Prostatic Hyperplasia
Benign prostatic hyperplasia
Also known as: Benign Prostatic Hyperplasia, BPH, Cystic Benign Prostatic Hyperplasia, CBPH
DogUrgency: LowHow common: Common
Compiled from veterinary literature and clinical references
Benign prostatic hyperplasia
Also known as: Benign Prostatic Hyperplasia, BPH, Cystic Benign Prostatic Hyperplasia, CBPH
In short
Benign prostatic hyperplasia (BPH) is a common, non-cancerous enlargement of the prostate gland that affects intact male dogs as they age. Driven by normal hormonal changes, BPH can cause straining to defecate, bloody urine, or discharge. Fortunately, it is highly treatable and completely curable through surgical castration, while medical options exist for breeding dogs.
TL;DR. Benign prostatic hyperplasia (BPH) is a common, age-related enlargement of the prostate in intact male dogs that can cause straining to defecate, bloody urine, or discharge, but is highly treatable with castration or medication.
Anatomical relationship of the canine prostate to the bladder and rectum.
Benign prostatic hyperplasia (BPH) is a common, spontaneous, and non-cancerous enlargement of the prostate gland in intact (unneutered) male dogs. The prostate is the only accessory sex gland in male dogs, and its primary function is to produce seminal fluid, which nourishes and transports sperm. Located within the pelvic cavity, the prostate sits directly below the rectum and completely surrounds the urethra—the tube that carries urine from the bladder out of the body.
As intact male dogs age, the prostate naturally undergoes structural changes. This process is primarily driven by the hormone dihydrotestosterone (DHT), a potent byproduct of testosterone. Over time, the prostate tissue experiences both hyperplasia (an increase in the number of normal cells) and hypertrophy (an increase in the size of individual cells). In some dogs, fluid-filled cavities can also develop within the tissue, a variation known as Cystic Benign Prostatic Hyperplasia (CBPH).
Because of the prostate's anatomical location, its enlargement can act like a clamp on the urethra and press upward against the rectum. This physical compression is responsible for the urinary and digestive symptoms associated with the condition. While BPH itself is benign and not cancerous, it is a progressive condition that can lead to significant discomfort and predispose dogs to secondary complications, such as infections or painful cysts, if left unmanaged.
BPH is considered a normal part of the aging process for intact male dogs. It is a hormone-mediated condition that begins relatively early in a dog's life, even if clinical signs do not appear until years later. A leading veterinary diagnostic cytology reference explains the underlying hormonal mechanism:
"Beginning as early as age 2 years, an overproduction of the hormone dihydrotestosterone (DHT) is the primary mediator of BPH, ultimately leading to both hyperplasia and hypertrophy of the stromal and glandular components. An alteration of the ratio of 17β-estradiol to testosterone secreted by the testes is also involved."
As a dog ages, the testes continue to produce testosterone, which is converted to DHT within the prostate gland by an enzyme called 5-alpha-reductase. Additionally, the ratio of estrogen (17β-estradiol) to testosterone shifts as the dog grows older. This hormonal shift sensitizes the prostate tissue, making it more responsive to the growth-promoting effects of DHT.
There are no documented breed predispositions for BPH; any intact male dog of any breed can develop this condition as they age. The primary risk factors are simply being an intact male and advancing in age. Neutered dogs do not develop BPH because the removal of the testes eliminates the source of testosterone and DHT, preventing the hormonal stimulation required for the prostate to enlarge.
Many dogs with mild to moderate BPH do not show any outward signs of illness. However, as the prostate continues to grow, it begins to compress the surrounding organs, leading to noticeable clinical signs. These signs are detailed in a standard veterinary internal medicine reference:
"Regardless of etiology, clinical signs that suggest disease of the prostate include urinary abnormalities, such as hematuria, dysuria, and pollakiuria, preputial or urethral discharge, tenesmus, and ribbon or tapered stools. Animals may be presented for abnormalities in micturition, although it is less frequent. Intact animals may also exhibit decreased fertility or loss of libido."
Ultrasound imaging helps vets visualize structural changes and fluid-filled cysts within the prostate.
If your dog is showing signs of prostatic disease, your vet will perform a comprehensive diagnostic workup to confirm BPH and rule out other conditions, such as bacterial infections (prostatitis), prostatic abscesses, or prostatic cancer.
Treatment for BPH is highly effective and tailored to whether the dog is a breeding animal or a family pet.
Surgical castration (neutering) is the treatment of choice and is considered curative for BPH. By removing the testes, the source of testosterone and DHT is eliminated. Without these hormones, the prostate gland undergoes rapid atrophy (shrinkage). Within days to weeks after surgery, the prostate will shrink significantly, and clinical signs like straining to defecate or bloody discharge will resolve. This is the most straightforward, permanent solution for dogs that are not intended for breeding.
For valuable breeding dogs, or for dogs that are poor candidates for general anesthesia and surgery, medical management is an excellent alternative.
The prognosis for dogs with BPH is excellent. For dogs undergoing surgical castration, the condition is completely cured, and the prostate will remain small and inactive for the rest of the dog's life. For dogs managed medically with finasteride, the prognosis is also excellent, provided the medication is administered consistently as directed by your vet.
If BPH is left untreated, however, the prognosis can become more guarded. Chronic, unmanaged BPH predisposes the prostate to secondary bacterial infections (prostatitis), large fluid-filled cysts, or painful prostatic abscesses. These complications are much more difficult to treat, often requiring long-term antibiotic therapy, surgical drainage, and intensive supportive care.
The only definitive way to prevent BPH is surgical castration. Neutering your dog before they reach maturity, or at any point in their adult life, will prevent the hormonal stimulation that causes the prostate to enlarge.
For intact male dogs, BPH is an inevitable consequence of aging. While it cannot be prevented if the dog remains intact, regular veterinary monitoring can help catch the condition early. If you own an intact male dog, ensure they receive regular digital rectal examinations during their annual veterinary checkups, starting around two years of age. Early detection allows for proactive management before uncomfortable clinical signs or secondary complications develop.
You should schedule an appointment with your vet if you notice any changes in your dog's urination or defecation habits. Watch closely for blood in the urine, dripping fluid from the prepuce, or mild straining when your dog tries to pass stool.
Some prostatic complications require immediate veterinary attention. Seek emergency veterinary care immediately if your dog exhibits any of the following red flags:
Treatment must be prescribed by a licensed veterinarian based on your pet. Specific drug doses are intentionally not shown here.
Benign prostatic hyperplasia (BPH) is a common, non-cancerous enlargement of the prostate gland that affects intact male dogs as they age. Driven by normal hormonal changes, BPH can cause straining to defecate, bloody urine, or discharge. Fortunately, it is highly treatable and completely curable through surgical castration, while medical options exist for breeding dogs.
Hematuria、Tenesmus、dysuria、pollakiuria、preputial discharge、urethral discharge、decreased fertility、loss of libido
Histological examination of a prostatic biopsy specimen、Canine prostate-specific arginine esterase (CPSE) blood measurement、Digital rectal examination、Fine-needle aspiration of the prostate、Radiography、Ultrasonography
Treatment must be prescribed by a licensed veterinarian based on your pet. Specific drug doses are intentionally not shown here.
This article is for general education and is not a substitute for professional veterinary advice. If your pet is unwell, please consult a veterinarian.
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