Signs & Symptoms Of Brucellosis In Dogs

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A major cause of infertility in dogs, the sinister bacterium Brucella canus invades a dog's body via the genitals, nose, eyes, or mouth and burrows deep into the moist mucous membranes. It travels through the bloodstream and lymph nodes, where it ultimately attacks the reproductive organs of female and male dogs culminating in a contagious, incurable disease known as brucellosis.

This dangerous bacterium can also migrate to the spinal column, liver, spleen, lymph nodes, and eyes. Of significant concern to breeders, brucellosis plays no favorites and any breed of dog, purebred or not, and mainly mature dogs can fall victim. Zoonotic and transmissible to humans, Brucella is indeed a tiny force to be reckoned with.

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Effects and symptoms of brucellosis in female and male dogs.

Transmitted by direct contact with infected fluids such as semen, vaginal secretions, urine, and aborted materials, during breeding or birth, brucellosis causes infertility and miscarriages in typically the third trimester in female dogs. A female's puppies may be stillborn, or, if born alive, they may be weak and sickly. In male dogs, brucellosis may cause scrotal or testicular inflammation, as well as infertility.


If you suspect brucellosis in your dog, some symptoms to watch for are:

  • Lethargy
  • Weight loss.
  • In females: Brownish or green-grey vaginal discharge.
  • In females: Aborting 45-to-55 days into gestation. Note the female will be highly contagious for several weeks.
  • Newborn puppies that are weak and sickly.
  • In males: Enlarged and painful testicles and inflammation of the skin around the scrotum.
  • In males: Severe inflammation or infection of the epididymis which is the part of the testicle where sperm matures and is stored.
  • Stiff gait with obvious difficulty in walking.
  • Acute signs of back pain.
  • In either sex, you may see inflammation of the skin, eyes, spine, or heart.


If the infection is allowed to continue without a diagnosis, the male's testes will become firm and shrunken, leading to irreversible testicular damage and sterility. In infected males, difficulty in urinating and defecating could indicate prostatitis or inflammation of the prostate gland.

How your veterinarian diagnoses brucellosis.

A diagnosis of brucellosis is not straightforward and is more difficult in the early stages. It often requires a battery of tests and still, 100 percent accuracy is elusive. Infected dogs are often asymptomatic. Some of the diagnostic screening tools used include:


  • Polymerase chain reaction (PCR) and special antibody tests to reveal the DNA strands of brucellosis.
  • Spinal X-rays for discospondylitis, which indicate changes consistent with brucellosis.
  • Cytology and culture tests reveal if a bacterial infection is present.
  • Complete blood count to rule out anemia or other blood disorders.
  • Tests to evaluate kidney, liver, and pancreatic function.
  • Blood tests to check for escalating sugar levels.
  • The rapid slide agglutination test (RSAT) that detects antibodies to Brucella spp.
  • Ultrasound and X-rays to show abnormalities in the prostate or testicles.

Treating brucellosis and prevention.

A combination of multiple antibiotics is routinely prescribed in the treatment of brucellosis. No vaccines are yet available for brucellosis. Canine brucellosis is a reportable disease in many states. Tragically, euthanasia may be indicated if the disease continually reoccurs.


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The breeding of dogs should always be carefully considered and is never to be taken frivolously or lightly by the average dog owner. Pet dog owners should not consider breeding their dogs whether they are purebred or not, and should always spay and neuter their dogs to prevent transmission of brucellosis and other diseases of intact dogs.


Professional breeders should always do blood tests at least annually for the presence of brucellosis before breeding their dogs. If detected, quarantine of the kennel is necessary with no new dogs brought onto the premises, selling, relocating or breeding. When brucellosis rears its ugly head in a breeding kennel, spaying and neutering their breeding stock is the first line of defense against the disease.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.