Tissue S100/calgranulin expression and blood neutrophil-to-lymphocyte ratio (NLR) in prostatic disorders in dogs.

BACKGROUND: Prostatic carcinoma (PCA) is a rare but severe condition in dogs that is similar to the androgen-independent form of PCA in men. In contrast to humans, PCA is difficult to diagnose in dogs as reliable biomarkers, available for PCA screening in human medicine, are currently lacking in small animal oncology. Calprotectin (S100A8/A9) and S100A12 are Ca2+-binding proteins of the innate immune system with promising potential to distinguish malignant from benign urogenital tract conditions, similar to the blood neutrophil-to-lymphocyte-ratio (NLR). However, both have not yet been extensively investigated in dogs with PCA. Thus, this study aimed to evaluate the expression of the S100/calgranulins (calprotectin, S100A12, and their ratio [Cal-ratio]) in prostatic biopsies from nine dogs with PCA and compare them to those in dogs with benign prostatic lesions (eight dogs with prostatitis and ten dogs with benign prostatic hyperplasia [BPH]) as well as five healthy controls. In addition, blood NLRs were investigated in twelve dogs with PCA and 22 dogs with benign prostatic conditions. RESULTS: Tissue S100A8/A9+ cell counts did not differ significantly between tissue from PCA and prostatitis cases (P = 0.0659) but were significantly higher in dogs with prostatitis than BPH (P = 0.0013) or controls (P = 0.0033). S100A12+ cell counts were significantly lower in PCA tissues than in prostatitis tissue (P = 0.0458) but did not differ compared to BPH tissue (P = 0.6499) or tissue from controls (P = 0.0622). Cal-ratios did not differ significantly among the groups but were highest in prostatitis tissues and significantly higher in those dogs with poor prostatitis outcomes than in patients that were still alive at the end of the study (P = 0.0455). Blood NLR strongly correlated with prostatic tissue S100A8/A9+ cell counts in dogs with PCA (ρ = 0.81, P = 0.0499) but did not differ among the disease groups of dogs. CONCLUSIONS: This study suggests that the S100/calgranulins play a role in malignant (PCA) and benign (prostatic inflammation) prostatic conditions and supports previous results in lower urinary tract conditions in dogs. These molecules might be linked to the inflammatory environment with potential effects on the inflammasome. The blood NLR does not appear to aid in distinguishing prostatic conditions in dogs. Further investigation of the S100/calgranulin pathways and their role in modulation of tumor development, progression, and metastasis in PCA is warranted.

Streptococcus canis prostatitis and endocarditis with thromboembolism in a dog with sertoli cell tumour in a cryptic testis and prostatic squamous metaplasia.

We describe an unusual case of prostatitis caused by Streptococcus canis evolving to endocarditis and splenic, renal, and cerebral thromboembolism in a dog, associated with a Sertoli cell tumour in a cryptic testis and diffuse prostatic squamous metaplasia. A nine-year-old, intact male, mixed-breed dog was presented to a veterinary teaching hospital with abdominal pain and prostration. Physical examination and abdominal ultrasonography revealed an atrophic right testicle located in the subcutaneous tissue. The left testicle was in the abdominal cavity with increased dimensions and irregular contours. Complete blood count analysis showed marked neutrophilic leukocytosis and thrombocytopenia. After clinical worsening, euthanasia was performed, and the dog was submitted to post-mortem examination. The main gross findings included testicular malposition with one cryptic and one ectopic testis, enlarged prostate with purulent content, distension of the urinary bladder with cloudy urine, vegetative valvular endocarditis in the mitral valve, and spleen and renal infarcts. Histological examination showed a Sertoli cell tumour in the abdominal testis, diffuse prostatic squamous metaplasia with marked keratinization associated with bacterial prostatitis, fibrinonecrotic cystitis, bacterial endocarditis with marked myxomatous degeneration in the mitral valve, and splenic, renal, and cerebral thromboembolism. Microbiological analysis identified Streptococcus canis in the prostate and mitral valve. Sertoli cell tumour of cryptic testis increases oestrogen production and leads to squamous metaplasia of the prostate, which should be considered as predisposing factors for ascending S. canis infection from the urogenital tract to the prostate. Then, haematogenous spread of S. canis from the prostate to mitral valve cause endocarditis and subsequent thromboembolism and infarcts, all decisive to poor prognosis in this case.

Prostatitis and prostatic abscessation in dogs: retrospective study of 82 cases.

OBJECTIVES: To describe clinical signs, diagnostics, treatments and outcomes of prostatitis and prostatic abscesses of dogs in a referral population. ANIMALS: Eighty-two dogs diagnosed with prostatitis and/or prostatic abscesses from three referral hospitals. PROCEDURES: Retrospective case series. RESULTS: A total of 82 dogs were included, and the median age was nine years. Acute prostatitis was diagnosed in 63% of cases, chronic prostatitis in 37% of cases and 40% of cases had prostatic abscessation. Prostatomegaly was the most common ultrasonographic finding. Mineralisation was identified in 20% of cases. The results of urine and prostatic bacterial culture were concordant in only 50% of cases. Antimicrobial resistance was encountered commonly, with 29% of cultures resistant to one antimicrobial and 52% resistant to two or more antimicrobials. Abscesses were treated with either antimicrobials alone, ultrasound-guided needle drainage or surgical drainage. CONCLUSIONS AND CLINICAL RELEVANCE: With antimicrobial treatment and castration, the prognosis for canine prostatitis appears good. Prostatic abscessation is commonly encountered and does not appear to infer a worse prognosis and antimicrobials alone, ultrasound-guided needle drainage and surgical drainage all appear to be reasonable treatment options. Antimicrobial resistance is commonly encountered, and the results of urine culture and susceptibility testing are frequently discordant with those from samples from the prostate. Sampling of the prostate is required to confirm a diagnosis and exclude other pathologies such as neoplasia, particularly as mineralisation is seen in a reasonable number of cases of dogs with prostatitis.

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

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

Association of bacterial isolates and antimicrobial susceptibility between prostatic fluid and urine samples in canine prostatitis with concurrent cystitis.

Most old, intact male dogs usually have prostate disorders, especially benign prostatic hypertrophy and prostatitis with or without abscesses, and concurrent cystitis. The successful treatment of dogs with prostatitis concurrent with cystitis has relied on choosing an appropriate antimicrobial drug based on a bacterial culture and drug sensitivity testing. The objective of the study was to compare the prevalence of bacterial species and results of drug susceptibility testing of bacteria that were isolated from the prostatic fluids and urine samples that were collected from dogs with both prostatitis and cystitis. One hundred and sixty intact male dogs, who presented with both diseases, were recruited for the study. The disease diagnoses were based on clinical history notes, physical examinations, abdominal ultrasonography, prostatic fluid cytology, urinalysis and bacterial cultures from both prostatic fluid and urine samples. The bacterial culture results demonstrated that the major species that were detected in either the prostatic fluid or urine samples were Staphylococcus spp., Escherichia coli, Pseudomonas spp., Streptococcus spp., Proteus mirabilis and Klebsiella pneumoniae. Staphylococcus spp. (26.5 %, 43/162) and Escherichia coli (26.1 %, 12/46) were the most prevalent species from the prostatic fluid and urine samples, respectively. Statistical tests revealed that there were no significantly different prevalence levels among the isolated bacteria between the prostatic fluid and urine samples. Imipenem and gentamicin were the most potent antimicrobial drugs tested against the bacterial isolates in the present study. However, the administration of imipenem to treat prostatitis and cystitis in dogs was of concern. Interestingly, there were no significant differences in the antimicrobial drug susceptibility trends between the prostatic fluid and urine samples. Based on these results, a urine sample might be considered as an optional sample for bacterial cultures and antimicrobial drug susceptibility testing when it is not possible to collect a prostatic fluid sample.

Highlights on the Canine Prostatic Specific Esterase (CPSE): A diagnostic and screening tool in veterinary andrology.

In the last years, the need to look for an accurate and precise diagnosis of prostatic diseases in dogs has grown. Among other diagnostic tools, the seric CPSE has been studied and identified as a valid and specific biomarker for prostatic disorders, since it can result significantly more elevated in dogs affected by several prostatic abnormalities, such as benign prostatic hyperplasia, bacterial prostatitis and prostatic carcinoma. Therefore, dosing CPSE in serum represents a new diagnostic and screening tool. Dosing CPSE in everyday clinical practice has three objectives: (a) the diagnosis of benign prostatic hyperplasia; (b) the preventive screening of prostatic disorders in healthy dogs; (c) the medical follow-up in subjects with prostatic disorders during and after medical therapy. Neither circadian rhythms nor transrectal palpation performed during the andrological examination do affect CPSE. A sexual rest of at least 24 hr before dosing CPSE is recommended as it is affected by ejaculation.

Diagnostic investigations of canine prostatitis incidence together with benign prostate hyperplasia, prostate malignancies, and biochemical recurrence in high-risk prostate cancer as a model for human study.

The aim of this study was to evaluate the prevalence of acute and chronic inflammation, benign prostatic hyperplasia (BPH), and cancer of the prostate glands in the canine as a human model in prostate disorders. The study was carried out on 12 cases of different male dogs of terrier (50%), German shepherd (25%) breeds, and Greden (25%), and the age of the dogs ranged from 6 to 13 years (average age 7.8 ± 3.6). The bodyweight ranged from 3.6 to 7.9 kg. Signalment, clinical signs, and diagnostic tools such as ultrasonography, urinary cytology, and histopathology are presented. Dysuria was the most common clinical sign in this study and occurred in 10/12 canine (83.3%) included. Other clinical signs included lameness (5/12 canine, 41.6%) and constipation (3/12 canine, 25%). The range of duration of clinical signs was 5 days to 7 months. Moreover, in the present study, the urinary biochemical markers of different prostate lesions include blood, protein, and glucose and were detected in 11/12 cases (91.6%), 5/12 cases (41.6%), and 2/12 cases (16.6%), respectively. Taken together, sonographic data were classified into four groups based on histological diagnosis. In 7/12 cases (58.4%), the prostate appeared to have BPH lesions, and the remaining lesions included inflammation (3/12 cases, 25%), abscess (1 case, 8.3%), and adenocarcinoma (1 case, 8/3%) on ultrasound. In all cases, prostate tissue had an irregular echotexture. None of the dogs had sonographic evidence of sublumbar lymph node enlargement. Histopathologically, we looked at the prevalence of inflammation (33.3% chronic and 8.3% acute) and BPH (58.4%) in dogs of different ages and breeds, and also, we observed chronic inflammation in >20% of dogs, which was about 25% in 3 cases of the 12 cases referred. More chronic inflammation was associated with more BPH. The majority of the asymptomatic inflammation that is detected in the prostate is classified as chronic inflammation (i.e., as evidenced by the presence of monocytic and/or lymphoplasmacytic inflammatory cell infiltrates); however, acute inflammation is also observed to a lesser degree. Acute inflammation, as is typically evidenced by the infiltration of neutrophils, is classically an indicator of an infectious process. Finally, the patients included seven castrated, four castrated together with antibiotic therapy, and one castrated together with chemotherapy intact male dogs, which were treated with the mentioned cases. In conclusion, chronic prostatic inflammation could be a central mechanism in BPH progression, but the pathological features of tissue inflammation were different between BPH and prostate cancer (PCa). Nevertheless, the histological examination of prostate biopsies remains the only way to diagnose prostatic disorders.

Pharmacological treatment for common prostatic conditions in dogs - benign prostatic hyperplasia and prostatitis: an update.

The two most frequent prostatic diseases in dogs are benign prostatic hyperplasia (BPH) and prostatitis. Prostatitis requires prolonged antibiotic treatment. In acute prostatitis, the blood-prostate barrier is broken, thus facilitating the penetration of antibiotics, whereas in chronic prostatitis, the barrier prevents the penetration of many drugs into the gland. The selection of antibiotic agents is based on the sensitivity test and the drug's ability to penetrate into the gland. Many protocols for the treatment of BPH are available. In non-breeding dogs, surgical and optionally pharmacological castration by means of GnRH agonists may be performed. In breeding dogs, drugs retaining fertility are used. Recently, androgen receptor antagonistic treatment with osaterone acetate has been applied. Other drugs used for BPH treatment include progestagens, oestrogens, antioestrogens and 5α-reductase inhibitors. Some of these compounds may provoke severe side effects. The efficiency of GnRH antagonists used for the treatment of prostatic diseases, such as neoplasia and BPH, in humans has been recently investigated in dogs. This androgen deprivation therapy (ADT) is devoid of an initial exacerbation of androgen-dependent symptoms, which is typical for GnRH agonistic treatment. In many cases, BPH and prostatitis must be treated simultaneously as these conditions may develop in combination.

Subclinical leishmaniasis associated with infertility and chronic prostatitis in a dog.

A stud dog was presented for acquired infertility. Haematospermia and teratozoospermia were found on two ejaculates 2 weeks apart. A presumptive diagnosis of prostatitis was made follo-wing ultrasound examination. An ultrasound-guided needle core biopsy was performed under general anaesthesia, revealing a mild chronic macrophagic and plasma cell prostatitis with intracytoplasmic amastigotes consistent with Leishmania spp. infection. Presence of Leishmania infantum, Leishmania donovani or Leishmania chagasi was confirmed by polymerase chain reaction in seminal plasma. Serology and serum protein electrophoresis confirmed the diagnosis of a subclinical active systemic leishmaniasis. A meglumine antimoniate and allopurinol treatment was given which clearly improved within 3 months both general condition and the quality of sperm. To the authors' knowledge, this is the first reported case of a prostatitis secondary to a Leishmania spp. infection. Subclinical systemic leishmaniasis should be considered in the differential diagnosis of infertility in dogs suffering from semen alterations.

Chronic prostatitis, cystitis, pyelonephritis, and balanoposthitis in a cat.

An adult, intact male domestic shorthair presented for preputial swelling and urinary incontinence. A caudal abdominal mass was palpated. A transabdominal ultrasound examination showed severe prostatomegaly with abnormal tissue extending along the urethra. The cat was euthanized due to the owner's financial constraints and the veterinarians' suspicion of a poor long-term prognosis. Biopsies showed chronic active inflammation of the prostate, bladder, kidneys, ureters, penis, and prepuce most consistent with a chronic infectious process. Reports of feline prostatic disease of any kind are rare. Chronic prostatitis may have a more favorable prognosis than feline prostatic adenocarcinoma, currently the most commonly reported disease of the feline prostate.

Avaliação histológica da próstata de cães adultos sexualmente intactos / Prostatic histological evaluation in adult not castrated dogs

Avaliou-se histologicamente a próstata de 30 cães adultos e idosos sexualmente intactos que apresentavam ou não sintomatologia clínica de doença prostática, e verificou-se a incidência de possíveis alterações da glândula. Dentre as alterações encontradas, a hiperplasia prostática benigna constituiu o diagnóstico mais comum, 85,6 por cento (n=24), seguida por prostatite crônica, 64,3 por cento (n=18), displasia do epitélio glandular, 42,8 por cento (n=12), atrofia do epitélio glandular, 39,3 por cento (n=11), infiltrado inflamatório focal, 25 por cento (n=7), dilatação glandular focal, 21,4 por cento (n=6), prostatite aguda, 7,1 por cento (n=2), metaplasia escamosa, 3,6 por cento, (n=1), metástase de neoplasia sistêmica, 3,6 por cento (n=1) e abscesso prostático, 3,6 por cento (n=1). Como em muitos casos os cães são assintomáticos, ressalta-se a importância da realização rotineira de exames clínicos específicos, como o toque retal e a ultrassonografia, para o diagnóstico precoce e o tratamento das afecções prostáticas.

The prostates of 30 not castrated old dogs with or without clinical symptoms of prostatic disease were histologically evaluated. It was observed the incidence of possible changes in the gland. Among the changes, benign prostatic hyperplasia (BPH) was the most common diagnosis, accounting for 85.6 percent (n=24), followed by chronic prostatitis, 64.3 percent (n=18), dysplasia of the glandular epithelium, 42.8 percent (n=12), atrophy of the glandular epithelium, 39.3 percent (n=11), focal inflammatory infiltrate, 25 percent (n=7), focal glandular dilation, 21.4 percent (n=6), acute prostatitis, 7.1 percent (n=2), squamous metaplasia, 3.6 percent (n=1), metastasis of systemic neoplasia, 3.6 percent (n=1), and prostatic abscess, 3.6 percent (n=1). Because the lack of symptoms in most of dogs with prostatic changes, the specific clinic exams in routine, as rectal palpation and ultrasonography, are very important to early diagnosis and treatment of dogs with prostatic disease.

Relationship between prostatomegaly, prostatic mineralization, and cytologic diagnosis.

Canine prostatic disease is commonly evaluated with abdominal ultrasound and radiographs. Mineralization of the prostate is often reported, but the clinical relevance of this finding is currently not known. The-purpose of this study was to characterize the relationship between ultrasonographic and radiographic prostate mineralization and the final diagnosis. Medical records of 55 dogs with evidence of prostatomegaly or prostatic mineralization and a cytologic diagnosis were evaluated. Radiographs and ultrasound images were assessed for caudal retroperitoneal lymphadenopathy, vertebral lesions, or other signs of metastasis, and mineralization was assessed semiquantitatively. Twenty-two of 55 (40%) dogs had prostatic neoplasia. Regarding neoplasia, mineralization in neutered dogs had a positive predictive value (PPV) of 100%, a negative predictive value (NPV) of 50%, and a sensitivity and specificity of 84% and 100%, respectively. Mineralization in intact dogs had a PPV of 22%, an NPV of 96%, and a sensitivity and specificity of 67% and 77%, respectively. All neutered dogs with prostatomegaly but not prostatic neoplasia had bacterial prostatitis and were castrated within the previous 3 months. Intact dogs with prostatomegaly and mineralization but not neoplasia had paraprostatic cysts (n = 3), benign prostatic hyperplasia (n = 2) or prostatitis (n = 2). Mineralization score was not indicative of neoplasia. In conclusion, neutered dogs with prostatic mineralization were very likely to have prostatic neoplasia. Intact dogs were unlikely to have prostatic neoplasia if no mineralization was found on radiographs or ultrasound.

Expression of androgen, oestrogen alpha and beta, and progesterone receptors in the canine prostate: differences between normal, inflamed, hyperplastic and neoplastic glands.

The expression of receptor for androgen (AR), oestrogen alpha and beta (ERalpha and ERbeta) and progesterone (PR) was examined immunohistochemically in canine prostate specimens (normal, hyperplastic, inflamed [prostatitis] or neoplastic). AR immunolabelling was seen in 100% of epithelial cells of normal and hyperplastic tissue, the corresponding figures for inflamed and carcinomatous tissue being 74% and 65%, respectively. ERalpha labelling was seen in 85% of epithelial cells in normal prostate glands, the corresponding figures for hyperplastic, inflamed and neoplastic glands being 35%, 22% and 12%, respectively. ERbeta labelling was seen in 85% of epithelial cells of normal glands and in about 70% of such cells in glands showing pathological changes. On the other hand, PR expression (weak) in normal glands was observed in fewer epithelial cells (44%) than in hyperplastic (70%), inflamed (62%) or neoplastic (64%) glands.

First cases of animal diseases published since 2000. 1. Dogs.

In this first article of a series of papers listing first case reports of animal diseases published since 2000, the following 19 cases of dog diseases are discussed: Blastomycotic granuloma involving the cranial vena cava. Congenital myocardial hamartoma. Discospondylitis: three cases caused respectively by Pseudomonas aeruginosa, Enterococcus faecalis and Staphylococcus epidermidis. Dystrophin deficient muscular dystrophy in a Labrador Retriever. Emphysematous prostatitis. Erythema multiforme major caused by a Parvovirus infection of keratinocytes. Hemochromatosis due to repeated blood transfusions. Intraspinal synovial cyst. Juvenile nephropathy in the Collie and the Irish Wolfhound. Primary cerebellar cortical degeneration (abiotrophy) in a Scottish terrier. Primary pulmonary artery chondrosarcoma. Renal dysplasia in a Bull Mastiff. Rhabdomyosarcoma (botryoid sarcoma) of the urinary bladder in a Maltese. Spinal mast cell tumor. Spongiform degeneration of the white matter in the central nervous system of Australian Cattle dog. Systemic pasteurellosis caused by Pasteurella canis. Thymic hemorrhage caused by dicumarol intoxication. Undimerized biclonal gammopathy with a single heavy chain class IgA in a dog with multiple myeloma. After a short introduction, the bibliographical data and the abstract of the author(s) and mostly some additional information derived from the article are given. The article will be regularly updated adding overlooked as well as new first reports.

Emphysematous prostatitis and carcinoma in a dog.

A 10-year-old, male beagle was presented for lethargy, anorexia, and straining to urinate. A mass was palpated in the caudal abdomen in the area of the bladder. Abdominal radiography revealed a gas-filled mass in the caudoventral abdominal quadrant. Subsequent positive-contrast cystography revealed that the mass was caudal to the bladder. Abdominal exploratory celiotomy resulted in the drainage of a prostatic abscess containing gas. The histopathological diagnosis of the prostate was a poorly differentiated tubular carcinoma with necrosis. To the authors' knowledge, this article is the first report of an emphysematous prostatitis in a dog.

Ultrasonographic estimation of prostatic size in canine cadavers.

The purpose of this study was to determine the accuracy of transabdominal ultrasound in estimating the volume and weight of the canine prostate gland, to derive a simple formula from actual and ultrasonographic prostate measurements for estimating prostate volume and weight, and to evaluate the reproducibility of ultrasonographic measurements of linear prostate dimensions. The prostate volume and weight were measured and also calculated in 77 male canine cadavers (60 entire and 17 neutered) with the aid of statistical computer programmes using actual linear dimensions of the prostate ('actual') and those measured ultrasonographically before ('in vivo') and after ('in vitro') removal of the prostate gland. Therefore, 'in vivo', 'in vitro' and 'actual' estimations of prostate size were obtained and compared with prostatic volume and weight. The evaluation of the reproducibility of the ultrasonographic measurements made was performed in 59 of the dogs in which the prostate was imaged three times in longitudinal and three times in transverse sections. This study demonstrated that prostatic weight and volume are related to body weight and age in entire dogs but not in neutered dogs. Formulae were derived to estimate prostate weight and volume from physical and ultrasonographic measurements. There were good correlations between the ultrasonographic and physical measurements and prostate size derived from these measurements provided a good estimate of actual prostate size. 'Best subsets' analyses indicated that prostate width and length (measured physically or ultrasonographically) were the best predictors of prostatic volume and weight, both when all dogs were considered together and in entire dogs only. Statistical analyses indicated that there were no significant differences between the repeated measurements of length and depth (P>0.05). However, there was a significant difference between repeated measurements of width (P= 0.0357).

Cystic prostatic disease associated with adrenocortical lesions in the ferret (Mustela putorius furo).

A review of case materials at the Armed Forces Institute of Pathology identified six cases of prostatitis in domestic ferrets (Mustela putorius furo). Five of these ferrets (83%) had one or more cysts and the remaining ferret had a paraprostatic cyst. Three of the six ferrets (50%) exhibited various degrees of prostatic squamous metaplasia. Inflammation ranged from subacute to chronic-active or pyogranulomatous. In addition to the prostatic lesions, hyperplastic and/or neoplastic adrenocortical lesions were present in 4/6 (66%) ferrets; 1/6 (17%) ferrets had previously been clinically diagnosed with adrenal gland-associated endocrinopathy. The remaining ferret had previously had the right adrenal gland removed, but the reason for the removal is unknown. Based upon the histologic findings in these six ferrets, there appears to be an association between proliferative adrenal lesions and cystic prostatitis in domestic ferrets.

Enrofloxacin concentrations in dogs with normal prostate and dogs with chronic bacterial prostatitis.

Chronic Escherichia coli-associated prostatitis was induced in 16 dogs; 9 noninfected dogs served as controls; and all dogs were vasectomized. Two to 3 weeks after instillation of bacteria directly into the prostate, the urine or prostatic fluid or both from 13 of 16 dogs were culture positive. Enrofloxacin, a fluoroquinolone antimicrobial agent, was administered orally to all dogs during the third or fourth week after surgery, at a dosage of approximately 5 mg/kg of body weight, every 12 hours for 7 days. Serum and prostatic fluid concentrations of enrofloxacin were concurrently measured in all dogs on days 2, 4, and 6 at 2 hours after dosing. Serum and prostatic tissue concentrations of enrofloxacin were concurrently measured in all dogs on day 7, at 1.5, 3, 4.5, and 6 hours after dosing. When values for these samples were compared, using a two-factor ANOVA, significant differences were not found. Use of this dosing regimen of enrofloxacin resulted in prostatic fluid and prostatic tissue concentrations exceeding the minimum inhibitory concentration of most pathogens that cause bacterial prostatitis. In addition, prostatic fluid-to-serum and prostatic tissue-to-serum concentration ratios were greater than 1.0.