Anatomy of a male dog’s genitals
Male dogs mature between the ages of 6 and 12 months, depending on the breed and other factors. In general, the larger the dog, the longer it will take for them to reach sexual maturity. The male canine reproductive system is comprised of the penis and the testicles, as well as the various ducts and tubes used to transport sperm and other fluids between them. The penis is covered by a prepuce, something equivocal to the human foreskin. The testicles are enclosed in the scrotum which should descend sometime around 2 months of age, but can often be delayed to around 6 months.
Both testicles should be firm, of a similar size, oval in shape and have regular consistency. The testicles should be housed in the scrotum. If they are not visible or you cannot feel them, they may still be inside the body. This could be due to a condition known as cryptorchidism, one of the most common genital defects in dogs[1]. This has various causes, but it will most likely mean the dog is sterile.
If only one of the testicles hasnt descended into the scrotum, this is known as monorchidism. These dogs are more likely to be fertile, so you will need to take precautions. If a dogs testicles have descended, but are particularly small in size, testicular hypoplasia may be present.
You may first be made aware of a possible problem in your dogs testicles when you see swelling or changes in color. You may wonder why are your dogs testicles red or even see lesions appear on their surface. Any change to the integrity of the dogs testicles needs to be understood. This is why we provide the main causes of testicular swelling in dogs.
If your dogs testicles have become swollen or enlarged it means they are exhibiting orchitis, the general term for testicular inflammation. We may also see canine epididymitis if the tube which allows sperm to enter (the epididymis) is swollen and the testicles swell as a result. These are symptoms of an underlying cause. The following are some of the most common causes of swollen dog testicles:
Infection will occur leading to inflamed and red testicles. From this initial infection, bacteria can travel to different parts of the body. In particular, it can spread through the spermatic cord. For this reason, it is very important we diagnose and treat the cause of a dogs swollen testicles as soon as possible
If your dog has inflamed testicles due to orchitis, we will likely notice the area is also painful or sensitive. If the dogs testicles are swollen, they will usually lick the area frequently. The increase in size and associated pain will lead them to be uncomfortable. This means they may have trouble walking, sitting or lying down. You may notice that both testicles are inflamed, but it is most common for only one testicle to be enlarged. Both testicles may inflame as the infection spreads.
If we notice that our dogs testicles have become inflamed, you will need to take them to the veterinarian. Treatment will depend on the diagnosis, but if an infection is confirmed, the most likely treatment will be the administration of an antibiotic. This antibiotic will be specific to canines and a vet is needed to give the right prescription after assessment.
It may also be likely the vet will prescribe an anti-inflammatory to reduce the swelling and pain. A gauze soaked in cold water may be applied to provide some temporary relief, but our vet will need to assert this is helpful. An Elizabethan collar may be given to prevent the dog from accessing the testicles and exacerbating the situation.
Other treatment can include antiparasitic drugs if the cause is due to parasites, antihistamines can be administered when there is an allergic reaction and antifungal treatment may be required for fungal infections. Viral infections cannot be cured, but we can manage the symptoms with various drugs. If the problem is due to an allergic reaction, we need to ensure we do not allow the dog to come in contact with the allergen in the future.
For testicular torsion in dogs, surgical treatment is usually necessary. This will be required to stop the testicle necrotizing, as well as stop the pain for the dog. Often a full castration of both testicles will be carried out due to the additional benefits of neutering the dog.
If our dog has orchitis, it is possible that the testicle will decrease and harden after the inflammation has been adequately controlled. After this happens, it is unlikely sperm will be able to be produced. In some cases, the infection may have progressed to the stage that it cannot heal and the removal of the testicle is recommended (known as an orchiectomy).
Removal of the testicles is often performed preemptively as a means of sterilization. The benefits of this procedure have been recorded as reducing certain behavioral problems as well as reducing the likelihood of some diseases[2]. There are potential side effects, but it is generally accepted by the veterinary community to improve their state of well-being.
Testicular tumors in dogs are more prevalent in dogs with undescended testicles, being relatively rare in dogs with testicles which have descended. In these cases, we often see that the dogs testicles are larger than they should be, are of a harder consistency and feel irregular to the touch. Some tumors do not cause an increase in size, but will change the consistency of the testicle. Some may create the feeling of nodules over the testicle.
Certain canine tumors can produce estrogen, a type of female hormone which can lead to the dog displaying features more typical of female dogs. This is why a male dog with tumors on their testicles may have enlarged or swollen breasts. They may also have looser skin on their prepuce or lose hair in this area. The treatment for testicular tumors in dogs is usually surgery in the form of an orchiectomy. This is why it is so important any change to the testicles should be reported to the vet.
This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.
If you want to read similar articles to Why Does My Dog Have Swollen Testicles?, we recommend you visit our Reproductive system diseases category. References
1. Moon, J. H., Yoo, D. Y., Jo, Y. K., Kim, G. A., Jung, H. Y., Choi, J. H., Hwang, I. K., & Jang, G. (2014). Unilateral cryptorchidism induces morphological changes of testes and hyperplasia of Sertoli cells in a dog. Laboratory animal research, 30(4), 185–189. https://doi.org/10.5625/lar.2014.30.4.185https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4306707/
2. Yates, D., Hayes, G., Heffernan, M., & Beynon, R. (2003). Incidence of cryptorchidism in dogs and cats. The Veterinary record, 152(16), 502–504. https://doi.org/10.1136/vr.152.16.502https://bvajournals.onlinelibrary.wiley.com/doi/abs/10.1136/vr.152.16.502
Table of Contents:
Orchitis is an inflammatory condition of the testes or testicles that can occur in dogs. It may involve one (unilateral) or both (bilateral) testicles and is often associated with epididymitis, which is inflammation of the epididymis, since the two structures are so closely related.
In dogs, orchitis is commonly caused by a bacterial infection where the bacteria enter the testes via the urine, prostatic secretions, blood, mucus membranes or trauma like a puncture wound. Other infectious agents that have been reported to cause orchitis include canine distemper virus, fungal infections (blastomycosis and coccidiomycosis) and tick borne diseases (ehrlichiosis and Rocky Mountain spotted fever).
Trauma to the testicles can also cause an immune mediated orchitis, lymphocytic orchitis, where the body’s own immune system causes the inflammation, and testicular damage.
Orchitis may occur rapidly (acute) or may develop slowly with time (chronic). Intact male breeding dogs or intact male dogs that are allowed to roam free are at increased risk for developing orchitis. Older intact male dogs with a history of chronic prostatic or urinary tract infections are also at risk, as infection can spread into the testicles.
Symptoms of Orchitis in Dogs may include:
A complete physical examination including the palpation of the testicles and prostate is essential. Additional tests may include:
If your dog was neutered, the incision should be checked daily for any sign of swelling or discharge. The scrotal sack may be slightly swollen post-operatively, but the swelling should slowly resolve within a week or two. If skin sutures are used, they should be removed in 7 to 10 days. If your dog begins to lick the area excessively, an Elizabethan collar (a collar designed to prevent licking) may be required.
The best prevention for orchitis is castration at an early age. Animals that are not neutered should have recheck evaluations.
The condition itself, or castration (even if unilateral), can result in permanent infertility. Your dogs semen should be checked for viability three months after the treatment.
Your veterinarian will perform a thorough physical examination on your dog, taking into account the background history of symptoms and any possible incidents that might have played a role in its onset. Other potential causes of the above mentioned symptoms include hernia of the scrotum, scrotal dermatitis, twisting of the spermatic cord, sperm-filled mass of inflamed tissue (granuloma), fluid-filled sacks on the spermatic cord (hydrocele), prostatitis, cystitis, and abnormal cell growth (neoplasia). Before treatment can begin, all of these condtions must first be ruled out.
In addition to this, your dog should be treated with antibiotics for at least three weeks. However, antibiotic treatment alone will not always lead to improvement.
If an open wound is present, it should be checked for bacterial infection. A bacterial culture may also be taken of the prostate, as well as of the fluid in the testes. Semen should also be collected and tested.
Get practical pet health tips, articles, and insights from our veterinary community delivered weekly to your inbox.