Diagnostic Approach Using Computerized Tomography and Successful Surgical Resolution of a Palatine Luxation and Entrapment in a Blue and Yellow Macaw (Ara ararauna)

A seven-month-old male blue and yellow macaw (Ara ararauna) was presented with an inability to move the maxillary beak after flying into a clothesline. Unsuccessful attempts to reduce the beak were performed, first by the owner at home and later within the same day by the referring veterinarian under general anesthesia. The patient was referred for assessment and treatment 5 days later. A palatine luxation and entrapment with a possible fissure of palatine bone was suspected based on history, a physical examination, and radiographic imaging. Another unsuccessful attempt to manually reduce the beak was performed under general anesthesia. A computed tomography (CT) scan was scheduled to evaluate the skull further. Rostrodorsal displacement and entrapment of the palatine bone on the rostral edge of the interorbital septum in the mesethmoid region were identified. In addition, the CT images provided useful information for the veterinary team to rule out other skeletal abnormalities, rendering a significantly more detailed evaluation of the skull bones before surgical intervention. Surgery was performed after the previously published pin insertion method over the dorsal aspect of the palatine bone. Pressure in the ventral direction was then applied on the pin while simultaneously further hyperextending the maxillary beak to unhook the palatine bone from the interorbital septum. The present case report describes an in vivo diagnosis of palatine luxation and entrapment in a blue and yellow macaw by means of a CT scan and successful surgical resolution.

Computed Tomographic Anatomy of the Head in Cockatiel (Nymphicus hollandicus)

BACKGROUND

Nowadays, computed tomography (CT) scanning is one of the most practical and precise diagnostic imaging methods that can be utilized to evaluate the head in birds.

OBJECTIVES

This study aimed to present the normal anatomical data of the head of the cockatiel (Nymphicus hollandicus) using the CT method. In this research, the features of this bird's head were investigated in terms of bones, joints, muscles, sinuses and other constituent tissues.

METHODS

The current retrospective cross-sectional study used carcasses of six adult cockatiels (Nymphicus hollandicus) (three males and three females) with an average age of 1-3 years and an average weight of 75-110 g. After preparing the CT images, the head of each parrot underwent gross anatomy studies.

RESULTS

Based on the results, reconstructed CT images could identify most structures of the cockatiel (Nymphicus hollandicus) head. Parietal, mandible, occiput, maxillary, premaxillary, palatine, pterygoid, quadrate, temporal bones, epithelial membranes, external ear canal and bony labyrinth, ossicles and entoglossal bones, different parts of the infraorbital sinus, brain hemispheres and various parts of the eyeball and conchae of the nasal cavities were examined in CT images. The results related to the CT evaluation and anatomical examination of the cockatiel (Nymphicus hollandicus) head demonstrated a high correlation.

CONCLUSION

The results of this research can be employed as a reference and a suitable atlas for identifying anatomical features, examining different species of the cockatiel (Nymphicus hollandicus), teaching anatomy and interpreting CT scan images, as well as performing clinical examinations and treating this type of parrot.

Successful conservative management of multiple skull fracture and quadrate-mandibular medial luxation in a blue-and-yellow macaw (Ara ararauna)

BACKGROUND

We present a case of beak trauma not previously been reported in a blue-and-yellow macaw (Ara ararauna) and its successful conservative treatment. Several cases of fractures affecting the mandibular, maxillary and maxillofacial bones and pterygo-palatine dislocations, which have been studied using traditional radiology and CT; however, quadrato-mandibular luxation has never been described, individually or associated with other trauma.

CASE PRESENTATION

A 4-year-old blue-and-yellow macaw (Ara ararauna) was referred for a recent head trauma. The parrot exhibited right lower beak deviation, difficulty in grasping food and difficulty closing the beak. The parrot was referred for multiple traumatic fractures involving the pterygoid bone, jugal bone and right mandibular arch. The X-ray projections showed an incomplete fracture of the right pterygoid bone, two fracture sites on the right jugal arch, and slight mediorostral displacement of the right quadrate bones. Computed tomography (CT) confirmed the X-ray findings, and indicated additional trauma. The right quadrate bone luxation was manually reduced, and conservative treatment was elected. Analgesia and nonsteroidal anti-inflammatory drugs were provided. Moreover, a soft food-based diet was recommended for 3 weeks to facilitate recovery and reduce facial bone movements and tension. The parrot started eating dry food approximately 1 month after the trauma; full return of apparently normal beak function was achieved by 2 months.

CONCLUSIONS

The CT examination allowed us to obtain a more detailed and complete view of the fractures and traumas and to evaluate the complex articular system of the Psittaciformes beak. For these reasons, CT is recommended for birds with a history of head trauma to select the best treatment for the specific case.

Diagnostic Imaging for Assessment of the Endocrine System in Exotic Animals

Diagnostic imaging can provide essential evidence supporting the diagnosis of endocrine diseases in exotic companion animals. The specific modality chosen depends on species, specific disease process/organ affected, equipment availability, and often, cost to the owner. While radiography is widely available in veterinary practices, the sensitivity for visualization of endocrine organs is low. Therefore, ultrasonography, computed tomography, or MRI may be preferred. Other specialized imaging modalities are useful for specific disease processes, such as nuclear scintigraphy and PET. This article compiles current evidence for diagnostic imaging of the endocrine system in exotic animals, organized by imaging modality, species, and disease process.

Computed tomographic and magnetic resonance imaging anatomy of the coelomic cavity in market-age commercial Pekin Ducks (Anas platyrhynchos domesticus)

Approximately 27 million ducks are raised commercially in the US each year and Pekin ducks (Anas platyrhynchos domesticus) are the most commonly raised breed. Additionally, an increasing number of Americans are raising small flocks of poultry, which often include ducks, in their own backyards. This creates a need to better understand the imaging anatomy of ducks. However, in avian species, superimposition of organs limits evaluation of the coelomic cavity using the most common imaging modality, radiography. The use of cross-sectional imaging including computed tomography (CT) and magnetic resonance imaging (MRI) has increased in veterinary medicine research and clinical use. An anatomic atlas is essential for guiding research and diagnostic imaging. To date, no CT or MRI atlas exists for Pekin ducks. The purpose of the study is to generate a CT atlas of market-age Pekin ducks as well as CT attenuation values and measurements of coelomic organs with corresponding gross and MRI images. A total of 20 market-age, commercial Pekin ducks were imaged. Five male and five female ducks were imaged with CT; four of these ten ducks, two male and two female, were frozen and sliced in approximately 5 mm transverse sections for gross anatomic reference images. Six additional ducks, three male and three female ducks, were dissected to measure major organs. Four additional ducks were imaged using CT and MRI and necropsied for gross anatomical comparisons and landmarks. The atlas contained here may be used for future research projects and clinically to aid in diagnosis of disease in ducks.

Anatomy, variation, and asymmetry of the bronchial tree in the African grey parrot (Psittacus erithacus)

The avian bronchial tree has a unique and elaborate architecture for the maintenance of unidirectional airflow. Gross descriptions of this bronchial arrangement have traditionally relied upon dissection and casts of the negative (air-filled) spaces. In this study, the bronchial trees of five deceased African grey parrots (Psittacus erithacus) were segmented from micro-computed tomography (μCT) scans into three-dimensional (3D) surface models, and then compared. Select metrics of the primary bronchi and major secondary branches in the μCT scans of 11 specimens were taken to assess left-right asymmetry and quantify gross lung structure. Analysis of the 3D surface models demonstrates variation in the number and distribution of secondary bronchi with consistent direct connections to specific respiratory air sacs. A single model of the parabronchi further reveals indirect connections to all but two of the nine total air sacs. Statistical analysis of the metrics show significant left-right asymmetry between the primary bronchi and the origins of the first four secondary bronchi (the ventrobronchi), consistently greater mean values for all right primary bronchus length metrics, and relatively high coefficients of variation for cross-sectional area metrics of the primary bronchi and secondary bronchi ostia. These findings suggest that the lengths of the primary bronchi distal to the ventrobronchi do not preserve lung symmetry, and that aerodynamic valving can functionally accommodate a wide range of bronchial proportions.

Computed tomographic and gross anatomy of the head of the blue-fronted Amazon parrot (Amazona aestiva)

The blue-fronted Amazon parrot is an extremely popular pet bird in Brazil. These birds are commonly raised in captivity and are often seen in veterinary practice. Modern imaging modalities such as computed tomography (CT), which had not been widely used in wild and exotic bird medicine until recently, are now becoming more popular due to wider availability and higher diagnostic accuracy. However, proper interpretation of tomographic findings requires species-specific anatomical references. Studies investigating normal tomographic anatomy of parrots are scarce. This study set out to describe the normal anatomy of the head of the blue-fronted amazon parrot (Amazona aestiva) using conventional CT. Anatomical descriptions may contribute to future comparative morphology studies and assist in clinical practice. The head of the blue-fronted Amazon parrot is structurally similar to other bird species. Major differences detected were are as follows: size and position of nasal conchae (long middle concha and small caudal concha located at the end of the nasal cavity), infraorbital sinus aperture located on the lateral aspect of the nasal cavity, presence of a nasopharyngeal duct connecting the nasal and oral cavities, longer infraorbital sinus with a larger number of caudal compartments and paraglossum with morphological features unique to psittacines. High-quality CT images were vital for identification and detailed description of most head structures. Multiplanar reconstruction was a useful tool for complete visualization of the head. However, conventional CT images were not good enough for visualization of the inner ear and related structures, as well the paratympanic sinus.

Digital dissection of the head of the rock dove (Columba livia) using contrast-enhanced computed tomography

The rock dove (or common pigeon), Columba livia, is an important model organism in biological studies, including research focusing on head muscle anatomy, feeding kinematics, and cranial kinesis. However, no integrated computer-based biomechanical model of the pigeon head has yet been attempted. As an initial step towards achieving this goal, we present the first three-dimensional digital dissection of the pigeon head based on a contrast-enhanced computed tomographic dataset achieved using iodine potassium iodide as a staining agent. Our datasets enable us to visualize the skeletal and muscular anatomy, brain and cranial nerves, and major sense organs of the pigeon, including very small and fragile features, as well as maintaining the three-dimensional topology of anatomical structures. This work updates and supplements earlier anatomical work on this widely used laboratory organism. We resolve several key points of disagreement arising from previous descriptions of pigeon anatomy, including the precise arrangement of the external adductor muscles and their relationship to the posterior adductor. Examination of the eye muscles highlights differences between avian taxa and shows that pigeon eye muscles are more similar to those of a tinamou than they are to those of a house sparrow. Furthermore, we present our three-dimensional data as publicly accessible files for further research and education purposes. Digital dissection permits exceptional visualisation and will be a valuable resource for further investigations into the head anatomy of other bird species, as well as efforts to reconstruct soft tissues in fossil archosaurs.

Orthopedic Diagnostic Imaging in Exotic Pets

Orthopedic diseases are a common problem in exotic pets. Diagnostic imaging modalities are more accessible and available in exotic animal veterinary medicine; the higher standards of care of the veterinary profession have progressed toward an increased offer of advanced imaging modalities. The literature on the use of diagnostic imaging modalities in orthopedic disease of exotic pets is scarce. This article discusses when to use the different diagnostic imaging techniques and reviews the imaging findings usually found in the most common orthopedic diseases in small mammal, avian, and reptile exotic pet species using different imaging modalities, especially radiography and computed tomography.

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.

Evidence-Based Advances in Avian Medicine

This article presents relevant advances in avian medicine and surgery over the past 5 years. New information has been published to improve clinical diagnosis in avian diseases. This article also describes new pharmacokinetic studies. Advances in the understanding and treatment of common avian disorders are presented in this article, as well. Although important progress has been made over the past years, there is still much research that needs to be done regarding the etiology, pathophysiology, diagnosis, and treatment of avian diseases and evidence-based information is still sparse in the literature.