Canine brucellosis is an important cause of reproductive failure,
particularly in kennels. The disease, which is caused by the bacteria
Brucella canis, can result
in abortions, stillbirths, epididymitis, orchitis and sperm
abnormalities in dogs. Other
Brucella species, such as B.
abortus, B. melitensis, and
B. suis, can also cause brucellosis in dogs but the occurrence of
those species in dogs is very rare.
B. canis can also infect
humans but the virulence is low, and only a few cases with mild
symptoms have been documented.
B. canis can be detected in
the fetus, placenta, fetal fluids and vaginal discharge after an
abortion or stillbirth caused by the bacteria. The bacteria will
persist in vaginal discharges for several weeks after an abortion, and
will be shed in normal vaginal secretions, particularly during estrus,
as well as in milk. High concentration of
B. canis may be found in
semen for weeks or months after infection, and intermittent shedding
of smaller quantities can occur for years. Infected dogs may shed the
bacteria in urine, and low concentrations of bacteria may also be shed
in saliva, nasal and ocular discharge, and feces
Although B. canis mainly enters
the body by ingestion and via the genital, oronasal and conjunctival
mucosa, transmission through broken skin has been documented. The
majority of cases, however, are infected through venereal transmission
or by contact with the fetus or fetal membranes after abortions and
stillbirths. Puppies can be infected in utero, and may remain
persistently infected even if they appear normal. Nursing puppies can
also be infected from feeding on contaminated milk.
These bacteria have a wide geographical distribution. They can be spread
on fomites and they can remain viable for several months in water,
aborted fetuses, feces, equipment and clothing. Like other
Brucella species, B. canis
can withstand drying, particularly when organic material is present,
and can survive in dust and soil for long periods.
B. canis is a gram-negative
coccobacillus or short rod bacterium and is a facultative
intracellular pathogen. It does not grow well in culture; overgrowth
of cultures by other organisms often prevents its detection by this
method. Serological detection of
B. canis infection has a low specificity because the
lipopolysaccharide surface (LPS) antigen on the surface of the
B. canis bacteria, which is
the common target of the serological detection method, is also found
in several other bacterial species. However, molecular detection by
polymerase chain reaction is highly specific, sensitive and fast.
(Keid et al, 2007).
Keid, L.B., Soares, R.M., Vieira, N.R., Megid, J., Salgado, V.R.,
Vasconcellos, S.A., da Costa, M., Gregori, F. and Richtzenhain, L.J.
(2007) Diagnosis of canine brucellosis: comparison between serological
and microbiological tests and a PCR based on primers to 16S-23S rDNA
interspacer. Vet. Res. Commun 31:951- 965.
0.2 ml fresh or frozen semen, or vaginal swab, or urethral swab,
or prepuce swab, or 0.2 ml EDTA whole blood, or 0.2 ml urine,
or 0.2 ml milk, or environmental surface swab; or swab or fetal
tissue (fresh or frozen) from abortion or stillbirth.
Contact Zoologix if advice is needed to determine an appropriate specimen type for a specific diagnostic application. For specimen types not listed here, please contact Zoologix to confirm specimen acceptability and shipping instructions.
For all specimen
types, if there will be a delay in shipping, or during very warm
weather, refrigerate specimens until shipped and ship with a cold pack
unless more stringent shipping requirements are specified. Frozen
specimens should be shipped so as to remain frozen in transit. See
shipping instructions for more
2 business days
Qualitative real time PCR