Swollen testicles in dogs can be an indication of a serious health condition, so should never be ignored. If your dog’s testicles are red and swollen, or look any different to usual, you should contact your vet as soon as you can; testicular swelling can occur in male dogs of any age and breed that haven’t been neutered.

While it’s easy to identify swollen testicles at home, you’ll need the advice and opinion of a professional to understand the possible cause and the correct treatment process.

So, if you’re asking, ‘why is my dog's testicle swollen?’ this guide can provide some answers.

Some symptoms of swollen testicles in dogs are simple and straightforward to notice. Obviously, clearly swollen testicles – one or both – is one of the clearer symptoms of a potential problem. The testicle, or testicles, could be red, swollen, or an unusual shape. These are all visible signs that could instantly ring alarm bells for a pet parent.

But, other symptoms of testicular swelling are less obvious. While the primary sign of testicular swelling is the swelling itself, your male dog may exhibit one or more of the following:

Why is my dog's testicle swollen?

Once you’ve noticed that your dog’s testicles might be red or swollen, you’ll next want to know the cause of the testicular swelling. It’s known that there are several possible causes associated with testicular swelling in dogs. These possible causes can include:

Male dogs can also suffer from orchitis, an inflammation of the testes in which one or both testicles become hard and swollen, or epididymitis, an inflammation of the testicular tube that contains sperm. Both of these are other possible causes of swollen testicles in dogs.

A major concern with any case of swollen testicles in dogs is that of testicular cancer. Testicular cancer, or testicular tumors, are a common type of cancer in canines, and one of the key reasons for neutering a male dog. Getting a dog neutered, removing the testicles, also completely removes the risk of your pet developing testicular cancer.

If your dog hasn’t been neutered, the risk of testicular cancer remains. There are, often, other symptoms of testicular cancer as well as swollen testicles in dogs – typically blood in the urine, a growth on the testicles, or hair loss. There are three different types of testicular tumors in dogs, too. Read more about testicular tumors in dogs here.

It sounds obvious, but we need to emphasise that if you notice anything different about your dog’s testicles — swollen, red, a change of shape or appearance — you need to contact your vet as soon as possible. It may not be an urgent situation but prompt diagnosis will help to confirm the correct course of treatment quickly.

Prompt diagnosis by a veterinary professional is also important, because — as with other areas of pain or discomfort — most dogs will continue to lick the scrotal area, causing further inflammation and irritation, until you begin treatment. Dogs will often excessively lick themselves to try and ‘fix’ the issue themselves, but it usually only worsens the situation.
The veterinarian will start the visit by conducting a thorough physical examination, which will include palpation of the scrotal area to assess the extent of the swelling.

It’s important for you to provide your vet with an account of the onset of your dog’s symptoms and information on any recent trauma he may have suffered. As there are many possible causes, any insight you may have will save you time and your dog pain.

Additionally, a complete blood count may be ordered to measure red and white blood cell and platelet counts. An elevated white blood cell count might indicate an infectious cause of your dog’s testicular swelling.

A chemical blood profile will check for irregularities in blood sugar, blood protein and electrolyte levels. A urinalysis will test for excess proteins in the urine, and may reveal blood and pus, which would indicate possible prostatitis or cystitis as the cause of the testicular swelling.

Further tests may include an ultrasound of the prostate, epididymis and testes in order to view a granuloma, scrotal hernia or neoplasia. If a neoplasia is found, a biopsy will be necessary in order to determine if it is benign or cancerous. Bacterial and mycoplasmal culture evaluation of semen may be helpful for diagnosis.

Treatment for swollen testicles in dogs will depend upon the exact diagnosis provided by your vet — and the prognosis for recovery depends on the cause.

The easiest and most effective treatment for most causes of testicular swelling is neutering. For the overall health of your dog, neutering is the best option. However, in some cases and if you are intending to breed your dog, partial castration, or the removal of only one testicle, may be possible with a guarded possibility for success.

For bacterial infection, antibiotic treatment is also necessary. Dog testicular infection treatment will also include cleaning of any wounds or the irritated scrotal area and administration of antibiotic ointment.

How long will it take for your dog to recover from swollen testicles? That really depends on the cause, and the course of treatment.

If your dog has been neutered, it’s important to monitor the site of your dog’s incision and follow all post-surgical care instructions. Your dog may be given medication to help with the pain during the recovery process, and you should administer the dosage exactly as prescribed. 

Additionally, you’ll need to monitor the incision site to ensure proper healing and clean as instructed. If your dog suffered any other wounds, be sure to keep them clean and dry.

If you choose not to have your dog neutered, recovery and management will be more difficult, depending on the cause of the swelling. You are likely to be advised to apply cold packs to your dog’s testicular area in order to ease swelling in the remaining testicle or testicles during immediate recovery.

If swelling does not go down, you will need to return to the veterinarian for further treatment. Your dog may still suffer from permanent infertility due to a partial castration or the trauma of the testicular swelling itself, and the condition may not improve, depending on the cause.