Orchitis in dogs is an acute inflammation of the testis, according to the Merck Veterinary Manual.
The spelling testis is singular, and testes, plural for the male dog's egg-shaped gonads in the scrotum where sperm develop. Orchitis can involve one (unilateral testis) or both (bilateral testes) testicles, according to Pet Place's Dr. Douglas Brum.
Orchitis can develop rapidly causing sudden pain, scrotal swelling, tiredness, and a reluctance to stand or walk. Orchitis can also develop over time, especially in the form of epididymitis, which is commonly diagnosed in dogs alongside orchitis. Epididymitis generally strikes adult dogs at the average age being four-years-old.
What is the difference between orchitis and epididymitis?
Epididymitis is an inflammation of the testicular tube where sperm is stored, states Pet MD, while orchitis is inflammation of the testes themselves.
So common are orchitis and epididymitis together their clinical names have been combined to form one word, epididymoorchitis.
Types of orchitis - macroscopic, microscopic or lymphatic
Technically, macroscopic orchitis is a swollen and painful testis. It is usually accompanied by epididymitis and or periorchitis. Periorchitis is an inflammation of the tunica vaginalis testis, according to the free Medical Dictionary definition.
Microscopic orchitis is seen in dogs with azoospermia. Azoosperia is a lack of live spermatozoa in the semen; classified as obstructive or non-obstructive depending on whether the cause is blockage of the tubules or ducts, by definition in the free Medical Dictionary.
Diniz et al (2005), in a study(Genital Lesions Associated with Visceral - Veterinary Pathology Online) found that 18% of dogs without evidence of exposure to Leishmania have inflammatory lesions. Leishmania is a zoonotic disease caused by intracellular protozoa belonging to the genus Leishmania. According to the World Health Organization, the disease is present in 88 countries, mostly in tropical areas and in the Mediterranean basin. Zoonotic diseases are transferable from animal to human. A few types are Rocky Mountain fever, giardia, bubonic plague and salmonella.
Lymphocytic orchitis is caused by failure of the animal's immune system to recognize the testis and the result is an autoimmune reaction. Eventual destruction of the testis usually follows. The immunologic attack is often triggered following testicular trauma, infection or inflammation in dogs with a genetic predisposition. The primary clinical sign is infertility and lack of sperm in the semen when both testes are involved. Because of the progressive nature of this condition, the prognosis for return of fertility is poor.
What would the testes of a dog with orchitis look like?
The testes changes from a healthy white pinkish color to an unhealthy white or red black.
Any inflammatory reaction within the testis is likely to cause tubular degeneration wherever it manifests.
Ten signs of orchitis
1 - Pain and swelling of the testes. A clear sign of orchitis is if testes feel warm to the touch.
2 - Pain and swelling of the epididymis. Epididymitis is infection or less frequently, inflammation of the epididymis (the coiled tube on the back of the testicle), according to eMedicine Health.
3 - Pain and swelling of the scrotum. The scrotum is located behind the testes.
4 - Excessive licking specifically scrotum, testes.
5 - Reluctance to move due to pain, as in walking stiffly or unwillingness to walk.
6 - Unable to eat, lack of appetite.
7 - Fever. A dog's normal temperature is 101.5 degrees F (38.9 degrees C). Not only is it important to know how to take a dog's temperature, it is also a good idea to have a fully stocked first aid kit available that includes a canine thermometer. Today there is a less invasive way to take a dog's temperature and that is through the ear or orally rather than rectally. Normal ear temperature in dogs is between 100 and 103 degrees Farenheit (37.8 to 39.4degrees Celsius). Ear temperature is measured through infrared heat waves. Knowing a dog's temperature can save its life.
8 - Infertility (especially important for breeders to understand that a stud dog's lack to breed could mean they have orchitis).
9 - Sleeping all the time, lethargy, more tired than usual.
10 - Appearance of open wounds.
Ten causes of orchitis
1 - Trauma. According to Pet Place, direct trauma to the scrotum can also cause an immune mediated orchitis, lymphocytic orchitis, where the body's own immune system causes the inflammation, and testicular damage.
2 - Injuries, such as any deep skin penetrations, open wounds. Bacteria and microorganisms have the ability to enter the system.
3 - Infection, such as fungal, bacteria or viral bacteria, which have entered the testes via the urine, prostatic secretions, blood, mucus membranes or injury (as above). In bacterial orchitis, the most common route of infection is via reflux from the bladder. In these cases, E.coli and Proteus vulgaris (species of bacteria Proteus) are the most commonly isolated organisms. Orchitis severe enough to cause clinical signs in the testis or scrotal sac is most commonly a bacterial infection.
4 - Brucella canis bacteria causes brucellosis, which in turn can cause severe orchitis.
5 - Canine distemper virus. The canine distemper virus infects the testis. There may be testicular degeneration present, according to McEntee et. al 1990 in a study titled, "Reproductive Pathology of Domestic Mammals", currently out of print, but found in references in Surgical Pathology of the Canine Male Reproductive Tract by Dr. Rob Foster, University of Guelph.
6 - Fungal infections such as blastomycosis, a rare infection caused by inhaling a fungus found in wood and soil. Fungal infection, coccidiomycosis or Valley Fever is also a result of inhaling soil or dust.
7 - Tick borne diseases can cause Rocky Mountain spotted fever. Dogs with Rocky Mountain Spotted Fever are reported to develop orchitis.
8 - Testicular torsion (like bloat in dogs) can develop rapidly.
9 - "Hydrocele" is a fluid-filled sack along the spermatic cord within the scrotum. The main symptom is a painless, swollen testicle, which feels like a water balloon. A hydrocele may occur on one or both sides.
10 - Bite wounds on any area of the body can also lead to the development of epididymitis or orchitis. It is very important if a dog is bitten to get immediate emergency care and to obtain detailed information from the dog and dog's owner that did the biting. Bites can cause other harmful diseases, such as orchitis, and are not just a concern for rabies. Treating a bite wound immediately could prevent more serious diseases.
What tests will veterinarians require?
Before treatment can begin, certain conditions need to be ruled out. There are ten steps a veterinarian may require.
1 - A complete physical examination.
2 - Blood work, CBC and a serum chemistry. An important reason for these tests is that white blood cell counts may be high in cases of infectious orchitis.
3 - Urinalysis with culture and sensitivity. If the root cause is prostatitis or cystitis, a urinalysis will likely reveal blood, pus, or excess proteins.
4 - Antibody testing should determine if an infectious organism is at the root of the problem.
5 - Scrotal ultrasonography. Ultrasounds of the prostate, testes, and epididymis are done to rule out other causes.
6 - Test for Brucella canis and fungal serology titers.
7 - Semen examination with bacterial and mycoplasmal cultures. Testicular specimens for cytology and culture are obtained by fine-needle aspiration and dogs in pain will be very sensitive to this procedure.
8 - Testicular biopsy for histopathology (may lead to castration).
9 - Bacterial culture may be performed of the prostate and of fluid in the testes, if needed, after less invasive diagnostic tests have been completed.
10 - Castration may be recommended.
Treatment of orchitis
Treatment is dependent on whether a dog will be used for breeding. If so, and the problem only affects one side of the testes (unilateral), partial castration may be an option.
If the condition affects both sides, or if dog is not intended for breeding, a full castration will be the recommended treatment.
In addition, antibiotic therapy may be required, but antibiotic treatment alone will not always lead to improvement.
Intravenous fluids may be needed.
Anti-inflammatory medication or analgesics (medication for pain relief), immunosuppressive drugs such as prednisone may be required.
In addition, cold compresses, anti-fungal medication may be required. Application of cool water packs may decrease testicular damage caused by local swelling and hypothermia.
Treatment is dependent on identifying the underlying cause of orchitis.
Complete cure of orchitis is rare without removal of the affected tissue.
Any purebred or mixed male dog can be susceptible to orchitis/epididymitis.
Clearly, the best preventative for orchitis is neutering and at an early age.