Evidence of amphotericin B resistance in Macrorhabdus ornithogaster in Australian cage-birds.

Amphotericin B is widely used for the treatment of Macrorhabdus ornithogaster infections. To date, however, there have been no randomized controlled trials confirming its efficacy where cure was confirmed by postmortem examination. To determine the efficacy of amphotericin B against M. ornithogaster, a three-part study was undertaken. Treatment outcomes of M. ornithogaster infected birds treated amphotericin B were reviewed. A pilot treatment trial with two naturally infected birds (Melopsittacus undulatus and Agapornis roseicollis) was undertaken, administering amphotericin B at 100 mg/kg twice daily for 30 days. Finally, a randomized controlled trial using experimentally infected chickens treated with amphotericin B at 25 mg/kg and 100 mg/kg twice daily for 10 days was performed. Retrospective analysis indicated treatment failure in 80.4% of 36 cases that met the inclusion criteria. The pilot study showed that amphotericin B did not clear, but significantly decreased Macrorhabdus ornithogaster burden, followed by profound rebound effect of the number of organisms shed in the feces. Finally, the randomized controlled trial found that amphotericin B given at 100 mg/kg did not clear, but significantly decreased the burden of M. ornithogaster compared with both the 25 mg/kg group (P = .037) and the no treatment control group (P = .001). A strong curvilinear correlation between body weight and M. ornithogaster infection burden was present in the infected chickens. These findings represent treatment failure in three scenarios and indicate that treatment with amphotericin B has poor efficacy against Macrorhabdus ornithogaster.

A Novel Technique for Extracapsular Repair of the Intertarsal Joint in a Duck.

The intertarsal joint is a synovial roll-and-glide joint. Ligament damage and luxations of this joint are often the result of traumatic injury or growth deformities and result in significant functional impairment. A 9-month-old female Pekin duck ( Anas platyrhynchos domesticus) was examined because of progressive, nonweight-bearing lameness of the left leg. Moderate effusive swelling was present at the level of the left intertarsal joint, without radiographic evidence of bone involvement. The duck failed to respond to nonsteroidal anti-inflammatory medications and analgesia and was diagnosed with rupture of the medial collateral ligament. Extracapsular surgical correction using bone tunnels and circumferential nylon suture on the medial aspect of the intertarsal joint led to a complete clinical resolution with normal return to function 2 weeks after surgery. This report reviews the anatomy and function of the intertarsal joint in the duck and details a simple extracapsular repair technique useful in the correction of collateral ligament rupture in this joint of ducks.

Avian Skull Orthopedics.

Because the avian skull is the reflection of the wide biodiversity of birds, many anatomic, morphologic, and functional variations are encountered. The main objectives of this article are to review the surgical considerations associated with the functional anatomy of the avian jaw apparatus and its variation among species, and to describe the general medical and surgical management of head traumatic and developmental disorders in birds.