Abstract:
Canine leishmaniasis (CanL), caused by Leishmania infantum, is a chronic zoonotic parasitic disease
with multisystemic involvement. The osteoarticular lesions described in CanL have been attributed to
immune complex–mediated disease associated with inflammation of the synovial membrane
microvasculature and/or the presence of the parasite within the synovium. The aim of this study was to
establish and describe the findings identified through joint ultrasonography (USG) in dogs naturally
infected with L. infantum, in order to evaluate the diagnostic effectiveness of this technique in the clinical
characterization of dogs with CanL. A total of 43 L. infantum PCR-positive dogs, examined between
February 2023 and January 2025 at the Zoonotic Leishmaniasis Outpatient Clinic of the Veterinary
Hospital at UFBA, were included. The dogs underwent general clinical examination, locomotor physical
assessment, laboratory tests, and imaging by radiography and/or USG. Ultrasonographic examinations
were performed on the tarsal joints of all dogs, while other joints were evaluated by USG when alterations
were identified during the locomotor physical exam. The dogs were divided into two groups: G1 (n=23),
composed of dogs assessed only by USG, and G2 (n=20), composed of dogs evaluated by both USG and
radiography. Most dogs were females (51.2%), adults (67.4%), and purebred (65.1%). Articular lesions
were identified by ultrasonography in 86% (37/43) of the evaluated dogs, with osteophytes (83.8%), joint
effusion (64.9%), and capsular thickening (56.7%) being the most frequent findings. Among dogs with
articular alterations detected by ultrasonography, 29.7% (11/37) did not show clinical orthopedic
abnormalities. Radiography detected tarsal joint lesions in 40% (8/20) of the dogs evaluated. Considering
the physical examination as the reference, ultrasonography showed a sensitivity of 89.7% in identifying
articular changes, whereas radiography showed a sensitivity of 66.7%. Overall, 88.4% (38/43) of the dogs
with CanL presented articular alterations detectable by imaging methods, consistent with degenerative
processes, even in the absence of clinical locomotor signs. We conclude that ultrasonography demonstrated
superiority over radiography in detecting joint alterations in dogs with CanL, including cases of subclinical
arthropathy. These findings support the recommendation of joint ultrasonography as a first-line tool in the
early diagnosis of osteoarticular lesions associated with L. infantum infection.
