Prostatic Disease In Dogs
Written by Shula Berg BVSc CertAVP(GSAS) GPAdvCert(SASTS) MRCVS
Clinically reviewed by Elizabeth McLennan-Green BVM&S CertAVP(SAM) MRCVS
Table Of Contents
- Overview
- Symptoms
- Diagnosis
- Treatment
- Outlook
The prostate is a gland which wraps around the urethra (the tube between the bladder and the outside world), found only in male animals. The glandular tissue secretes fluid and protein that helps sperm motility and viability. Although both dogs and cats have a prostate gland, we only tend to see prostatic disease in dogs.
In young dogs, the prostate sits within the pelvic canal. Over time, the influence of testosterone (from the testicles) causes the prostate to increase in size and move forwards into the abdomen. This is known as benign prostatic hyperplasia (BPH), and can affect entire male dogs from as young as two years of age. Prostatic enlargement is common in the majority of entire male dogs older than four years. A proportion of dogs with BHP will go on to develop symptoms, either due to the BPH directly or due to secondary conditions.
What are the symptoms of Prostatic Disease?
Prostatic enlargement can partially obstruct the pelvic canal. This makes it difficult for faeces to pass, and dogs may be seen to strain excessively, pass narrow or thin stools, or appear constipated. Prostatic enlargement alone does not affect the ability to urinate.
Changes in the prostatic tissue due to BPH make bacterial infection (known as prostatitis) more likely. Dogs with prostatitis often find it painful to pass urine and/or faeces, and have abdominal discomfort on examination. They may have a fever, which can make them lethargic and off their food. Occasionally, prostatic infection can lead to formation of abscesses within the prostate.
Less commonly, BPH can cause blockage of the ducts within the prostate. This can lead to formation of cysts either within the prostatic tissue, or extending out from the prostate into the abdomen. Prostatic cysts do not always cause symptoms, but if large enough, can put pressure on the bladder and cause difficulty urinating or incontinence. Some cysts can become extremely large, causing visible distension of the abdomen and other symptoms.
Prostatic cancer is uncommon in dogs, and can occur in both castrated and uncastrated males. It causes enlargement of the prostate similar to BPH, so will cause similar symptoms. Prostatic cancer is much more likely to also affect urination, however, and dogs often have blood in their urine.
Which tests are used to diagnose Prostatic Disease?
In the majority of dogs, the prostate can be examined during a rectal examination. This allows assessment of the size and shape of the gland, and will quickly tell us if the gland is painful or not. In an otherwise well dog, who has a large but non-painful prostate, we can often assume a diagnosis of BPH due to the high probability. In some dogs, especially large breeds, the prostate has moved too far into the abdomen to be palpable rectally.
Ultrasound examination is ideal for examining the prostate. This is performed with the dog awake, or under sedation, and should not be painful. The prostate can be measured and the structure examined for changes typical of BPH, as well as the presence of abscesses or cysts.
If more information is needed, samples can be taken from the prostate for analysis. This is commonly performed using one of two methods. A prostatic wash requires a small urinary catheter to be placed to the level of the prostatic urethra. Sterile fluid is flushed in while the prostate is massaged, before being suctioned out again. This aims to dislodge cells from the prostate into the sample. Alternatively, it is sometimes appropriate to remove cells or fluid directly from the prostate using a fine needle. This is performed under ultrasound guidance, often with sedation. With both methods, the samples retrieved can be examined under a microscope and/or cultured to identify the presence and type of bacteria.
How is Prostatic Disease treated?
Treatment of BPH requires removal of testosterone. The simplest, most effective way to achieve this is with surgical castration. This is a routine procedure and is appropriate for all dogs who are fit to undergo anaesthesia. Chemical castration is also an option, either using an implant or oral medication. However, these treatments are only temporary. There is a risk of the condition recurring when they wear off, so repeat treatment is likely to be needed every 5-12 months.
Prostatitis is treated using oral antibiotics, usually with pain relief/anti-inflammatory medication alongside. As BPH is the underlying cause, it is often advised to treat this as described above either at the same time, or after the antibiotics have taken effect. Some prostatic abscesses will respond to this treatment as well, however, if they have been present for a long time, management can be extremely challenging as antibiotics will not penetrate deeply enough.
Prostatic cysts, and non-responsive prostatic abscesses, often require surgical management. This allows the cysts or abscesses to be physically drained and flushed. To create an ongoing drainage system, the prostate is packed with omentum, the fine tissue that surrounds organs in the abdomen. The omentum is full of blood vessels and is naturally good at fighting infection. Surgery is delicate, as the prostate surrounds the urethra and has several nerves associated with it, so referral to an experienced surgeon may be advised.
Unfortunately, there are very few options for treatment of prostatic cancer. It is typically poorly responsive to hormone reduction or chemotherapy, and has often spread by the time it is diagnosed. Radiotherapy can sometimes prolong survival but is not suited to every case; your vet will be able to advise you of available options.
What is the outlook for dogs with Prostatic Disease?
The prognosis for dogs with BPH or mild prostatitis is very good, especially if castration is an option as this can lead to a complete cure. The prognosis is slightly more guarded for dogs with severe prostatitis, prostatic abscessation or prostatic cysts. Although not life-threatening, they can be more challenging to treat and may require multiple examinations and courses of medication, or surgery, to achieve complete resolution. The majority of cases will be treatable, however, this can be a slow and sometimes frustrating process.
Almost all prostatic problems can be prevented by castration before symptoms develop, or at the first signs of BPH. Castration may not be suited to every dog, however, your vet will be happy to discuss the pros and cons with you to reach an informed decision.
Page last reviewed: 12th June 2024
Next review due: 12th June 2026
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