Small Sized Testes in Dogs

There are varying conditions that can be described as causing the testes to become small, or even not present. Symptoms can range from a simple observation made by you or the veterinarian at a regular check-up, to signs of illness or discomfort exhibited by your canine companion.

• Your pet may display normal sexual behavior even though his testes have not developed normally
• With some conditions sperm is not produced 
• With certain disorders, the testes may become inflamed before shrinking
• One or both testes can be small
• The testes can be hard, or soft and flabby
• Testes that are retained can be smaller than those that have descended
• Disorders with the penis and prepuce may accompany the problem

Types

The more common types of small testes conditions are described here.

Cryptorchidism

• The testicals (one or both) do not descend into the scrotum
• The condition is inherited
• Dogs with both testicles undescended are sterile
• Puppies testicles can retract when cold or when playing, and then descend again which is a normal occurrence and not considered cryptorchid
• Dogs with this condition are prone to cancers
• They can have accompanying problems like hip dysplasia and umbilical hernia
• Breeds predisposed: Miniature and Toy Poodle, Miniature Schnauzer, Shetland Sheepdog, Lakeland Terrier, Boxer, English Bulldog, Cairn Terrier, Chihuahua, Dachshund, Maltese, Yorkshire Terrier, Pomeranian, Pekinese, Old English Sheepdogs

Monorchidism

• This is congenital; at birth only one testical has descended

Testicular Hypoplasia

• At sexual maturity, the testes are small
• This is congenital and is due to the tissue not developing properly

Testicular Degeneration

• An acquired condition, with degeneration the testes change from normal size to small
• Diseases like parvovirus and canine distemper can bring on the condition
• It can be temporary but there is also the chance of permanent sterility

Orchitis

• This is an acquired infection
• Infertility can result
• Bites, punctures, Brucella canis (bacteria), and chemical irritation can be the cause

Immune-mediated Orchitis

• An acquired condition also, the sperm enter the bloodstream and produce antisperm antibodies which, in turn, destroy the body’s own sperm
• The testes become small and hard
• Trauma is often the cause

Small sized testes can be caused by many factors and as a result of this condition, your pet may be rendered sterile. For those owners who were not planning to breed, infertility is not a problem. However, the condition must still be addressed because illness and other problems may be the reason for the change in size or shape. In addition, health issues can result or accompany the problem.

• Genetics may play a part
• Purebred dogs are more prone to problems with testes size
• Age
• Hormones
• Prostate infection
• Bacteria from Brucella canis
• Tumor
• Trauma resulting from a wound, bite, vehicle collision
• Trauma to the scrotum
• Testes move from the scrotum back into the inguinal canal (found in the groin); this can occur up to 6 months of age which is when the canal closes as part of development and maturity
• Inflammatory cells in the body treat tissue as a foreign matter and mistakenly destroy the body’s own spermatogenic cells
• Fever related illnesses can cause the testes to become smaller due to body temperature changes (leptospirosis, canine distemper, parvovirus)

Your pet may be exhibiting signs of trouble like a painful stance or a swollen and hot  scrotum in relation to the testicular changes, or he could be asymptomatic and the discovery of small sized testes is found by the veterinarian at a routine check-up. Whatever the case may be, a physical examination of the reproductive organs will be the first step in diagnosing small sized testes.

Your veterinarian will do a palpation of the testes and scrotum, which may or may not cause pain for your pet. This will depend on the condition. The testes may be hard to find if they are retained, or may present as hard lumps. If there is degeneration or atrophy, the testes could be soft and pliable.

In addition to the examination, your veterinarian will order the standard wellness tests of complete blood count, biochemistry profile, urinalysis and fecal analysis. In some instances, the veterinarian may decide to do a hormone assay if endocrine problems are suspected. Depending on the findings from the initial tests and examination, a biopsy or fine needle aspiration may be scheduled as well.

Surgical castration, or removal of the testicles (orchiectomy), is the most common treatment for small sizes testes in dogs. The reason for this is that complications related to the testes can often develop further. For example, a dog with cryptorchidism may be prone to illnesses related to testosterone such as testicular cancer. Also considered in the dog with cryptorchidism is the chance that the hereditary defect could be passed along to the next generation (in the case of a dog with one descended testicle who is still fertile).

Antibiotics, NSAID’s, corticosteroids, and sexual rest may be the recommended therapy for orchitis or testicular degeneration, but the response is individual to each canine. In addition, the degree of the underlying disease process (leptospirosis for instance) is always part of the cure and recovery. Some dogs may regain a normal sperm production and can experience a reversal of the disorder. The testes can revert to normal size. However, some pets remain sterile.