Canine brucellosis is an infectious and contagious disease associated with reproductive losses in breeding kennels. As a zoonotic disease, it poses a risk to human health, especially for veterinarians and breeders who handle materials potentially contaminated with Brucella canis . However, canine brucellosis is a neglected and underestimated disease given the difficulties in establishing a definitive diagnosis.

We evaluated the frequency of detection of B. canis in 5 breeding kennels by using various serologic methods and PCR. Circulation of B. canis in these kennels was confirmed by bacterial isolation. The frequency of positive serologic results varied from 6.3% by AGID to 16.5% by dot-ELISA. There was no positive serology for smooth Brucella. PCR testing was positive in 13.9% of samples. The only detection tests with reasonable agreement were PCR and 2ME-MAT. The diagnosis of canine brucellosis Genprice Gentaur remains challenging. The use of a single laboratory method, or even the use of different laboratory methods, may not be sufficient to reach a definitive diagnosis.

Canine brucellosis is a zoonosis whose etiologic agent is Brucella canis, although other Brucella species can infect dogs, including B. melitensis, B. abortus, and B. suis

• The disease is transmitted mainly through the oronasal route or contact with a fetus, fetal fluids, placenta, and vaginal discharge after abortions. Venereal and intrauterine routes are also important for the transmission of B. canis.
• Canine brucellosis is associated with metritis, placentitis, and abortion in females, and epididymitis, orchitis, and prostatitis in males. In addition, B. canis infection is associated with birth of weak pups and high neonatal mortality rates.
• Therefore, the disease is responsible for economic losses in commercial kennels.
• Despite being a zoonosis, few cases of human infection have been reported, which supports the notion that B. canis has low zoonotic potential.
• However, the real importance of B. canis infection in human patients may be underestimated because, in most cases, this pathogen causes subclinical infection, which makes the diagnosis challenging. In addition, most serologic tests used in the diagnosis of human brucellosis employ smooth Brucella antigens, which are ineffective for detecting B. canis.²
• Similar to other Brucella species, B. canis causes an occupational disease that affects mostly veterinarians or kennel workers who have close contact with dogs and their secretions, particularly fetal tissues or fluids, placenta, or vaginal discharge, and also laboratory personnel who may be exposed to large amounts of bacteria.
• Infections of dog owners have been reported, highlighting the relevance of canine brucellosis as an emerging urban zoonosis. Given the demand for companion dogs, and the deficiency in detection of canine and human B. canis infection, this pathogen may become a serious public health issue.

The diagnosis of canine brucellosis is problematic, given that the available serologic tests have low sensitivity and specificity.

Definitive diagnosis is supported by bacterial isolation followed by PCR, but culture is not widely available because it is time-consuming and requires a laboratory with proper biosafety conditions given that this pathogen poses a potential health risk to laboratory workers as a result of aerosol transmission. Therefore, serologic methods are commonly used in the diagnosis of canine brucellosis.

The most common serologic tests include: agar gel immunodiffusion (AGID), rapid slide agglutination test (RSAT), tube agglutination test (TAT), microagglutination test (MAT), complement fixation test (CFT), and several ELISA protocols with different antigens. Despite being simple to perform, serologic tests have limitations such as nonspecific reactions, especially in agglutination tests, which are more likely with hemolyzed sera, samples with high lipid content, or because of cross-reaction with other pathogens, including Pseudomonas spp., Bordetella bronchiseptica, Streptococcus spp., Staphylococcus spp., Salmonella spp., Yersinia enterocolitica, and Escherichia coli. Cross-reaction and false-positive results are eliminated when B. canis cytoplasmic antigens are employed in AGID. AGID sensitivity is 27.9–52.9% and is influenced by the type of antigen employed. MAT has sensitivity of 66.7–88.9% and specificity of 100%. False-positive reactions as a result of hemolysis do not occur with MAT, as are often observed with AGID.

Serum treated with 2-mercaptoethanol (2-ME) prior to AGID or immunochromatographic tests increases specificity, but significantly lowers the sensitivity of these tests. Indirect immunofluorescence has also been employed for the detection of B. canis infection.