Airsacculitis Caused by Enterobacteria and Occurrence of Eggs of the Superfamily Diplotriaenoidea in Feces of Tropical Screech Owl (Megascops choliba) in the Amazon Biome

This study aims to report the clinical signs, therapeutic strategy, necropsy results, and histopathological findings of airsacculitis caused by enterobacteria and the occurrence of eggs from the superfamily Diplotriaenoidea in the feces of Megascops choliba in the Amazon biome. A tropical screech owl nestling was rescued and admitted for hand-rearing. The animal was kept hospitalized for five months. It was fed a diet based on Zophobas morio larvae and thawed chicken breast meat with vitamin and mineral supplements. On the 37th day of hacking training for release, the owl showed weakness, lack of appetite, regurgitation, cachexia, dyspnea, ruffled feathers, dry droppings in the vent and pericloaca, and diarrhea. The parasitological examination showed eggs of the Diplotriaenoidea superfamily in the feces. The therapy employed included oxytetracycline, sulfamethoxazole, mebendazole, Potenay, sodium chloride 0.9%, and Mercepton. However, five days after starting the treatment, the bird died. Upon necropsy, prominence of the keel, pieces of undigested food in the oral cavity and proventriculus, intestinal gas, and thickened and turbid air sacs were found. The microbiological analysis of air sacs identified Escherichia coli, Klebsiella pneumoniae, and Enterobacter aerogenes. Histopathological examination showed heterophilic bacterial airsacculitis.

A computed tomography-based survey of paramedullary diverticula in extant Aves

Avian respiratory systems are comprised of rigid lungs connected to a hierarchically organized network of large, regional air sacs, and small diverticula that branch from them. Paramedullary diverticula are those that rest in contact with the spinal cord, and frequently invade the vertebral canal. Here, we review the historical study of these structures and provide the most diverse survey to date of paramedullary diverticula in Aves, consisting of observations from 29 taxa and 17 major clades. These extensions of the respiratory system are present in nearly all birds included in the study, with the exception of falconiforms, gaviiforms, podicipediforms, and piciforms. When present, they share connections most commonly with the intertransverse and supravertebral diverticula, but also sometimes with diverticula arising directly from the lungs and other small, more posterior diverticula. Additionally, we observed much greater morphological diversity of paramedullary airways than previously known. These diverticula may be present as one to four separate tubes (dorsal, lateral, or ventral to the spinal cord), or as a single large structure that partially or wholly encircles the spinal cord. Across taxa, paramedullary diverticula are largest and most frequently present in the cervical region, becoming smaller and increasingly absent moving posteriorly. Finally, we observe two osteological correlates of paramedullary diverticula (pneumatic foramina and pocked texturing inside the vertebral canal) that can be used to infer the presence of these structures in extinct taxa with similar respiratory systems.

Radiography and computed tomography of the heart and lower respiratory tract in toco toucans (Ramphastos toco)

This study aimed to evaluate normal features of the heart and lower respiratory tract in toco toucans by means of radiography and helical computed tomography (CT) scanner. Fifteen healthy adult toco toucans (Ramphastos toco), 10 females and 5 males, average body mass of 650 g were studied. CT examination as well as right lateral and ventrodorsal radiographic examinations of the coelomic cavity were performed under chemical restraint. Heart, lungs, air sacs, trachea and syrinx were analysed. The mean values of heart length, heart width and thoracic cavity in radiographs were, respectively, 23.76 mm, 25.94 mm and 48.87 mm. In both X-rays and CT scans, the lung parenchyma had honeycomb-like pattern. The topographic areas of the anterior and posterior air sacs were visualized as dark and air-filled spaces in X-rays. On CT evaluation, the air sacs occupied a larger area in the coelomic cavity compared to X-ray. In the lateral radiographic view, the cervical part of the trachea was positioned more ventrally in the transition from cervical to thoracic regions showing a V-shaped appearance. In all CT planes was visible division of the trachea into the right and left main bronchi at the level of 3rd thoracic vertebra. The syrinx was difficult to visualize in X-rays, but on CT it was easily identified in axial slice. In conclusion, the normal features of toco toucan's heart and lower respiratory tract that were determined on X-rays and CT scans are useful to compare with sick toco toucans, as well as other bird species.

Gross morphological features of the air sacs of the hooded crow (Corvus cornix)

Air sacs are considered to be one of the controlling factors of bird behaviour and habits in addition to their roles in ventilation, regulating body temperature, swimming and flight. As a scavenger and an omnivorous flight bird, air sacs of the hooded crow were the focus of this study. Eight healthy, adult hooded crows were used to examine the morphological characteristics of the air sacs, which were examined grossly and with latex and cast preparations. In general, the morphological overview of the hooded crow air sacs is similar to other avian species. We observed nine air sacs; four paired sacs (cervical, cranial thoracic, caudal thoracic and abdominal air sacs) and one unpaired sac; the clavicular air sac. The cervical air sac communicated to the lung through the medioventral bronchus and had three diverticula; intermuscular, subscapular and subcutaneous. The clavicular air sac communicated with lung through the medioventral bronchus and had subscapular, axillary, humeral, subpectoral and sternal diverticula. The cranial and caudal thoracic air sacs were communicated with lung through the lateroventral bronchi and the both sacs did not have any diverticula. The abdominal air sacs were posterior to the caudal thoracic air sacs. The left abdominal sac was the largest air sac. The right and left abdominal sacs gave off branches to diverticula that pneumatized synsacrum. The abdominal air sacs gave off femoral diverticula behind the hip joint as well as perirenal diverticula.

Central European parasitic flatworms of the Cyclocoelidae Stossich, 1902 (Trematoda: Plagiorchiida): molecular and comparative morphological analysis suggests the reclassification of Cyclocoelum obscurum (Leidy, 1887) into the Harrahium Witenberg, 1926

Cyclocoelidae Stossich, 1902 are medium-sized to large digenean bird parasites. Although these parasites bear few visible autapomorphic signs, and their diagnostic characters are unstable in response to the pressure applied during preparation, the numerous hitherto suggested re-classifications within the family have not been supported by any molecular analysis. We analyse here cyclocoelids found during the extensive examination of central European birds performed from 1962 to 2016, provide comparative measurements, host spectra, prevalence and intensity, and provide and analyse sequences of four DNA loci of five of the cyclocoelid species. Cyclocoleum Brandes, 1892 appears paraphyletic; thus we suggest the re-classification of Cyclocoleum obscurum (Leidy, 1887) as Harrahium obscurum (Leidy, 1887) Sitko and Heneberg comb. n. Molecular phylogenetics questioned also the validity of Cyclocoelinae Stossich, 1902 and Hyptiasminae Dollfus, 1948, which formed a single clade, whereas Allopyge Johnston, 1913, Prohyptiasmus Witenberg, 1923 and Morishitium Witenberg, 1928 formed another clade. Haematotrephinae Dollfus, 1948 are newly characterized as having a pretesticular or intertesticular ovary that forms a triangle with the testes. Analyses of non-European genera of the Cyclocoelidae and an examination of the position of families within Echinostomata La Rue, 1926 are needed.

[Radiographic findings in raptors affected with a mycosis of the respiratory tract]

OBJECTIVE

Summary of typical radiographic signs in birds of prey with aspergillosis compared to signs previously established in parrots.

MATERIALS AND METHODS

Evaluation of radiographs of 110 falcons (Falco spp.) with aspergillosis confirmed by endoscopy.

RESULTS

Compared to parrots primarily subtle radiographic signs were detected in falcons (especially inhomogeneously increased radiodensities of the airsacs/lungs). Two typical signs for diseased falcons consisted of the poor delineation of the cardiac silhouette and the line-shaped increased radiodensity of the caudal lung border. Radiographic diagnosis of the lung is limited due to the strong flight musculature.

CONCLUSION

The varying results between avian species can be explained by the different radiographic anatomy, husbandry conditions and x-ray technique (digital versus analog).

CLINICAL RELEVANCE

A pet bird-experienced practitioner should be aware of specific radiographic signs in birds of prey suspected of having aspergillosis.

Comparative mechanisms of branching morphogenesis in diverse systems

Much progress has been made in recent years toward understanding mechanisms controlling branching morphogenesis, a fundamental aspect of development in a variety of invertebrate and vertebrate organs. To gain a deeper understanding of how branching morphogenesis occurs in the mammary gland, we compare and contrast the cellular and molecular events underlying this process in both invertebrate and vertebrate organs. Thus, in this review, we focus on the common themes that have emerged from such comparative analyses and discuss how they are implemented via a battery of signaling pathways to ensure proper branching morphogenesis in diverse systems.

Subcuticular microstructure of the hornet's gaster: Its possible function in thermoregulation

The present study set out to elucidate the structure and function of the large subcuticular air sacs encountered in the gaster of the Oriental hornet Vespa orientalis (Hymenoptera, Vespinae). Gastral segments I, II, III, together with the anterior portion of segment IV, comprise the greater volume of the gaster, and inside them, beneath the cuticle, are contained not only structures that extend throughout their entire length, like the alimentary canal, and the nerve cord with its paired abdominal ganglia, situated near the cuticle in the ventral side, but also the heart, which is actually a muscular and dorsally located blood vessel that pumps blood anteriorly, toward the head of the hornet. The mentioned structures take up only a small volume of the gaster, while the rest is occupied by air sacs and tracheal ducts that also extend longitudinally. Interposed between the two air sacs, there is a hard partition and above it, at the center - a paired tracheal duct that extends the entire length of the air sacs. The endothelium of the air sacs is very anfractuous, thereby enlarging and strengthening the surface area. In each gastral segment there is an aperture for the entry of air, namely, a spiracle. Additionally, in each segment, in the antero-lateral aspect of its tergum and situated between two successive segments, there is an intersegmental conjunctive bearing parallel slits of 1-2 microM in width and 10-30 microM in length. The latter are arranged concentrically around bundles of tracheae that traverse the cuticle from segment to segment. From the upper rims of the slits are suspended downward fringe-like structures or "shutters" ranging between 3-10 microM in length. We discuss the possibility that the Oriental hornet resorts to internal circulation of air, along with a thermoelectric heat pump mechanism, in order to achieve cooling and thermoregulation of its body.

Composite cellular defence stratagem in the avian respiratory system: functional morphology of the free (surface) macrophages and specialized pulmonary epithelia

Qualitative and quantitative attributes of the free respiratory macrophages (FRMs) of the lung--air sac systems of the domestic fowl (Gallus gallus variant domesticus) and the muscovy duck (Cairina moschata) were compared with those of the alveolar macrophages of the lung of the black rat (Rattus rattus). The birds had significantly fewer FRMs compared to the rat. In the birds, the FRMs were found both in the lungs and in the air sacs. Under similar experimental conditions, the most robust FRMs were those of the domestic fowl followed by those of the rat and the duck. Flux of macrophages onto the respiratory surface from the subepithelial compartment and probably also from the pulmonary vasculature was observed in the birds but not in the rat. In the duck and the domestic fowl, a phagocytic epithelium that constituted over 70% of the surface area of the blood-gas (tissue) barrier lines the atrial muscles, the atria and the infundibulae. The epithelial cells of the upper respiratory airways contain abundant lysosomes, suggesting a high lytic capacity. By inference, the various defence strategies in the avian lung may explain the dearth of FRMs on the respiratory surface. We counter-propose that rather than arising directly from paucity of FRMs, an aspect that has been over-stressed by most investigators, the purported high susceptibility of birds (particularly table birds) to respiratory ailments and afflictions may be explained by factors such as inadequate management and husbandry practices and severe genetic manipulation for fast growth and high productivity, manipulations that may have weakened cellular and immunological defences.