The skin and oral cavity are common sites of neoplasia in avian species. Radiation therapy has been described for the treatment of these tumors in birds; however, its observed effectiveness has been variable. One possible explanation for this variability when radiation is used to treat the head is the unique anatomy of the avian skull, which contains an elaborate set of sinuses not found in mammalian species. To compare a calculated dose of radiation intended to be administered and the actual amount of radiation delivered to the target area of the choana in 3 adult military macaws (Ara militaris), computed tomography scans were obtained and the monitor unit was calculated to deliver 100 cGy (1Gy) by using radiation planning software. The birds received 3–4 radiation treatments each from a megavoltage radiation therapy unit. A thermoluminescent dosimetry chip (TLD) placed in the choana of the birds was used to measure the amount of ionizing radiation delivered at each treatment. The TLDs were kept in place using Play-Doh as a tissue analog. The actual dose of radiation delivered was lower than the 100-cGy calculated dose, with the 95% confidence limits of predicted bias values between 2.35 and 5.39 (radiation dose from 94.61 to 97.65 cGy). A significant difference was identified between the actual amount of radiation delivered and the calculated radiation goal (P < .001). None of the TLDs received the intended dose of 100 cGy of radiation. The results revealed that the amount of radiation delivered did not reach intended levels. Because the combination of the significance of this discrepancy and the standard dose inhomogeneity could lead to greater than 10% dose inhomogeneity, future investigation is warranted for accurate dose calculation and efficacy of radiation therapy for neoplasia at the lumen of the choana in birds.

The efficacy and safety of topically applied rocuronium in Hispaniolan Amazon parrots (Amazona ventralis) was assessed in a group of 10 adult birds. A complete ophthalmic examination (including Schirmer tear test, ocular reflexes, applanation tonometry, fluorescein staining, and slit-lamp biomicroscopy) was performed, and rocuronium bromide (0.15 mg in both eyes) was administered. Pupillary light reflex (PLR) and pupillary diameter were recorded in a darkened room at the following time points: 0, 10, 20, 30, 40, 50, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 300, and 360 minutes, and 24 hours. Fluorescein staining in both eyes was performed at 24 hours. By 10 minutes, PLR was absent in all birds (at 5 minutes, 8 birds; at 10 minutes, remaining 2 birds). Pupil diameter differed significantly from baseline at all time points. Additionally, PLR was decreased in 7/10 birds at 360 minutes and normal in all birds at 24 hours. Superficial corneal ulceration was observed at 24 hours in the left eye of 2/10 of the birds after fluorescein stain application. This study demonstrated that rocuronium bromide was an effective mydriatic agent in Hispaniolan Amazon parrots with rapid onset and prolonged duration of action.

To determine the pharmacokinetics of meloxicam in Caribbean flamingos (Phoenicopterus ruber ruber), a pilot study was performed first, followed by a complete pharmacokinetic study. Four healthy birds were divided into 2 groups and administered 1 mg/kg of either oral (n = 2) or subcutaneous (n = 2) meloxicam. Plasma meloxicam concentrations were determined with liquid chromatography–mass spectrometry. Based on the pilot study results, 12 healthy birds were assigned into 2 groups and administered either 3 mg/kg PO (n = 6) or 1.5 mg/kg SC (n = 6) of meloxicam. Blood samples were collected at baseline and at 9 time intervals per group after administration of meloxicam in all flamingos. Plasma concentrations after administration of 3 mg/kg PO meloxicam reached a mean maximum plasma concentration of 1.449 μg/mL at 2.35 hours with a terminal half-life of 1.832 hours. After administration of 1.5 mg/kg SC meloxicam, maximum plasma concentration was 4.059 μg/mL at 0.91 hour with a terminal half-life of 1.104 hours. The plasma profile from the main oral study (3 mg/kg PO) differed markedly from the pilot study (1 mg/kg PO), suggesting a delayed absorption with the higher dose and lack of dose proportionality. The different doses for subcutaneous administration resulted in a proportional change in plasma concentrations. Further studies are needed to evaluate the effects of the drug volume administered and fasting status when oral dosing is used. Future studies are also needed to investigate multiple-dose pharmacokinetics of meloxicam and to determine the therapeutic meloxicam plasma concentration in Caribbean flamingos.

Sarcoma developing in association with a metallic orthopedic procedure is an uncommon but well-recognized complication in mammals. We report on a synovial sarcoma that developed at the site of an intramedullary pin after surgery to treat a bone fracture. A 17-year-old female peach-faced lovebird (Agapornis roseicollis) developed a spherical mass on the distal right dorsal wing at a site that was previously fractured and surgically repaired with an indwelling intramedullary pin. The right wing was amputated at the scapulohumeral joint. One year later, the bird died. Postmortem examination revealed metastases in the right lung, left thoracic wall, and proventricular serosa. Histologically, the tumor had a characteristic biphasic pattern. The tumor was immunohistologically and ultrastructurally identified as a synovial sarcoma. This is the first report of a suspected fracture-associated sarcoma in a bird.

A juvenile mute swan (Cygnus olor) was presented with right lateral deviation of the mandible. Radiographs demonstrated a healed fracture of the right mandibular ramis, which had compromised osteogenesis. A corrective osteotomy was performed and an osteogenic distractor was inserted over the lateral aspect of the right mandible. Dental acrylic implants were fixed to the rhinotheca to correct rotational alignment. A pharyngostomy tube was placed to facilitate administration of nutrition and medication. Postoperative images confirmed correct alignment of the mandible in relation to the maxilla. Implants were removed and postoperative complications were not reported. This is the first report of an osteogenic distractor used to correct mandibular deviation in an avian species. Distraction osteogenesis should be considered as a valid surgical option in juvenile or adult avian patients with pathologic bone shortening.

An approximately 5-year-old female grey-headed parrot (Poicephalus fuscicollis suahelicus) was evaluated after exposure to outdoor temperatures below −20°C (−4°F) for approximately 22 hours. Severe frostbite affecting multiple digits, as well as dehydration and a depressed attitude, were diagnosed. Treatment included oral antibiotics, antifungals, nonsteroidal anti-inflammatories (NSAIDs), pentoxifylline, and topical aloe vera. Surgical amputation of the affected toes was not performed. Mild to moderate pododermatitis over the intertarsal joints developed because of a shift in weight bearing after the loss of most digits. Within 5 months after initial presentation, all frost-damaged toes had self-amputated, and the bird was able to function independently with no limitations in mobility.

Anterior gastrointestinal tract obstruction by a foreign body has been reported in several avian species, most commonly in captive birds. It is often associated with behavioral issues that lead to compulsive consumption of bedding materials or bright moving objects. In penguins, foreign bodies are most commonly identified at necropsy and often are found in the ventriculus because of anatomic characteristics of the species. A captive African black-footed penguin (Spheniscus demersus) was diagnosed with a ventricular foreign body. The anatomic and physiologic differences that should be taken into account when surgically removing a ventricular foreign body in a penguin are described. These differences include the caudal location in the coelom and the large size of the ventriculus in proportion to the penguin's body size; the presence of a simple stomach, uniform in thickness and lacking muscular development; a simple gastrointestinal cycle (gastric contraction); and variability in pH of stomach contents. No complications were observed after surgery, and the bird recovered completely. Management of foreign bodies in birds should be based on the clinical signs of the individual bird, the species affected and its anatomic characteristics, the nature and location of the foreign body, available tools, and the preference and experience of the surgeon. This particular case demonstrates that the most indicated and preferred method is not always possible and that knowledge of biologic, anatomic, and physiologic differences of the species may allow the use of an alternative and more invasive approach with favorable outcomes.

Three hand-reared, 50–53 day-old, red-legged seriema (Cariama cristata) chicks were evaluated for acute lameness and reluctance to ambulate. Two of the 3 chicks presented with angular limb deformities of the proximal tarsometatarsi and external rotation of the legs. Radiographs demonstrated decreased opacity of the long bone of the legs, with poorly delineated cortices and deviation of the proximal tarsometarsi. Serum concentrations of 25-hydroxycholecalciferol revealed all 3 chicks were deficient in vitamin D₃ at presentation. The chicks were administered injectable vitamin D₃ (cholecalciferol), oral vitamin D₃, and an ultraviolet B (UV-B) light was placed in their enclosure. Elastic, therapeutic taping was used to correct angular limb deformities present in 2 of the 3 chicks. Taping was continued until the angular limb deformities were corrected and lameness resolved. Hypovitaminosis D is a common cause of metabolic bone disease in captive avian species. Cholecalciferol administration, UV-B light supplementation, and elastic, therapeutic taping were effective treatments for osteodystrophy and secondary angular limb deformities due to hypovitaminosis D. This multifaceted treatment may be useful in other long-legged juvenile birds with similar clinical signs.

An adult Canada goose (Branta canadensis) was presented unable to walk. On physical examination, conscious proprioception was absent in both legs, and motor function was decreased. The bird did not improve with supportive care and was euthanatized and submitted for postmortem examination. Sagittal sectioning of the spine revealed an intradural growth causing segmental deformity of the lumbosacral spinal cord. The growth was diagnosed as an infiltrative spinal lipoma. Infiltrative lipomas are locally invasive, benign tumors that can be found in any host tissue. They have been documented in small and exotic companion animals, including birds; however, this is the first report of an infiltrative lipoma in the spinal canal of a bird or free-living wild animal.

Heterotopic ossification is the process of pathologic bone formation in soft tissue structures that usually do not form bone. An immature golden eagle (Aquila chrysaetos) was examined 2 months after a gunshot wound in the right wing. A solid oval mass with a gun pellet at its core was found attached to the ulna by a bony pedicle and was surgically excised. Heterotopic ossification secondary to gunshot and fragment wounds in the right ulna was diagnosed based on clinical, radiographic, and histopathologic findings. This report is the first to describe heterotopic ossification occurring around a gun pellet in a bird.