Effect of a long acting GnRH analogue or placebo on plasma LH/FSH, urethral pressure profiles and clinical signs of urinary incontinence due to Sphincter mechanism incompetence in bitches

Chronic Use of Deslorelin in Dogs: Six Cases (2005-2022)

Deslorelin is currently registered for the induction of temporary infertility in male dogs, male cats, male ferrets, and also prepubertal female dogs, but research has shown its usefulness for other conditions requiring chronic treatment. This paper presents six cases of dogs chronically treated with deslorelin for indications such as benign prostatic hyperplasia, control of fertility, abnormal reproductive behavior and urinary incontinence. All animals were in good health during treatment. Treatment duration was 2-9 years. No short-term side effects were observed except for flare-up reactions, which were observed only in 1/4 intact males. Two dogs developed a neoplasia: a spayed bitch treated for urinary incontinence developed a pituitary carcinoma, and an intact male dog implanted for control of fertility developed a bladder carcinoma. While the pituitary carcinoma seems unlikely to be related to deslorelin, the bladder carcinoma could be due to the neutered condition of the dog (which was treated for 9 years) as urinary tract neoplasia is more common in dogs following gonadectomy. Chronic treatment with deslorelin is regarded as safe when an animal is being treated for life. The possibility that a pause in the treatment might be helpful for the animal should be investigated.

Canine splenic hemangiosarcoma cells express and activate luteinizing hormone receptors in vitro

OBJECTIVE

To determine luteinizing hormone receptor (LHR) expression and response to LHR activation in isolated canine splenic hemangiosarcoma cell lines in vitro.

SAMPLES

In vitro cultures of commercially available canine splenic hemangiosarcoma cell lines (EFS, GRACE-HSA, and DAL-4).

PROCEDURES

The percentage of each cell line expressing LHR was determined by immunocytochemistry. Cells were then treated with increasing doses (7.5 ng/mL, 75 ng/mL) of recombinant canine luteinizing hormone (cLH) for 48 hours and evaluated using a cell proliferation assay.

RESULTS

The percentage of cells expressing LHR was 17.2 ± 4.5%, 11.8 ± 3.1%, and 6.9 ± 2.5% in EFS, GRACE-HSA, and DAL-4, respectively. There was significant increase in cell count in the DAL-4 and EFS cell lines following a 48-hour incubation at the highest cLH concentration (P = .028 and P = .019, respectively). There was not a significant increase in cell count in the GRACE-HSA cell line at either cLH concentration.

CLINICAL RELEVANCE

Activation of LHR results in cell proliferation in some canine splenic hemangiosarcoma cell lines. These results may explain why spayed and castrated dogs with high circulating LH concentrations may develop hemangiosarcoma more frequently than intact dogs.

Long-term effect of repeated deslorelin acetate treatment in bitches for reproduction control

Long-acting gonadotropin-releasing hormone (GnRH) analogs, which are approved for male dogs and ferrets, have been used off-label to suppress estrus in bitches predisposed to the side effects of spaying. Health data from the past 12 years were evaluated from bitches without progestogen pretreatment that received deslorelin acetate (DA) to suppress estrus for the first time before the age of 4.5 years. The study population included 32 client-owned bitches repeatedly treated with either 4.7 mg or 9.4 mg DA implants for a period of 5.3 ± 3.4 years (range 0.5-11.3 years). Follow-up information concerning immediate side effects of DA occurring within five months after the first DA treatment (n = 23) as well as long-term side effects of sustained gonadal suppression occurring after five months up to three years (n = 2), three years up to five years (n = 2) or more than five years (n = 8) were assessed through a questionnaire. Treatment was considered successful if no major side effects requiring medical treatment occurred, which applied to 26 out of 32 (81 %) bitches. In the six remaining bitches, the following major side effects led to treatment discontinuation: persistent urinary incontinence (n = 1), reoccurring induced heat (n = 1), uterine disease (n = 3) and/or ovarian tumor (n = 3). The bitches recovered completely after surgical spaying and/or DA implant removal. Minor side effects that did not require therapy or affect animal welfare included body weight changes (n = 18), subtle behavioral changes (n = 13), induced heat (n = 12), coat changes (n = 11), pseudocyesis (n = 6), transient urinary incontinence (n = 4), and/or temporary thickening of the uterine wall with little anechogenic content (n = 2). To examine a possible causal relationship between adverse side effects and DA treatment, further studies should compare the frequency of pathologies between groups of GnRH-treated, intact and spayed bitches of similar breeds and ages. Nevertheless, DA application before the age of 4.5 years may be a means of postponing surgical spaying for several years in breeds at high risk for developing urinary incontinence. Before DA is used in bitches, owners should be fully informed regarding possible side effects.

Spaying and urinary incontinence in bitches under UK primary veterinary care: a case-control study

Objectives

To evaluate associations between spaying and urinary incontinence in bitches under primary veterinary care in the UK.

Materials and Methods

A case–control study was nested within the study population of 333,910 bitches, which included all bitches within the VetCompass database with an electronic patient record in 2016 or in both 2015 and 2017. The electronic records were searched automatically for urinary incontinence cases, which were manually reviewed for inclusion. All non‐cases were included as controls. Additional demographic and clinical information was extracted on cases and controls.

Results

The study included 427 incident cases and 1708 controls that were presented between November 1, 2014 and October 31, 2017. Prior spaying was associated with increased odds of urinary incontinence (odds ratio: 3.01; 95% CIs: 2.23 to 4.05). Increased odds of urinary incontinence were additionally associated with increasing age and increasing bodyweight. Age at spay was not associated with urinary incontinence.

Clinical Significance

The findings support spaying as a major risk factor associated with urinary incontinence, but age at spay appears to be of less clinical importance. These results will help assist clinicians in making evidence‐based recommendations on spaying while taking other considerations for urinary incontinence into account.

Canine Incontinence

Incontinence is a frustrating condition for both pet owners and their veterinarians. Fortunately, most causes are easily diagnosed and most dogs respond to appropriate therapy. This article reviews normal urine storage and voiding, causes of incontinence, typical clinical presentation, diagnostics, and treatment.

Kastration der Hündin – neue und alte Erkenntnisse zu Vor- und Nachteilen

Die Beratung von Hundehaltern bezüglich der Vorteile und Nachteile sowie des optimalen Zeitpunktes der Kastration einer Hündin ist komplex und sollte sich auf verlässliche Daten aus der Wissenschaft stützen sowie individuelle Belange berücksichtigen. Bei genauerer Betrachtung der aktuellen Publikationen zu diesem Thema fällt auf, dass einige lange für robust gehaltene Informationen etwas angepasst oder aktualisiert werden müssen. Ein offensichtlicher Vorteil der elektiven Kastration ist, dass Erkrankungen der Ovarien und sexualsteroidabhängige Erkrankungen wie Metropathien nicht auftreten. Weiterhin ist ein gewisser protektiver Effekt einer frühzeitigen Kastration auf die Entstehung von Mammatumoren anzunehmen, wenngleich dafür derzeit eine schwache wissenschaftliche Evidenz besteht und der Effekt vermutlich geringer ausfällt, als in einigen älteren Publikationen angegeben wurde. Die Kastration hat jedoch auch Nachteile. Als häufigste negative Folge wird seit Jahrzehnten die Harninkontinenz beschrieben. Aussagen zur Inzidenz sowie zu weiteren Einflussfaktoren, wie Kastrationszeitpunkt in Bezug zur Pubertät, sind jedoch uneinheitlich. Aktuell werden vor allem das gehäufte Auftreten verschiedener Tumorerkrankungen, die nicht direkt mit dem Reproduktionstrakt in Verbindung stehen, sowie ein höheres Risiko für Erkrankungen des Bewegungsapparats bei kastrierten Tieren diskutiert. Weitere Einflussfaktoren wie der Ernährungszustand des Hundes, Alter und/oder Haltung wurden jedoch häufig nicht erfasst. Die Datenlage zur Auswirkung der Kastration auf den Stoffwechsel und das Immunsystem der Hündin ist derzeit ungenügend. Wünscht der Tierbesitzer eine Kastration, bedarf es in jedem Fall einer eingehenden Beratung, die individuelle, rasse- und haltungsbezogene Aspekte einschließt. Derzeit ist eine Kastration am ehesten zwischen der ersten und zweiten Läufigkeit zu empfehlen, da ein gewisser protektiver Effekt auf die Entstehung von Mammatumoren anzunehmen ist und das Risiko unerwünschter Nebenwirkungen nach heutigem Wissensstand moderat ausfällt.

Urethral Sphincter Mechanism Incompetence in 163 Neutered Female Dogs: Diagnosis, Treatment, and Relationship of Weight and Age at Neuter to Development of Disease

BACKGROUND

Urethral sphincter mechanism incompetence (USMI) is the most common cause of urinary incontinence in neutered bitches and is most common in dogs weighing >20 kg.

OBJECTIVES

To describe a population of neutered bitches with USMI and investigate their initial presentation, the relationship between weight and age at neuter, and treatment.

ANIMALS

One hundred and sixty-three female dogs with USMI (UI) diagnosed between January 2009 and December 2012, and 193 continent neutered control (C) bitches.

METHODS

Retrospective data were collected from neutered female dogs with USMI and healthy, continent neutered females presented between January 2009 and December 2012.

RESULTS

Urinary incontinent dogs weighed more than C dogs (P = .003), and there was no difference in age at neuter. The relationship between weight at diagnosis and age at neuter was found to impact the hazard of USMI. A decrease in the hazard of USMI was found in dogs weighing >25 kg for every month delay of neuter in the first year. The hazard did not change for dogs <15 kg. Median time from neuter to development of incontinence was 3.73 years. Phenylpropanolamine was prescribed in 75.5%, diethylstilbestrol in 21.5%, and both in 3.1% of dogs.

CONCLUSIONS AND CLINICAL IMPORTANCE

Neutering bitches expected to be >25 kg adult weight later in their first year may decrease the hazard of developing USMI, whereas age at neutering of bitches <25 kg may not impact continence. Heavier dogs have increased risk of USMI, and onset occurs within a few years of neuter.

Mortality, cardiovascular risk, and androgen deprivation therapy for prostate cancer: A systematic review with direct and network meta-analyses of randomized controlled trials and observational studies

Androgen deprivation therapy (ADT) is a cornerstone therapy for advanced prostate cancer (PCa). We hypothesized that cardiovascular (CV) risk is different across the various ADT modalities to compare their effects on CV morbidity and mortality, and all-cause mortality in patients with PCa. To investigate more in depth potential CV risk heterogeneity focusing on coronary (main outcome) and cerebrovascular risk, CV, and overall mortality. We performed a Medline and Embase query, without language restriction, since 1950 up to July 2014. We included randomized controlled trials (RCTs) and observational studies providing that they compared at least 1 ADT modality to another one or to placebo and they gave data on CV event or all-cause mortality. Sixty-eight studies out of 3419 met our eligibility criteria. Eleven observational studies were analyzed. Direct meta-analyses showed that antiandrogen was associated with a 30% decrease risk for myocardial infarction (MI) compared to GnRH agonists (RR, 0.70 [0.54-0.91]); combined androgen blockade (CAB) was associated with a 10% increase risk for stroke when compared to antiandrogen (RR, 1.10 [1.02-1.19]). With regard to RCTs, 57 were included: direct meta-analyses suggested that CAB was associated with a 10% decrease of all-cause mortality when compared to GnRH agonist (RR, 0.90 [0.82-1.00]). Network analysis could only be performed for all-cause mortality and it remains difficult to disentangle benefit (positive impact on cancer survival) and risk (including CV risk). The impact of the ADT modalities on CV morbidity remains difficult to quantify and more detailed prospective collection is required.

REGISTRATION

PROSPERO, CRD42014010598.

Urinary incontinence in the bitch: an update

Urinary incontinence (UI), defined as the involuntary loss of urine during the filling phase of the bladder (Abrams et al. 2002), is a commonly seen problem in veterinary practice. Urinary sphincter mechanism incompetence (USMI) after spaying is the most common micturition disorder, and its medical treatment is normally successful, even though the underlying pathophysiological mechanism is not fully understood. Hormonal changes inducing structural and functional alterations in the bladder, as well as in the urethra composition, are discussed. To manage incontinent patients successfully, possible underlying abnormalities besides USMI should be ruled out. In the majority of cases, history, physical examination and simple tests including urinalysis and urine bacterial culture lead to a presumed aetiology. If USMI is the most likely cause, then the advantage of further diagnostic tests should be discussed with the owner before starting a trial therapy with alpha-adrenergic drugs. Potential side effects of this therapy have to be mentioned even though they rarely occur. It is important to thoroughly evaluate the success of the initial treatment. Its failure should lead to further diagnostic testing. Specialized clinical assessments may provide an aetiological diagnosis, and this could serve as a basis for discussing further treatment options. Surgical procedures, which may in rare cases cause irreversible side effects, may be instituted. If incontinence reoccurs after initial treatment was successfully performed, the diagnostic work-up including urinalysis should always be repeated. As results of urinalysis did not correlate well with results of bacterial culture, a urine culture is recommended (Comer and Ling 1981). Cystocentesis is the preferred method of urine collection (Bartges 2004). Equivocal results of quantitative cultures of urine samples obtained during midstream voiding or by catheterization require repeat collection by cystocentesis (Comer and Ling 1981).

Gonadotropin-releasing hormone immunization for the treatment of urethral sphincter mechanism incompetence in ovariectomized bitches

We have investigated GnRH immunization for the treatment of urethral sphincter mechanism incompetence in ovariectomized bitches. It has been reported that decreasing LH secretion through the use of GnRH agonists temporarily restores continence in some bitches. Therefore, decreasing the circulating LH concentrations by immunizing against GnRH might temporarily maintain continence in incontinent dogs. Sixteen incontinent dogs given phenylpropanolamine (PPA) to control incontinence were recruited for this study. Eleven dogs were immunized against GnRH (novel treatment group) at week 0, and nine dogs were vaccinated again 4 weeks later. Five dogs (standard treatment group) were vaccinated with a placebo twice at 4-week intervals. PPA was discontinued in the novel treatment group 2 weeks after revaccination, and standard-treatment dogs were given PPA for the duration of the study. Blood samples were collected before each treatment and at 6, 8, 10, 12, 16, 20, and 24 weeks and owners recorded episodes of incontinence throughout the study. Ten of the eleven dogs in the novel treatment group experienced side effects as a result of vaccination; two of these dogs experienced more severe side effects after the first vaccination and were withdrawn from the study as a result. Of the nine dogs that completed the vaccination series, four dogs remained continent after PPA was discontinued. For these four dogs, there was no difference in incontinent episodes when they were given PPA versus treatment with the vaccine. All nine novel-treatment dogs developed a GnRH antibody titer and experienced a significant decrease in circulating LH concentrations. In conclusion, GnRH immunization was effective in maintaining continence in four of the nine incontinent ovariectomized dogs, and in these dogs, treatment with the vaccine was comparable with treatment with PPA.

The heart: a novel gonadotrophin-releasing hormone target

Gonadotrophin-releasing hormone (GnRH) is a hypothalamic hormone transported by the hypophyseal portal bloodstream to the pituitary gland, where it binds to GnRH receptors. However, GnRH receptors are expressed in multiple extrapituitary tissues, although their physiological relevance is not fully understood. GnRH agonists are employed extensively in steroid deprivation therapy, especially to suppress testosterone in prostate cancer. Because GnRH agonist treatment is associated with increased coronary heart disease and myocardial infarction, we investigated the impact of GnRH on cardiomyocyte contractile function. Cardiomyocytes were isolated from mouse hearts and mechanical and intracellular Ca(2+) properties were evaluated, including peak shortening amplitude (PS), time-to-PS (TPS), time-to-90% relengthening (TR(90) ), maximal velocity of shortening/relengthening (± dLdt), electrically-stimulated rise in Fura-2 fluorescence intensity (ΔFFI) and Ca(2+) decay. GnRH (1 ng/ml) increased PS, ± dL/dt, resting FFI and ΔFFI, and prolonged TPS, TR(90) and Ca(2+) decay time, whereas 1 pg/ml GnRH affected all these cardiomyocyte variables, except TPS, resting FFI and ΔFFI. A concentration of 1 fg/ml GnRH and the GnRH cleavage product, GnRH-[1-5] (300 pg/ml), had no effect on any cardiomyocyte parameter. The 1 pg/ml GnRH-elicited responses were attenuated by the GnRH receptor antagonist cetrorelix (10 μm), the protein kinase A (PKA) inhibitor H89 (1 μm) but not the protein kinase C inhibitor chelerythrine chloride (1 μm). These data revealed that GnRH is capable of regulating cardiac contractile function via a GnRH receptor/PKA-dependent mechanism. If present in the human heart, dysfunction of such a system may play an important role in cardiac pathology observed in men treated with GnRH agonists for prostate cancer.

Acquired urinary incontinence in the bitch: update and perspectives from human medicine. Part 2: The urethral component, pathophysiology and medical treatment

Various pathologies can affect the bladder and/or urethral contractility causing signs of urinary incontinence. In this second part of a three-part review, the pathophysiology of impaired urethral contractility (including urethral hyper- and hypotonicity) in the bitch and in women is discussed. Urethral sphincter mechanism incompetence (USMI) is the most common form of acquired urinary incontinence in bitches and is characterized by a decreased urethral tone. The pathophysiology and current recommended medical treatment options for USMI and cases of modified urethral tonicity due to a neurological disorder or functional outlet obstruction are discussed. Treatment options in human medicine in cases of impaired urethral contractility are described.

Effects of gonadotrophin-releasing hormone outside the hypothalamic-pituitary-reproductive axis

Gonadotrophin-releasing hormone (GnRH) is a hypothalamic decapeptide with an undisputed role as a primary regulator of gonadal function. It exerts this regulation by controlling the release of gonadotrophins. However, it is becoming apparent that GnRH may have a variety of other vital roles in normal physiology. A reconsideration of the potential widespread action that this traditional reproductive hormone exerts may lead to the generation of novel therapies and provide insight into seemingly incongruent outcomes from current treatments using GnRH analogues to combat diseases such as prostate cancer.

Spaying-induced coat changes: the role of gonadotropins, GnRH and GnRH treatment on the hair cycle of female dogs

Although spaying can result in qualitative hair coat changes in dogs, the influence of spaying on the hair growth cycle has never been described. The study aims were to examine the effect of spaying and gonadotropin-releasing hormone (GnRH) treatment on canine hair coat, cycle stages of hair follicles, plasma gonadotropin concentrations and mRNA transcription of luteinizing hormone (LH) and GnRH receptors in hair follicles. Fifteen female dogs were examined before and 1 year after spaying and 24 spayed dogs before and after GnRH treatment. Spaying resulted in increased plasma gonadotropin concentrations and increased anagen : telogen ratio of hair follicles, but only 20% of the dogs developed coat changes. No differences were found in mRNA transcription of LH and GnRH receptors. GnRH treatment resulted in reduced plasma gonadotropin concentrations and improvement of coat changes in 79% of patients. This was associated with an increase in catagen hair follicles without changes in the anagen : telogen ratio. The present study demonstrated that spaying had an effect on the anagen : telogen ratio of hair follicles. Spaying-induced coat changes did not correlate with the anagen : telogen ratio. GnRH treatment reduced gonadotropin concentrations and reversed coat changes in some dogs, but had no effect on the hair growth cycle other than increasing the number of catagen hair follicles. A weak positive correlation between the plasma LH concentration and the anagen : telogen ratio was noted; however, our data did not suggest a direct receptor-mediated hormonal effect on the hair follicle. The present study did not identify the pathomechanism of spaying-induced coat changes.

Differences in the expression of luteinizing hormone and follicle-stimulating hormone receptors in the lower urinary tract between intact and gonadectomised male and female dogs

Receptors for LH (LHR) and FSH (FSHR) are expressed in the canine lower urinary tract (LUT). As gonadectomy results in an increase in plasma LH and FSH, the objective of this study was to determine whether there are any differences in the expression of LHR and FSHR in the LUT between intact and gonadectomised dogs. Four regions of the LUT, i.e. body and neck of the bladder as well as proximal and distal urethra, were collected from 20 healthy dogs (5 intact males, 5 intact anoestrous females, 4 castrated males and 6 spayed females). The mRNA and protein expression of receptors was determined by in situ hybridization and immunohistochemistry, respectively, and assessed semi-quantitatively incorporating both the distribution and the intensity of specific staining. Expression of LHR and FSHR was present in all tissue layers (epithelium, sub-epithelial stroma and muscle) of each region with different levels of the expression. Overall mRNA and protein expression for both LHR and FSHR was significantly (P<0.001) lower in gonadectomised dogs. Intact dogs had more (P<0.05) LHR and FSHR mRNA and protein in all tissue layers of the four regions, except for LHR mRNA expression in the sub-epithelial stroma where no differences were observed between the two statuses. Decreases in LHR and FSHR mRNA and protein in gonadectomised dogs appeared to be more consistent in spayed bitches compared to castrated males. Lower expression of LHR and FSHR observed in gonadectomised dogs may adversely affect the normal canine LUT function.

Comparative quantitative assessment of GnRH- and LH-receptor mRNA expression in the urinary tract of sexually intact and spayed female dogs

Ovariectomy interrupts the regulatory loop in the hypothalamus-pituitary-gonad axis, leading to a several-fold increase in gonadotropin levels. This rise in hormonal secretion may play a causal role in ovariectomy-related urinary incontinence. The purpose of this study was to examine the effect of ovariectomy in bitches on the expression of GnRH- and LH-receptors in the lower urinary tract, and assess the relationship between receptor expression and plasma gonadotropin concentrations. Plasma gonadotropins were measured in 37 client-owned bitches. Biopsies were harvested from the mid-ventral bladder wall in all dogs, and from nine further locations within the lower urinary tract in 17 of the 37 animals. Messenger RNA of the LH and GnRH receptors was quantified using RT-PCR with the TaqMan Universal PCR Master Mix. Gonadotropins were measured with a canine-specific FSH-immunoradiometric assay and LH-radioimmunoassay. The hierarchical mixed ANOVA model using MINITAB, Mann-Whitney U-test, unpaired means comparison and linear regressions using StatView were applied for statistical analyses. Messenger RNA for both receptors was detected in all biopsy samples. Age was negatively correlated to mRNA expression of the LH and the GnRH receptors. A relationship between the mRNA values and the plasma gonadotropin concentrations was not established. Evaluation of results within each of the biopsy locations revealed greater LH-receptor expression in the proximal second quarter of the urethra in spayed bitches than in intact bitches (P=0.0481). Increased mRNA expression of LH receptors in this location could possibly play a role in the decrease in closing pressure of the urethra following ovariectomy.

Urodynamic parameters and plasma LH/FSH in spayed Beagle bitches before and 8 weeks after GnRH depot analogue treatment

The pathophysiology of urinary incontinence due to spaying remains unknown. Incontinent bitches can be treated successfully with depot preparations of GnRH-analogues and there are differences in plasma gonadotropin levels between continent and incontinent spayed bitches. It is therefore assumed that the supraordinated hormones, GnRH, FSH, and/or LH, have an effect on the urodynamic parameters. In this study, the potential influence of these hormones on the lower urinary tract was investigated by measuring urethral pressure profiles and cystometry. Simultaneously, plasma concentrations in 10 spayed Beagle bitches were determined 5 weeks prior to and 8 weeks after treatment with the GnRH analogue leuprolide. Within 1 week of GnRH analogue administration, plasma FSH and LH levels decreased from 72.5 and 7.7 to 7.75 and 0.72ng/mL, respectively. These plasma gonadotropin levels correspond with those of intact bitches during anoestrus. Urethral pressure profiles indicated that the treatment had no significant effect on maximum urethral closure pressure, functional and total length of the urethra, or area of the closure pressure curve. The data obtained by cystometry regarding mean bladder threshold volume showed a significant increase from 109 to 172mL. The improvement in bladder function after the application of GnRH-application is presumably a direct effect of the GnRH as a relationship between the plasma gonadotropin levels and the urodynamic parameters could not demonstrated.