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Orchitis (Inflammation on the Testicles) in Dogs

Occurrence: rarer
Location of illness: Abdomen/pelvis

Author: Dr. med. vet. Gisa Löwe | Last modified: 06.11.2025

Orchitis is an inflammatory condition of the testicles in dogs, often caused by infections, which can lead to Pain, Swelling, and other health problems.

The most important facts at a glance

Orchitis in dogs is an inflammation of the testicles that can be acuteAcute refers to a condition that occurs suddenly and is usually of short duration. In a medical context, it describes symptoms or illnesses that can quickly become serious and require immediate attention. or chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time.. It is mainly caused by bacterial infections such as Brucella canis, Escherichia coli, and other pathogens. The infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. can be transmitted through contact with infected bodily fluids or through mating. Symptoms include Pain, Swelling, Fever, and Infertility. DiagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. is made by clinical examination, blood tests, ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow., and sometimes biopsies. Treatment depends on the cause and includes antibiotics, anti-Inflammatory conditions medications, and in severe cases, orchiectomyAn orchiectomy is a surgical procedure to remove one or both testicles. In dogs and cats, this procedure is often performed for castration / neutering to prevent reproduction, reduce behavioral problems, and reduce the risk of certain diseases or conditions of a testicle.. The prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. is often favorable with early treatment, but treatment of Brucella canis can be challenging. Untreated cases can lead to permanent damage and Infertility. Preventive measures include good hygiene, regular veterinary examinations, and tests for Brucella canis, especially in breeding animals. Research focuses on improving diagnostic methods, new treatment approaches, and understanding immune responses. Genetic predispositionA predisposition is an innate inclination or susceptibility of an organism to certain diseases or conditions. In dogs and cats, there may be a genetic predisposition to certain conditions such as hip dysplasia or certain heart diseases. and quality of life of affected dogs are also research fields. Vaccinations and castration can reduce the risk of orchitis.

Causes

Orchitis in dogs refers to the inflammation of one or both testicles. This inflammation can be acuteAcute refers to a condition that occurs suddenly and is usually of short duration. In a medical context, it describes symptoms or illnesses that can quickly become serious and require immediate attention. or chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time.. AcuteAcute refers to a condition that occurs suddenly and is usually of short duration. In a medical context, it describes symptoms or illnesses that can quickly become serious and require immediate attention. orchitis develops suddenly and is often associated with severe Pain and Swelling, while chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. orchitis develops more slowly and often shows fewer symptoms.

The main cause of orchitis is a bacterial infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease.. BacteriaBacteria are microscopic, single-celled organisms that exist in almost every environment on Earth. Some types of bacteria are beneficial or even essential to life, while others can cause disease. can enter the testicles through various routes, including ascending infections from the urethra or prostate, through bloodstream infections, or through direct injuries to the testicles. The most common bacterial pathogens include Brucella canis, Escherichia coli, Staphylococcus spp., Streptococcus spp., and Proteus spp.

Brucella canis, a bacterium that occurs specifically in dogs, is known to cause orchitis. This infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. can be transmitted through direct contact with infected bodily fluids or through mating. Brucellosis is also a zoonotic disease, meaning it can be transmitted from animals to humans.

Other causes of orchitis can include viralViral refers to viruses and their effects on the organism. Viral infections in dogs and cats can range from harmless colds to severe, life-threatening diseases. infections, fungal infections, or traumatic injuries to the testicles. In some cases, an autoimmune reaction of the body can also cause the inflammation. Hormonal problems or tumors can also play a role, but are less common.

Symptoms

Very common symptoms:

Common symptoms:

The symptoms of orchitis in dogs vary depending on the severity and cause of the inflammation. One of the most common signs is visible Swelling of the affected testicle. The affected area may be hot and sensitive to Pain. Dogs with orchitis tend to lick or bite their abdomenThe abdomen, also known as the abdominal cavity, is the part of the body located between the rib cage and the pelvis. It houses several important organs, including the stomach, liver, kidneys, intestines, and spleen. to relieve the discomfort.

Other symptoms include Fever, malaise, lethargy, and loss of appetite. In some cases, Vomiting may occur. The Pain can change the dog’s gait, and some dogs show a stiff or hesitant movement. If the orchitis is caused by a systemic infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease., other signs of a general illness may also occur.

In severe cases, untreated orchitis can lead to atrophyAtrophy is the process of tissue, organ, or muscle reduction or wasting, often resulting from disease, disuse, or malnutrition. of the testicle, in which the tissue dies and the testicle shrinks. This can lead to Infertility. In chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. courses, the inflammation can also show less pronounced symptoms that are often overlooked.

Diagnosis

The diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. of orchitis begins with a thorough clinical examination by the veterinarian. The veterinarian will palpate the testicular area to determine Swelling, Pain, or other abnormalities. A complete historyThe medical history is the systematic collection of a patient's medical history through questioning. It includes information about previous illnesses, treatments, allergies, and lifestyle habits., including information about recent injuries, mating behavior, or other health problems, is also important.

Blood tests can be performed to detect signs of infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. or Inflammatory conditions. An increased number of white blood cells may indicate a bacterial infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease.. Specific tests for Brucella canis are necessary if Brucellosis is suspected, as this requires special treatment.

An ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow. examination of the testicles can be performed to assess the extent of the inflammation and possible Abscesses or other structural changes. In some cases, a fine needle aspiration or biopsyA biopsy is a medical procedure in which a small amount of tissue is removed from the body to be examined under a microscope for signs of disease. Biopsies can help diagnose cancer and other conditions. of the testicular tissue may be necessary to determine the exact cause of the inflammation.

Therapy

The treatment of orchitis depends on the cause of the inflammation. For bacterial infections, antibiotics are the treatment of choice. The selectionSelection refers to the process of natural or artificial selection of specific individuals for reproduction, based on desired genetic traits. In breeding, this is applied to promote specific characteristics in dogs and cats. of the antibiotic is often based on the identification of the specific pathogenA pathogen is a microorganism or virus that can cause disease in its host. Pathogens include bacteria, viruses, fungi, and parasites. and its sensitivity. A treatment lasting several weeks is often necessary to completely eliminate the infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease..

For severe Pain and Inflammatory conditions, anti-inflammatory drugsAnti-inflammatory drugs are medications that reduce inflammation. They can be divided into nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids and are used in dogs and cats to reduce Inflammatory conditions and Pain. and Pain relievers can be used to relieve the symptoms. Bed rest and restriction of physical activity may also be recommended to promote healing.

In cases where a Brucellosis infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. is present, a special antibiotic treatment is required, as this infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. is difficult to treat and requires special precautions to prevent the spread of the disease.

In severe or chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. cases where medical treatment is not successful or complications occur, surgical removal of the affected testicle (orchiectomyAn orchiectomy is a surgical procedure to remove one or both testicles. In dogs and cats, this procedure is often performed for castration / neutering to prevent reproduction, reduce behavioral problems, and reduce the risk of certain diseases or conditions of a testicle.) may be necessary. This may be the case especially with testicular tumors or severe Abscesses.

Prognosis and follow-up care

The prognosis for dogs with orchitis depends on the cause and severity of the disease. With early diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. and appropriate treatment, the prognosis is often favorable, and many dogs recover completely.

However, treatment can be more challenging for infections caused by Brucella canis, and the prognosisThe prognosis is the prediction of the likely course and outcome of a disease based on the general state of health, the nature of the disease, and the response to treatment. It can provide information on how a disease is expected to develop. may vary. In some cases, the infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. can become chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. and cause recurring symptoms. Complete eliminationElimination refers to the process by which waste products and toxins are removed from the body. This includes excretion via the kidneys (urine), intestines (stool), lungs (breath), and skin. of the infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. is difficult, and affected dogs may remain carriers of the pathogenA pathogen is a microorganism or virus that can cause disease in its host. Pathogens include bacteria, viruses, fungi, and parasites. permanently.

Untreated or severe cases of orchitis can lead to permanent damage to the testicular tissue, which can impair the dog’s fertilityFertility refers to the ability to conceive and bear offspring. In women, it refers to the ability to initiate and carry a pregnancy; in men, it refers to the ability to produce fertile sperm. or cause permanent Infertility.

Prevention

The preventionPrevention includes measures taken to prevent diseases or injuries. In veterinary medicine, this includes vaccinations, parasite control, and health monitoring. of orchitis focuses on the management of the dog’s general health and hygiene. Regular veterinary examinations can help to detect and treat infections early. Good hygiene in the care and keeping of the dog can reduce the risk of infections.

To minimize the risk of Brucellosis infections, it is important to avoid contact with infected animals. Breeding dogs should be tested regularly for Brucella canis, especially before breeding. Newly introduced animals should be tested for Brucellosis before being integrated into a breeding group.

Vaccinations against some infectiousInfectious describes the ability of a pathogen to be transmitted from one individual to another and trigger an infection. It also refers to diseases caused by such pathogens. diseases that can cause orchitis are also available and should be considered as part of a dog’s general health plan. In addition, castration of dogs that are not intended for breeding can significantly reduce the risk of orchitis and other testicular diseases.

Outlook on current research

Research on orchitis in dogs is a dynamic field that focuses on improving diagnostic methods, treatment options, and understanding the underlying causes. One area that is receiving a lot of attention is the identification of infectiousInfectious describes the ability of a pathogen to be transmitted from one individual to another and trigger an infection. It also refers to diseases caused by such pathogens. agents that cause orchitis. BacteriaBacteria are microscopic, single-celled organisms that exist in almost every environment on Earth. Some types of bacteria are beneficial or even essential to life, while others can cause disease. such as Brucella canis are known causes, but there are a variety of other bacteriaBacteria are microscopic, single-celled organisms that exist in almost every environment on Earth. Some types of bacteria are beneficial or even essential to life, while others can cause disease., viruses, and even fungi that may also be involved. Researchers are striving to develop new diagnostic tests that allow for faster and more accurate identification of these pathogens, which could lead to more targeted therapy.

Another area of research is the study of the dog’s immune responseAn immune response is the immune system's reaction to foreign substances (antigens), such as microorganisms or proteins. It involves a series of processes aimed at recognizing, fighting, and eliminating these antigens. to these infections. Scientists are trying to understand how the immune systemThe immune system is the body's defense system against infectious agents such as bacteria, viruses, fungi, and parasites. It comprises a complex network of organs, cells, and molecules that work together to protect the body. responds to different pathogens and what factors cause the inflammation to become chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time.. These findings could help to develop new treatment approaches that not only relieve the symptoms but also prevent the progressionProgression refers to the advancement or worsening of a disease over time. It describes an increase in the severity or extent of the disease symptoms. of the disease.

In addition, research is being conducted on the development of new therapeutic approaches. While antibiotics remain the mainstay of treatment, alternative therapies such as anti-inflammatory drugsAnti-inflammatory drugs are medications that reduce inflammation. They can be divided into nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids and are used in dogs and cats to reduce Inflammatory conditions and Pain. and immunomodulatorsImmunomodulators are substances that affect the immune system by increasing or decreasing its activity. They are used in dogs and cats to treat autoimmune diseases, allergies, or as cancer therapy. are being investigated. The possibility of developing vaccines against certain pathogens is also an exciting topic that has the potential to significantly reduce the occurrence of orchitis in the dog populationIn veterinary medicine, the term population refers to a group of animals of a particular species living in a specific geographic area or environment..

Another interesting area of research is the genetic predispositionA predisposition is an innate inclination or susceptibility of an organism to certain diseases or conditions. In dogs and cats, there may be a genetic predisposition to certain conditions such as hip dysplasia or certain heart diseases. of dogs to orchitis. There is evidence that certain breeds or genetic lines may be more susceptible to this disease. By identifying genetic markers, breeders may be able to selectively breed against this susceptibility in the future, which could reduce the incidenceIncidence refers to the number of new cases of a disease or condition that occur within a specific time period in a specific population group. It provides information about the risk of contracting the disease. of the disease in the long term.

Finally, research is also being conducted on improving the quality of life of affected dogs. Studies are examining how chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. orchitis affects the behavior and well-being of dogs and what support methods could improve the quality of life. From physiotherapyVeterinary physiotherapy encompasses a range of treatment methods aimed at improving the mobility and well-being of animals through exercise, massage, and other manual techniques. to special diets, there are many approaches that aim to support affected dogs and enable them to live as normal a life as possible.

Frequently asked questions (FAQs)

What is orchitis in dogs? Orchitis is an inflammatory condition that affects a dog’s testicles. It can be caused by various infections, injuries, or autoimmune processes. The disease can be acuteAcute refers to a condition that occurs suddenly and is usually of short duration. In a medical context, it describes symptoms or illnesses that can quickly become serious and require immediate attention. or chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. and usually requires veterinary treatment.
What are the most common symptoms of orchitis in dogs? The most common symptoms include Swelling and Pain in the testicular area, lethargy, Fever, increased licking of the genital area, and occasionally loss of appetite. In some cases, discoloration of the skin or discharge from the penis may also occur.
How is orchitis diagnosed in dogs? The diagnosisA diagnosis is the identification of a disease or condition by its symptoms and/or results from diagnostic tests. It is the first step in the management and treatment of patients. is usually made through a combination of clinical examination, blood tests, and imaging procedures such as ultrasoundUltrasound refers to sound waves that are above the hearing threshold of the human ear. In medicine, ultrasound is used for diagnostic imaging procedures to visualize internal organs, tissues, and blood flow.. The veterinarian may also take samples to identify the specific pathogens that are causing the inflammation.
What treatment options are available for orchitis in dogs? Treatment depends on the cause of the orchitis. In most cases, antibiotics are prescribed to fight infections. Anti-Inflammatory conditions medications may also be used to relieve symptoms. In severe cases, surgical removal of the affected testicle may be necessary.
Can orchitis be prevented in dogs? Preventing orchitis can be difficult, especially if it is caused by bacterial infections that are present in the environment. However, good hygiene, regular veterinary examinations, and avoiding injuries to the genital area can help reduce the risk.
Is orchitis contagiousContagious means infectious. Diseases that can easily be transmitted from one animal to another or from animals to humans are referred to as contagious. in dogs? Orchitis itself is not contagiousContagious means infectious. Diseases that can easily be transmitted from one animal to another or from animals to humans are referred to as contagious., but the infectiousInfectious describes the ability of a pathogen to be transmitted from one individual to another and trigger an infection. It also refers to diseases caused by such pathogens. agents that cause it can be. For example, Brucella canis can be transmitted between dogs, so it is important to keep infected animals away from others until they are fully treated.
Which dogs are most often affected by orchitis? Orchitis can affect dogs of any age and breed, but is more common in older, unneutered males. Certain breeds may be genetically more susceptible, which is being investigated by current research.
What happens if orchitis is left untreated in dogs? Untreated orchitis can lead to serious complications, including Infertility and the spread of the infectionAn infection is the colonization and multiplication of pathogens such as bacteria, viruses, fungi, or parasites in an organism, which often, but not always, leads to a disease. to other parts of the body. In some cases, it can also lead to chronicChronic refers to a condition or disease that is long-lasting or permanent. Chronic diseases often develop slowly and can lead to persistent or recurring health problems over time. Pain and a deterioration of general health.
Can neutered dogs get orchitis? Orchitis is rare in neutered dogs because the testicles are the main target of the inflammation. Other causes of similar symptoms in neutered dogs should be investigated by a veterinarian.
What aftercare is required after treatment for orchitis? After treatment, it is important to follow the veterinarian’s instructions carefully. This usually includes administering medications, monitoring the dog for signs of relapse, and regular follow-up examinations. Good aftercare can help ensure full recovery and prevent future problems.