Testicular Torsion and Swelling in Dogs

Testicular torsion in dogs involves a situation which can present in an acute manner.  It is torsion that involves the twisting of one or both testes (testicles) on the connective tissue.  It can also involve any inflammation that blocks the blood flow in the connective tissue. The resulting inflammation is caused by the closing off of the blood supply to the testes as a result of the epididymis (the tube that lies at the back of the testicle which both stores and carries sperm) becoming kinked and blocked.  The testes are suspended within the scrotum by a single bundle of tissue that also serves to carry blood to and from the scrotum.  

If the testis rotates, this connective tissue gets kinked and flow within it is impeded.  When this happens, pain and swelling of the affected testis is the result.  Not only is this painful for the animal, but also can be dangerous as the longer the blood supply is impeded from the affected testicle the more likely the testicle will suffer irreparable damage or death.

Testicular torsion is defined as a twisting of the testis or testicle on its connective tissue.  It can occur alongside orchitis and epididymitis as these terms refer to symptoms of inflammation that are caused by infection, trauma or metastasis.

Other causes of testicular swelling include orchitis and epididymitis.

The symptoms of testicular torsion in dogs are what one might expect:

• Swelling and pain in the scrotum 
• Upon examination the scrotum may have wounds from a penetrating trauma, such as bite wounds
• If your pet is noted to be licking this area frequently, an examination will likely reveal dermatitis 
• If the pain and swelling are acute, you will likely notice a significant change in the behavior of your pet such as no desire for food or water and cries of pain with movement

Causes of testicular swelling:

Torsion occurs when the testicle actually twists on its connective tissue.  This causes the connective to kink or bind up to restrict or block the blood flow.

Orchitis and epididymitis usually occur together though they are considered only occasional problems in dogs.  These two conditions involve inflammation that causes swelling that restricts or blocks the blood flow through the connective tissue that suspends the testes within the scrotum. 

Testicular torsion is rare in dogs. It occurs more commonly in intra abdominal testicles. It can be caused by tumours, trauma or anatomical defects.

Testicular swelling due to inflammation, or orchitis,  can be caused by the below-listed conditions or situations:

• Trauma (described as penetrating), usually a bite or other puncture wound that allows the introduction of bacteria into the scrotum  
• Associated with many systemic diseases some of which are life-threatening to your pet  such as distemper, ehrlichiosis, coccidioidomycosis, blastomycosis and brucellosis  
• Brucellosis is the only one of these systemic diseases that is listed as a significant cause of the orchitis and the life of the animal is not the primary concern
• Lymphocytic orchitis is potentially part of an autoimmune disease that can have multiorgan involvement; like that described in the Beagle breed for example
• Fungal, bacterial or viral infections, these can be hematogenous (blood borne) or urologic in origin

Testicular torsion is usually diagnosed from a physical exam.Imaging may be required, especially when the torsion occurs in an intra-abdominal testicle.

To obtain a diagnosis or orchitis, it is necessary to be sure to include testing for Brucella canis infection.  Cytologic evaluation of semen with both bacterial and mycoplasmal cultures will also be helpful.  Here is a list of some of the testing that could be required to make the accurate diagnosis:

• Brucella canis blood cultures
• Cytologic evaluation of semen 
• Testicular or epididymal specimens for cytological evaluation, can be obtained via fine needle aspiration
• Possible testicular biopsy for histopathological review and bacterial culture may be needed after less invasive diagnostics have been done
• Digital imaging of the scrotum if lesion or mass is felt or suspected
• If there is no plan for breeding in the future, the specimens noted above can be obtained more easily during the castration process

In the case of testicular torsion in dogs, and given the potential damage to the reproductive system of your dog, the outlook for maintaining fertility in the animal is guarded at best.  This is true regardless of how aggressive the therapy is, as there is considerable potential for irreversible damage to the structures of the reproductive system. 

Surgical removal of the twisted testicle is the preferred treatment, to prevent recurrence and provide immediate relief.

For orchitis:

• Systemic antibiotics should be administered for 3 to 4 weeks if an infection is found
• Applying cool water packs to help decrease the swelling and heat generated by the inflammation
• Hemicastration (removal of one testicle only) could be considered prudent to keep the infection away from the fellow testicle especially as damage occurs within hours in the case of testicular torsion and is irreversible
• All antifungal medications will interfere with spermatogenesis 
• Fluoroquinolones are generally the best antibiotics to use if there is potential for prostate involvement after the inflammation has calmed down
• Culture and sensitivity testing may be required to refine the treatment plan over time
• There is no totally successful treatment for Brucella canis infection. 

Additional retesting and cultures to determine success of the treatment plan may be required.

The potential for your dog to have a return of normal fertility is grave in cases of chronic orchitis/epididymitis and is impossible if ischemic damage has occurred in testicular torsion cases.  This is not the best news if you are planning to breed your dog, but is good news for a family pet.  The quality of life and life expectancy are not significantly affected as long as the root cause can be determined and treated successfully in most cases.