, respectively). The results of this study support the hypothesis that contrast enhanced CT imaging may aid in the assessment of SLN metastasis in dogs with mammary gland neoplasms.

Surgical Management of Feline Extrahepatic Biliary Tract Diseases.

Extrahepatic biliary obstruction occurs infrequently in cats. Pathophysiology of biliary obstruction is characterized by cholestasis, obstruction, inflammation, and exudation. Clinical signs and laboratory examination findings are nonspecific. Ultrasonographic examination of the biliary tract aids significantly in diagnosis. The aims of feline biliary surgery are to determine the underlying cause and extent of the obstruction, restore bile flow to the gastrointestinal tract, and prevent bile leakage and subsequent peritonitis. Surgical techniques to restore bile flow and decompress the biliary distension include cholecystostomy tube placement and choledochal stenting, cholecystectomy, choledochotomy, and biliary diversion procedures. Surgical management of extrahepatic biliary obstruction carries a fair to guarded prognosis. Cats undergoing biliary diversion procedures have poorer outcomes than those undergoing nondiversion procedures. Cats with neoplastic involvement have significantly shorter lives than those with inflammatory involvement.

Jackson-Henderson technique for the revision surgery following PDA rupture in a dog.

A 3-month-old female intact Maltese dog, was referred for further investigation and management of a patent ductus arteriosus (PDA), which was diagnosed with a grade V murmur during thoracic auscultation and a palpable thrill in the left third intercostal space during routine vaccination. Echocardiographic findings included left ventricle dilatation, high velocity continuous ductal flow in the pulmonary valve and a patent ductus arteriosus. Hematological and biochemical abnormalities were not detected. A left forth intercostal thoracotomy was performed and during dissection, the medial wall of the duct was perforated resulting in hemorrhage. Digital pressure was applied over the ductus and bleeding ceased. An attempt for further dissection aggravated bleeding so it was decided to abandon surgery and to reoperate the dog using a different technique. Three months after surgery a second procedure was scheduled. A Jackson-Henderson technique was chosen for the ductus ligation, which was completed through a left fourth intercostal thoracotomy and the dog was discharged 2 days postoperatively. The dog was reexamined at 2 and 8 months after surgery and found with no clinical evidence of heart disease. In conclusion the Jackson-Henderson technique was used in the second surgery for closure of the ductus in order to avoid dissection of the medial aspect of the ductus, where adhesions were formed and the dog was free of clinical signs of heart disease 2 and 8 months postoperatively.

The Benefits of Expert Instruction in Microsurgery Courses.

BACKGROUND: Microsurgery requires repeated practice and training to achieve proficiency, and there are a variety of curriculums available. This study aims to determine the importance of an expert instructor to guide students through procedures. We compared student proficiency across two microsurgery courses: one with (Columbia University, United States [CU] cohort) and one without a dedicated microsurgery instructor (University of Thessaloniki, Greece [UT] cohort). METHODS: Students were divided into two cohorts of 22 students (UT cohort) and 25 students (CU cohort). Student progress was evaluated by examining patency (lift-up and milking tests), anastomotic timing, and quality (Anastomosis Lapse Index [ALI]) of end-to-end arterial and venous anastomoses on day 1 and again on day 5. Chi-squared tests evaluated patency immediately and 30 minutes postoperation. t-Tests evaluated anastomotic timing and ALI scores. p-Values < 0.05 were considered significant. RESULTS: We evaluated progress within and between each cohort. Within the CU cohort, the quality of the arterial and venous anastomosis improved, respectively (by 54%, p = 0.0059 and by 43%, p = 0.0027), the patency of both the arterial and venous anastomosis improved, respectively (by 44%, p = 0.0002 and by 40%, p = 0.0019), and timing of arterial and venous anastomosis reduced respectively (by 36%, p = 0.0002 and by 33%, p = 0.0010). The UT cohort improved the quality of their arterial anastomoses (by 29%, p = 0.0312). The UT cohort did not demonstrate significant improvement in the other above-mentioned parameters. The CU cohort improved materially over the UT cohort across categories of quality, patency, and timing. CONCLUSION: There are clear benefits of an expert instructor when examining the rate of progress and proficiency level attained at the conclusion of the course. We suggest students who are seeking to maximize proficiency in microsurgical procedures enroll in courses with an expert instructor.

Contrast-enhanced voiding urosonography: A new, radiation-free, alternative method for imaging of urinary bladder and urethra in healthy dogs.

Contrast-enhanced voiding urosonography (CE-VUS) has been generally considered as a promising tool to diagnose vesicoureteral reflux and abnormalities in lower urinary tract in human patients, especially in children. The purpose of this prospective study is to evaluate the quality of images of the urinary bladder and urethra obtained by CE-VUS using a second-generation ultrasound contrast agent (SonoVue®) in healthy dogs and to investigate the safety profile of SonoVue® after intravesical administration. Eighty-four CE-VUS examinations with SonoVue® were successfully performed in both unsedated (39/84) and sedated (45/84) dogs. Contrast-enhanced voiding urosonography examination of urinary bladder was technically successful in all (84/84) dogs. The image quality was not considered adequate in five (5/84) dogs including three dogs in whom layering of contrast media during filling phase was observed and two dogs with premature destruction of microbubbles. In these five dogs, the problem was readily recognized and corrected such that the procedure was still successfully undertaken. The assessment of the urethra during spontaneous micturition was successfully performed in all (84/84) dogs in whom voiding was elicited during the examination. No side effects were observed after intravesical application of SonoVue®. This study demonstrates that CE-VUS is a feasible and valuable technique to evaluate low urinary tract morphology and function in dogs. Based on our review of the literature, there are no published reports about the use of this method in dogs.

Congenital Unilateral Ureteral Stenosis With Hydronephrosis in a Kitten.

A 4-month-old, intact male, domestic longhair cat was admitted with a 2-month history of abdominal distention. Physical examination revealed a mild inspiratory distress and a large palpable intraabdominal mass, in an otherwise bright and alert cat. Abdominal ultrasonography revealed a large hypoechoic cystic structure compatible with hydronephrosis or a renal cyst. On exploratory celiotomy, hydronephrosis of the right kidney was documented and ureteronephrectomy was performed. Histopathology of the excised tissues revealed severe stenosis in the proximal ureteral lumen without evidence of obstructive material, a normal ureteral epithelium and severe atrophy of the renal cortex and medulla, supporting the diagnosis of congenital unilateral ureteral stenosis. The cat recovered uneventfully and 8 months later was in excellent clinical condition. Congenital ureteral stenosis with secondary hydronephrosis may occur rarely in cats and should be included in the differential diagnosis of progressive abdominal distention in young cats.

Retroperitoneal Abscess Associated With a Migrating Grass Awn in a Cat: Treatment With Omentalization and Grass Awn Removal.

An 18-month-old domestic short hair male castrated cat presented with a history of fever of unknown origin of 1-year duration. Abdominal ultrasound revealed a mixed echogenicity mass. Cytological examination of the fluid obtained through fine needle aspiration was consistent with a retroperitoneal abscess. The cat underwent a midline celiotomy and the abscess was opened, lavaged, and omentalized. Antibiotics were also administered. Two months after surgery, the cat represented with a fluctuant swelling in the right flank region at the lumbodorsal triangle. Abdominal and mass ultrasound showed a mixed echogenicity swelling in the right flank. Under gas anesthesia, the swelling was surgically explored and a 0.4 cm long grass awn was found and removed. Telephone communication with the owners 6 months after surgery found the cat to be free of clinical signs.

Clinical topographical anatomy of the gastro-oesophageal junction in the cat.

Objectives The purpose of the present study was to describe histologically the gastro-oesophageal junction in the cat and interrelationships of this region. Our hypothesis was that cats are devoid of abdominal oesophagus. Methods Three centimetres of the terminal oesophagus, the phreno-oesophageal membrane with 1-2 cm margins of the diaphragmatic crural muscle and the proximal 3 cm of the gastric cardia were obtained from nine domestic shorthair cats and one domestic longhair cat that were euthanased for reasons other than digestive tract pathology. Longitudinal samples were examined histologically. Evaluated parameters included the location of the phreno-oesophageal membrane with reference to the transition between the oesophageal and gastric mucosa, the thickness of the circumferential smooth muscle of the muscular layer of the distal oesophagus at points 3 mm and 6 mm cranial to the mucosa transition, and the thickness of the circumferential smooth muscle layer at the mucosa transition level. Median differences in the thickness of the smooth muscle layer were compared by performing non-parametric statistical analysis using the Mann-Whitney U-test. Results The transition of the oesophageal to gastric mucosa was abrupt and corresponded to the point of insertion of the phreno-oesophageal membrane at the diaphragm level in all cats. The mean thickness of the circumferential smooth muscle layer at the point of oesophageal to gastric mucosa transition was significantly greater than the mean thickness of the oesophageal circumferential smooth muscle layer at 3 mm and 6 mm cranial to the mucosa transition ( P ⩽0.05). The increased muscle thickness at the gastro-oesophageal junction correlates with the accepted location of the high-pressure zone, reflecting the caudal oesophageal sphincter. It seems that the whole oesophagus was situated within the thoracic rather than the abdominal cavity. Conclusions and relevance No distinct abdominal oesophagus was observed in nine domestic shorthair cats and one domestic longhair cat. These findings might have implications for the pathophysiology of hiatal hernia in cats.

ASSESSMENT OF SENTINEL LYMPH NODE METASTASIS IN CANINE MAMMARY GLAND TUMORS USING COMPUTED TOMOGRAPHIC INDIRECT LYMPHOGRAPHY.

In the staging process of the breast cancer, demonstrating metastasis of the sentinel lymph node (SLN) has an important prognostic value, in both humans and animals. The aim of this prospective case-control study was to determine the diagnostic value of computed tomographic indirect lymphography (CT-LG) for detecting SLN metastasis in dogs with mammary cancer. Thirty-three female dogs with tumors in the abdominal and inguinal mammary glands were prospectively selected and subjected to CT-LG, 1 and 5 min after injection of 1 ml of contrast agent (iopamidol) in the subareolar tissue of the neoplastic and the contralateral normal mammary glands. The pattern of postcontrast opacification, degree of postcontrast enhancement, and size and shape were assessed in 65 SLNs in total and were correlated with histopathological findings. The absence of opacification or heterogeneous opacification 1 min after contrast medium injection showed the highest sensitivity, specificity, and accuracy (93%, 100%, and 98.4%, respectively). In images taken 1 min after injection, an absolute density value lower than 444 Hounsfield units (HU) in the center of the SLN also provided significant sensitivity and specificity (93.8% and 75%, respectively). The size and shape of the SLN (maximum and minimum diameter, maximum/minimum diameter ratio, maximum diameter/height of fifth thoracic vertebral body ratio) showed the lowest sensitivity and specificity. Results of this study support the hypothesis that CT-LG could help in the assessment of SLN metastasis in cases of mammary gland tumors in dogs.

Comparison of maximum force to failure of 4 thoracostomy tube connecting devices.

OBJECTIVE: To compare the maximum force and displacement to failure of 4 different types of thoracostomy tube connecting devices. STUDY DESIGN: Experimental in vitro study. STUDY POPULATION: Four types of thoracostomy tube connecting devices (n = 10 each). METHODS: Four different connecting device configurations (10 constructs each) were tested by maximum distraction to failure using a dynamometer: (1) CTTWW-a 3-way connector with a male luer slip attached to a thoracostomy tube by a Christmas tree adapter and secured to the tube with 21 gauge orthopedic wire; (2) CTTWRCW-a 3-way connector with a male luer lock with a rotating collar attached to a tube by a Christmas tree adapter and secured to the tube with 21 gauge orthopedic wire; (3) LVSBC-a Lopez valve attached to a tube with its short-barbed connector; and (4) LVLBC-a Lopez valve attached to a tube with its long-barbed connector. RESULTS: The maximum distraction force to failure was significantly greater for CTTWRCW (250.9 N; range 143.7-293.6) than CTTWW (132.9 N; range 84.2-224.1), LVLBC (90.8 N; range 74.0-123.4), and LVSBC (54.6 N; range 39.6-164.2). The median displacement to failure of CTTWRCW (150 mm; range 54-190) was significantly longer than that of CTTWW (34.5 mm; range 22-70), LVLBC (32.5 mm; range 24-57), and LVSBC (16 mm; range 11-69). CONCLUSION: The CTTWRCW group required greater force to create failure and had a longer displacement to failure, making it a more secure choice for connection to thoracostomy tubes.