Presentation, diagnosis, and outcomes of cats undergoing surgical treatment of ectopic ureters

OBJECTIVE

To describe the signalment, treatment, complications, and outcomes of cats treated surgically for ectopic ureters.

STUDY DESIGN

Retrospective, multi-institutional study.

ANIMALS

Twelve client-owned cats.

METHODS

Medical records of cats diagnosed with unilateral or bilateral ectopic ureters were reviewed and analyzed. Data reported included signalment, clinical signs, diagnostics, open celiotomy, or cystoscopic surgical interventions, and outcomes.

RESULTS

Seven of the 12 cats in the study population were female or female spayed and the median age at time of presentation was 4 years, with an interquartile range (IQR) of 6 months-14 years. Presurgical diagnostic imaging diagnosed ectopic ureters by abdominal ultrasound (8/10), contrast enhanced computed tomography (3/3), fluoroscopic urography (3/4), or cystoscopy (6/7). Eight of 12 cats had extramural ectopic ureters and six cats were affected bilaterally. Eight affected cats underwent ureteroneocystostomy, one cat underwent neoureterostomy, two cats underwent cystoscopic laser ablation, and one cat underwent nephroureterostomy. Immediate postoperative complications occurred in three cats; one cat required additional surgical intervention. Short-term complications occurred in three cats, and long-term complications in two cats. All cats that underwent surgical or cystoscopic intervention had improvement of their urinary incontinence scores, with complete resolution in 11 cats.

CONCLUSION

Surgical correction of ectopic ureters in cats is associated with good long-term outcomes. Ectopic ureters in cats are commonly extramural and bilateral. Postoperative outcomes were acceptable and there were few postoperative complications, with varying forms of surgical correction.

CLINICAL SIGNIFICANCE

Ectopic ureters in cats are rare but urinary incontinence can be corrected or improved successfully with surgery.

Canine Prostate Cancer: Current Treatments and the Role of Interventional Oncology

Prostate carcinoma is one of the most common cancers worldwide in men, with over 3 million men currently living with prostate carcinoma. In men, routine screening and successful treatment schemes, including radiation, prostatectomy, or hormone therapy, have allowed for high survivability. Dogs are recognized as one of the only mammals to spontaneously develop prostate neoplasia and are an important translational model. Within veterinary medicine, treatment options have historically been limited in efficacy or paired with high morbidity. Recently, less invasive treatment modalities have been investigated in dogs and people and demonstrated promise. Below, current treatment options available in dogs and people are reviewed, as well as a discussion of current and future trends within interventional treatment for canine PC.

Investigating PSMA differential expression in canine uroepithelial carcinomas to aid disease-based stratification and guide therapeutic selection

BACKGROUND

In male dogs, uroepithelial cancers include invasive urothelial carcinoma (iUC) and prostate carcinoma (PCA). The inability to distinguish iUC involving the prostate from PCA results in indiscriminate clinical management strategies that could be suboptimal as first-line chemotherapy for iUC (cisplatin) and PCA (docetaxel) differ in people. Prostate specific membrane antigen (PSMA) is a transmembrane protein, and its overexpression has been identified in human prostate carcinoma and neovasculature associated with solid tumor growth. This study investigates whether differential PSMA expression exists between presumptive canine iUC and PCA among cell lines and archived patient samples, which might allow for improved accuracy in disease-based stratification and optimal chemotherapy selection. Additionally, in vitro sensitivities of reported canine iUC and PCA cell lines to uroepithelial directed chemotherapeutic agents were characterized.

RESULTS

Normalized PSMA gene and protein expressions were not significantly different between 5 iUC and 4 PCA cell lines. PSMA protein expression was uniformly observed in uroepithelial cancers regardless of anatomic origin from archived patient samples, further confirming that PSMA cannot differentiate iUC from PCA. In vitro sensitivity of cell lines to uroepithelial directed chemotherapeutics revealed that vinblastine exerted the broadest cytotoxic activity.

CONCLUSIONS

Differential expression of PSMA was not identified between canine iUC and PCA cell lines or archived patient samples, and PSMA alone cannot be used for disease stratification. Nonetheless given its conserved overexpression, PSMA may be a targetable surface marker for both canine iUC and PCA. Lastly, in uroepithelial carcinomas, vinblastine might exert the broadest anticancer activity regardless of cellular origin.

Diseases of the Canine Prostate Gland

In dogs, the most frequent diseases of the prostate gland are benign prostate gland hyperplasia (BPH), acute and chronic prostatitis, squamous metaplasia, and prostate tumors. New diagnostic tools comprise diagnostic markers in the blood and urine, as well as advanced imaging methods. The therapy can be initialized with the 5α-reductase-inhibitor finasteride or an anti-androgenic compound, and prolonged with a long-acting gonadotropin-releasing-hormone (GnRH)-agonist such as deslorelin. In case of prostatitis, effective antibiotics must be applied for weeks. Antibiotics must be able to penetrate into the prostate tissue; fluoroquinolones, clindamycin, and erythromycin are good choices and are in addition effective against mycoplasms. The chronical prostatitis cannot be differentiated from a neoplasia by sonography; a biopsy, histological, and bacteriological examination are required. Tumors of the prostate gland are seldom and mostly occur in castrated but in intact dogs. For the final diagnosis, a biopsy must be taken. Partial and total resection of the prostate gland by use of laser technique is possible but coincedes with many side effects and the prognosis is still futile. Immunotherapy combined with NSAIDs, targeted noninvasive thermotherapy, BRAF gene inhibitors, or prostate artery chemoembolization are promising methods.

Comparison of leakage pressures of vesicourethral anastomosis performed with intracorporeal suturing in a simulator and conventional suturing ex vivo in canine cadaveric tissue

OBJECTIVE

To compare conventional and intracorporeal vesicourethral anastomosis (VUA) in canine cadaveric tissue.

STUDY DESIGN

Cadaveric ex vivo study.

STUDY POPULATION

Twenty-eight canine bladders with urethra.

METHODS

Specimens after prostatectomy were randomly divided into intracorporeal (I) group or conventional (C) group. For the I group, VUA was performed in a simulator with laparoscopic needle holders and telescope. For the C group, the anastomosis was performed in vitro with standard instruments. The VUA was performed with 4-0 monofilament absorbable suture and was completed with two simple continuous sutures. Surgical time, leakage pressure, site of leakage, and number of suture bites were recorded.

RESULTS

Fourteen samples were entered in each group. The dorsal side of the anastomosis was initially performed, followed by the ventral side. The median suturing time was 30.8 minutes (range, 19.3-39.2) for the I group and 17.3 minutes (range, 9.2-21.3) for the C group (P < .0001). The median leakage pressure was 10.9 mm Hg (range, 4.1-29.7) for the I group and 10.8 mm Hg (range, 6.2-18.5) for the C group (P = .94). The median number of stitches was 20 (range, 14-26) for the I group and 19 (range, 11-28) for the C group (P = .96). The distribution of the site of leakage was similar between groups (P = .381).

CONCLUSION

Vesicourethral anastomosis can be performed with leakage pressures similar to intracorporeal and conventional suturing.

CLINICAL SIGNIFICANCE

This study represents the first step toward laparoscopic radical prostatectomy in dogs.

Comparative Pathobiology of Canine and Human Prostate Cancer: State of the Art and Future Directions

First described in 1817, prostate cancer is considered a complex neoplastic entity, and one of the main causes of death in men in the western world. In dogs, prostatic carcinoma (PC) exhibits undifferentiated morphology with different phenotypes, is hormonally independent of aggressive character, and has high rates of metastasis to different organs. Although in humans, the risk factors for tumor development are known, in dogs, this scenario is still unclear, especially regarding castration. Therefore, with the advent of molecular biology, studies were and are carried out with the aim of identifying the main molecular mechanisms and signaling pathways involved in the carcinogenesis and progression of canine PC, aiming to identify potential biomarkers for diagnosis, prognosis, and targeted treatment. However, there are extensive gaps to be filled, especially when considering the dog as experimental model for the study of this neoplasm in humans. Thus, due to the complexity of the subject, the objective of this review is to present the main pathobiological aspects of canine PC from a comparative point of view to the same neoplasm in the human species, addressing the historical context and current understanding in the scientific field.

Anti-CCR4 treatment depletes regulatory T cells and leads to clinical activity in a canine model of advanced prostate cancer

Background

Targeting regulatory T cell (Treg) infiltration is an emerging strategy for cancer immunotherapy. However, its efficacy in advanced prostate cancer remains unclear. Here, we showed the therapeutic efficacy of anti-Treg treatment in a canine model of advanced prostate cancer.

Methods

We used dogs with naturally occurring prostate cancer to study the molecular mechanism underlying Treg infiltration and the effect of anti-Treg treatment. Tumor-infiltrating Tregs was evaluated by immunohistochemistry, and the association with prognosis was examined in dogs with spontaneous prostate cancer. The molecular mechanism of Treg infiltration was explored by RNA sequencing and protein analyses. A non-randomized canine clinical trial was conducted to define the therapeutic potential of anti-Treg treatment for advanced prostate cancer. Human prostate cancer datasets were analyzed to compare gene expression in dogs and humans.

Results

Tumor-infiltrating Tregs were associated with poor prognosis in dogs bearing spontaneous prostate cancer. RNA sequencing and protein analyses showed a possible link between the CCL17–CCR4 pathway and the increase of tumor-infiltrating Tregs. Dogs with advanced prostate cancer responded to mogamulizumab, a monoclonal antibody targeting CCR4, with decreased circulating Tregs, improved survival, and low incidence of clinically relevant adverse events. Urinary CCL17 concentration and BRAF^V595E mutation were independently predictive of the response to mogamulizumab. Analysis of a transcriptomic dataset of human prostate cancer showed that the CCL17–CCR4 axis correlated with Foxp3. In silico survival analyses revealed that high expression of CCL17 was associated with poor prognosis. Immunohistochemistry confirmed that tumor-infiltrating Tregs expressed CCR4 in human patients with prostate cancer.

Conclusions

Anti-Treg treatment, through CCR4 blockade, may be a promising therapeutic approach for advanced prostate cancer in dogs and some population of human patients.

Comparison of outcomes between medical and surgical treatment in dogs with prostatic adenocarcinoma: a retrospective study

Background

Prostatic cancer is uncommon in dogs. Dogs with prostatic carcinoma have been reported to have a poor prognosis. Information regarding prognosis with various surgery options as well as prognosis with surgical vs. medical treatment is lacking. This retrospective study compares the outcomes of medical management to surgical treatment in dogs with prostatic adenocarcinoma and assesses the surgical outcomes of patients who underwent total prostatectomy (TP) and prostatocystectomy (TPC). The medical records of 41 dogs with prostatic adenocarcinoma, between February 2008 and June 2019, were reviewed for information on signalment, clinical signs in the initial evaluation, preoperative diagnostic imaging findings, treatment type (non-surgical or surgical), surgery type, postoperative complications, adjunctive medical therapy, and survival time. The dogs were divided into non-surgical (n = 12) or surgical (n = 29) groups. The surgical group was subdivided into the TP (n = 20) and TPC (n = 9) subgroups.

Results

Age was not significantly different between the surgical (median 13.1 years [8.4–15.4] years) and the non-surgical groups (median 10.8 [7.7–15.3] years). Body weight (BW) was also not significantly different between the surgical (median 6.8 kg [2.4–34.5 kg]) and non-surgical groups (median 6.4 kg [3.7–9.12 kg]). The overall median survival time (MST) from the initial evaluation was significantly longer in the surgical than in the non-surgical group (337 vs. 90.5 days). The postoperative MST was significantly longer in the TP group than in the TPC subgroup (510 vs. 83 days). As TPC was performed in cases of tumor progression, its postoperative complications were severe, resulting in a shorter MST. Ten (50%) and 6 patients (30%) in the TP subgroup postoperatively showed mild and severe urinary incontinence, respectively, whereas all patients in TPC subgroup did show severe incontinence.

Conclusion

Results of the study suggest that surgical treatment of prostatic carcinoma results in longer survival times over medical management alone. In particular, TP might be recommended for improving survival time and quality of life in canine prostatic adenocarcinoma that does not infiltrate the bladder. Early detection is key for a survival advantage with surgical treatment.

Total Perineal Prostatectomy: A Retrospective Study in Six Dogs

Simple Summary

Prostatectomy is a surgical procedure that involves the removal of the prostate, either partially (partial prostatectomy) or completely (total prostatectomy). Total prostatectomy is considered technically difficult to perform, carrying with it many complications and unwanted side effects. The standard total prostatectomy provides a caudal celiotomy: a pubic symphysiotomy or pubic and ischial osteotomies may be required in order to improve access to the prostate gland and the pelvic urethra. Perineal hernia refers to the herniation of pelvic and abdominal viscera into the subcutaneous perineal region through a pelvic diaphragm weakness. A concomitant prostatic disease is observed in 25–59% of cases: the prostate can remain in the physiological location or displace within the hernial contents. Surgery is the treatment of choice in case of perineal hernia. The aim of this article is to describe retrospectively the total perineal prostatectomy in dogs presenting perineal hernia with concomitant prostatic diseases which required the removal of the gland. The experience in six patients (three dogs with the prostate within hernial contents and three dogs with intrapelvic prostate) are reported as well as advantages, disadvantages, and limitations of the surgical procedure.

Abstract

Perineal hernia refers to the herniation of pelvic and abdominal viscera into the subcutaneous perineal region through a pelvic diaphragm weakness: a concomitant prostatic disease is observed in 25–59% of cases. Prostatectomy involves the removal of the prostate, either partially (partial prostatectomy) or completely (total prostatectomy). In case of complicated perineal hernia, staged procedures are recommended: celiotomy in order to perform colopexy, vasopexy, cystopexy, and/or to treat the prostatic disease, and perineal access in order to repair the perineal hernia. Very few reports relate prostatectomy using a perineal approach and, to the extent of the author’s knowledge, this technique has not been thoroughly investigated in the literature. The aim of this article is to retrospectively describe the total perineal prostatectomy in dogs presenting perineal hernia with concomitant prostatic diseases which required the removal of the gland. The experience in six dogs (three dogs with the prostate within hernial contents and three dogs with intrapelvic prostate) is reported as well as advantages, disadvantages, and limitations of the surgical procedure. In the authors’ clinical practice, total perineal prostatectomy has been a useful surgical approach to canine prostatic diseases, proven to be safe, well tolerated, and effective.

Comparative pathology of dog and human prostate cancer

Though relatively rare in dogs, prostate cancer (PCa) is the most common non-cutaneous cancer in men. Human and canine prostate glands share many functional, anatomical and physiological features. Due to these similarities, canine PCa has been proposed as a model for PCa in men. PCa is typically androgen-dependent at diagnosis in men and for this reason, androgen deprivation therapies (ADT) are important treatments for advanced PCa in men. In contrast, there is some evidence that PCa is diagnosed more commonly in castrate dogs, at which point, limited therapeutic options are available. In men, a major limitation of current ADT is that progression to a lethal and incurable form of PCa, termed castrate-resistant prostate cancer (CRPC), is common. There is, therefore, an urgent need for a better understanding of the mechanism of PCa initiation and progression to CRPC to enable the development of novel therapeutic approaches. This review focuses on the functional, physiological, endocrine and histopathological similarities and differences in the prostate gland of these species. In particular, we focus on common physiological roles for androgen signalling in the prostate of men and dogs, we review the short- and longer-term effects of castration on PCa incidence and progression in the dog and relate how this knowledge may be relevant to understanding the mechanisms of CRPC in men.

Procedural description and prospective evaluation of short-term outcome for the use of prostatic artery embolization in dogs with carcinoma of the prostate

OBJECTIVE

To describe the procedure of prostatic artery embolization (PAE) in dogs with prostatic carcinoma and to evaluate the short-term outcome for treated dogs.

ANIMALS

20 client-owned dogs with prostatic carcinomas between May 2014 and July 2017.

PROCEDURES

In this prospective cohort study, dogs with carcinoma of the prostate underwent PAE with fluoroscopic guidance. Before and after PAE, dogs underwent CT and ultrasonographic examinations of the prostate, and each owner completed a questionnaire about the dog's clinical signs. Results for before versus after PAE were compared.

RESULTS

Prostatic artery embolization was successfully performed in all 20 dogs. Tenesmus, stranguria, and lethargy were significantly less common 30 days after PAE (n = 2, 1, and 0 dogs, respectively), compared with before PAE (9, 10, and 6 dogs, respectively). Median prostatic volume was significantly less 30 days after PAE (14.8 cm3; range, 0.4 to 48.1 cm3; interquartile [25th to 75th percentile] range, 6.7 to 19.5 cm3), compared with before PAE (21.7 cm3; range, 2.9 to 77.7 cm3; interquartile range, 11.0 to 35.1 cm3). All dogs had a reduction in prostatic volume after PAE, with a median prostatic volume loss of 39.4% (95% CI, 20.3% to 59.3%).

CONCLUSIONS AND CLINICAL RELEVANCE

Prostatic artery embolization was associated with decreased prostate volume and improved clinical signs in this cohort. The short-term response to PAE appears promising, and evaluation of the long-term impact on survival time is needed.

Laparoscopic-assisted cutaneous ureterostomy in a canine patient with prostatic carcinoma

A 9‐year‐old neutered male Dachshund dog was assessed for stranguria. An enlarged prostate was identified on physical examination, and a diagnosis of prostatic carcinoma confirmed by cytology. Due to a neoplastic lower urinary tract obstruction, palliative surgical urinary diversion treatment was performed with laparoscopic assisted cutaneous ureterostomy (LACU). The dog recovered well without any major complications. Adjuvant chemotherapy was maintained and continued for post‐surgical medical therapy. This report describes a novel minimally invasive assisted technique in canine patients for palliative treatment of prostatic neoplasia.

Drug-eluting bead chemoembolization for the treatment of nonresectable hepatic carcinoma in dogs: A prospective clinical trial

Background

Effective treatment options for nonresectable hepatic carcinoma (HC) in dogs are limited.

Hypothesis/Objective

Objectives were to report outcomes, complications, and tumor responses via computed tomography (CT) assessment after drug‐eluting bead transarterial chemoembolization (DEB‐TACE) for nonresectable HC in dogs. The authors hypothesized that major complications would be uncommon and short‐term CT assessment would demonstrate stable disease or partial response.

Animals

Client‐owned dogs (n = 16) with nonresectable HC.

Methods

Prospective, single‐arm clinical trial. Drug‐eluting bead transarterial chemoembolization was performed to varying levels of blood flow stasis. Computed tomography imaging was compared before and approximately 12 weeks after initial treatment.

Results

Drug‐eluting bead transarterial chemoembolization was successfully administered in all attempts. Based on percent change in elliptical tumor volume response (mL), stable disease (8/13; 62%) was the most common outcome followed by partial response (3/13; 23%) and progressive disease (2/13; 15%) with a median of 74 days (range, 39‐125) after initial treatment. Median tumor volume (mL) after DEB‐TACE decreased in volume by 13% (range, 56% decrease to 77% increase). Mild complications consistent with postembolization syndrome occurred after 7/27 (26%) treatments. Major complications occurred after 3/27 (11%) treatments: hepatic abscess/septicemia (2) and cholecystitis/death (1), resulting in treatment‐induced death after 2/27 (7%) treatments. Median survival time after treatment was 337 days (range, 22‐1061). Dogs with a presenting complaint of weight loss (P = .02) had a significantly shorter median survival time (126 days; range, 46‐337) than those dogs without prior history of weight loss (582 days; range, 22‐1061).

Conclusions

Drug‐eluting bead transarterial chemoembolization for nonresectable HC is a feasible procedure, which promoted stable disease or partial response in 85% of dogs in this study sample.

Investigation of the use of microwave ablation with and without cooling urethral perfusion for thermal ablation of the prostate gland in canine cadavers

OBJECTIVE

To investigate the use of microwave ablation (MWA) with cooling urethral perfusion and with no perfusion (MWA-UP and MWA-NP, respectively) for prostate gland ablation in canine cadavers.

ANIMALS

Cadavers of 18 sexually intact male dogs.

PROCEDURES

After technique refinement in 2 cadavers, laparotomy with ultrasound-guided MWA-UP (n = 8) or MWA-NP (8) of the prostate gland was performed in 16 cadavers. Normograde cystourethroscopy was performed before and after treatment; recorded images were reviewed in a blinded manner for scoring of urethral mucosal discoloration and loss of integrity. Difficulty with cystoscope insertion was recorded if present. Excised prostate glands were fixed for serial sectioning, gross measurements, and calculation of percentage ablation. Percentages of prostate tissue necrosis from MWA, denuded urethral mucosa, and depth of epithelial surface loss in an adjacent section of the colon were estimated histologically. Variables of interest were statistically analyzed.

RESULTS

Difficulty with cystoscope insertion after treatment was significantly more common and scores for urethral mucosal discoloration and loss of integrity were significantly higher (indicating more severe lesions) for the MWA-NP group than for the MWA-UP group. The histologically assessed percentage of denuded urethral mucosa was also greater for the MWA-NP group. Overall median percentage prostate gland ablation was 73%; this result was not associated with prostate gland volume or chronological order of treatment.

CONCLUSIONS AND CLINICAL RELEVANCE

MWA-UP induced subtotal thermal necrosis of prostate glands in canine cadavers while limiting urethral mucosal injury. Further study is required to optimize the technique and evaluate its safety and efficacy in vivo as a future curative-intent treatment for prostatic tumors in dogs.

Penile urethral resection and anastomosis augmentation with regional tissue tension relieving technique: A cadaveric mechanical study and clinical outcome in two dogs

OBJECTIVE

To describe penile urethral augmentation anastomosis (PURAA) for resection anastomosis (RA) of the canine penile urethra by using autogenous tissue in two dogs and to determine the mechanical properties of the augmentation technique in cadaveric specimens.

STUDY DESIGN

Cadaveric study and two case reports.

ANIMALS

Sixteen canine cadavers and two dogs with urethral obstruction.

METHODS

The lower urogenital system was harvested from cadavers and randomized into two groups: simple (S) and augmented (AUG) RA of the urethra. Tensile strength and peak load were compared between the two groups. Two dogs were treated with PURAA for urethral obstruction secondary to juxtaurethral neoplasms.

RESULTS

Minimal tensile strength (MITS) and maximal tensile strength (MATS) were greater in the AUG group (MITS, 54.36 ± 24.0 N; MATS, 75.37 ± 34.79 N) compared with the S group (MITS, 11.78 ± 4.93 N, P = .0014; MATS, 13.74 ± 3.89 N, P = .0015). Both dogs recovered without complications. Histopathological examinations were consistent with a lipomatous mass in both cases. Both dogs had good medium-to-long-term outcomes.

CONCLUSION

The augmentation technique improved the tensile properties of penile RA in normal cadavers and was associated with successful outcomes in two dogs.

CLINICAL SIGNIFICANCE

Penile urethral augmentation anastomosis may help prevent stricture or leakage secondary to tension at the surgical site after penile urethral RA.

Treatment of genitourinary carcinoma in dogs using nonsteroidal anti-inflammatory drugs, mitoxantrone, and radiation therapy: A retrospective study

Background

Locoregional tumor control and prolonged survival for dogs with genitourinary carcinoma (CGUC) reportedly are achievable using treatment with radiotherapy (RT) with or without adjunctive chemotherapy and nonsteroidal anti‐inflammatory drugs (NSAIDs).

Objectives

To characterize event‐free and overall survival after treatment of CGUC using NSAIDs, mitoxantrone (MTX), and a standardized RT protocol (57 Gy in 20 fractions).

Animals

Fifty‐one client‐owned dogs treated between 2008 and 2017.

Methods

Dogs were retrospectively categorized into treatment groups: (a) first‐line concurrent chemoradiotherapy (≥1 dose of MTX started within 1 month of RT); (b) first‐line chemotherapy (MTX administered for >1 month before RT without tumor progression); (c) RT as a salvage procedure (MTX, surgery or both with subsequent locoregional tumor progression before RT). Treatment‐induced toxicoses, event‐free survival (EFS), and overall survival times (OSTs) were recorded. The influence of demographics, staging, and treatment‐related factors on survival was assessed using Cox proportional hazards modeling.

Results

Median EFS and OST for all dogs were 260 and 510 days with no significant differences among groups 1 (n = 39), 2 (n = 4), and 3 (n = 8). Both EFS and OST were shorter in dogs with moderate to severe clinical signs (P < .001 and P < .001, respectively); OST was shorter in dogs with prostatic involvement (P = .02). Permanent urinary incontinence developed in 16 dogs (31%) at a median of 70 days postirradiation; other toxicoses were mild and self‐limiting.

Conclusions and Clinical Importance

Mild clinical signs and lack of prostate involvement were associated with favorable prognosis for survival. Client education regarding the risk of urinary incontinence is warranted.

Contrast-Enhanced Ultrasound Imaging of Prostate Gland in Neutered Dogs

Prostatic neoplasia (PN) occurs in 5-7% of dogs with prostatic disease, with castrated dogs having the same or higher prevalence when compared to intact dogs. Considering the promising results achieved by performing contrast-enhanced ultrasound (CEUS) in intact dogs to detect PN, the present study aimed to acquire data on the prostatic perfusion pattern in neutered dogs. CEUS was performed in 64 neutered dogs, using a 5-7.5 MHz linear transducer with coded harmonic capability, dedicated analytical software, and a second-generation contrast agent, SonoVue. After B-mode evaluation was performed to assess mean prostate volume, the CEUS examination was undertaken. The flow of contrast agent was visible 10 s after injection. The subcapsular vessels were highlighted and produced rapid peripheral rim enhancement. Subsequently, the contrast agent reached the prostatic urethra via the parenchymal arterioles and gradually reached the entire prostate. Perfusion peak intensity (PPI) and time to peak (TTP) values were respectively 45.3% and 34.1 s. The measured parameters were compared with those obtained in previous studies on intact dogs with normal and with pathological patterns. In this study, CEUS showed features that may be promising for its use as a diagnostic tool for early detection of PN in neutered dogs.

Urodynamic and morphometric characteristics of the lower urogenital tract of male Beagle littermates from four months to two years of age

OBJECTIVE

To describe functional and anatomic changes of the lower urogenital tract of healthy male dogs during the sexually immature period and up to 2 years of age by urodynamic and morphometric assessment.

ANIMALS

6 sexually intact male Beagle littermates.

PROCEDURES

Dogs underwent electromyography-coupled urodynamic tests, CT-assisted retrograde urethrography, prostatic washes, and blood sampling monthly from 4 through 12 months of age and then at 3-month intervals. Urodynamic and morphometric variables and serum canine prostate-specific esterase concentrations were analyzed by statistical methods.

RESULTS

Integrated pressure of the urethra was significantly increased beginning at 8 months of age, compared with earlier time points. Urethral pressure peak amplitudes varied among anatomic regions. During bladder filling, few electromyographic signals were concurrent with urethral pressure peaks; these were most commonly detected in the penile portion of the urethra. Urethral length and prostate gland volume were significantly greater from 7 to 24 months of age than at younger ages. Urethral length was approximately 26 to 27 cm after 9 months, and prostate gland volume was approximately 11 to 12 cm³ after 11 months of age. Serum canine prostate-specific esterase concentrations correlated with prostate gland volume. Urinary bladder threshold volume was significantly increased at 6 months of age, compared with that at 4 months, with a maximum of 197.7 mL at 24 months.

CONCLUSIONS AND CLINICAL RELEVANCE

Urethral resistance was acquired at approximately 8 months of age, when growth of the lower urinary tract was incomplete. Electromyographic and integrated pressure measurement results and the distribution and amplitude of urethral pressure peaks highlighted the potential role of the prostate gland and possibly the bulbocavernosus muscles in control of continence.

PDA Indolylmaleimides Induce Anti-Tumor Effects in Prostate Carcinoma Cell Lines Through Mitotic Death

Castrate resistant prostate cancer in men shares several characteristics with canine prostate cancer (PCa). Due to current insufficient therapies, evaluating novel therapeutic agents for late-stage PCa is of considerable interest for both species. PDA indolylmaleimides showed anticancer effects in several neoplastic cell lines. Herein, a comparative characterization of PDA-66 and PDA-377 mediated effects was performed in human and canine PCa cell lines, which is also the first detailed characterization of these agents on cells derived from solid tumors in general. While PDA-377 showed only weak growth inhibition on human PCa cell lines, PDA-66 inhibited proliferation and induced apoptosis in human and canine cell lines with concentrations in the low micromolar range. Morphological characterization and whole transcriptome sequencing revealed that PDA-66 induces mitotic death through its microtubule-depolymerizing ability. PDA-66 appears to be a worthwhile anti-mitotic agent for further evaluation. The similarities in cellular and molecular response observed in the cell lines of both origins form a solid basis for the use of canine PCa in vivo models to gain valuable interchangeable data to the advantage of both species.

Do Canine Pancreatic Neuroendocrine Neoplasms Resemble Human Pancreatic Neuroendocrine Tumours? A Comparative Morphological and Immunohistochemical Investigation

Although canine pancreatic neuroendocrine neoplasms (PanNENs) have been proposed as a model for the counterpart human neoplasms, the type or grade of human PanNEN that they resemble is unclear. PanNENs in animals are classified as adenoma or carcinoma, whereas in humans they are classified as pancreatic neuroendocrine tumour (PanNET) if well-differentiated, or as pancreatic neuroendocrine carcinoma (PanNEC) if poorly differentiated. We evaluated 16 canine primary PanNENs and two metastases histologically and immunohistochemically, and graded them using the animal and human grading systems. All neoplasms had local or vascular invasion and were classified as pancreatic islet cell carcinomas according to the current WHO classification. The Ki-67 index was low in all cases (0.01-1.50%). All had cytoplasmic expression of synaptophysin and insulin but were immunonegative for glucagon, confirming a functional diagnosis of canine insulinoma. Membranous expression of SSTR2A and nuclear expression of ATRX, but no p53 expression, was found in all neoplasms. One primary tumour was diagnosed as a mixed neuroendocrine-non-neuroendocrine neoplasm, which is the first report of this neoplasm in dogs. The other 15 primary tumours and both metastatic tumours were graded as PanNET G1, according to the human WHO classification. We conclude that canine PanNENs share well-differentiated histomorphology, SSTR2A expression and absence of nuclear p53 immunolabelling with human PanNETs G1. However, they differ in ATRX gene expression and functionality, and seem to have a worse prognosis than human PanNETs G1, although their generally low Ki-67 index precludes more precise assessment of prognosis. Membranous SSTR2A expression renders canine PanNENs potentially amenable to treatment with somatostatin analogues or SSTR targeted in-vivo imaging methods.

Prostatectomy as a treatment for canine prostate cancer: a literature review

Canine prostate cancer is a relatively rare condition that accounts for less than 1% of all cancers diagnosed in dogs (Obradovich et al., 1987; Bryan et al., 2007). Out of 431 dogs with prostatic conditions diagnosed in a Dutch center, 56 suffered from prostatic carcinoma (Teske et al., 2002). Several forms have been identified, of which adenocarcinoma (AC), transitional cell carcinoma (TCC), and undifferentiated cell carcinoma are the most common (Bennett et al., 2018; Cunto et al., 2019).

First robot-assisted radical prostatectomy in a client-owned Bernese mountain dog with prostatic adenocarcinoma

OBJECTIVE

To describe robot-assisted radical prostatectomy (RARP) and report the short-term outcome of a dog with prostatic cancer treated with RARP.

STUDY DESIGN

Case report ANIMALS: Client-owned 6-year-old male-neutered Bernese mountain dog.

METHODS

Robot-assisted radical prostatectomy was performed with a daVinci Si Surgical System through a transperitoneal approach. An interfascial nerve-sparing approach was used to preserve the neurovascular bundles and increase the likelihood of postoperative urinary continence. Urinary continence was assessed by placing white cloth bedding in the kennel during hospitalization and by owners' observation at home.

RESULTS

The console time was 120 minutes, and the estimated intraoperative blood loss was 30 mL. No intraoperative complications were observed. The urinary catheter was removed after 7 days, at which point the dog urinated normally. Peritoneal carcinomatosis was diagnosed 43 days after surgery, and the dog was euthanized.

CONCLUSION

Robot-assisted radical prostatectomy was successfully completed in a dog with prostatic neoplasia and led to postoperative urinary continence.

CLINICAL SIGNIFICANCE

This single-case report provides evidence to justify further evaluation of RARP in dogs with prostatic neoplasms.

A Case of Adenocarcinoma of Uterus Masculinus in a Pomeranian Dog

Introduction: Persistent Müllerian duct syndrome (PMDS), or uterus masculinus, is a rare autosomal recessive form of male pseudohermaphroditism due to the failure of paracrine anti-Müllerian hormone (AMH) secretion by Sertoli cells or failure of the Müllerian ducts to respond to AMH secretion. The malignant degeneration of persistent Müllerian remnants is rare. In human medicine, few related reports exist. In veterinary medicine, this is the first report describing adenocarcinoma of the uterus masculinus involving the prostate in a dog. Clinical history: An 11-year-old, male, neutered Pomeranian dog was referred for computed tomography due to the suspicion of prostatic carcinoma based on ultrasound and cytological examinations. The computed tomography findings were consistent with a uterus masculinus mass with possible prostatic infiltration. Uterus masculinus removal and total prostatectomy were performed; termino-terminal urethral anastomosis was carried out. Dehiscence of the anastomosis was observed 3 days after surgery. The owner declined any further procedures, and the dog was euthanized 5 days after surgery. Histopathological evaluation revealed adenocarcinoma of the uterus masculinus. Conclusion: Adenocarcinoma of the uterus masculinus may occur, suggesting that patients with PMDS should be evaluated for malignant changes of Müllerian remnants.

Outcomes associated with vaginectomy and vulvovaginectomy in 21 dogs

OBJECTIVE

To report the outcomes of dogs with lesions of the genitourinary tract treated by vaginectomy or vulvovaginectomy.

STUDY DESIGN

Multi-institutional retrospective study.

ANIMALS

Female dogs that underwent vulvovaginectomy, complete vaginectomy, or subtotal vaginectomy from 2003 to 2018 with complete medical records and a minimum of 60 days follow-up.

METHODS

Data collected from medical records included preoperative, intraoperative, and postoperative data, such as the occurrence of urinary incontinence (UIC), disease recurrence, and death/euthanasia.

RESULTS

This study included 21 dogs. Four dogs had vulvovaginectomy, six had complete vaginectomy, and 11 had a subtotal vaginectomy performed. The mean age at surgery was 9.2 years (SD, 3.3). Thirteen dogs were intact at presentation. Smooth muscle tumors were diagnosed most commonly (10 leiomyomata, three leiomyosarcomas, two leiomyofibromas). The median duration of follow-up was 520 days (range, 71-1955). Major complications requiring revision surgery were recorded in two dogs. Postoperative UIC occurred in six of 21 dogs, resolving spontaneously within 60 days in three dogs. Dogs with malignant tumors (n = 6) survived at least 71 days (median, 626; 95% CI, 71-1245), and recurrence of disease occurred in two dogs. In dogs with benign tumors (n = 15), the median survival time was not reached. These dogs survived at least 104 days and had no recurrence of the disease.

CONCLUSION

Vaginectomy and vulvovaginectomy resulted in prolonged survival and low rates of major complications and UIC.

CLINICAL SIGNIFICANCE

This study provides evidence to recommend that the risks of this procedure and expectations should be discussed with clients.

Less enhancement and low apparent diffusion coefficient value on magnetic resonance imaging may be helpful to detect canine prostate adenocarcinoma in case series

In dogs, diagnosis of prostate cancer is often delayed because clinical signs are not pathognomonic. Although ultrasonography is mainly performed to detect prostate cancer, the ultrasonographic appearance is not specific. In humans, magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI) is used to localize the prostate tumour. To our knowledge, there are no studies of MRI findings for detecting or localizing prostate cancer. The purpose of this study was to assess MRI findings of prostate cancer. As a control, three prostate hyperplasia cases were included. MRI data were analysed, and the following parameters were noted: signal intensity (SI) of prostate lesion on T2-weighted imaging, T1-weighted imaging and DWI, enhancement pattern of prostate lesion, and relative contrast enhancement indices (RCEI) and apparent diffusion coefficient (ADC) value of prostate lesion. For MRI examination, the mean RCEI of the adenocarcinoma was significantly lower than that of hyperplasia (P = .01, r = .8). The SI of the DWI of adenocarcinoma was significantly higher compared to hyperplasia (P = .03, φ = 1). The mean ADC values of the adenocarcinoma were significantly lower than that of hyperplasia (P = .03, r = .82). Thus, less enhancement on MRI, and low ADC value on MRI may help to detect prostate adenocarcinoma.

Lasers in the surgical treatment of canine prostatic neoplasia and selected tumours of the male reproductive system

Light-based technologies are applied in various fields of medicine: for example optical diagnostics, light-activated therapy and surgery. Although light-based surgical procedures had hardly been a novelty, the revolutionizing moment for surgery came with the first use of light to cut tissue. Nowadays, surgical lasers are routinely used across numerous medical specialties, including gynaecology and urology. They are a part of the surgical treatment of benign prostatic hyperplasia, prostate carcinoma, penis carcinoma, genital skin lesions and orchidectomy. While in human urology lasers continue to establish their position as one of the standard surgical tools, veterinary patients are rarely treated with what here is still considered a technical innovation. However, through research on laser treatment of the prostate hyperplasia conducted on a canine model, veterinary medicine has gained a massive portion of data. It may prove beneficial for our clinical patients. In this review, we introduce the very principles of laser surgery as well as its current and future applications in oncologic surgery of the canine prostate gland and the male reproductive system.

Use of transrectal ultrasonography for assessment of the size and location of prostatic carcinoma in dogs

OBJECTIVE

To evaluate the use of transrectal ultrasonography (TRUS) for the assessment of prostatic tumors in dogs and to compare results for TRUS with results for other imaging modalities.

ANIMALS

10 client-owned male dogs.

PROCEDURES

Client-owned dogs identified with prostatic carcinoma were enrolled. Fluoroscopy, transabdominal ultrasonography (TAUS), TRUS, and MRI were performed on all dogs. Tumor measurements, urethral penetration (identification of abnormal tissue within the urethral lumen), and tumor extension into the urinary tract were recorded for all imaging modalities. Agreement between results for MRI (considered the criterion-referenced standard) and results for other modalities were compared.

RESULTS

Median body weight of the 10 dogs was 26.3 kg (range, 9.4 to 49.5 kg). No complications were encountered during or after TRUS. Significant moderate to good agreements (intraclass correlation coefficients, 0.60 to 0.86) among TAUS, TRUS, fluoroscopy, and MRI were identified for tumor length and height. Assessments of urethral penetration and tumor extension into the bladder with TRUS did not differ significantly from those made with MRI and were superior in terms of absolute agreement with MRI when compared with those for TAUS.

CONCLUSIONS AND CLINICAL RELEVANCE

TRUS was successfully and safely used to evaluate prostatic carcinoma in dogs. There was moderate to good agreement with MRI results for tumor height and length measurements, and TRUS was found to be superior to TAUS for some assessments. Transrectal ultrasonography can be considered an adjunctive imaging modality for the performance of prostatic interventional procedures or assessment of response to treatment.

Prostatic Neoplasia in the Intact and Castrated Dog: How Dangerous is Castration?

Elective gonadectomy in the dog is a topic of interest for clinicians, pet-owners, and society. Although canine prostatic neoplasia (CPN) has a low incidence (0.35%), reports of an increased risk for castrated dogs attract attention and cause concern in pet-owners. Our aim is to provide professionals and non-professionals with a detailed description of this possible side effect of gonadectomy in the dog. The mean age at diagnosis of CPN ranges from 8.5 to 11.2 years. Medium to large size breeds are more frequently affected. Symptoms and findings of non-invasive examinations are not pathognomonic, therefore, cytological or histological examinations are needed for diagnosis. Overall, the incidence of metastasis reaches up to 80%, yet lung metastasis reportedly has no negative impact on median survival time (MST). It has been reported that castrated males have a significantly higher MST than intact males. Differences in inclusion criteria for studied populations make a comparison of studies difficult. Citation of odds ratios without consideration of the context of the reference may result in premature conclusions. We conclude that elective gonadectomy of adult male dogs under six years of age cannot be excluded from the veterinary practice due to concern of causing CPN until clear and strong evidence is available.

Definitive-intent intensity-modulated radiation therapy for treatment of canine prostatic carcinoma: A multi-institutional retrospective study

No standard of care is currently recognized for treatment of canine prostatic carcinoma (PC). This retrospective study assesses outcome following definitive-intent, intensity-modulated radiation therapy (RT) in dogs with PC. Medical records review was performed, including 18 patients from four institutions undergoing definitive-intent intensity-modulated radiotherapy to treat PC. Diagnosis was incidental in 7/18 (39%) patients. Five dogs (28%) had evidence of metastasis to loco-regional lymph nodes at diagnosis. Seventeen patients received concurrent non-steroidal anti-inflammatory drugs; 15/18 (83%) patients received maximally-tolerated dose (MTD) chemotherapy, with variable drugs and protocols employed. Total prescribed radiation dose ranged from 48 to 54 Gy (median 50 Gy) delivered as daily doses of 2.5-2.8 Gy. One patient was euthanized prior to completing radiotherapy. Acute toxicity was observed in nine patients; Grade 1-2 diarrhoea was the most common toxicity observed. Suspected late toxicity (urethral stricture, ureteral stricture and hindlimb oedema) was observed in three patients. Median event-free survival (EFS) following RT was 220 days, and median overall survival was 563 days. Local progression occurred in seven patients at a median of 241 days. Median overall survival was significantly longer in incidentally diagnosed dogs (581 vs 220 days in symptomatic dogs, P = .042). EFS was significantly longer in patients treated with MTD chemotherapy (241 vs 25 days, P < .001), and significantly shorter in patients presenting with evidence of metastatic disease (109 days) vs those without (388 days, P = .008). These findings suggest that definitive-intent radiotherapy is a valuable treatment option for local control of canine PC with moderate risk of toxicity.

Isoquinolinamine FX-9 Exhibits Anti-Mitotic Activity in Human and Canine Prostate Carcinoma Cell Lines

Current therapies are insufficient for metastatic prostate cancer (PCa) in men and dogs. As human castrate-resistant PCa shares several characteristics with the canine disease, comparative evaluation of novel therapeutic agents is of considerable value for both species. Novel isoquinolinamine FX-9 exhibits antiproliferative activity in acute lymphoblastic leukemia cell lines but has not been tested yet on any solid neoplasia type. In this study, FX-9′s mediated effects were characterized on two human (PC-3, LNCaP) and two canine (CT1258, 0846) PCa cell lines, as well as benign solid tissue cells. FX-9 significantly inhibited cell viability and induced apoptosis with concentrations in the low micromolar range. Mediated effects were highly comparable between the PCa cell lines of both species, but less pronounced on non-malignant chondrocytes and fibroblasts. Interestingly, FX-9 exposure also leads to the formation and survival of enlarged multinucleated cells through mitotic slippage. Based on the results, FX-9 acts as an anti-mitotic agent with reduced cytotoxic activity in benign cells. The characterization of FX-9-induced effects on PCa cells provides a basis for in vivo studies with the potential of valuable transferable findings to the benefit of men and dogs.

Perioperative complications and outcome after surgery for treatment of gastric carcinoma in dogs: A Veterinary Society of Surgical Oncology retrospective study of 40 cases (2004-2018)

OBJECTIVE

To describe the clinical characteristics, perioperative complications, and outcomes in dogs surgically treated for gastric carcinoma.

STUDY DESIGN

Multi-institutional retrospective case series.

ANIMALS

Forty client-owned dogs with histologically confirmed gastric carcinoma.

METHODS

Medical records were reviewed for preoperative diagnostics, surgery, histopathology, postoperative complications, adjuvant chemotherapy, disease progression, and survival. Variables were assessed for associations with outcome by using Cox proportional hazards regression analysis.

RESULTS

Surgical treatment included partial gastrectomy (28 dogs), Billroth I (9 dogs), subtotal gastrectomy (2 dogs), and submucosal resection (1 dog). Major postoperative complications occurred in 8 of 40 dogs, including septic peritonitis secondary to dehiscence in 4 dogs. The median progression free interval was 54 days, and the median survival time (MST) was 178 days (range, 1-1902). According to multivariable analysis results, experiencing an intraoperative complication was associated with an increased risk of death (hazard ratio [HR] 3.5, 95% CI 1.1-9.8, P = .005), and administration of adjuvant chemotherapy correlated with an improved survival (HR 0.4, 95% CI 0.2-0.9, P = .03).

CONCLUSION

In this population of dogs, MST exceeded historically reported data, major postoperative complication rates were comparable to established literature, and administration of adjuvant chemotherapy was associated with improved survival.

CLINICAL SIGNIFICANCE

Results from this study may be used to counsel owners more accurately regarding prognosis for dogs undergoing surgical excision for gastric carcinoma.

Lower Urinary Tract Neoplasia

Lower urinary tract neoplasia in companion animals is a debilitating and often life-threatening disease. Tumors of the bladder, urethra, and prostate often occur independently, although extension of these tumors into adjacent regions of the lower urinary tract is documented frequently. The most common lower urinary tract tumor in dogs and cats is transitional cell carcinoma (TCC). In both dogs and cats, TCC affecting the urinary bladder is generally considered to be highly aggressive with both local and metastatic disease potential, and this disease poses unique treatment challenges. Whereas much literature exists regarding the TCC disease process, treatment options, and prognosis in dogs, relatively few studies on feline TCC have been published due to the lower incidence of TCC in this species. Prostate tumors, most commonly adenocarcinomas, occur less commonly in dogs and cats but serve an important role as a comparative model for prostate neoplasia in humans. This article serves as a review of the current information regarding canine and feline lower urinary tract neoplasia as well as the relevance of these diseases with respect to their human counterparts.