To determine the pharmacokinetics of piperacillin/tazobactam in Hispaniolan Amazon parrots (Amazona ventralis), 8 healthy adult parrots of both sexes were used in a 2-part study. In a pilot study, piperacillin (87 mg/kg) in combination with tazobactam (11 mg/kg) was administered intramuscularly (IM) to 2 birds, and blood samples were obtained at 0, 0.5, 1, 1.5, 2, 3, 4, 6, 8, and 10 hours after administration. Based on the results obtained, a main study was done in which piperacillin/tazobactam was administered at 2 different doses. In 3 birds, the initial dose of piperacillin (87 mg/kg)/tazobactam (11 mg/kg) IM was administered, and in 3 birds, the dose was doubled to piperacillin (174 mg/kg)/tazobactam (22 mg/kg) IM. In all 6 birds, blood samples were obtained at 0, 5, 15, and 30 minutes and at 1, 1.5, 2, 2.5, 3, and 4 hours after administration. Quantification of plasma piperacillin and tazobactam concentrations was determined by validated liquid chromatography–mass spectrometry assay. Pharmacokinetic parameters were determined by noncompartmental analysis. After intramuscular administration, the mean ± standard error values of T_1/2 (h) was 0.52 ± 0.05 and 0.32 ± 0.07, T_max (h) was 0.28 ± 0.09 and 0.25 ± 0.10, C_max (μg/mL) was 86.34 ± 20.62 and 9.03 ± 2.88, and C_max/dose was 0.99 ± 0.24 and 0.83 ± 0.26 for piperacillin (87 mg/kg) and tazobactam (11 mg/kg), respectively. When the doses were doubled, the T_1/2 (h) was 0.65 ± 0.08 and 0.34 ± 0.02, T_max (h) was 0.28 ± 0.12 and 0.14 ± 0.06, C_max (μg/mL) was 233.0 ± 6.08 and 22.13 ± 2.35, and C_max/dose was 1.34 ± 0.03 and 1.02 ± 0.11 for piperacillin and tazobactam, respectively. Results indicate that piperacillin is rapidly absorbed and reaches high initial concentrations; however, it is also rapidly eliminated in the Hispaniolan Amazon parrot, and tazobactam has similar pharmacokinetics as piperacillin. Administration of piperacillin at 87 mg/kg IM q3–4h is recommended for this species to control infections attributed to susceptible bacteria with a minimum inhibitory concentration of ≤4 μg/mL.

Previous studies have validated the clinical use of opioids with μ-receptor affinities for pain management in raptors. Buprenorphine appears to have a longer duration of action and minimal adverse effects when compared to other opioids in American kestrels (Falco sparverius). To determine the pharmacokinetics of a sustained release formulation of buprenorphine in kestrels, we administered a commercially available product (Buprenorphine SR-LAB; Wildlife Pharmaceuticals, Windsor, CO, USA) intramuscularly and subcutaneously to adult kestrels in a partial-crossover experimental design study. A total of 12 birds (6 males and 6 females) were assigned randomly to 3 groups of 4 birds each. A single dose of Buprenorphine SR-LAB (1.8 mg/kg) was administered intramuscularly (IM), and blood samples were collected at 0.25, 3, and 24 hours (n = 4); 1, 6, and 48 hours (n = 4); and 2, 12, and 72 hours (n = 4) after drug administration. Plasma buprenorphine concentrations were measured by tandem liquid chromatography–mass spectrometry. Pharmacokinetic parameters were determined by use of least squares linear regression and noncompartmental analysis of naïve pooled data. After 1 year, the same dose of buprenorphine was administered subcutaneously (SC) to 12 birds divided into 3 groups as previously, and blood samples were collected at the same times after drug administration. Maximum plasma buprenorphine concentration was measured at 15 minutes after IM and SC administration. Mean plasma buprenorphine concentrations were >1 ng/mL for 48 hours after IM and SC administration. The elimination half-life was 13.5 and 11.1 hours for IM and SC administration, respectively. Depending on the severity and type of pain, adjunctive therapy, and the individual response, Buprenorphine SR-LAB administered at 1.8 mg/kg IM or SC to American kestrels would require administration every 12 to 72 hours to manage pain. Further pharmacodynamic and clinical evaluations are warranted in kestrels and other raptors to establish accurate dosing recommendations.

To evaluate the toxicity of short-term high doses of meloxicam in American kestrels (Falco sparverius), 32 male captive-born, 1- to 4-year-old American kestrels were randomly assigned to 4 groups: 3 groups treated with meloxicam (n = 9 per group) and a control group (n = 5). Meloxicam was administered orally via feeding tube in the proventriculus at 2, 10, and 20 mg/kg every 12 hours for 7 days for the treatment groups, while the control group received saline solution. The birds were evaluated for the presence of clinical signs, abnormalities in the complete blood cell count and in the plasma biochemical panel for the 20-mg/kg group, and gross and histopathologic lesions. No clinical signs or mortality were observed in any group. No significant differences of clinical relevance were found in results of the packed cell volume, total solids, and biochemical panel, and no evidence of renal toxicity was found in the treatment or control groups. A significant correlation was found between hepatic lipidosis and meloxicam dose (P = .02). Two of 9 birds in the 20-mg/kg group developed gastric ulcers, although this result was not significant. None of the birds in the 2- and 10-mg/kg groups had similar lesions. Finally, meloxicam dosages up to 20 mg/kg did not result in nephrotoxicity in American kestrels. Further toxicologic studies to evaluate hepatotoxicity and gastrotoxicity of meloxicam in avian species are needed.

Aspergillosis is a common fungal infection in both wild and pet birds. Although effective antifungal medications are available, treatment of aspergillosis can require months of medication administration, which entails stressful handling one or more times per day. This study examined the delivery of the antifungal drugs itraconazole, voriconazole, and terbinafine to Japanese quail (Coturnix japonica) via an impregnated implant. Implants contained 0.5, 3, 8, or 24 mg of itraconazole, voriconazole, or terbinafine. The implants were administered subcutaneously over the dorsum and between the scapulae. Blood was collected from birds before and 2, 7, 21, 42, and 56 days after implant placement. Plasma was analyzed by high-performance liquid chromatography for concentrations of itraconazole, voriconazole, or terbinafine, as appropriate. During the course of the study, targeted terbinafine concentrations were achieved in some birds at various time points, but concentrations were inconsistent. Itraconazole and voriconazole concentrations were also inconsistent and did not reach targeted concentrations. Currently, the implant examined in this study cannot be recommended for treatment of aspergillosis in avian species.

Contrast imaging studies are routinely performed in avian patients when an underlying abnormality of the gastrointestinal (GI) tract is suspected. Fluoroscopy offers several advantages over traditional radiography and can be performed in conscious animals with minimal stress and restraint. Although birds of prey are commonly encountered as patients, little is known about GI transit times and contrast imaging studies in these species, especially owls. Owls are commonly encountered in zoological, educational, and wildlife settings. In this study, 12 adult barred owls (Strix varia) were gavage fed a 30% weight-by-volume barium suspension (25 mL/kg body weight). Fluoroscopic exposures were recorded at 5, 15, 30, 60, 120, 180, 240, and 300 minutes after administration. Overall GI transit time and transit times of various GI organs were recorded. Median (interquartile range [IQR]) overall GI transit time was 60 minutes (IQR: 19–60 minutes) and ranged from 5–120 minutes. Ventricular and small intestinal contrast filling was rapid. Ventricular emptying was complete by a median of 60 minutes (IQR: 30–120 minutes; range: 30–240 minutes), whereas small intestinal emptying was not complete in 9/12 birds by 300 minutes. Median small intestinal contraction rate was 15 per minute (IQR: 13–16 minutes; range: 10–19 minutes). Median overall GI transit time in barred owls is more rapid than mean transit times reported for psittacine birds and red-tailed hawks (Buteo jamaicensis). Fluoroscopy is a safe, suitable method for investigating GI motility and transit in this species.

Macrorhabdus ornithogaster is a yeast organism that infects multiple species of captive and wild birds. Diagnosis of infection in vivo has proven difficult historically, as shedding can be intermittent, and not all positive animals are clinically ill. We compared polymerase chain reaction (PCR) of cloacal swab samples and fecal Gram's stain (FGS) for diagnosis of active shedding of M ornithogaster in a captive flock of budgerigars (Melopsittacus undulatus). Of the 100 birds sampled, 57 (57%) were positive for M ornithogaster by PCR and 24 (24%) were positive for M ornithogaster by FGS. All FGS-tested birds also were positive on PCR. There was a significant association between the two methods, but the overall percent agreement for the two methods was only 67%. Based on these findings, cloacal swab PCR is more likely to diagnose the presence of M ornithogaster than FGS in budgerigars.

Nutritional support is a primary therapy administered to oiled animals during responses to oil spills, but data informing nutritional decision-making during events are limited. In this study, 44 common murres (Uria aalge) and 6 Western grebes (Aechmophorus occidentalis), naturally oiled by oceanic seeps off the coast of Ventura and Santa Barbara Counties, CA, USA, were assigned to 1 of 4 groups fed diets with varying levels (6.8% [no added oil], 11%, and 20%) and types (salmon, corn) of oil added to a partially purified basal diet. Birds used in the study ranged from extremely emaciated to thin body condition (62%–80% wild bird mean body mass). Acid-insoluble ash was used as an indigestible dietary marker to quantify nitrogen retention, apparent nitrogen digestibility, nitrogen-corrected apparent metabolizable energy, energy digestibility, fat retention, fat digestibility, and estimated fat excretion. Fat excretion is important in these species because once birds have been cleaned they are at risk of plumage recontamination from excreted fat during care. Lower fat diets resulted in lower fat excretion but higher nitrogen retention, higher apparent nitrogen digestibility, and higher apparent metabolizable energy. Decreases in nitrogen retention were significantly related to increases in fat excretion. Regardless of diet, energy digestibility significantly declined with declines in body mass, suggesting severity of emaciation reduced a birds' ability to extract energy from food. Energy digestibility was highest in the 11% (low) salmon oil diet; hence, this diet had the highest effective energy content despite a lower gross kcal/kg diet. Diets fed during oil spills historically have had high fat concentrations to provide maximum caloric support. Results of this study suggest that lower fat diets may be more efficacious for nutritionally depleted seabirds. This study provides valuable data to guide clinical decision making regarding nutritional support during oil spills and other mass stranding events.

Cryptococcus gattii infection in mammals and birds has been confined historically to tropical and subtropical regions in Australia, Southeast Asia, Africa, and South America. Since the early 2000s, numerous reports describe the emergence of C. gattii on the Pacific Coast of North America. We report on a C. gattii infection in an 8-year-old male citron-crested cockatoo (Cacatua sulphurea citrinocristata) hatched on the Canadian Pacific Coast and raised in the province of Québec, Canada. The bird developed a slow growing ulcerated, fleshy, crusty, and hemorrhagic mass infiltrating the left lower rhamphotheca. Cryptococcus gattii infection was confirmed by cytologic examination of a fine needle aspirate of the mass, and results of fungal culture and sequencing. The genotype of the strain was determined to be VGIIa sequence type 20, the strongly overrepresented subgroup found on the Canadian Pacific coast. Minimum inhibitory concentrations for multiple antifungal drugs were determined. The bird received fluconazole but died acutely 55 days after initial presentation. Postmortem examination revealed a disseminated infection, with involvement of the beak, lungs, spleen, and brain.

A 15-year-old, female Vieilott's fireback pheasant (Lophura rufa) presented with a 2-day history of a drooping right wing. Examination revealed severe soft tissue swelling in the area extending from the right shoulder to the humeral-radio-ulnar joint with associated bruising and feather loss. Results of a complete blood cell count revealed marked heterophilia and lymphocytosis, and results of serum biochemical analysis showed severe increases in creatine kinase and aspartate aminotransferase activities, hypoproteinemia, and hypoalbuminemia. Radiographs revealed osteolytic lesions of the right humerus with pathologic fractures and circumferential soft tissue swelling. Although surgical wing amputation was successful, the bird died the next day while being treated. The mass was diagnosed histologically and immunohistochemically as a leiomyosarcoma. This is the first neoplasia of any kind reported in this species, to our knowledge, and one of the very few reports of smooth muscle neoplasms affecting the limb of a bird.

A 3-month-old male umbrella cockatoo (Cacatua alba) was presented because of acute non–weight-bearing lameness of the right leg. Marked soft tissue swelling was present around the femorotibiotarsal (stifle) joint, and the radiographic diagnosis was right medial femorotibiotarsal subluxation. Surgical management was elected, and the stifle joint was approached via a lateral parapatellar incision. Joint exploration revealed damage to the lateral meniscus, tendon of origin of the cranial tibial muscle, and cranial cruciate ligament. After debriding the disrupted meniscus, the stifle joint was anatomically reduced. The femorotibiotarsal joint was stabilized by using a lateral extracapsular suture in a modified technique using a self-tapping cortical screw in the lateral femoral condyle and a hole through the proximal tibiotarsus. The bird regained function of the femorotibiotarsal joint for 3 months after surgery, allowing sufficient time for the bird to establish a physiologic perching angle so that ankylosis occurred to maintain functionality of the leg as a unit. This combination of orthopedic techniques adapted from techniques commonly used in small companion-animal species may be considered to provide young birds with femorotibiotarsal luxations and subluxation a good quality of life despite ankylosis of the joint.