Assessing the prostate with ultrasound

Prostate scanning for the purpose of diagnosis or treatment can only be performed by a veterinarian. However, a number of experienced scanners do check their own animals (never take the legal risk of scanning anyone else’s).

Where to find it

Just like pregnancy scanning, the best method is to use the bladder as your landmark. The prostate can be found at the neck of the bladder, and it is often easier to find with the dog (or cat – however, feline prostate disease is rare, and very few owners would attempt a prostate scan) standing and/or when he has a full bladder, both of which help to displace the prostate cranially (towards the head).

What settings to use

The prostate is a relatively superficial structure, and so you should scan at a high frequency if possible. Smaller probes are also more easily angled and manoeuvred than larger ones, so a microconvex probe is ideal for the job both in terms of footprint size and ultrasound frequency.

What to look for

Your first few times looking for your dog’s prostate will feel a little bit like when you first started to scan; very frustrating! The echogenicity (appearance on ultrasound) of the prostate is closer to that of the surrounding tissue than a fluid-filled uterus is, and discerning it can be a challenge in some dogs. In very young dogs, the prostate is smaller and less echogenic (darker), so it’s even more difficult.

The prostate becomes increasingly echogenic with age, and also increases in size in older, unneutered dogs.

Normal changes

The appearance of the prostate in various disease states is beyond the scope of this article, but many breeders choose to become familiar with the appearance of the normal prostate, in order to perhaps detect any early changes in their own dogs.

Age-related changes have already been mentioned. A relatively small and dark structure in a young dog will appear lighter than surrounding tissues in an older one. It’s also important to remember that in dogs older than 2 years, cystic areas are common within the prostate. Look for acoustic enhancement below the fluid-filled region in order to confirm this.

With castration, the prostate will shrink by at least 50% within 3-4 months.