5.4LOWER URINARY TRACT: PROSTATIC DISEASE 5.4 LOWER URINARY TRACT: PROSTATIC DISEASE

Diseases of the prostate are rare in cats but are common in older dogs and all may present with similar histories and clinical signs:
Secondary complications include prostatitis (common in older dogs and one possible cause of intractable haematuria) and perineal rupture. It is important to differentiate benign hyperplasia (which is common) from prostate neoplasia (carcinoma) which is less common and life-threatening. Paraprostatic cysts are also seen occasionally and these may complicate the diagnosis. Radiography, ultrasound and physical examination are all useful diagnostic aids which can be further reinforced by prostatic washes or biopsy

If prostatic carcinoma is suspected, survey radiographs should be performed to identify evidence of metastatic spread, especially to the lungs, and also to bone and lymph nodes Surgical removal can be difficult but is successful in providing remission in some cases. Usually it is combined with castration. I have had some success with surgical excision and cryoon tissue that is difficult to resect locally.

For prostatic hyperplasia, castration with or without therapeutic agents such as stilboestrol is indicated. In old dogs that are an anaesthetic risk, medical treatment alone may be necessary.

Paraprostatic cysts (often there are more than one lying alongside the urinary bladder) are difficult to manage, there being no medical therapy, and surgical techniques such as excision and marsupialisation to provide permanent drainage being reported to have mixed success. I prefer to attempt surgical resection.

Prostatitis can be difficult to treat and quite often antibiotic therapy has to be continued for 6-8 weeks. Ideally the antibiotic of choice will be based upon culture and sensitivity tests and it is important that the diagnostic laboratory test for sensitivity is based upon urine concentrations of the drug and not just the blood concentrations achieved. A history of chronic haematuria or urinary tract infection in male dogs should always suggest the possibility of prostatitis.

There are three main differential diagnoses of prostatic disorders in old dogs (see Table 5.2).

Other, less common, prostatic disorders include prostatic cysts and trauma. Aids to diagnosis include: