Yes, dogs can contract sexually transmitted diseases (STDs), though they are not identical to those seen in humans. In veterinary medicine, these infections are often called canine venereal diseases. They spread primarily through mating but can also be transmitted via other close contact. Understanding these conditions is important for responsible pet ownership, especially if you allow your dog to breed or interact with unfamiliar dogs.
This article explains the most common canine STDs, how they spread, what symptoms to watch for, and how to keep your dog safe. Whether you are a new dog owner or an experienced breeder, knowing the facts helps you make informed health decisions for your pet.
What Are STDs in Dogs?
Canine sexually transmitted diseases are infections primarily passed through reproductive contact. Unlike human STDs, many canine venereal diseases are caused by bacteria, viruses, or even cancer cells. They can affect both male and female dogs and may lead to serious health problems if left untreated.
It is important to note that not all reproductive tract infections in dogs are sexually transmitted. Some are caused by general bacteria or yeast. True STDs in dogs are specific pathogens that rely on close contact during mating for transmission.
Common Types of STDs in Dogs
Several distinct diseases fall under the umbrella of canine STDs. The most common ones are brucellosis, canine herpesvirus, and transmissible venereal tumor. Each has unique characteristics and treatment approaches.
Brucellosis
Brucellosis is caused by the bacterium Brucella canis. It is one of the most significant canine STDs because it can cause infertility, abortion in pregnant females, and chronic infections. Males may develop epididymitis and prostate infections. The disease is also zoonotic, meaning it can spread to humans, though the risk is low for healthy individuals.
Transmission occurs through breeding, but also through contact with aborted fetal tissues or vaginal discharges. Infected dogs may show no symptoms for months, making routine testing important for breeding animals.
Canine Herpesvirus
Canine herpesvirus (CHV) is a viral infection that primarily affects puppies, causing a fatal hemorrhagic disease in newborns. In adult dogs, it often goes unnoticed or causes mild respiratory signs. However, it can lead to abortion in pregnant bitches and may cause genital lesions. The virus remains latent in the body and can reactivate during stress.
Transmission occurs through direct contact with infected mucosal surfaces during mating or through licking. There is no cure, but supportive care and vaccination of breeding females can reduce puppy mortality.
Transmissible Venereal Tumor (TVT)
TVT is a unique contagious cancer that is transmitted directly through the transfer of living cancer cells during mating. It appears as cauliflower-like masses on the genitals, mouth, or nose. TVT is most common in tropical and subtropical regions but can occur anywhere.
Unlike most cancers, TVT is usually highly responsive to chemotherapy, and spontaneous regression can occur. However, it can be distressing for owners. Treatment with vincristine is typically successful, and spaying or neutering helps prevent transmission.
Other Infections
Less common but still possible are infections caused by mycoplasma, chlamydia, or ureaplasma. These organisms can cause vaginitis, balanoposthitis, and mild respiratory signs. They are often secondary to other conditions and may be treated with antibiotics. Good hygiene and avoiding contact with infected dogs reduce risk.
How Do Dogs Contract STDs?
The primary route of transmission is through mating. When a male dog mounts a female, direct contact with genital mucous membranes allows pathogens to pass. However, some infections like brucellosis can also spread through contact with contaminated urine, bedding, or during artificial insemination if proper hygiene is not maintained.
Puppies can acquire canine herpesvirus from their mother during birth, through contact with infected vaginal secretions, or after birth from infected littermates. TVT can be transmitted to areas outside the genitals if dogs lick or sniff tumor masses.
Symptoms of STDs in Dogs
Symptoms vary widely depending on the disease. Some dogs show no outward signs, especially in early stages. Others develop noticeable genital abnormalities, discharge, or systemic illness.
General Signs
Common signs include genital licking, discharge from the penis or vulva, swollen testicles or vulva, and small bumps or masses on the genitals. Female dogs may have a persistent bloody or pus-like discharge not associated with heat cycles. Males may have difficulty urinating or blood in the urine.
Specific Symptoms per Disease
Brucellosis often causes abortion in late pregnancy, stillbirth, and infertility in both sexes. Canine herpesvirus in adults may cause tiny blisters on the vulva or penis but is usually asymptomatic. In newborns, it leads to sudden death, weakness, and abdominal pain. TVT presents as visible, friable, bleeding masses that may resemble a small cauliflower. They can ulcerate and become infected.
Diagnosis and Treatment
If you suspect your dog has an STD, consult a veterinarian. Diagnosis typically involves a physical exam, blood tests, swabs of discharge, or biopsy of masses. Early detection improves treatment outcomes and reduces spread.
Veterinary Examination
The vet will take a history of your dog’s breeding and exposure. For brucellosis, blood tests (serology) are standard. Canine herpesvirus can be detected through PCR tests on swabs. TVT is often diagnosed via cytology (examining cells from the mass) or biopsy. Always inform your vet if your dog has recently mated.
Treatment Options
Brucellosis is difficult to treat and may require long-term antibiotics like doxycycline combined with aminoglycosides. Even then, relapses are common, and neutering is recommended to prevent spread. Canine herpesvirus has no specific antiviral treatment; supportive care and vaccination of breeding females help. TVT responds excellently to chemotherapy with vincristine, often requiring 4-6 weekly treatments. Surgical removal is not recommended due to risk of recurrence. Other bacterial infections are treated with appropriate antibiotics.
Prevention of STDs in Dogs
Prevention is the best approach. Spaying and neutering not only prevent unwanted litters but also eliminate the drive to mate, reducing exposure. If you intend to breed your dog, test for brucellosis before mating, and only breed with dogs that have been tested negative.
For canine herpesvirus, a vaccine is available for pregnant females to protect puppies. Maintaining good hygiene, avoiding contact with stray or unknown dogs, and quarantining new dogs before introducing them to your breeding program are also effective measures. Regular veterinary check-ups can catch infections early.
Can Dogs Transmit STDs to Humans?
The zoonotic potential of canine STDs is low. Brucella canis can infect humans, especially immunocompromised individuals, through direct contact with blood, tissues, or discharges. Symptoms in humans include fever, fatigue, and muscle aches. However, most cases are mild and treatable.
Canine herpesvirus and TVT are not transmitted to humans. Simple precautions like wearing gloves when handling aborted fetuses or cleaning genital discharge, and washing your hands after contact with infected dogs, minimize any risk. If you are concerned, consult your doctor.