My dog ​​has swollen testicles - Causes and what to do


Author: Onmeda WritingMedical review: Dr. Tomás Rodelgo (December 16, 2016)

Orchitis is an inflammation of the testicles caused by viruses or bacteria. It can occur in one testicle or both and develop as acute or chronic disease. Its main symptoms are pain and testicular edema. In most cases it appears next to an inflammation of the epidemic (epididymitis), the so-called orchiepididymitis.

The most frequent orchitis is caused by a mumps virus infection. In 30% of adult males suffering from mumps (mumps), it is complicated by inflammation of the testicles. There may also be other pathogens and infections that can cause an orchitis, such as a sexually transmitted infection (gonorrhea or chlamydia), mononucleosis, chicken pox, leprosy, tuberculosis or congenital syphilis, among others. Orchitis may also appear attached to infections of the prostate or epididymis.

The typical symptoms of a testicular inflammation (orchitis) they are, in the acute moment, pains in the genital area, fever and malaise. The testicles are swollen (testicular enlargement) and the skin that covers the scrotum appears flushed. Pain may also occur when urinating (burning or burning when urinating), perineal, lower back or lower back pain.

To determine if it is really an orchitis or it could be another type of disease, such as a rotation of the testicle on its longitudinal axis (testicular torsion), a secondary acute inflammation or another disease such as a testicular tumor, blood tests are performed to rule out or confirm the causative virus or ultrasound. In rare cases, surgery may be necessary.

The treatment of testicular inflammation will depend on the cause that caused it. If the orchitis has occurred>

The most serious complication of an orchitis is the irreversible lesion in the testicular tissue, which can result in a decrease in reproductive capacity, that is, lead to sterility in the case of both testicles being affected. That's why it is It is advisable to prevent mumps, which is the most common cause of this disease, with its corresponding preventive vaccine when you are still a baby.

Testicular inflammation, also called orchitis, is an inflammation of the testicles. It may be acute or chronic. In most cases, the cause is viruses, and more rarely, bacteria. When the testicles are inflamed, this inflammation usually spreads, so the orchitis ends up developing an inflammation of the epididymis (epididymitis) called orchiepididymitis.

The word testicle derives from the Latin testis (witness) and culus (diminutive suffix). Therefore, he is the small witness of man's virility. The term didimitis is synonymous with testicular inflammation and is derived from the Greek didimos (double, twin).


Between 20 and 25% of all cases of mumps that appear after puberty, are accompanied by an inflammation of the testicles. From 10 to 30% of cases, it occurs in both testicles. 60% of patients with mumps orchitis develop testicular atrophy. Orchiepididymitis in prepubertal age is a process almost as prevalent as testicular torsion. It is more frequent in children under 5 years and in people over 10 years, being rare between both ages.

An acute inflammation of the testicles (orchitis) is usually due to a virus infection, and more rarely, bacteria. The pathogens enter either through the blood or through neighboring structures, as occurs in the case of an inflammation of the epididymis or infection of urine. In rare cases, acute inflammation of the testicles may be caused not by infections, but by severe bruises or autoimmune diseases. The most common cause of an orchitis is a mumps (mumps) due to the so-called paramyxovirus and the testicles become inflamed. In addition, testicular inflammation may also be caused by infectious mononucleosis virus, influenza or chickenpox.

A testicular inflammation caused by bacteria is very rare and is usually manifested by a purulent inflammation of the testicular tissue. Bacterial orchitis is caused by the transmission of the pathogen from the epididymis or from the scrotum to the testis.

Typical causes of bacterial inflammation of testicles in sexually active men are sexually transmitted diseases, such as gonorrhea and in homosexuals due to coniform bacteria (H.influenzae). In children the most common cause is urinary infection and in elderly men prostatitis. It can also be a symptom of some systemic disease such as CBT, brucellosis, cryptococcosis, among others.

Bacterial blood infections can also lead to orchitis. This is the case, for example, of streptococci A of scarlet fever or of the pathogen Treponema pallidum pallidum in advanced state of a syphilis. Further, In the case of children, pneumococci and salmonella can also cause a bacterial infection of the testicles.

There is also a form of testicular inflammation that is not infectious, whose causes are autoimmune disorders. In it, the body forms antibodies and blood cells that attack the body tissue itself and can end up affecting the testicles in the long term.

The so-called nonspecific granulomatous orchitis and chronic appears in a testicle and in most cases in men with urination problems at an age between 60 and 70 years.

The classic symptoms of a testicular inflammation (orchitis) are severe scrotal pain, that is, the testicles feel sore and inflamed. The skin that covers the scrotum is flushed and very hot. The inflammation begins in the tail of the epididymis and extends to the testis. The spermatic cord is thickened and swollen and the existence of reactive hydrocele is frequent. The elevation of the testicle causes decreased pain (positive Prehn's sign). In many cases, fever and difficulty urinating or a need to urinate urgently. Since orchitis usually develops as an accompanying infection, for example, from a mumps, symptoms usually appear between 4 and 7 days after the main disease manifests itself, although rarely it can accompany or even precede it.

If the inflammation caused by an orchitis spreads to surrounding structures, characteristic symptoms may appear in those organs. Inflammation of the testicles often appears accompanied by an inflammation of the epididymis (epididymitis).

In addition, other symptoms such as fever, malaise, nausea, headache or myalgias may develop.


Generally, in the case of an inflammation of the testicles, the diagnosis can be determined with an examination of the testicles and performing complementary tests to determine if the testicles are inflamed, in which case when examining them it will be seen that they are swollen, hard and sore .

When raising an inflamed testicle, the characteristic is that it usually stops hurting (positive Prehn's sign) unlike a testicular torsion, in which the pain persists, although this sign is not decisive. The blood test shows high inflammatory values, in addition, depending on the disease, there may be antibodies against certain pathogens or own tissue.

Sometimes it is difficult to differentiate what is an inflammation of the testicles from other diseases such as inflammation of the epididymis, testicular torsion or a testicular tumor. In these cases, a color Doppler ultrasound safely determines the diagnosis of an orchitis. In rare cases it is necessary to open the testicle in a surgical intervention to ensure the correct diagnosis.


Proper treatment of a testicular inflammation depends on the original cause. The general measures would be to rest in bed, and keep the testicle high and cold. Nonsteroidal anti-inflammatory drugs and analgesics also relieve pain. An orchitis caused by mumps needs to be treated in the same way as virals.

If the cause has been bacteria, the recommended treatment is antibiotics. In the event that the inflammation of the testicle is very marked or purulent abscesses have formed in the testicular tissue, surgery may be necessary in very rare cases to clean the testicle and thus allow the antibiotic to be effective.

In general, testicular inflammation (orchitis) usually develops acutely and disappears after a week. The prognosis is better in young children than after puberty. In approximately half of the affected patients, the inflammation of the testicles heals without causing problems to the testicular tissue.


In rare cases, la testicular inflammation (orchitis) can cause several complications, including abscesses, testicular infarction, testicular atrophy, development of chronic epididymal induration and infertility. This happens especially when the testicles swell repeatedly or when the treatment has not been followed long enough.

A common complication is that the inflammation of the testicles passes to the epididymis or scrotum. In the bacterial case, the inflammation, which is usually also purulent, the existing suppuration presses against the scrotum so that it can further affect the tissue. In addition, purulent formations can be encapsulated and lead to abscesses.

An inflammation of the testicles is linked to the risk that the inflammatory process and the pressure increased by the swelling will destroy the testicular tissue. The consequence is an atrophy of the nuclear tissue of the testis, which can be complicated by impairing its function. If both testicles are affected, it can lead to a decrease in reproductive capacity. If orchitis causes that, it should be known that there is no treatment that can improve sperm production. But a reproductive disability or sterility caused by an inflammation of the testicles is a rare case.


The inflammation of the testicles can be prevented in many cases without problems. Since it is usually the consequence of a mumps infection, and that it can evolve into an orchitis, it is advisable to get vaccinated against it and the best thing to do is when you are still a baby.

You can avoid gonorrhea or other sexually transmitted diseases, which can cause an orchitis, using condoms during sexual intercourse.

The genital apparatus of the dog

Dogs mature between 6 and 12 months, depending on the breeds, taking longer ones of larger size. Your reproductive system consists of the penis, covered by the foreskin, and testicles, which must be found, both, inside the bag called scrotum, to which they usually descend towards two months of life, although in some dogs it can be delayed until six.

Both testicles must have a similar size, a firm and regular consistency and an oval shape. When the testicles are not in the scrotum, that is, they are not visible or palpable, they will be inside the dog's body, a disorder known as cryptorchidism. These dogs are sterile. Sometimes only one of the testicles is retained. This case is called monorchidism. It is possible that these dogs are fertile, so we must take precautions.

The testicles descended but of a very small size will present testicular hypoplasia. We will see below what disorders can cause our dog to have swollen testicles.

Orchitis in dogs

If our dog has swollen testicles it may be suffering an infection in them, known by the name of orchitis. Its origin is usually in a wound produced in the scrotum or in the testicle itself. These wounds can appear after a bite in a fight with another dog, an injury caused by a sharp object or even a frostbite or burn.

If our dog has the irritated testicles By having come into contact with nettles or some chemical substance, you can also end up developing an infection. These wounds can make our dog have the inflamed and red testicles. From them, bacteria can access the body and start an infection, which can also spread through the sperm ducts.

Symptoms of orchitis in dogs

If our dog has swollen testicles as a result of an orchitis we will notice that feel pain. The dog will have the swollen testicles and the area will be licked frequently. In addition, the testicle enlarges and hardens, so we will see that the dog has an inflamed testicle, since it is likely that the infection affects only one of them. East Increase in size and the associated pain causes the dog to keep the hind legs apart and walk abnormally, avoiding rubbing.

The consequences of orchitis

If our dog has suffered an orchitis, it is possible that, after controlling the inflammation, the testicle will decrease in size and harden. Thus can't produce sperm. In other cases, the infection does not end and the removal of that testicle is recommended.

To prevent orchitis, all the wounds we see in our dog's scrotum should be checked by your veterinarian, as they are easily infected. We insist on the benefits of castration to avoid this and other health problems. In the next section we will see another cause that can explain why our dog has swollen testicles.

Testicular tumors in dogs

These tumors usually occur in testicles that are retained inside the dog's body, being more rare in those that are normally descended. In these cases we will see that the dog has an inflamed testicle, of greater consistency and irregular or nodular touch. Other tumors do not cause an increase in size but consistency.

Some of these tumors can cause estrogen, which are hormones that will make the dog show typical features of females. Therefore, if our dog suffers from one of these tumors it will also present the enlarged breasts and we can see the foreskin hanging and an equal loss of hair on both sides.

The treatment for testicular tumors is castration. Therefore, any change in the size or consistency of the testicles must be assessed by a veterinarian.

This article is purely informative, at we have no power to prescribe veterinary treatments or make any kind of diagnosis. We invite you to take your pet to the veterinarian in case he presents any type of condition or discomfort.

If you want to read more articles similar to My dog ​​has swollen testicles - Causes and what to do, we recommend that you enter our Diseases section of the reproductive system.


Epididymitis is the inflammation of the testicular tube where sperm are stored, while orchitis is the inflammation of the testicles themselves. Although the condition may be chronic, acute forms caused by direct trauma to the scrotum are more common. Epididymitis is commonly diagnosed in dogs, in general, most notable in adulthood, an average age of affected dogs is four years old. The breed does not indicate the probability that a dog is affected.