Development of canine benign prostatic hyperplasia with age

Negative impact of benign prostatic hyperplasia on fertility in dogs-a mini-review

The aim of this article is to provide a comprehensive review of the negative impact of benign prostatic hyperplasia (BPH) on fertility in dogs. BPH is the most common disease of the prostate gland and one of the major causes of infertility in dogs, associated with impaired semen quality. Hormonal imbalance, oxidative stress, biochemical changes in prostatic fluid and haematospermia have been discussed as causes of reduced semen quality in dogs with BPH. Chronic prostatitis often occurs concurrently with BPH and has an additive negative effect on semen quality and fertility. In breeding dogs with infertility associated with BPH, treatment with the anti-androgen osaterone acetate or the 5α-reductase inhibitor finasteride is recommended to reduce prostate size and clinical symptoms and to restore fertility. Combined occurrence of BPH and chronic prostatitis requires simultaneous treatment of both conditions, including microbials with good penetration into the prostate. The use of antioxidants in the supportive treatment of BPH seems reasonable.

Case report: A follow-up report of omental packing and drug therapy for canine prostate adenocarcinoma

Canine prostate is susceptible to diseases such as cysts, abscesses, and tumors. A 15-year-old male castrated Chinese rural dog underwent staged treatment. Preliminary diagnosis is based on examination results, including clinical symptoms (tenesmus, dysuria, frequent urination, and hematuria); hematology (elevated neutrophil count); X-rays (swelling of the prostate); ultrasound examination (less uniform echo in the prostate region, no echo effect in parenchyma); biopsy smear of prostate tissue (large number of neutrophils and rod-shaped bacteria). Therefore, the dog was preliminarily diagnosed with a prostate abscess. Antibiotic therapy was used for treatment. Three days later, the symptoms of hematuria and frequent urination did not improve, and the state was poor. The owner was advised to undergo surgical treatment-omental packing. Meanwhile, bacterial culture identification, drug sensitivity test and histopathological examination were performed. Pathological diagnosis was prostate adenocarcinoma. Subsequently, antibiotic therapy with enrofloxacin and antineoplastic maintenance therapy with mitoxantrone were administered. Six months later, the dogs were followed up, and the results showed no disease in the prostate tissue and no metastatic lesions. This is the report describing the use of omental packing for the treatment of prostate adenocarcinoma in dogs. In order to provide an important theoretical basis for the treatment of prostate cancer - omental packing into veterinary routine.

The Omentum-A Forgotten Structure in Veterinary Surgery in Small Animals' Surgery

The greater and lesser omentum are derived from embryonic mesogastrium. The expansive greater omentum in dogs covers intestinal coils, while in cats, it is smaller. Comprising distinct portions, the greater omentum is rich in lymphatics and blood vessels. Conversely, the lesser omentum spans the liver, stomach, and duodenum. Studies on canine omentum reveal unique immune cell composition and regenerative potential attributed to adipose tissue-derived stromal cells (ADSCs). These cells hold promise in regenerative medicine, showing enhanced abilities compared with ADSCs from other sources. The omentum is critical in tissue repair and pathology, making it invaluable in veterinary surgery across various medical fields. The aim of this article was to research current knowledge about the applications of the omentum in veterinary surgery and the possibilities of using this structure in the future.

Potential role of oxidative stress in pathogenesis of benign prostatic hyperplasia in male dogs

The pathogenesis of benign prostatic hyperplasia (BPH) in dogs is still not fully understood. Some studies suggest that oxidative stress may have a potential role in the pathogenesis of BPH in dogs. Age-related hormonal changes may activate a chronic inflammatory response in the prostate. This causes the generation of reactive oxygen species (ROS) and results in oxidative stress. Excessive production of ROS results in DNA damage and hyperplastic transformation of prostatic cells. The use of antioxidants for improvement of treatment outcomes for canine PBH has been discussed. Further research is needed on the importance of oxidative stress in the development of BPH in dogs and the usefulness of antioxidants in the supportive treatment of this condition.

Comparative Evaluation of Diagnostic Methods for Subclinical Benign Prostatic Hyperplasia in Intact Breeding Male Dogs

Benign prostatic hyperplasia (BPH) is an androgen-related non-neoplastic enlargement of the prostate gland that commonly affects both reproductive capabilities and the general health of intact dogs. The subclinical form of BPH can be challenging to diagnose due to a lack of clinical signs, even if rectal palpation is performed. Left untreated, this condition poses risks to the dogs' health and breeding status. This study, involving 65 male dogs, aimed to investigate subclinical BPH through rectal palpation, ultrasonography, and analysis of canine prostatic-specific esterase (CPSE). Of the participants, 35 had subclinical BPH, and 30 served as a healthy control group. Dogs suspected of subclinical BPH, as determined by examination results from ultrasonography and CPSE analysis, underwent fine needle aspiration (FNA) guided by ultrasound to enhance diagnostic precision. Findings revealed distinct differences in rectal palpation and ultrasonography between subclinical BPH and healthy dogs. This study established diagnostic thresholds based on prostatic volume and CPSE values and proposed new thresholds for subclinical BPH. Additionally, results showed that prostate gland volume depended on the weight and the age of the dog. In conclusion, early detection of this condition is possible through various examinations, such as changes in ultrasound features, CPSE levels, and rectal palpation. All together, these methods can aid practitioners in early detection of BPH and assist with scheduling screening programs for dogs, ultimately promoting their overall health and reproductive well-being. In conclusion, we advocate for routine, non-invasive prostate screenings in breeding males, underlining the effectiveness of a combination of various multiple techniques for early subclinical BPH detection.

Comparative Serum Proteome Profiling of Canine Benign Prostatic Hyperplasia before and after Castration

BPH is the most prevalent prostatic condition in aging dogs. Nevertheless, clinical diagnosis and management remain inconsistent. This study employed in-solution digestion coupled with nano-liquid chromatography tandem mass spectrometry to assess serum proteome profiling of dogs with BPH and those dogs after castration. Male dogs were divided into two groups; control and BPH groups. In the BPH group, each dog was evaluated at two time points: Day 0 (BF subgroup) and Day 30 after castration (AT subgroup). In the BF subgroup, three proteins were significantly upregulated and associated with dihydrotestosterone: solute carrier family 5 member 5, tyrosine-protein kinase, and FRAT regulator of WNT signaling pathway 1. Additionally, the overexpression of polymeric immunoglobulin receptors in the BF subgroup hints at its potential as a novel protein linked to the BPH development process. Conversely, alpha-1-B glycoprotein (A1BG) displayed significant downregulation in the BF subgroup, suggesting A1BG's potential as a predictive protein for canine BPH. Finasteride was associated with increased proteins in the AT subgroup, including apolipoprotein C-I, apolipoprotein E, apolipoprotein A-II, TAO kinase 1, DnaJ homolog subfamily C member 16, PH domain and leucine-rich repeat protein phosphatase 1, neuregulin 1, and pseudopodium enriched atypical kinase 1. In conclusion, this pilot study highlighted alterations in various serum proteins in canine BPH, reflecting different pathological changes occurring in this condition. These proteins could be a source of potential non-invasive biomarkers for diagnosing this disease.

Controversial Topics in Animal Welfare in Latin America: A Focus on the Legislation Surrounding the Human-Companion Animal Relationship and Animals Used for Recreational Practices

Animal welfare is a societally relevant issue that is globally attracting increased attention. This is in addition to the importance placed on welfare for the animals themselves. However, the content and application of laws protecting animals' welfare vary across countries. In Latin America, there are a range of common practices or activities involving certain animal species, many of which are legal, that can impair an animal's quality of life. These include the performance of aesthetic surgical procedures; bull-, cock-, and dog fighting; and the existence of circuses that exhibit animals. The extent and impact of these practices being dependent on the socioeconomic, cultural, territorial, and regulatory landscape of each country. Particularly, Ibero-American regions face welfare challenges that might be influenced by traditions and relevant legal gaps. The objective of this article is to review controversial practices carried out in companion and entertainment animals in Latin America, with a focus on legal aspects, as well as the current efforts being made to address and incorporate global welfare standards into domestic and wild animal practice and regulation.

Age, weight and circulating concentrations of total testosterone are associated with the relative prostatic size in adult intact male dogs

Prostatic hyperplasia (PH) is an androgen-dependent condition associated with increased prostatic size that is common in intact dogs, and similar to the condition in men. In dogs, the increase in prostatic size is most prominent the first years, and after approximately four years (in beagles), a plateau is reached, and further growth is slower. Why the prostate continues to grow more in some individuals is not clear. Most testosterone in the circulation is bound to albumin or sex hormone binding globulin (SHBG) and only a minor part is unbound and biologically active. The binding to SHBG has higher affinity than that to albumin. In addition, SHBG has own biological functions, modifying testosterone action. The aim of the present study was to investigate if there is an association between relative prostatic size and the variables total testosterone concentration, SHBG concentration, an estimation of bioavailable testosterone: the ratio between testosterone and SHBG (free androgen index, FAI), estradiol concentration, the estradiol/testosterone ratio, dog age and dog weight. Hormone concentrations were measured in serum from 79 intact male dogs aged ≥ four years, weighing ≥ five kg. The size of the prostate was estimated using ultrasonography, and relative prostate size, S_rel, was calculated as the estimated size related to the normal size for a 4-year-old dog of the same weight. There as a negative correlation between testosterone concentration and age (ρ = -0.27, P = 0.018) and a positive correlation between age and S_rel (ρ = 0.27, P = 0.016) and between SHBG and weight (ρ = 0.38, P = 0.001). The FAI was negatively correlated with dog weight (ρ = -0.32, P = 0.004). There were no significant correlations between S_rel and SHBG or FAI or between estradiol or estradiol/testosterone and S_rel, age or weight. A multiple regression analysis showed significant associations between log S_rel and log testosterone concentration, log age and log weight of the dog, with an adjusted R² of 9.5%. Although the variables total testosterone concentration, age and weight of the dog were all significantly associated with S_rel, the coefficient of determination was low, indicating that they only explained a minor part of the prostatic size. The results support the analysis of total testosterone in studies of prostatic growth in the dog.

Oxidative stress biomarkers in dogs with benign prostatic hyperplasia

BACKGROUND

The aim of this study was to evaluate total antioxidant capacity (TAC) and biomarkers of lipid and protein peroxidation in the blood serum of dogs with benign prostatic hyperplasia (BPH). The study was conducted on 36 intact male dogs of various breeds. The dogs were assigned to two groups: BPH group (n = 18) and non-affected group (n = 18). Blood samples were collected from the cephalic vein. The antioxidant status of the serum was assessed using TAC. The levels of bityrosine, formylkynurenine and SH-groups were used as protein peroxidation biomarkers and the level of radical cations of N,N-diethyl-paraphenylene diamine (RC-DEPPD) was used as a marker for lipid peroxidation. TAC and the concentrations of SH-groups and RC-DEPPD in the serum were determined spectrophotometrically, the concentrations of bityrosine and formylokynurenine, were determined using spectrofluorimetric methods.

RESULTS

The mean value of TAC in the serum was significantly lower (P = 0.01) in BPH dogs than in non-affected dogs (3.10 ± 0.56 vs 4.20 ± 1.60 μmol/g protein). Mean levels of protein and lipid oxidation biomarkers showed a trend towards oxidative imbalance, but there were no statistically significant differences between dogs with BPH and controls (P > 0.05).

CONCLUSION

In conclusion, significantly lower serum TAC in dogs with BPH compared to non-affected dogs suggests a potential involvement of oxidative stress in the pathogenesis of BPH in dogs. More studies are needed to clarify the role of oxidative stress in the development of BPH in dogs.

Assessment of the utility of platelet indices to diagnose clinical benign prostatic hyperplasia in dogs

Introduction

Platelet indices changes in severely ill people and in dogs with inflammation are compatible findings. This study aimed to compare platelet indices between dogs with clinical benign prostatic hyperplasia (BPH) and healthy controls. Additionally, to determine whether there is a correlation between the relative prostatic size (S _rel) and the platelet indices in BPH dogs.

Methods

Thirty-five adult intact male dogs of different breeds were allocated to the experimental groups: dogs with clinical BPH (groups A; n = 24; median age of 6 years; the median weight of 8.50 kg) and healthy dogs (group B; n = 11; median age 5.50 years; the median weight of 7.00 kg) based on physical examination, clinical signs, and S _rel detected by ultrasonographic findings. The individual prostatic volume (IPV) was divided by the expected prostatic volume (EPV) to determine the relative prostatic size in dogs over 4 years old. Platelet indices were compared between the two groups, and a correlation between S _rel and these indices was calculated.

Results

The median S _rel of dogs in group A was significantly higher (P = 0.001), and the mean plateletcrit (PCT) was significantly lower (P = 0.003) compared with those in group B. S _rel showed a significant negative correlation with PLT and PCT (r = -0.388; P = 0.02 and r = -0.402; P = 0.01). Receiver operating characteristic (ROC) analysis showed PLT and PCT thresholds for estimating S _rel > 1 with 75% and 87.5% sensitivity and 71.82 and 63.64% specificity.

Discussion

The findings of this study support the use of platelet indices like PLT and PCT to detect clinical BPH in dogs. However, more research is needed to confirm their utility in conjunction with other previously described diagnostic factors.

Assessment of the possibility of using biomarkers (CCL11 and TGF-beta 1) in the diagnosis of prostate gland hyperplasia in dogs

Prostatic hyperplasia (PH) is the most common reproductive disorder in dogs and can lead to discomforting problems such as haematuria, urinary incontinence, constipation, difficulty in defecating and stiffness of the hind limbs. The diagnosis of PH is nowadays based on digital rectal examination (DRE), ultrasonography (US) and radiography (X-ray). However, markers associated with PH are barely used for diagnostic purposes. Recently, there have been reports on the use of certain biomarkers for diagnosing PH in dogs such as canine PSA (Prostate Specific Antigen), microRNA and vascular endothelial growth factor (VEGF). Nevertheless, it has been generally accepted that these biomarkers play only an auxiliary role. Accordingly, the aim of our study was to evaluate the usefulness of the CCL11 (eotaxin-1) and TGF-beta 1 markers, which are used in the diagnosis of prostate diseases in humans, in case of dogs with PH. The study was carried out on 40 dogs of different breeds divided into three groups. Group I (n = 9) comprised dogs up to 5 years of age without changes indicative of PH. Group II (n = 17) included dogs aged 5-10 that were examined and diagnosed with (PH) and Group III (n = 14) which consisted of dogs over 10 years of age who were also diagnosed with PH. The study demonstrated that CCL11 levels did not differ significantly between the study groups and the median levels were 7.27 pg/mL, 7.57 pg/mL, 6.81 pg/mL, and IQR ranges 1.55 pg/mL, 1.74 pg/mL, 2.32 pg/mL, respectively. In contrast, TGF-beta 1 levels were detectable only in 6 dogs of group III and averaged the median of 28.86 pg/mL, IQR ranges 10.07 pg/mL. The study proved that CCL11 and TGF-beta 1 markers are of a limited use when diagnosing PH in dogs as no significant correlation related to age, body weight or prostate size was found.

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.

Ultrasonographic measurements of the prostate gland in castrated adult dogs

Background

The dimensions of the prostatic gland in castrated adult dogs, as assessed by ultrasonography, is currently not yet reported in veterinary literature. The current study was aimed at reporting the prostatic dimensions in castrated dogs and investigate the relationship between the dogs’ body weight and prostate size. A second aim of the study was to investigate whether there was a relationship between the dogs’ age and prostate dimensions. A prospective, single-centre, observational study was conducted and 72 privately owned, adult, male castrated dogs with a range of breeds and ages met the final inclusion criteria. The subjects were divided into three categories based on body weight.

Results

A Kruskal–Wallis test found prostatic length and prostatic depth in the longitudinal orientation to be significantly different among the 3 categories (P < 0.005), with an increase in both prostatic length and prostatic depth with increasing body weight. Linear regression of the data set provided comprehensive formulas calculating prostatic length and depth based on the body weight of the dog (r² of 0.69 and 0.53 for prostatic length and depth respectively). Kendall’s Tau rank test showed no correlation between dogs’ age and prostate dimensions (P > 0.100).

Conclusions

The current study is the first to provide a comprehensive, weight-based reference for the canine prostate gland of castrated dogs when assessed on ultrasonography.

A Review on Canine and Feline Prostate Pathology

Prostatic diseases are very common in male dogs, accounting for 3-10% of cases submitted to the veterinary practitioners. Commonly reported canine prostatic disorders include prostatic hyperplasia, prostatitis, prostatic cysts and prostatic carcinoma. However, clinical signs may be non-specific, or many cases are asymptomatic, thus leading to a difficult estimation of the actual prevalence of clinical cases. On the other side, because of the rare occurrence of prostate disease in cats, very little is known about pathogenesis, diagnostic approaches and treatment. The goal of this review is to provide detailed clinical and pathological overview of the feline and canine prostatic pathology, including the most up-to-date classification systems and histological findings. Emphasis is places on gross, cytological and histological features that are critical to reach a definitive diagnosis for a proper treatment and prognosis.

MicroRNA and vascular endothelial growth factor (VEGF) as new useful markers in the diagnosis of benign prostatic hyperplasia in dogs

Numerous specific biomarkers with a prognostic and diagnostic value comparable to histopathological findings are now used for non-invasive diagnosis of prostate diseases in humans. Meanwhile, as far as dogs are concerned, the diagnosis of prostate disorders is based solely on clinical examination and ultrasound (USG). Therefore, the aim of the study was to assess the usefulness of two biomarkers, i.e. miRNA-129 and VEGF for the diagnosis of BPH in dogs. The study involved 40 dogs divided into three groups. Group I (n = 9) comprised healthy dogs up to the age of 5 years, Group II (n = 17) comprised dogs between the ages of 5-10 suffering from BPH as confirmed by the examination and Group III (n = 14) comprising dogs over 10 years of age, which also had BPH confirmed. The results demonstrated that dogs in group II and III exhibited a significant decrease in miRNA expression (P < 0.0001) and a significant increase in serum VEGF levels (P = 0.025) when compared to the dogs in group I. There was also a positive correlation between the prostate size and VEGF level. The findings led to the conclusion that the determination of miRNA-129 and VEGF can significantly contribute to the diagnosis of prostate disorders in dogs.

An investigation on the relevance of prolactin, insulin-like growth factor-1 and 25-hydroxyvitamin D3 (25-OHD3 ) in canine benign prostatic hyperplasia in a predisposed breed model

Serum concentrations of prolactin (PRL), insulin-like growth factor-1 (IGF-1) and 25 hydroxyvitamin D₃ (25-OHD₃ ) were analysed to investigate their possible involvement in the pathogenesis of benign prostatic hyperplasia (BPH). For this, dogs of the Rhodesian Ridgeback (RR) breed were used because of a verified breed disposition for the development of BPH. Labrador Retrievers (LR) served as controls. The prostate gland status was characterised by the prostate gland volume, clinical signs of BPH (haemospermia and sonographic findings) and the plasma concentration of canine prostate-specific arginine esterase (CPSE). Breed specificity in the RR was expressed by a correlation of PRL with breed (p < 0.05). Similar relationships existed in the dogs with normal CPSE (CPSEn) with respect to the IGF-1 concentrations (LR: p < 0.05). The latter were negatively correlated with prostatic volume and age (both p < 0.05). Concentrations of 25-OHD₃ were tendentially (p = 0.18) lower in the RR with increased CPSE (CPSEi) compared with the CPSEn LR and RR showing clinical signs of BPH. A negative correlation between serum 25-OHD₃ and age (p < 0.05) existed in the CPSEi RR. Proof of 25-OHD₃ in prostatic secretion proved to be a breed specific feature in the RR (p < 0.0001). For all RR dogs showing clinical signs of BPH, a close to significant (p = 0.06) positive correlation with prostate gland volume was found. The results of the present study reveal no clear hints towards the significance of PRL and IGF-1 in the pathogenesis of canine BPH. In the RR breed there were indications of a causal relationship with age-dependent changes in the vitamin D metabolism. The data suggest the possibility of preventing or treating canine BPH by administering vitamin D or substances involved in the intraprostatic vitamin D metabolism.

Surgical treatment and outcome of sterile prostatic cysts in dogs

OBJECTIVE

To describe the surgical treatment and outcome of a large cohort of dogs with sterile prostatic cysts (PCs).

STUDY DESIGN

Retrospective study.

ANIMALS

Forty-four client-owned dogs.

METHODS

Dogs with sterile PCs with at least 6 months of follow-up were included. Clinical variables, type of surgery, complications, recurrences, and outcomes (telephonic interviews or rechecks) were recorded.

RESULTS

Extra- and intraparenchymal cysts were diagnosed in 29 and 11 dogs, respectively. Four dogs had both types. Extraparenchymal cysts were treated by partial resection and omentalization (n = 22) and complete resection (n = 7). Drainage and intracapsular omentalization were performed in all dogs with intraparenchymal cysts. The four dogs with both types of cyst were treated by omentalization. Resolution was documented in 39/44 dogs (88.6%). Intraoperative complications occurred in one dog (urethral tear). Major complications resulting in death occurred in three dogs (oliguric kidney injury, cardiac arrhythmia, and persisting urinary tract obstruction). Minor complications (n = 10) consisted of temporary urinary incontinence (n = 2), permanent urinary incontinence (n = 5), urinary retention (n = 2), and dysuria (n = 1). Recurrence occurred in two dogs with extraparenchymal cysts. Median long-term follow-up was 528 days (range, 250-730 days). Thirty-nine dogs had no signs associated with prostatic disease at long-term follow-up.

CONCLUSION

Partial or complete resection and/or omentalization of sterile PCs led to resolution of clinical signs in most dogs, although postoperative urinary incontinence was frequent.

IMPACT

This study is the largest case series relative to canine sterile PCs treated surgically and provides evidence on the prognosis and rate of complications.

Concentrations of canine prostate specific esterase, CPSE, at baseline are associated with the relative size of the prostate at three-year follow-up

Background

Enlargement of the prostate is associated with prostatic diseases in dogs, and an estimation of prostatic size is a central part in the diagnostic workup. Ultrasonography is often the method of choice, but biomarkers constitute an alternative. Canine prostate specific esterase (CPSE) shares many characteristics with human prostate specific antigen (PSA) and is related to prostate size. In men with clinical symptoms of prostatic disease, PSA concentrations are related to prostate growth. The aims of the present follow-up study were to evaluate if the concentration of CPSE is associated with future growth of the prostate, and if analysis of a panel of 16 steroids gives further information on prostatic growth. Owners of dogs included in a previous study were 3 years later contacted for a follow-up study that included an interview and a clinical examination. The prostate was examined by ultrasonography. Serum concentrations of CPSE were measured, as was a panel of steroids.

Results

Of the 79 dogs included at baseline, owners of 77 dogs (97%) were reached for an interview, and 22 were available for a follow-up examination. Six of the 79 dogs had clinical signs of prostatic disease at baseline, and eight of the remaining 73 dogs (11%) developed clinical signs between baseline and follow-up, information was lacking for two dogs. Development of clinical signs was significantly more common in dogs with a relative prostate size of ≥2.5 at baseline (n = 20) than in dogs with smaller prostates (n = 51). Serum concentrations of CPSE at baseline were not associated with the change in prostatic size between baseline and follow-up. Serum concentrations of CPSE at baseline and at follow-up were positively associated with the relative prostatic size (S_rel) at follow-up. Concentrations of corticosterone (P = 0.024), and the class corticosteroids (P = 0.0035) were positively associated with the difference in S_rel between baseline and follow-up.

Conclusions

The results support the use of CPSE for estimating present and future prostatic size in dogs ≥4 years, and the clinical usefulness of prostatic size for predicting development of clinical signs of prostatic disease in the dog. The association between corticosteroids and prostate growth warrants further investigation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-02874-1.

[Development of a large intraprostatic cyst following the use of a GnRH agonist-implant in a male dog with benign prostatic hyperplasia]

A male dog with benign prostatic hyperplasia and several small intraprostatic cysts was treated with a GnRH-agonist implant containing 4,7 mg deslorelin (Suprelorin^®). Within 2 weeks after the implantation, the prior urethral bleeding worsened. A large intraprostatic cyst was detected sonographically. The patient was subsequently treated with osaterone acetate (0.4 mg/kg p. o. once a day for 7 days) and enrofloxacin (5 mg/kg p. o. once a day for 21 days). The clinical symptoms receded within 10 days. Within one month, the cyst regressed completely. The mechanisms of cyst enlargement are discussed.

Animal models of benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) and associated lower urinary tract symptoms are common clinical concerns that affect aging men all over the world. The underlying molecular and cellular mechanisms remain elusive. Over the past few years, a number of animal models of BPH, including spontaneous model, BPH-induction model, xenograft model, metabolic syndrome model, mechanical obstruction model, and transgenic model, have been established that may provide useful tools to fill these critical knowledge gaps. In this review, we therefore outlined the present status quo for animal models of BPH, comparing the pros and cons with respect to their ability to mimic the etiological, histological, and clinical hallmarks of BPH and discussed their applicability for future research.

Prostatic hyperplasia: Vascularization, hemodynamic and hormonal analysis of dogs treated with finasteride or orchiectomy

As a consequence of a hormonal imbalance, Prostatic Hyperplasia (PH) is characterized by increased prostate volume, along with higher local angiogenesis and vascularization. Orchiectomy is the common treatment for dogs, however it is not an option for breeding animals. Thus, finasteride arises as the drug of choice for stud dogs. Therefore, the aim of this study was to evaluate the effects of orchiectomy or finasteride therapies on hormonal and vascular dynamics of PH dogs. Fifteen dogs, aged 6–13 years were assigned to: Untreated Group (dogs diagnosed with PH—n = 5), Finasteride treated group (PH dogs treated with finasteride—n = 5) and Orchiectomy treated group (PH dogs submitted to orchiectomy–n = 5). Evaluations were performed in a monthly interval (first day of treatment; after 30 and 60 days). Doppler ultrasonography was performed to measure prostatic volume, vascularization and hemodynamic profile of prostatic artery. Dihydrotestosterone, estrogen and testosterone concentrations were measured. At day 60, prostatic biopsy was performed for histological, immunohistochemical and qPCR analysis for VEGF-A expression. At day 60, vascularization score was higher in untreated compared to treated groups (finasteride and orchiectomy). Furthermore, VEGF-A expression was lower in the Orchiectomy Treated Group, but VEGF-A was immunohistochemically lower in both treated groups (finasteride and orchiectomy) compared to the Untreated Group. The efficiency of finasteride treatment in reducing clinical signs, prostate volume and vascularization appears to be similar to orchiectomy. In conclusion, both PH medical and surgical therapy lead to reduction in prostate dimension and VEGF-A expression and, consequently, lower local vascularization. However, orchiectomy promotes marked hormonal changes, which ultimately lead to prostate atrophy.

Rhodesian Ridgebacks have an increased risk to develop benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is an age-dependent primarily non-inflammatory enlargement of the accessory gland in the intact dog. The aim of the present study was to control a previously raised suspicion of a breed-related higher incidence of BPH in dogs of the Rhodesian Ridgeback breed. For this, 18 Labrador Retrievers/LR and 20 Rhodesian Ridgebacks/RR were assigned to the age groups 18-24 months (n = 12), 25-48 months (n = 13) and 49-72 months (n = 13). Prostate gland status was determined by rectal palpation, B-mode ultrasound, calculation of the prostate gland volume and semen analysis regarding haemospermia and was classified according to blood plasma concentrations of canine prostate-specific arginine esterase (CPSE) (normal ≤ 60 ng/ml, increased ≥ 61 ng/ml; Pinheiro et al., 2017). Concentrations of testosterone, 5α-dihydrotestosterone and estradiol were analysed in peripheral blood serum or plasma for detecting breed-specific conditions regarding the endocrine metabolism. Prostatic volume was significantly larger in RR irrespective of the CPSE status. In RR, BPH occurred more frequently and started at an earlier age compared with the LR. Breed-related specificities in steroid metabolism in the RR were indicated by correlations of 5α-dihydrotestosterone and estradiol with age and of testosterone with prostate gland volume. Although the incidence of sonographic signs of BPH and haemospermia did not fit with normal and increased CPSE concentrations, a breed-specific higher incidence of BPH in the RR breed could be clearly verified.

Changes in specific serum biomarkers during the induction of prostatic hyperplasia in dogs

BACKGROUND

Prostatic hyperplasia (PH) is one of the most important disorders in intact dogs. In this study, we aimed to induce PH experimentally using the combination of testosterone and estrogen and evaluate important factors associated with this disease.

RESULTS

The results showed that in the induction group, prostate volume and prostate specific antigen (PSA) concentration increased significantly on day 21 onwards compared to those of the control group. Canine prostatic specific esterase (CPSE) and dihydrotestosterone (DHT) concentrations increased significantly on day 42 onwards while the testosterone levels increased on day 63. In addition, prostatic acid phosphatase (PAP) concentration did not change significantly in the control and induction groups. Biochemistry profiles and hematologic factors were measured for monitoring the function of liver and kidney, and there were no adverse effects following the induction of PH.

CONCLUSIONS

It seems that testosterone and estrogen administration led to prostatic hyperplasia during 2 months. Investigating the size of the prostate, accompanied by prostate markers including CPSE, PSA, DHT, and testosterone, is helpful for the PH diagnosis. However, further studies should be carried out on PAP.

Histopathological Terminology Standards for the Reporting of Prostatic Epithelial Lesions in Dogs

The terminology applied to canine prostatic epithelial lesions, especially carcinomas, is currently not standardized and this hampers the ability of pathologists to study the biological and clinical significance of these lesions. The aim of this review is to present the essential histomorphological diagnostic attributes of a wide spectrum of prostatic epithelial lesions in dogs. In addition to the traditionally recognized prostatic hyperplasia, hormonal atrophy, prostatitis, squamous metaplasia, adenocarcinoma and transitional cell (urothelial) carcinoma, new entities are described and discussed in order to provide veterinary pathologists with a basic atlas of common histological lesions of the canine prostate that is comprehensive and easy to use.

Generation and Regulation of Spontaneous Contractions in the Prostate

Spontaneous myogenic contractions have been shown to be significantly upregulated in prostate tissue collected from men with Benign Prostatic Hyperplasia (BPH), an extremely common disorder of the ageing male. Although originally thought likely to be involved in 'housekeeping' functions, mixing prostatic secretions to prevent stagnation, these spontaneous myogenic contractions provide a novel opportunity to understand and treat BPH. This treatment potential differs from previous models, which focused exclusively on attenuating nerve-mediated neurogenic contractions. Previous studies in the rodent prostate have provided an insight into the mechanisms underlying the regulation of myogenic contractions. 'Prostatic Interstitial Cells' (PICs) within the prostate appear to generate pacemaker potentials, which arise from the summation of number of spontaneous transient depolarisations triggered by the spontaneous release of Ca²⁺ from internal stores and the opening of Ca²⁺-activated Cl^- channels. Pacemaker potentials then conduct into neighbouring smooth muscle cells to generate spontaneous slow waves. These slow waves trigger the firing of 'spike-like' action potentials, Ca²⁺ entry and contraction, which are not attenuated by blockers of neurotransmission. However, these spontaneous prostatic contractions can be modulated by the autonomic nervous system. Here, we discuss the mechanisms underlying rodent and human prostate myogenic contractions and the actions of existing and novel pharmacotherapies for the treatment of BPH. Understanding the generation of human prostatic smooth muscle tone will confirm the mechanism of action of existing drugs, inform the identification and effectiveness of new pharmacotherapies, as well as predict patient outcomes.

Testosterone-induced benign prostatic hyperplasia rat and dog as facile models to assess drugs targeting lower urinary tract symptoms

Benign prostatic hyperplasia (BPH) is an age-related disease, affecting a majority of elderly men worldwide. Medical management of BPH is an alternative to surgical treatment of this disease. Currently, α1-adrenergic receptor (α1-AR) antagonists are among the first line drugs to treat BPH by reducing the tension of urinary track and thus the obstructive symptoms in voiding. In drug development, old male dogs with spontaneous BPH are considered the golden standard of the animal models. However, old dogs (>6 years) are expensive and not all old dogs develop BPH. So it is necessary to develop more accessible animal models for drug efficacy evaluation. Here we describe the development of testosterone-induced BPH models in both rats and young adult dogs and their applications in the in vivo evaluation of α1-AR antagonist. The BPH rats and dogs induced by chronic testosterone treatment have significantly increased micturition frequency and reduced mean voided volume, very similar to the clinical symptoms of BPH patients. Silodosin, an α1-AR antagonist, significantly reduces the urinary frequency and increases the voided volume in BPH model animals in a dose-dependent manner. The results demonstrate that testosterone-induced BPH rat and dog models might provide a more efficient way to evaluate micturition behavior in anti-BPH drug studies.

Evaluation of biomarker canine-prostate specific arginine esterase (CPSE) for the diagnosis of benign prostatic hyperplasia

Background

Benign prostatic hyperplasia (BPH) is the most common canine prostatic disorder. Although most or even all intact male dogs may develop BPH by 5–8 years of age, many show no clinical signs. Taking into account the non-specific character of clinical and ultrasonographic findings, a new diagnostic approach has recently been proposed based on the augmentation of blood canine prostate-specific arginine esterase (CPSE) in hyperplasic dogs. The aim of the present study was to verify CPSE levels in negative controls and hyperplasic dogs, considering cytological findings as the reference method and taking into account the fact that controls were middle-aged intact dogs (median of 5.0 years), contrarily to previous studies carried out with very young control dogs.

Results

Significant differences of median CPSE levels were found between controls and hyperplasic dogs (29.1 versus 160.7 ng/mL, respectively); and significant positive correlations were found between median CPSE levels and age or prostatic volume (r = 0.549 and 0.448, respectively; p < 0.001). Sensitivity, specificity, positive and negative likelihood ratios put into evidence the good performance of the test. The agreement between methods was found to be very high, notably between CPSE levels and cytological results (Cohen’s kappa coefficients above 0.8).

Conclusions

Considering the results all together, measurement of CPSE is confirmed as a useful and accurate method and should be considered as an alternative or complementary tool to conventional methods for the diagnosis of BPH in middle-aged dogs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-017-0996-5) contains supplementary material, which is available to authorized users.

Review of Prostate Anatomy and Embryology and the Etiology of Benign Prostatic Hyperplasia

Prostate development follows a common pattern between species and depends on the actions of androgens to induce and support ductal branching morphogenesis of buds emerging from the urogenital sinus. The human prostate has a compact zonal anatomy immediately surrounding the urethra and below the urinary bladder. Rodents have a lobular prostate with lobes radiating away from the urethra. The human prostate is the site of benign hyperplasia, prostate cancer, and prostatitis. The rodent prostate has little naturally occurring disease. Rodents can be used to model aspects of human benign hyperplasia, but care should be taken in data interpretation and extrapolation to the human condition.

Bawu decoction () ameliorates benign prostatic hyperplasia in rats

OBJECTIVE

To evaluate the efficacy of Bawu Decoction (, BWD, Palmul-tang in Korean) against benign prostatic hyperplasia (BPH).

METHODS

Twenty-four male Wistar rats were divided into 4 groups, with 6 rats in each group. The 4 study groups included sham-operated group (CON), BPH model group, fifinasteride-treated group, and BWD-treated group. All the groups except CON group received a subcutaneous injection of 10 mg/kg of testosterone, while CON group received saline. Finasteride at a dose of 5 mg/kg was administered to the finasteride-treated group for a period of 4 weeks. BWD group received BWD at a dose of 200 mg/kg for 4 weeks. The prostatic weight, prostate weight to body weight ratio, relative prostate weight ratio, serum testosterone and dihydrotestosterone (DHT) level, and histological analysis of prostatic tissue were analyzed.

RESULTS

Compared to BPH model group, BWD administration was associated with reductions in prostatic weight, prostate and relative prostate weight ratio weight to body weight ratio (P<0.05). The concentration of serum testosterone and DHT were higher in BPH group compared with CON group (P<0.05). Administration of finasteride and BWD suppressed the elevation of serum testosterone and DHT levels signifificantly (both P<0.05). In addition, BWD suppressed the growth of prostatic tissue (P<0.05).

CONCLUSION

BWD has suppressant effects on development of BPH through inhibition of serum testosterone and DHT.

Isolation and analysis of discreet human prostate cellular populations

The use of lineage tracing in transgenic mouse models has revealed an abundance of subcellular phenotypes responsible for maintaining prostate homeostasis. The ability to use fresh human tissues to examine the hypotheses generated by these mouse experiments has been greatly enhanced by technical advances in tissue processing, flow cytometry and cell culture. We describe in detail the optimization of protocols for each of these areas to facilitate research on solving human prostate diseases through the analysis of human tissue.

Current perspectives on the optimal age to spay/castrate dogs and cats

Spaying and castrating of dogs and cats has been considered for decades to be a routine standard of practice in veterinary medicine in the US for the prevention of numerous undesirable behaviors, medical conditions, and diseases. Additionally, the procedures have been promoted as a method of curbing the severe pet-overpopulation problem in the US. Recently, however, this routine practice has come under scrutiny and become a very controversial topic. The general wisdom and safety of the procedures have been questioned by those who are concerned that the procedures may have some unintended consequences that are only recently being recognized. The purpose of this paper is to critically examine the scientific literature regarding elective spay/castration procedures and present both risks and benefits of elective gonadectomy. After the literature is examined, it becomes clear that there may not be a single absolute optimal age to spay or castrate all dogs and cats, but that the optimal age may be dependent upon several factors, including species, breed, body size, and breed-specific diseases, among others. Determining the optimal age to perform elective gonadectomy is much clearer in cats, and the literature demonstrates that the procedures can typically be safely performed at any age after 6–8 weeks of age. The optimal age to spay or castrate dogs of certain breeds (rottweiler, golden retriever, Labrador retriever, and vizsla) is becoming less clear as studies are being conducted as to the health benefits and risks in those breeds. This review will examine these controversies and make recommendations as to the optimal age to spay/castrate dogs based upon the scientific literature.

Embolization therapy for benign prostatic hyperplasia: influence of embolization particle size on gland perfusion

PURPOSE

To assess the influence of embolic size on the therapy response of prostatic arterial embolization (PAE) based on perfusional changes seen on dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Twelve beagles underwent PAE, four dogs with each particle size: A: 100-300 μm; B: 300-500 μm; and C: 500-700 μm. Prior to and 1 month after the embolization all dogs underwent prostate DCE MRI.

RESULTS

After embolization, time to maximal perfusion intensity for prostate parenchyma increased in B (188 vs. 135 sec, P = 0.023) and C (200 vs. 120 sec, P = 0.001), while it did not change for A (139 vs. 124 sec, P = 0.39). The maximal relative intensity increased after embolization in C (3.84 vs. 2.38, P < 0.001), while it did not change for A (2.50 vs. 2.44, P = 0.36) and B (3.23 vs. 2.9, P = 0.21). The extent of visualized intraprostatic urethral wall increased after embolization in B compared with A and C, 239.5 ± 138.1% vs. 56.1 ± 34.3, P = 0.04. Enhancement changes correlated with prostate volume changes: prostate volumes in A decreased less as compared with B and C (77 ± 34% vs. 56 ± 14%), P = 0.02.

CONCLUSION

The enhancement and morphological data are useful to monitor response to therapy after embolization. Embolization with 300-500 and 500-700 μm particle may provide better results than with 100-300 μm particles in a canine model.

Recent Trends in Feline Intestinal Neoplasia: an Epidemiologic Study of 1,129 Cases in the Veterinary Medical Database from 1964 to 2004

A retrospective epidemiologic study evaluated 1,129 feline intestinal tumor patients via data entered into the Veterinary Medical Database (VMDB) from 1964 to 2004. Cases were analyzed by breed, age, yr of diagnosis, tumor type, and location. The VMDB incidence of all intestinal tumors reported during this 40 yr period was 0.4%, with small intestinal tumors predominating. The most common intestinal tumor was lymphoma, but the most common nonlymphoid tumor was adenocarcinoma. The Siamese breed and increasing age after 7 yr conferred an increased risk. Intact males and females appeared to have a decreased risk compared with neutered patients, but this may be explained by the age difference among these patients as older patients were more likely to be neutered. Prospective studies evaluating neuter status predilection and prognosis are warranted.

The effects of aging on the molecular and cellular composition of the prostate microenvironment

Background

Advancing age is associated with substantial increases in the incidence rates of common diseases affecting the prostate gland including benign prostatic hyperplasia (BPH) and prostate carcinoma. The prostate is comprised of a functional secretory epithelium, a basal epithelium, and a supporting stroma comprised of structural elements, and a spectrum of cell types that includes smooth muscle cells, fibroblasts, and inflammatory cells. As reciprocal interactions between epithelium and stromal constituents are essential for normal organogenesis and serve to maintain normal functions, discordance within the stroma could permit or promote disease processes. In this study we sought to identify aging-associated alterations in the mouse prostate microenvironment that could influence pathology.

Methodology/Principal Findings

We quantitated transcript levels in microdissected glandular-adjacent stroma from young (age 4 months) and old (age 20–24 months) C57BL/6 mice, and identified a significant change in the expression of 1259 genes (p<0.05). These included increases in transcripts encoding proteins associated with inflammation (e.g., Ccl8, Ccl12), genotoxic/oxidative stress (e.g., Apod, Serpinb5) and other paracrine-acting effects (e.g., Cyr61). The expression of several collagen genes (e.g., Col1a1 and Col3a1) exhibited age-associated declines. By histology, immunofluorescence, and electron microscopy we determined that the collagen matrix is abundant and disorganized, smooth muscle cell orientation is disordered, and inflammatory infiltrates are significantly increased, and are comprised of macrophages, T cells and, to a lesser extent, B cells.

Conclusion/Significance

These findings demonstrate that during normal aging the prostate stroma exhibits phenotypic and molecular characteristics plausibly contributing to the striking age associated pathologies affecting the prostate.

[Ultrasonographic histological study on the evolution of a canine model of hormone-induced benign prostatic hyperplasia]

INTRODUCTION

Despite exhibiting histological differences from the human process, canine hormone-induced benign prostatic hyperplasia (BPH) is still the most widely used animal model for evaluating treatment strategies.

OBJECTIVES

The aim of this study is to determine the optimal moment for starting a therapeutic trial in this animal model.

MATERIAL AND METHODS

Six male beagle dogs over one year of age were used in this study. All animals received a combination of steroid hormones, namely 17beta-estradiol and 5alpha-androstene 3alpha 17beta-diol, every other day during three (Group 1, n=3) or five months (Group 2, n=3). Transrectal ultrasonographic examinations to measure prostate volume were performed monthly. Animals were euthanized after five months for histological study of their prostates.

RESULTS

All animals developed BPH, with prostate volume increasing over time as hormones were administered (r=0,910). All ultrasonographic studies performed up to the third month evidenced a significant increase in prostate volume when compared to the prior ultrasound measurement. A significant decrease in prostate volume was seen in Group 1 once hormone administration was interrupted, whereas Group 2 animals showed a continuing increase in prostate size. Histological examination showed almost no evidence of BPH in Group 1 animals, while Group 2 animals clearly exhibited moderate epithelial hyperplasia.

CONCLUSIONS

The administration of a combination of steroid hormones is effective in inducing benign prostatic hyperplasia in canines, but this hyperplasia disappears when hormone treatment is interrupted. In order to be useful for experimental studies, hormones should be administered for at least three months before commencing any treatment, and they should be continued throughout the length of the study..

Immunohistochemical characterization of canine prostatic carcinoma and correlation with castration status and castration time

The purpose of this study was to characterize canine prostate cancer using immunohistochemical staining specific for acinar and urothelial/ductal tissue and correlate these results with the dogs' castration status/castration time. Seventy dogs with prostate cancer were included, 71% were castrated and 29% were intact. Compared with an age-matched control population, castrated dogs were at increased risk of prostate cancer, odds ratio 3.9. Immunohistochemical staining was performed on 58 cases. Forty-six of the 58 stained positive for cytokeratin 7 (CK 7) (ductal/urothelial origin) and one of the 58 stained positive for prostate-specific antigen. Dogs with CK 7-positive tumours were younger when castrated than dogs with CK 7-negative tumours, 2 versus 7 years (P = 0.03); dogs castrated at <or=2 years of age were more likely to be CK 7-positive (P = 0.009). These results show that most canine prostatic carcinomas are of ductal/urothelial, androgen-independent origin. This is consistent with the epidemiological findings, showing increased risk in castrated dogs. Canine prostate cancer may, therefore, not be a realistic model for the human disease.

Inhibitory effect of traditional Chinese medicine Zi-Shen Pill on benign prostatic hyperplasia in rats

In the present study, we investigate the effects of an extract isolated from traditional Chinese medicine Zi-Shen Pill (ZSPE) on benign prostatic hyperplasia (BPH) in rats induced by testosterone after castration. A total of 50 rats were equally divided into five groups: Group 1 served as control (sham-operated group); Group 2 was model group; Group 3 and Group 4 animals were administered with ZSPE at dose levels of 300 mg/kg and 600 mg/kg; Group 5 was served as positive control group and treated with finasteride at a dose of 1 mg/kg. The drugs were administered orally once a day for 28 days consecutively. The prostate weight, prostatic index, and serum dihydrotestosterone (DHT) levels were significantly reduced and the pathological changes in BPH were also by ameliorated ZSPE. Immunohistochemical examination revealed that the expressions of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in prostate were inhibited by ZSPE treatment, whereas the levels of transforming growth factor-beta1 (TGF-beta1) were increased. These results suggest that ZSPE has a definite inhibitory effect on BPH and might be an alternative medicine for treatment of human BPH.