Rectal Exam
The anus and perineum are examined for masses, hernias (male primarily), and perianal fistulas.
A gloved and well‑lubricated finger is gently inserted into the rectum of dogs. (This is rarely performed rarely in awake cats).
Normal structures evaluated during the rectal examination include:
- Rectal wall thickness
- Anal glands
- Prostate
- Contours of the pelvis and sacrum, brim of the pelvis
- Pelvic urethra
Abnormal structures that could be palpated on the rectal exam include:
- Masses, either within the rectal lumen or extra-luminal causing compression of the rectum
- Prostatic masses, pain, or overall enlargement
- Enlarged sublumbar lymph nodes
- Stones or masses within the pelvic urethra
Anal glands are normally located at the four and eight o’clock positions, just inside the anus.
The normal prostate is small, symmetrical and non‑painful on palpation. The median raphe should be easily distinguished. Normal prostate in a neutered male dog is small and can be difficult to reach on the rectal exam. Prostate gland in intact male dogs is larger and more easily palpable. Masses or abscesses can also make the prostate enlarged, often the enlargement is asymmetrical and the dog will show pain on palpation.
To assist in rectal palpation, the other hand of the examiner can be used to gently push the prostate into a more dorsal caudal position via abdominal palpation.
This video reviews a diagram of the rectal exam approach:
Here is an example of the rectal exam on a dog:
