*4.2.5 Therapy*

Canine intraprostatic cysts up to 3 cm in diameter can be treated with a 5α-reductase-inhibitor (Finasteride) or with anti-androgens; mostly they regress

#### **Figure 4.**

*Sonography (B-mode) of a prostate gland with BPH and intraprostatic cysts. A small cyst is visible (white crosses). Cysts up to 3 cm in diameter can regress with anti-androgen therapy. Cysts filled with urine have a higher recidive rate, also after puncture.*

#### **Figure 5.**

*Sonography (B-mode) of a paraprostatic cyst. On the left side, the urinary bladder is visible; the mucus membrane is irregular and thickened. To the right, a paraprostatic cyst is situated, filled with hypoechoic fluids. The dog showed mild symptoms of a BPH with bloody preputial discharge and stranguria.*

within 2–3 weeks. When the treatment is ineffective or in case of larger cysts, they have to be punctured and the secretions aspirated or the cysts must be surgically removed. The puncture should be done with the aid of sonography and transcutaneously (**Figure 6**). The treatment mostly has to be repeated one to four times and only if these measures stay without success, the operation should be considered [93]. The ultrasound-guided percutaneous drainage with alcohol sclerotherapy is controversial,

#### **Figure 6.**

*Transabdominal puncture of a prostate abscess. The gland was visualized with a 7.5 MHz convex probe, the cyst was punctured with a 0.9×40 mm needle, connected to an extension and a three-way cock. The contents were sucked off with a sterile syringe and examined cytologically and bacteriologically.*

even though some reports are promising [94]. Recently, canine autologous plateletrich plasma (PRP) obtained through separation of liquid and solid components from whole blood, it was instilled after removal of cystic fluid in dogs with BPH and prostatic cysts [95]. The PRP dose was half the fluid removed from the cyst. Sixty days later, the cysts were no longer detectable sonographically. The PRP is known to affect antibacterial, analgesic, and anti-inflammatory [96]. The surgical treatment and the treatment of abscesses will be discussed in the following chapter.

#### *4.2.6 Prophylaxis*

As described in the chapter BPH

#### **4.3 Inflammatory diseases of the prostate gland**

#### *4.3.1 Causes*

In dogs, inflammatory diseases can be acute or chronical; they are mostly complicated by infections that ascend via the urethra or spread via the blood circulation [39, 97]. Prostatitis therefore may occur in both castrated and intact dogs. In some cases, a BPH, squamous metaplasia or neoplasia is complicated by an infection. In one study, in 66.6% of male dogs with clinical BPH, bacteria were isolated in the sperm-rich phase of the ejaculate; out of these, 61.1% were positive for mycoplasms, and out of these, 54.5% were positive for *Mycoplasma (M.) canis* [36]. In 2/3 of all cases of prostatitis, a mixed bacterial culture can be found, and only in 1/3 of patients a monoculture [98]. Infectious agents mostly are *E. Coli*, Staphylococcus spp., Streptococcus spp., Proteus spp., Pseudomonas spp., Klebsiella spp., *Brucella canis,* etc., as well as anaerobe germs; Seldom are viruses like the canine distemper virus, or blastomyces and cryptococci in urine, semen, or prostate secretions [9, 39, 97, 99]. It is important to know that abscesses in the prostate gland can be infectious or sterile [7, 41, 99].

#### *4.3.2 Clinical findings*

The acute prostatitis can cause severe symptoms like acute anuria or obstipation. A frequent symptom in dogs is purulent-bloody preputial discharge. Fever, inappetence, vomiting, and diarrhea are possible. In case of an abscess, palpation of the gland is highly painful and fluctuation is typical; rupture will cause septic shock.

The chronical prostatitis usually starts with symptoms of the BPH, and then the course is recurrent, causing loss of weight and shaggy hair. Superinfections frequently occur.

#### *4.3.3 Diagnosis*

The diagnosis should be done by clinical examination of the dog, sonography, and examination of urine and semen inclusive bacteriological examination. In addition, prostate secretions and the contents of cysts can be examined cytologically [19]. Rectal palpation will be painful. The gland can be asymmetric; the consistency will be elastic in case of acute inflammation, in case of chronical inflammation increased and sometimes hard, the surface can be uneven.

In dogs, hematuria and bloody preputial discharge frequently occur, and pyuria or purulent discharge may occur in case of prostate gland abscess. Bacteriological examination is mostly positive [41].

#### *Diseases of the Canine Prostate Gland DOI: http://dx.doi.org/10.5772/intechopen.105835*

Blood picture: in case of acute prostatitis and abscesses, leucocytosis and neutrophilia are frequent, in chronical prostatitis, these findings may be lacking. An increased concentration of the enzyme canine-prostate-specific esterase (CPSE) may indicate a prostatic disease; however, differentiation between BPH, prostatitis, and neoplasia is not possible in dogs. Furthermore, the literature provides variable cut-off values [48, 75, 77] and the secretion of the CPSE is age-dependent in dogs. The measured values, therefore, have to be carefully interpreted; the diagnosis must include other findings.

Semen collection in case of acute prostatitis will not be possible but may be helpful in case of the chronical prostatitis. The semen quality initially shows the same abnormalities as in BPH and will decrease in case of infection. Admixture of erythrocytes is a frequent finding, furthermore decreased motility and an increase in morphological abnormalities [19, 39, 40]. The bacteriological examination of the semen or prostatic secretions is mostly positive [7, 9, 39]; additional cytological examination of the prostatic secretions is useful, in case of acute prostatitis and abscesses, granulocytes, blood cells, and bacteria are frequently found, whereas prostate cells appear normal [42, 99].

In dogs, the cytological findings correlate well with the patho-histological findings [39]; however, not with the bacteriological findings [100]. Collection of prostatic secretions is not sterile because of the physiological mixed flora in the urethra [101]; therefore, the quantitative bacteriological findings have to be considered as well.

The transcutaneous, sonographically guided fine-needle-aspiration (FNA) of the prostate tissue and puncture of fluid-filled cysts are important for differentiation between canine BPH and chronical prostatitis or neoplasia [39, 41, 44, 102] (**Figure 6**). The collected material should be examined cytologically and bacteriologically. Up to 70% of prostatitis cases were correctly diagnosed by use of FNA [102]. Complications rarely occur; in some cases, low-grade bleeding and inflammation were observed, especially in case of inflammatory changings [93]. Even though at the time of puncture or FNA it is not known, whether the obtained material is infectious or not, the procedure is safe for the patient, when performed in a sterile manner. The dog should receive nonsteroidal anti-inflammatory drugs (NSAID) for 3 days after the puncture and should be treated as soon as possible with suitable antibiotics according to the resistance test. In rare cases, spreading of tumor cells is possible [103].

B-mode-Sonography: in dogs, enlargement, asymmetry, and heterogeneity are prevailing symptoms. In case of acute prostatitis and abscesses, hypoechogenic sites can be found (**Figure 7**); in chronical prostatitis, hyperechoic sites are frequent, and in case of neoplasia also mineralization (**Figure 8**) [45, 63, 104].

Unfortunately, it is not possible to differentiate between chronically inflammatory and tumorous changings, not with B-mode and Doppler sonography; in these cases, an FNA or biopsy is obligatory in dogs [8, 44, 73]. With grey-scale or pulse-wave Doppler-sonography, it was not even possible to differentiate between inflammatory and normal canine tissue [105]. Similarly, other imaging methods like CT or MRI cannot provide a secure diagnosis; however, in case of canine prostatitis, the CT findings correlated well with the CT outcome [68]. When using CT, the age of the dog must be considered since the normal CT findings change in the aging dog. The prostate growth shows three phases [106]: during the first phase (1–5 years), the gland reaches normal morphology; in the second phase (6–10 years), first hyperplastic changings occur; and in the third phase (≥11 years), senile involution is typical. These changings can be observed in the CT pictures as well [67].

As described in the chapter BPH, the echostructure analysis revealed typical findings in case of prostatitis; homogeneity was significantly decreased in comparison to BPH [62]. Further investigations are necessary to prove these first results.

#### **Figure 7.**

*Sonography of a prostate gland with acute prostatitis. Prostate gland of a 12-year-old dog with fever, apathia, urine loss, obstipation, and a painful abdomen. The prostate gland was painful upon digital-rectal palpation. The gland was high-grade enlarged and the structure was inhomogenous. An intraprostatic cyst, 1,5x2 cm in size, was visible. The urine was examined bacteriologically and Streptococcus canis +++ was found. The dog received effective antibiotics according to the resistency test for 6 weeks and the antiandrogen cyproterone acetate (3 mg/kg SID, s.c.). A sonographical control 2 weeks later showed that the cyst had diminished.*

#### **Figure 8.**

*Sonography of a chronical prostatitis. The gland was high-grade enlarged and the structure was inhomogenous, mainly most areas hyperechoic. Very small cysts were visible. The dog showed chronic recurrent bloody preputial discharge, dyschezia, and obstipation. The semen was examined bacteriologically and ++ E. coli was isolated.*
