Prostatitis

From Dog
Severe acute prostatitis in a dog. There is marked periprostatic edema and haemorrhage[1]
Chronic follicular cystitis and purulent prostatitis in a 13-year-old Labrador[2]

Prostatitis is an inflammatory or infectious disease of the prostate, and can affect both entire and desexed male dogs[3].

Associated with prostatitis in entire dogs is reduced androgen receptor expression[4].

Causes include:

- Mycoplasma canis[6]
- Leishmania spp[7]
- Brucella canis[8]
- Bacteroides spp
- Blastomyces spp
- prostatic adenocarcinoma[9]
  • Miscellaneous causes
- prostatic cysts
- rectourethral fistula[10]
- emphysematous prostatitis[11][12]

It is assumed that prostatitis occurs mostly by ascending or descending infection, although hematogenous spread occurs with Brucella spp. Infections from epididymitis is also possible.

Bacterial infections are usually Gram-negative varieties and release endotoxin, resulting in inflammation. With time, the interstitial response will become more obvious, with lymphocytes and plasma cells predominating. This interstitial phase will also be accompanied with fibrosis.

Clinical signs in dogs are variable or absent, but can include haematuria, dysuria and fever if acute severe prostatitis. Preputial discharge and preputial edema have also been reported[13].

Diagnosis is based on rectal examination[14], ultrasound and ultrasound-guided biopsy and culture of prostatic tissue[15].

Most cases present histologically with chronic lymphocytic or lymphoplasmocytic changes[16]. Many dogs have foci of inflammatory cells in the interstitial tissues), suggesting that subclinical infection may be common[17].

Treatment of canine prostatitis is cause-dependent, but bacterial or parasitic prostatitis can be treated effectively with appropriate drug therapy.

Early castration may prevent the development of prostatitis and cavitary lesions (prostatic abscesses or cysts). In intact dogs, castration should always be part of the specific surgical treatment because it enhances treatment success and may prevent recurrence[18].

Approximately 5 - 7% of dogs with prostatitis have underlying prostatic neoplasia, most commonly adenocarcinoma (it occurs in both intact and castrated dogs), which often metastasizes and has a very poor prognosis[19].

If neoplasia is suspect, prostatectomy or laser ablation and coagulation[20] may be required.

Injecting long-acting antimicrobial drugs such as cefovecin directly into the prostate may be of benefit as experimental studies have shown the efficacy of this procedure[21].

References

  1. Uni of Guelph
  2. University of Lisbon
  3. Smith J (2008) Canine prostatic disease: a review of anatomy, pathology, diagnosis, and treatment. Theriogenology 70(3):375-383
  4. Gallardo F et al (2007) Expression of androgen, oestrogen alpha and beta, and progesterone receptors in the canine prostate: differences between normal, inflamed, hyperplastic and neoplastic glands. J Comp Pathol 136(1):1-8
  5. Agut A et al (2006) A urethrorectal fistula due to prostatic abscess associated with urolithiasis in a dog. Reprod Domest Anim 41(3):247-250
  6. L'Abee-Lund TM et al (2003) Mycoplasma canis and urogenital disease in dogs in Norway. Vet Rec 153(8):231-235
  7. Mir F et al (2012) Subclinical leishmaniasis associated with infertility and chronic prostatitis in a dog. J Small Anim Pract 53(7):419-422
  8. Corrente M et al (2010) Detection of Brucella canis in a dog in Italy. New Microbiol 33(4):337-341
  9. Teske E et al (2002) Canine prostate carcinoma: epidemiological evidence of an increased risk in castrated dogs. Mol Cell Endocrinol 197(1-2):251-255
  10. Silverstone AM & Adams WM (2001) Radiographic diagnosis of a rectourethral fistula in a dog. J Am Anim Hosp Assoc 37(6):573-576
  11. Elsinghorst TA (2003) First cases of animal diseases published since 2000. 1. Dogs. Vet Q 25(3):112-123
  12. Rohleder JJ & Jones JC (2002) Emphysematous prostatitis and carcinoma in a dog. J Am Anim Hosp Assoc 38(5):478-481
  13. Duque J et al (2010) Two unusual cases of canine prostatitis: prostatitis in a castrated dog and preputial oedema in an intact male. Reprod Domest Anim 45(5):199-200
  14. Mukaratirwa S & Chitura T (2007) Canine subclinical prostatic disease: histological prevalence and validity of digital rectal examination as a screening test. J S Afr Vet Assoc 78(2):66-68
  15. Vignoli M et al (2011) Assessment of vascular perfusion kinetics using contrast-enhanced ultrasound for the diagnosis of prostatic disease in dogs. Reprod Domest Anim 46(2):209-213
  16. Newell SM et al (1998) Doppler ultrasound of the prostate in normal dogs and in dogs with chronic lymphocytic-lymphoplasmocytic prostatitis. Vet Radiol Ultrasound 39(4):332-336
  17. James RW & Heywood R (1979) Age-related variations in the testes and prostate of beagle dogs. Toxicology 12(3):273-279
  18. Freitag T et al (2007) Surgical management of common canine prostatic conditions. Compend Contin Educ Vet 29(11):656-658
  19. Memon MA (2007) Common causes of male dog infertility. Theriogenology 68(3):322-328
  20. Rieken M et al (2010) Laser vaporization of the prostate in vivo: Experience with the 150-W 980-nm diode laser in living canines. Lasers Surg Med 42(8):736-742
  21. Bahk JY et al (2000) Concentration of ofloxacin in canine prostate tissue and prostate fluid after intraprostatic injection of biodegradable sustained-releasing microspheres containing ofloxacin. J Urol 163(5):1560-1564