Registered users receive a variety of benefits including the ability to customize email alerts, create favorite journals list, and save searches.
Please note that a BioOne web account does not automatically grant access to full-text content. An institutional or society member subscription is required to view non-Open Access content.
Contact helpdesk@bioone.org with any questions.
The aim of this study was to describe the anesthetic effects of an injectable anesthetic protocol, based on ketamine, midazolam, and medetomidine, followed by inhalational sevoflurane, in 8 elegant-crested tinamous (Eudromia elegans) undergoing experimental surgery. Initial doses for both injectable agents were tested in 1 bird and then refined with an algorithm based on the effects observed in the pilot procedure. Heart and respiratory rates, as well as nociceptive reflexes, were evaluated before anesthesia (baseline) and intraoperatively, at 10 minute intervals. The time from injection to anesthetic induction and surgical anesthesia, as well as the time from atipamezole injection to recovery, was recorded for each bird. The median doses of medetomidine and ketamine were 0.075 mg/kg and 33 mg/kg, respectively. Anesthetic induction was achieved within 10 (range, 4–45) minutes from intramuscular injection, whereas time to surgical anesthesia was 22 ±16 minutes. The baseline heart rate values were significantly higher than those measured intraoperatively at any time point (P = .001). Intraoperatively, 5 of 8 tinamous (63%) developed cardiac arrhythmias. Other encountered complications were regurgitation in 2 birds (25%), cardiac arrest in 1 bird (13%) soon after injection of the anesthetic agents, and prolonged recovery in another bird (13%), which was euthanized. Necropsy of the 2 fatal outcomes (25%) showed evidence of hepatic lipidosis in both (100%) and intramyocardial fat accumulation in 1 bird (50%). This report highlights the challenges of tinamou anesthesia. Cardiac complications are common in this species, and close monitoring of intraoperative cardiovascular variables is recommended for prompt recognition and treatment.
The objective of this investigation was to determine radiographic measurements, without chemical restraint, of the cardiac silhouette in 34 healthy, adult blue-fronted Amazon parrots (Amazona aestiva) of unknown sex with a mean body weight of 393 g. The birds were fasted 3 hours before the radiographic examinations. Three thoracic radiographic views (ventrodorsal, right lateral, and left lateral) were obtained from each bird for assessment. There was no significant statistical difference between right and left radiographic measurements. The mean values of the measurements in the ventrodorsal views were heart width of 21.04 mm and coelomic cavity width of 50.61 mm. The mean values of the measurements in the lateral views were left heart length of 23.44 mm, right heart length of 23.40 mm, left sternal length of 65.69 mm, and right sternal length of 65.03 mm. A strong correlation and ratio of 43% between the heart width and coelomic cavity width and a moderate correlation and ratio of 36% between the heart length and sternal length were observed. In conclusion, the radiographic measurements of the cardiac silhouette in healthy blue-fronted Amazon parrots can be obtained without chemical restraint. The values obtained can be used to assist in the detection of cardiomegaly or microcardia in blue-fronted Amazon parrots.
This study examined the pharmacokinetics of orally administered amoxicillin and clavulanic acid tablets (Clavamox, 125 mg/kg PO q12h for 9 doses) in domestic hens and examined both amoxicillin and clavulanic acid concentrations in eggs. Therapeutic plasma concentrations (0.5 µg/mL) of amoxicillin were not reached at any time point, and no amoxicillin was detected in plasma after 2 hours. Pharmacokinetic parameters could not be calculated. The clavulanic acid half-life was 1.1 hours and it was detected up to 8 hours after dosing. No amoxicillin was detected in eggs 4 days postdosing, nor was clavulanic acid detected in any eggs during the same time period. On the basis of these results, orally dosing hens with amoxicillin and clavulanic acid tablets at 125 mg/kg PO q12h does not reach therapeutic plasma concentrations. Additional studies are needed to examine different doses and formulations of medication to determine better dosing and withdrawal recommendations for domestic chickens.
Jessica A. Robertson, David Sanchez-Migallon Guzman, James L. Graham, Kimber L. Stanhope, Jamie M. Douglas, Peter J. Havel, Hugues Beaufrère, Heather Knych, Thomas N. Tully, Joanne R. Paul-Murphy
Atorvastatin is a synthetic statin administered in its active form and used for the treatment of dyslipidemias. In the current study, the effects of atorvastatin were evaluated on plasma lipid profiles and the potential for adverse effects after once daily PO dosing of atorvastatin for 30 days in Hispaniolan Amazon parrots (Amazona ventralis). Sixteen adult parrots (10 female, 6 male) with hypercholesterolemia were used for this study. Birds were assigned to 2 groups (treatment and control) of 8 parrots each (3 male, 5 female) after balancing for age, sex, originating institution, and baseline plasma cholesterol values. Compounded atorvastatin oral suspension (10 mg/kg) was administered PO once daily via gavage into the crop. Equivalent volumes of placebo suspension were administered to the control group. Plasma biochemistry and plasma lipid profile analysis (total cholesterol, high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], and triglycerides [TGs]) were analyzed on days 0, 14, and 30. Plasma samples and HDL-C fractions were evaluated for cholesterol and TG concentrations via enzymatic assays. Subtraction of HDL-C values from total cholesterol yielded the non–HDL-C concentration for each bird. Birds were routinely assessed for appetite, activity, and urofeces. Plasma atorvastatin concentrations were obtained from 7 of 8 birds in the treatment group from banked samples. Those samples were obtained on days 14 and 30, with drug administration 6 to 8 hours before collection. No significant differences were observed in total cholesterol, HDL-C, non–HDL-C, or TG between treatment and control groups at days 0, 14, and 30. Plasma atorvastatin concentrations were variable on day 14 (0.54–5.41 ng/ mL for 6 of 7 samples, with 1 outlier of 307 ng/mL) and on day 30 (0.79–6.74 ng/mL). No adverse effects were noted in any of the birds during the study period. When dosed PO at 10 mg/kg once daily, atorvastatin did not result in significant changes to plasma lipid profiles (eg, lowering of plasma total or non–HDL-C concentrations) at any time point during this study. Future studies to investigate pharmacokinetic and pharmacodynamic properties of atorvastatin in parrots may require increased doses and/or frequency of administration.
An inability of the body to appropriately respond to extreme temperatures will result in pathological changes to vital organs and adverse hematological changes. Mild heat exposure of a bird to a temperature above the zone of thermoneutrality can induce subclinical heat stress, which may be a precursor to illness. The ability to identify subtle changes that may be associated with subclinical heat stress can be important in early diagnosis and treatment of heat stress in birds. Pathological changes to internal body organs, post–heat exposure, were microscopically examined in 13 budgerigars (Melopsittacus undulatus), 15 zebra finches (Taeniopygia guttata), and 8 diamond doves (Geopelia cuneata) as model species for the bird orders Psittaciformes, Passeriformes, and Columbiformes, respectively. There was mild to moderate congestion of the lungs of 28/36 birds examined, including all of the budgerigars and diamond doves. In 8/15 zebra finches no significant lung congestion was noted. Interstitial and pulmonary hemorrhage was in observed in one diamond dove. The most common hepatic pathologic change identified was micro- and macro-vesicular hepatocellular vacuolation (4/15 zebra finches, 5/13 budgerigars, and 8/8 diamond doves). There was mild to moderate congestion in the kidneys of 1/15 zebra finch, 2/ 13 budgerigars, and 4/8 diamond doves, as well as in the gastrointestinal tract of 1/15 zebra finch and 7/8 budgerigars. Budgerigars showed a decrease in hematocrit and a significant change in the numbers of heterophils and lymphocytes following heat exposure. The basophil population of cells remained relatively stable in both budgerigars and diamond doves. These findings indicate avian species differences in body organ and hematological changes following exposure to similar elevations in environmental temperatures.
Aspergillosis is a common cause of morbidity and mortality in captive penguins. Itraconazole, an antifungal drug, is commonly used to treat aspergillosis infections in avian species; however, commercially available human formulations are costly, and studies have shown the effectiveness of compounded formulations to be unreliable. The US Food and Drug Administration (FDA) recently approved a veterinary formulation of itraconazole, Itrafungol, for use in cats. This study provides preliminary results from limited sampling evaluating whether this veterinary formulation is suitable for future studies in the African penguin (Spheniscus demersus). A 20 mg/kg PO itraconazole dose was administered to 9 African penguins. Blood samples were taken over the course of 24 hours; each sample was collected from a different bird to minimize stress to the animals. Plasma was analyzed by high-performance liquid chromatography for concentrations of itraconazole. The drug was absorbed in all penguins, and plasma concentrations in 5 of 9 penguins (56%) were found to be greater than the established therapeutic dose of 1.0 µg/ mL. To our knowledge, this is the first study that has investigated a 20 mg/kg dose of itraconazole in a penguin species. The small sample size limits the conclusions that can be drawn from this preliminary study. Nonetheless, we demonstrate encouraging evidence that the FDA-approved formulation of oral itraconazole solution should be considered for future study as a cost-effective treatment for aspergillosis in African penguins and other avian species.
A 33-year-old male blue and gold macaw (Ara ararauna) presented with a 5-month history of an ulcerated lesion and feather loss at the tail base. Two 4-mm biopsies obtained by the primary care veterinarian were consistent with uropygial gland adenocarcinoma. The bird was examined at the Veterinary Medical Teaching Hospital, University of California, and on physical evaluation, the dorsal and ventral surface of the tail base were devoid of feathers, ulcerated and crusted without an identifiable uropygial gland. Complete blood count, plasma biochemistry panel, whole-body radiographs, and an echocardiogram were performed before surgery. The bird was anesthetized, and a complete amputation of the tail was performed. The skin was incised with a radiofrequency electrosurgical system approximately 2 mm circumferentially cranial to the diseased tissue. The musculature was transected to the level of the vertebral column, disarticulating between the second and third caudal vertebrae and transecting the spinal cord with a no. 15 blade. Lateral vertebral processes of the second vertebra were removed with a rongeur. Coccygeus lateralis muscles and tensor fasciae latae muscles and skin were closed laterolaterally with 2 layers and 3-0 polydioxanone suture. The bird recovered uneventfully and was discharged after 6 days of hospitalization. The histopathological diagnosis was adenocarcinoma with squamous differentiation, marked scirrhous response, and superficial epithelial ulceration. It was determined that narrow margins of unaffected tissue were achieved from the pathological examination of submitted material. The bird was evaluated 24 days after surgery and again 3.5 months after surgery, without evidence of complications or recurrence. Approximately 10 days after the last reexamination, the bird was euthanatized after being found minimally responsive at home. A postmortem examination was not performed.
Clostridium perfringens types A and C, which are gram-positive, anaerobic, spore-forming bacteria, can cause necrotic enteritis in birds. Although Clostridium perfringens is considered a commensal organism in the avian intestinal tract, in association with severe stress, other infectious agents, or immunosuppressive conditions, it can cause disease outbreaks. This report describes a disease occurrence of necrotic enteritis caused by C perfringens in macaws (Ara ararauna). Two adult male blue and gold macaws maintained in a zoo exhibit were presented for postmortem examinations after histories of sudden death. Based on the gross examinations and microscopic evaluation of submitted tissue from both birds, the cause of death was determined to be necrotic enteritis. Microbiologic assays followed by polymerase chain reaction analyses identified the isolated strains as C perfringens type A, indicated by only being positive for the cpa gene that encodes the α-toxin. The birds were maintained in an exhibit in which patrons can interact with the animals within their environment. Thus, organisms, such as this pathogen, may present a danger for other birds because visitors could disperse the bacterium to other parts of the zoo.
Two great blue herons (Ardea herodias) and an anhinga (Anhinga anhinga) were presented to the Wildlife Center of Texas with extensive plumage soiling from polyisobutylene (PIB), a synthetic rubber polymer used in manufacturing. All animals were provided supportive care and sedated for evaluation for hematologic and plasma biochemical values; one of the great blue herons was critically ill, based on the diagnostic evaluations and died approximately 24 hours after admission. On postmortem examination, it was diagnosed with coelomic migration of Eustrongylides species resulting in verminous peritonitis that was likely the primary cause of its poor condition and death, rather than the PIB exposure. Standard decontamination efforts with commercial liquid dish soap were unsuccessful. Application of margarine was used to emulsify the PIB on the remaining 2 birds and was followed by standard wash protocols for successful removal. These animals were successfully released after decontamination. The use of margarine for decontamination of PIB is unreported and could prove useful in future decontamination events in birds and other wildlife when traditional methods to remove hydrocarbon compounds are unsuccessful.
A 26-year-old female umbrella cockatoo (Cacatua alba) was presented for reoccurrence of a soft tissue mass extending from a fractured area of the rhinotheca. The mass was originally observed 12 years before, after unknown trauma. Histopathology after initial removal was consistent with inflammatory granulation tissue. The mass reoccurred 3 additional times in the same location despite surgical removal and cryogenic therapy. On the fourth surgical resection, strontium-90 radiotherapy was applied to the site immediately after the surgical procedure. No recurrence of the tissue mass from this location has been observed for almost 2 years. This case demonstrates the novel use of strontium radiotherapy to treat exuberant granulation tissue in a bird.
Osteofibrous dysplasia is a rare and benign nonneoplastic condition of unknown etiology in humans and mammals. An adult female cockatiel (Nymphicus hollandicus) was presented with the following problems: a soft tissue mass on the left frontal area of the head that extended over the left eye, anorexia, lethargy, and emaciation. Computed tomographic imaging and ultrasonography revealed a soft tissue opacity in the left cranial area of the head with multifocal heterogeneous opacities and foci of mineralization. Cytological, histopathological, and immunohistochemistry examinations were performed on biopsy samples from tissue collected from the mass. Following surgical removal of the cranial mass the patient was treated with a nonsteroidal anti-inflammatory drug and antibiotic medication. The surgical site healed with no complications and through follow-up examinations there were no signs of reoccurrence of the abnormal tissue for 2 months. Through cytological and histopathological examination and immunohistochemistry testing of the submitted tissue, a diagnosis of osteofibrous dysplasia was determined.
Pododermatitis is prevalent in falcons and is characterized by inflammation and infection of the plantar aspect of the feet, particularly at the central metatarsal pad. Suboptimal perch design and increased weight loading on the plantar skin have been proposed as major risk factors for the development of pododermatitis. Prevention and treatment are challenging, but weight load reduction on the affected area of the foot is an accepted goal of initial treatment. To date, to our knowledge no studies have compared the performance of different bandage-perch surface combinations on weight redistribution away from the central metatarsal pad. An ex vivo factorial experiment was designed using the feet from a peregrine falcon cadaver to quantify weight load reduction on the central metatarsal pad with different combinations of perch surfaces (wood, neoprene, artificial turf) and bandages (none, interdigital, silicone shoe). Feet were attached to a digital force gauge mounted on a manual test stand for compression testing. Weight loading at the central metatarsal pad was measured using a small force sensor. Perch-surface combinations in randomized order were tested at 250 g, 500 g, and 1 kg with 9 replicates per foot. At 250 g, all combinations reduced measured metatarsal pad forces, but otherwise performed similarly. As compression forces increased, differences emerged with the shoe combinations performing better overall, followed by a group including the neoprene and artificial turf-interdigital bandage combinations, and a third group including the interdigital/wood and no bandage-artificial turf. All combinations performed better than control (no bandage on wood). This study may assist veterinarians in selecting appropriate perching surface/bandage combinations when treating falcons with pododermatitis.
This article is only available to subscribers. It is not available for individual sale.
Access to the requested content is limited to institutions that have
purchased or subscribe to this BioOne eBook Collection. You are receiving
this notice because your organization may not have this eBook access.*
*Shibboleth/Open Athens users-please
sign in
to access your institution's subscriptions.
Additional information about institution subscriptions can be foundhere