The results of a complete blood count and serum chemistry profile were normal except for thrombocytopenia (133 x 103 /µl; normal = 200 to 500 x 103 /µl). Urinalysis by cystocentesis revealed a urine specific gravity of 1.058, proteinuria (30 mg/dl; normal = 0 to trace),
hematuria (1 to 3 RBC/hpf; normal = 0/hpf), pyuria (5 to 10 WBC/hpf; normal = 0 to 5/hpf), and a few squamous epithelial cells
per low-power field. No bacteria were seen on sediment examination. Samples were submitted for aerobic and anaerobic bacterial
blood and quantitative bacterial urine cultures and antimicrobial susceptibility testing. A blood sample was submitted for
Brucella canis immunofluorescent antibody and tube agglutination tests.
Additional test results and treatment
Initial treatment, pending culture and serologic test results, consisted of cephalexin (30 mg/kg orally b.i.d.), etodolac
(10 mg/kg orally once a day), and strict cage rest. The dog was discharged the same day. No improvement was noted after three
days. Serologic titer results indicated exposure to B. canis (1:200 on the immunofluorescent antibody test and 1:100 on the tube agglutination test). Results of the aerobic blood culture
revealed a Brucella species. A Brucella species (2,000 cfu/ml) was also identified on quantitative urine culture. Results of the anaerobic blood culture were negative.
The Brucella species isolated was susceptible to all tested antimicrobials with the exception of trimethoprim-sulfadiazine. A sample of
the cultured Brucella species was submitted for species identification (National Veterinary Services Laboratories, 1800 Dayton Ave., Ames, IA 50010),
and the isolate was confirmed to be B. canis.
The owner elected to continue treatment after being advised of the zoonotic risk and guarded long-term prognosis. The owner
was informed that dog-to-human transmission of B. canis is rare but that the owner should consult with a physician, avoid contact with the dog's body fluids (e.g. urine), and practice good hygiene after contact with the dog. We discontinued the cephalexin and initiated enrofloxacin (15
mg/kg orally once a day) and doxycycline hyclate (5 mg/kg orally b.i.d.) for a planned treatment course of at least 10 weeks.
The etodolac therapy and cage rest were continued.
On our recommendation, the dog was castrated two days later. Bilateral testicular and epididymal tissue samples were submitted
for aerobic culture. A Brucella species was isolated from all four samples. Both testes and epididymides were submitted for histologic evaluation. Scattered
small, multifocal aggregates of plasma cells, lymphocytes, and occasional macrophages were present in the interstitium of
the epididymides and between the seminiferous tubules (Figure 2). Occasional focal areas of inflammation between the seminiferous tubules contained intralesional spermatozoa (sperm granulomas).
Multifocal areas of the testes contained degenerating and atrophied seminiferous tubules with spermatidic multinuclear giant
cells. In the most profound areas of seminiferous tubular atrophy, increased interstitium and scattered interstitial macrophages
and fibroblasts surrounded remnants of the tubules. The histologic findings of testicular atrophy with orchitis and epididymitis
were present bilaterally, but the atrophy was more extensive in the left testicle.
2. A photomicrograph of a section of testicle. Lymphocytes and plasma cells are present in the interstitium (arrows) between
seminiferous tubules and are multifocally infiltrating the tubules (arrowheads) (hematoxylin-eosin; bar = 100 µm).