Page 242 - Canine Lameness

214 14 Elbow Region

Early stages of the disease may not be detectable with radiography. If panosteitis is suspected, yet
no radiographic changes are evident, advanced imaging such as CT or nuclear scintigraphy may be
utilized. Alternatively, repeat radiographs in two to four weeks in combination with an improve-
ment in clinical symptoms may verify the diagnosis.

14.12 Septic Arthritis

Septic (or infectious) arthritis results from one of three general mechanisms: direct introduction
(i.e. via surgery or trauma), hematogenous seeding, or local spread of infectious organisms into the
synovium/joint space. Regardless of the mechanism, the most common cause of infection is bacte-
rial. However, fungal, protozoal, mycoplasmal, mycobacterial, and rickettsial infections have all
been reported and should therefore be considered as differential diagnoses particularly if treat-
ment with antibiotics is unsuccessful. Since lameness associated with septic arthritis requires a
change of the treatment plan, it is an important differential diagnosis to consider.
Septic arthritis resulting from direct introduction via surgery is probably the most common form
of septic arthritis in dogs, yet the incidence is fairly low (approximately 1–5%). The stifle, elbow,
and carpus have been reported to be most commonly affected.
ELBOW REGION dogs. Two different types have been described: a juvenile form in dogs <1 year of age (Fitch
Hematogenous septic arthritis is likely the second most common form of septic arthritis in

et al. 2003) and an adult form, recently also termed “spontaneous septic arthritis,” that is
described in middle-aged dogs with preexisting joint disease (e.g. osteoarthritis; Benzioni
et al. 2008; Mielke et al. 2018). Regardless of the type, in small animals with hematogenous
septic arthritis, most often a single joint is affected. The juvenile form appears to be rare, but
large-/giant-breed dogs appear predisposed and the elbow is most frequently affected (Fitch
et al. 2003). Spontaneous septic arthritis of both the elbow and hip joint has been described
(Benzioni et al. 2008; Mielke et al. 2018). It is unknown why preexisting joint disease predis -
poses to hematogenous spread to the joint, although, increased synovial vascularity/blood
flow due to chronic osteoarthritis may ease hematogenous introduction of bacteria into the
joint (Clements et al. 2005).
Joint infection causes local inflammation followed by release of catabolic enzymes and loss of
glycosaminoglycan resulting in further deterioration of the joint. As such, early intervention
including at least joint aspiration, culture, and antibiotic therapy should be instituted as soon as
possible. Other treatment options such as joint irrigation, arthroscopic debridement/lavage, and
local antibiotics may also be considered.

14.12.1 Signalment and History
Most dogs with septic arthritis have a history of surgical intervention, trauma, or previous osteo-
arthritis in the affected joint. Particularly in the latter case, it can be difficult for owners to dif-
ferentiate infection from the variable severity of clinical signs associated with osteoarthritis. Dogs
presenting for septic arthritis after surgery can be of any age and breed. Infection after surgery is
observed frequently during the early postoperative phase but may also be seen months–years after
surgery with low-grade infections. Dogs with septic arthritis secondary to chronic osteoarthritis
are frequently middle-aged to older medium large-breed dogs (Clements et al. 2005; Milgram
et al. 2018). If acute worsening of a dog with previously diagnosed osteoarthritis is observed,
spontaneous septic arthritis should be considered an important differential diagnosis.