Orch Inflammation in Dogs (Orchitis)

  • Occurrence: rarer
  • Location of disease: Abdomen/pelvis
Author: Dr. med. vet. Gisa Löwe | Last modified: 09.08.2026
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When to visit the vet?

Non-urgent see a veterinarian within 2–3 days

?

If the condition worsens / symptoms persist, consult a veterinarian.

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Definition

Orchitis is an inflammatory condition of the testicle 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 acute or chronic. It is mainly caused by bacterial infections, such as Brucella canis, Escherichia coli, and other pathogens. The infection can be transmitted through Contact with infected bodily fluids or through mating. Symptoms include Pain, Swelling, Fever, and Infertility. The diagnosis is made through a clinical examination, blood tests, ultrasound, and sometimes biopsies. The therapy depends on the cause and includes antibiotics, anti-inflammatory drugs, and, in severe cases, an orchiectomy. The prognosis is often favorable with early treatment, but the 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, developing new treatment approaches, and understanding immune responses. Genetic predisposition and the quality of life of affected dogs are also fields of research. Vaccination 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 acute or chronic. Acute orchitis develops suddenly and is often associated with severe Pain and Swelling, while chronic orchitis develops more slowly and often shows fewer symptoms.

The main cause of orchitis is a bacterial infection. Bacteria can enter the testicle through various routes, including ascending infections from the urethra or prostate, through bloodstream infections, or through direct injury to the testicle. Common bacterial pathogens include Brucella canis, Escherichia coli, Staphylococcus spp., Streptococcus spp., and Proteus spp.

Brucella canis, a bacteria specific to dogs, is known to cause orchitis. This infection 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 viral or fungal infections, as well as traumatic injuries to the testicle. 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

Rare 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 abdomen 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 stiff or hesitant movement. If the orchitis is caused by a systemic infection, other signs of general illness may also appear.

In severe cases, untreated orchitis can lead to atrophy of the testicle, in which the tissue dies and the testicle shrinks. This can lead to Infertility. In chronic cases, the inflammation may also show less pronounced symptoms that are often overlooked.

Therapy

The therapy for orchitis depends on the cause of the inflammation. For bacterial infections, antibiotics are the treatment of choice. The selection of the antibiotic is often based on the identification of the specific pathogen and its sensitivity. Treatment lasting several weeks is often required to completely eliminate the infection.

For severe Pain and Inflammatory conditions, anti-inflammatory drugs and painkillers can be used to relieve symptoms. Bed rest and restriction of physical activity may also be recommended to promote healing.

In cases of brucellosis infection, a special antibiotic treatment is required, as this infection is difficult to treat and requires special precautions to prevent the spread of the disease.

In severe or chronic cases where medical treatment is not successful or complications occur, surgical removal of the affected testicle (orchiectomy) may be necessary. This can be the case particularly 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 condition. With early Diagnosis and appropriate therapy, the Prognosis is often favorable, and many dogs recover completely.

However, for infections caused by Brucella canis, treatment can be more challenging, and the Prognosis may vary. In some cases, the infection can become chronic and cause recurring symptoms. Complete elimination of the infection is difficult, and affected dogs may remain permanent carriers of the pathogen.

Untreated or severe cases of orchitis can lead to permanent damage to the testicular tissue, which can impair the dog’s fertility or cause permanent Infertility.

Prevention

The prevention of orchitis focuses on the care 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 housing 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 regularly tested for Brucella canis, especially before breeding. Newly introduced animals should be tested for Brucellosis before integration into a breeding group.

Vaccinations against some infectious diseases that can cause orchitis are also available and should be considered as part of a dog’s general health plan. Likewise, the 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 into orchitis in dogs is a dynamic field focusing on improving diagnostic methods, treatment options, and understanding the underlying causes. A highly regarded area is the identification of infectious agents that cause orchitis. Bacteria such as Brucella canis are known causes, but there are a variety of other bacteria, viruses, and even fungi that can 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 system response to these infections. Scientists are trying to understand how the immune system reacts to different pathogens and what factors cause the inflammation to become chronic. These insights could help develop new treatment approaches that not only alleviate symptoms but also prevent the progression of the disease.

In addition, research is being conducted into new therapeutic approaches. While antibiotics remain the mainstay of treatment, alternative therapies such as anti-inflammatory drugs and immunomodulators are being investigated. The possibility of developing a vaccine against certain pathogens is also an exciting topic that has the potential to significantly reduce the incidence of orchitis in the dog population.

Another interesting area of research is the genetic predisposition of dogs to orchitis. There is evidence that certain breeds or genetic lines may be more susceptible to this condition. By identifying genetic markers, breeders could selectively breed against this susceptibility in the future, which could reduce the incidence of the disease in the long term.

Finally, research is also being conducted into improving the quality of life of affected dogs. Studies are examining how chronic orchitis affects the behavior and well-being of dogs and what support methods could improve their quality of life. From physiotherapy to special diets, there are many approaches aimed at supporting affected dogs and enabling them to live as normal a life as possible.

Frequently Asked Questions (FAQs)

1. What is orchitis in dogs?
Orchitis is an inflammatory disease that affects a dog's testicles. It can be caused by various infections, injuries, or autoimmune processes. The condition can be acute or chronic and usually requires veterinary treatment.
2. What are the most common symptoms of orchitis in dogs?
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, skin discoloration or discharge from the penis may also occur.
3. How is orchitis in dogs diagnosed?
Diagnosis is usually made through a combination of clinical examination, blood tests, and imaging procedures such as ultrasound. The veterinarian may also take samples to identify the specific pathogens causing the inflammation.
4. What treatment options are available for orchitis in dogs?
Treatment depends on the cause of the orchitis. In most cases, antibiotics are prescribed to combat infections. Anti-inflammatory medications may also be used to relieve symptoms. In severe cases, surgical removal of the affected testicle may be necessary.
5. Can orchitis in dogs be prevented?
Preventing orchitis can be difficult, especially when caused by bacterial infections found in the environment. However, good hygiene, regular veterinary check-ups, and avoiding injuries to the genital area can help reduce the risk.
6. Is orchitis in dogs contagious?
Orchitis itself is not contagious, but the infectious agents that cause it can be. For example, Brucella canis can be transmitted between dogs, so it's important to keep infected animals away from others until they are fully treated.
7. Which dogs are most commonly affected by orchitis?
Orchitis can affect dogs of any age and breed, but it is more common in older, unneutered males. Certain breeds may be genetically more susceptible, which is being investigated by current research.
8. What happens if orchitis in dogs remains untreated?
Untreated orchitis can lead to serious complications, including Infertility and the spread of the infection to other parts of the body. In some cases, it can also lead to chronic Pain and a deterioration of general health.
9. Can neutered dogs get orchitis?
Orchitis rarely occurs in neutered dogs, as the testicles are the primary target of the inflammation. Other causes of similar symptoms in neutered dogs should be investigated by a veterinarian.
10. What aftercare measures are required after the treatment of orchitis?
After treatment, it is important to follow the veterinarian's instructions precisely. This usually includes administering medication, monitoring the dog for signs of relapse, and regular follow-up examinations. Good aftercare can help ensure complete recovery and prevent future problems.

Literature

  • Goericke-Pesch, S., Reifarth, L., Behrens Mathiesen, C., Schuler, G., Umbach, A.-K., & Körber, H. (2022). Chronic immune-mediated orchitis is the major cause of acquired non-obstructive azoospermia in dogs. Frontiers in Veterinary Science, 9, Article 865967. https://doi.org/10.3389/fvets.2022.865967
  • Spada, S., Russo, M., Arlt, S. P., Frehner, B. L., Pagani, G., Carvalho, J. R., Jainek, H., Ambrosio, N., De Felice, D., & Herbel, J. (2025). Ultrasonographic features of epididymitis in dogs: A case series. Frontiers in Veterinary Science, 12, Article 1691917. https://doi.org/10.3389/fvets.2025.1691917
  • Camargo-Castañeda, A. M., Stranahan, L. W., Rush, S., & Smith, D. R. (2021). Characterization of epididymal and testicular histologic lesions and use of immunohistochemistry and PCR on formalin-fixed tissues to detect Brucella canis in male dogs. Journal of Veterinary Diagnostic Investigation, 33(2), 352–356. https://doi.org/10.1177/1040638720986883
  • Santos, R. L., Souza, T. D., Mol, J. P. S., Eckstein, C., & Paixão, T. A. (2021). Canine brucellosis: An update. Frontiers in Veterinary Science, 8, Article 594291. https://doi.org/10.3389/fvets.2021.594291
  • Egloff, S., Schneeberger, M., Gobeli Brawand, S., Krudewig, C., Schmitt, S., Reichler, I., & Peterhans, S. (2018). Brucella canis infection in a young dog with epididymitis and orchitis. Schweizer Archiv für Tierheilkunde, 160(12), 743–748. https://doi.org/10.17236/sat00190
  • Aurich, S., Prenger-Berninghoff, E., Semmler, T., & Ewers, C. (2023). Brucella suis biovar 1 infection in a dog with orchitis in Germany. Frontiers in Veterinary Science, 10, Article 1233118. https://doi.org/10.3389/fvets.2023.1233118
  • Hollett, R. B. (2009). Orchitis and epididymitis. Clinical Theriogenology, 1(1), 31–42.
  • Davidson, A. P. (2024). Orchitis and epididymitis in dogs and cats. In MSD Veterinary Manual. MSD/Merck & Co.