Osteochondrosis versus arthritis in bovine carcasses
Over the past year, we received various inquiries regarding joint lesions in bovine carcasses, asking about their etiology and significance. In this post, we have collected the osteochondrosis cases recently received at SESC and explain the criteria that can be followed to differentiate them from arthritis processes.
Osteochondrosis is a developmental bone disorder that consists of a lack of ossification, which can affect the articular cartilage and compromise the joint. It affects nearly all production animal species during growth phases and is considered multifactorial in nature (with genetic, traumatic, nutritional, and growth rate factors, among others). Osteochondrosis dissecans (the most visible case at the slaughterhouse level) is characterized by the detachment of articular cartilage due to ischemic necrosis of the underlying tissue. In these cases, the epiphyseal cartilage can ossify and become incorporated into the synovial membrane, thickening and altering it. In the cases identified through SESC, microbiological culture of the synovial fluid always results in no bacterial growth.
On the other hand, arthritis —mostly bacterial— is characterized by exudation in its acute phase. In these cases, purulent to fibrinopurulent exudate appears in the joint capsule. When the process becomes chronic, the capsule thickens and fibroses.
It is essential to differentiate osteochondrosis from arthritis since, due to its infectious nature, the diagnosis changes. In cases where osteochondrosis affects multiple joints, it can be considered a localized lesion. In contrast, in bacterial polyarthritis, it must be taken into account that it represents a generalized bacterial disease with septicemia.
Table 1: Main Differences Between Osteochondrosis and Septic Arthritis
| Osteochondrosis | Septic Arthritis |
| Cartilage development disorder (degenerative process). It can progress to osteochondrosis dissecans (with inflammation). | Inflammatory/infectious process. |
| Increased synovial fluid. Normally transparent, slightly yellowish. | Increased synovial fluid but with inflammatory exudate: turbid, fibrinous, suppurative, or hemorrhagic. |
| Often affects the knee (femorotibial) and tarsal joints. More than one joint may be affected. | More than one joint affected. |
| No evident lymphadenopathy or other lesions. | Evident reactive lymphadenopathy. A detailed inspection is recommended to rule out signs of septicemia. |
| Partial condemnation of the affected joint and surrounding tissues. | Total condemnation. |
Below, you will find images of osteochondrosis from recent cases for identification. (AC)
Bovine Knee. In this case, a portion of the patellar articular cartilage has detached, along with a large part of the femoral articular cartilage. Due to the significant joint damage, a strong synovial reaction is observed, along with an increased volume of synovial fluid and thickening of the capsule.
Bovine Elbow. In this case, regions where the articular cartilage has detached are also observed. The joint fluid was excessive in this joint; however, it was transparent (in arthritis cases, it would be expected to be turbid).
Bovine Joint. In this case, multiple erosions of the articular cartilage are also observed, along with some capsule reaction and overproduction of synovial fluid.
Examples of Septic Arthritis in Cattle with Purulent/Fibrinous Exudate. Source: A: P. Mulon et al 2016 and B: Mahmood et al 2017 Suppurative Arthritis due to Mycoplasma bovis
