B. canis is not curable, not a benign disease in the dog, and is a zoonotic risk, because of this the primary management recommendation for positive B. canis cases is euthanasia.
Sterilization (if intact), long term antibiotic treatment, isolation in the home, and repeated testing are offered as a second management option.
High-risk dogs and dogs presenting with clinical signs should be screened for B. canis. Because B. canis, like other Brucella species, is difficult to diagnose, CDA has developed a flow chart to help guide screening programs.
Management Recommendations
B. canis cases are challenging, can be expensive, and are not considered curative.
Long term antibiotic use, even intermittent use, can cause antimicrobial resistance. The bacterium can sequester in areas such as the prostate, making it difficult for antibiotics to penetrate and eliminate all the pathogens. Recurrence may be observed when administration of antibiotics is discontinued resulting in long-term treatment with combinations of medically important antibiotics. Ultimately, many cases result in euthanasia of the animal due to the secondary clinical signs that cannot be effectively treated.
An owner who chooses not to euthanize their B. canis positive dog has the responsibility to limit the spread of this disease.
Read CDA’s Guidance for Owners of Infected Dogs, which outlines prevention and control measures.
CDA recommends that shelter/rescue dogs that test positive for B. canis (even if the test performed is considered a screening test) are euthanized. An alternative option is to hold, isolate, and retest after 30-60 days. Dogs presenting to a shelter/rescue with any risk factors should be tested prior to adoption and, when possible, immediately upon intake and isolated until results are obtained.
B. canis infected dogs should not be placed in foster care nor adopted.
Should a B. canis positive dog be placed in a home, the adopters must be notified of the disease and have an understanding of the infection and potential risks to family members. Similarly, veterinarians have the responsibility to discuss the risks with owners of dogs that test positive and provide the owner with appropriate education on isolation and disease spread prevention. Anyone with knowledge of a positive B. canis case must report the case to CDA.
Resources
Veterinarians
- B. canis Prevention and Control for Veterinarians
- B. canis Test Interpretation Flow Chart
- B. Canis Test Surveillance (Risk factors, symptoms, testing, management)
- Q&A for Veterinarians
Owners
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Guidance for Testing and Surveillance of High Risk Canines
CDA would like veterinarians and animal caretakers who work with and live with dogs from high-risk populations to be aware of the potential disease risk. Through education and surveillance testing, our goal is to reduce the number of B. canis positive animals placed into homes, thereby reducing the risk to animal and human health. We encourage animal shelters, animal rescue organizations, and concerned animal owners to work with a local veterinarian when trying to evaluate risk for B. canis.
CDA considers high-risk dogs and/or dogs that should be tested to be:
- Animals that originate from a population with a high number of intact, stray dogs.
- New intakes at a shelter/rescue of a mature, intact animal if testing history is unavailable.
- Dogs with exposure to a known B. canis positive dog.
- Periparturient dogs that were not tested prior to breeding.
- Sexually intact dogs as part of a routine pre-breeding exam.
- Dogs with symptoms consistent with B. canis infection which cannot be explained by other diseases.
The clinical signs* associated with B. canis in dogs include:
- Reproductive abnormalities: abortion, stillbirth, weak puppies that die soon after birth, infertility
- Genital abnormalities: orchitis, epididymitis, scrotal edema
- Discospondylitis
- Lymphadenitis
- Unexplained lameness or pain
- Uveitis
- Lethargy
- Anorexia
*Many patients with B. canis are asymptomatic
Laboratory Criteria for Diagnosis and Case Definitions
Suspect
Positive screening test without symptoms or symptomatic dog with high risk history
- Positive ELISA S/P > 1.470
- Positive Multiplex
Management: Isolate and retest after 30-60 days.
Probable
Positive screening test with symptoms and/or high risk history with the following criteria OR an asymptomatic dog with increasing titers
- Positive Cornell Multiplex Assay
- Positive ELISA with symptoms OR an S/P>2.000
Management: Isolate and retest after 30-60 days Euthanasia is an acceptable option
Confirmed
Definitive laboratory test positive with/without symptoms
- Any two positive tests
- Positive Culture
- Positive PCR or bacterial isolation
Management: Euthanasia strongly recommended
- Alternate option: lifelong quarantine, spay/neuter, and adhere to Prevention and Control Guidelines set out by USDA.
Brucella Canis Testing Options
Brucella testing is a serial testing process that starts with a screening test followed by a confirmatory test of all non-negative samples. The purpose of a screening test is to detect ANY potential positive animal. This means there WILL BE nonspecific reactors, which require additional testing for definitive diagnosis. Serial testing improves diagnostic specificity and positive predictive value of a test process and asks the animal to “prove” it is affected by the condition being tested.
CDA recommends starting serial testing for B. canis with CDA’s Animal Health Lab B. canis ELISA or the Multiplex Assay test that is offered through the Cornell Animal Health Diagnostic Center.
A positive result on the B. canis ELISA test may indicate: a true infection, titers due to exposure (or from maternal antibodies if <6 months old), or cross-reaction to another pathogen. A negative result on the ELISA is considered a true negative unless the patient exhibits symptoms that are not explained by another disease.
View the B. canis screening flow chart. See the following table for additional testing information.