Use ultrasonography to identify testicular torsion in dogs with acute onset testicular swelling and pain. Other Ddx: scrotal hernia and epididymitis (usually bilateral).
Doppler ultrasonography of a torsed testicle will show reduced or absent perfusion, testicular enlargement, decreased parenchymal echogenicity, and enlargement of the epididymis and spermatic cord.
Clinical signs with testicular torsion are very suggestive. The contralateral testis is normal in size and shape, which differs from testicular tumors that often alter secretion of sex hormones, causing atrophy of the unaffected testicle.
Additionally, dogs with testicular torsion are in severe pain; often the patient needs very deep sedation for palpation and ultrasonography. Give appropriate doses of opioids and/or ketamine early if suspect testicular torsion.
Tx with castration to remove the affected testicle. This post-op image shows a hemorrhagic and infarcted right testicle (compared to normal left), consistent with torsion.
Image courtesy of Dr Kalumet.
