Genome Resequencing Reveals Congenital Causes of Embryo and Nestling Death in Crested Ibis (Nipponia nippon).

The crested ibis (Nipponia nippon) is endangered worldwide. Although a series of conservation measures have markedly increased the population size and distribution area of these birds, the high mortality of embryos and nestlings considerably decreases the survival potential of this bird species. High-throughput sequencing technology was utilized to compare whole genomes between ten samples from dead crested ibises (including six dead embryos and four dead nestlings aged 0-45 days) and 32 samples from living birds. The results indicated that the dead samples all shared the genetic background of a specific ancestral subpopulation. Furthermore, the dead individuals were less genetically diverse and suffered higher degrees of inbreeding compared with these measures in live birds. Several candidate genes (KLHL3, SETDB2, TNNT2, PKP1, AK1, and EXOSC3) associated with detrimental diseases were identified in the genomic regions that differed between the alive and dead samples, which are likely responsible for the death of embryos and nestlings. In addition, in these regions, we also found several genes involved in the protein catabolic process (UBE4A and LONP1), lipid metabolism (ACOT1), glycan biosynthesis and metabolism (HYAL1 and HYAL4), and the immune system (JAM2) that are likely to promote the normal development of embryos and nestlings. The aberrant conditions of these genes and biological processes may contribute to the death of embryos and nestlings. Our data identify congenital factors underlying the death of embryos and nestlings at the whole genome level, which may be useful toward informing more effective conservation efforts for this bird species.

Infundibular Pulmonic Stenosis in a Moluccan Cockatoo (Cacatua moluccensis).

A 31-year-old female Moluccan cockatoo (Cacatua moluccensis) was examined for intermittent foot clenching of 4 months' duration. Physical examination revealed feather-destructive behavior and clinical findings compatible with hypovitaminosis A. Neurologic examination was unremarkable. Results of radiographs, hematologic testing, plasma biochemical analyses, and measurement of lead and trace element blood concentrations were unremarkable, except for degenerative joint disease of several thoracic intervertebral joints and a low blood copper concentration. Increased dietary copper was recommended. After a 6-month period without clinical signs, the bird presented again for episodes of foot weakness. Radiographic review was suggestive of mild pulmonary trunk enlargement. Echocardiography revealed mild mitral and aortic regurgitation, dilation of the ascending aorta, and a dilated right ventricle with turbulent right ventricular outflow. An electrocardiogram revealed a sinus rhythm and normal-appearing complexes. Nonselective fluoroscopic angiography was performed 3 weeks later because of persistent episodes of foot clenching and weakness. Infundibular pulmonic stenosis, poststenotic dilation of the pulmonic trunk, and proximal main pulmonary arteries were identified, as well as a mild narrowing of the descending aorta compatible with aortic stenosis. The bird was discharged without medication but with dietary recommendations and experienced 2 clenching episodes in the days after the last visit. No recurrence of clinical signs has been reported over the 18-month follow-up period. To our knowledge, this is the first report of infundibular pulmonic stenosis in a bird. This case illustrates the application of basic and advanced diagnostic imaging modalities in evaluating cardiac disease in birds.

Removal of a Presumed Peripheral Cerebral Cyst via Craniectomy in a Crested Pekin Duck ( Anas platyrhynchos f dom).

A juvenile, male crested pekin duck ( Anas platyrhynchos f dom) was presented for neurologic signs suggestive of cerebellar disease. Physical examination revealed microphthalmia, erratic head movements, and ataxia. Computed tomography scan of the head and neck regions revealed 2 full-thickness skull-bone defects within the caudal portion of the cranium. The cerebellum appeared to be ventrally compressed by a homogeneous, triangular, fluid-attenuating region (0-10 Hounsfield units). A craniectomy was performed, and a presumed peripheral cerebral cyst was removed with suction and gentle dissection. No postoperative complications occurred, and the patient showed clinical improvement for 5 months after surgery. However, after 5 months, the owners elected euthanasia because of poor prognosis after finding the duck minimally responsive in a water enclosure. At necropsy, a thin-walled, epithelial structure was present in meninges and was adhered to the skull at the presumed surgical site.

Investigation of an outbreak of craniofacial deformity in yellow-eyed penguin (Megadyptes antipodes) chicks.

AIM: To investigate an outbreak of severe craniofacial deformity in yellow-eyed penguin (Megadyptes antipodes, hoiho) chicks at a single breeding site on the Otago Peninsula in the South Island of New Zealand. METHODS: Morbidity and mortality of yellow-eyed penguins breeding on the coastal regions of Otago was monitored from November 2008 to March 2009. Dead chicks and unhatched eggs were recovered and examined. Between October and December 2008 32 eggs were recorded at 17 nests in the Okia Reserve. Eleven chicks survived to about 90 days of age, of which eight were found to have moderate to severe craniofacial deformity. The six most severe chicks were subject to euthanasia and examined in detail at necropsy, and the remaining two affected chicks were released to the wild after a period of care in a rehabilitation centre. Post-mortem samples were analysed for inorganic and organic toxins. RESULTS: The six deformed chicks all had severe shortening of the mandible and maxilla by 20-50 mm. The rostral and caudal regions of the skull were approximately 40 and 80% of normal length, respectively. Other, more variable lesions included cross bill deformity, malformed bill keratin, microphthalmia with misshapen scleral ossicles and oral soft tissue excess thought to be secondary to bony malformations. During the same year, mild sporadic bill deformities were also reported in 10 unrelated chicks from >167 chicks at other breeding sites on the southern Otago coast. Concentrations of organic toxins and heavy metals in body tissues from affected chicks were apparently similar to those in unaffected chicks on other beaches. CONCLUSIONS: No cause of this outbreak of craniofacial deformity could be established although the high prevalence at a single site suggests that it was due to an unidentified local teratogen.

Photoreceptor cell dysplasia in two Tippler pigeons.

Two 12-week-old Tippler pigeons were evaluated for ocular abnormalities associated with congenital blindness. The pigeons were emaciated and blind. Biomicroscopy and direct and indirect ophthalmoscopy findings of the Tippler pigeons were normal with the exception of partially dilated pupils at rest. Scotopic (blue stimuli) and photopic monocular electroretinograms were extinguished in the blind Tippler pigeons. Histological and electron microscopy studies revealed reduced numbers of rods and cones, and an absence of the double cone complex. The photoreceptor cells' outer segments were absent, and the inner segments were short and broad. The number of cell nuclei in the outer and inner nuclear layers was decreased, and the internal and external plexiform layers were reduced in width. Photoreceptor cell endfeet with developing synaptic ribbons were present in the external plexiform layer. Inflammatory cell and subretinal debris was not seen. The electroretinographic, histopathological, and ultrastructural findings of the blind Tippler pigeons support the diagnosis of a photoreceptor cell dysplasia.

Causes of mortality in captive Attwater's prairie chickens (Tympanuchus cupido attwateri) at the San Antonio Zoo, 1997-2000.

Necropsy records for 102 Attwater's prairie chickens (Tympanuchus cupido attwateri) that had been captive-reared and had died at the San Antonio Zoo over a 4-yr period were evaluated to determine the causes of mortality. Gross necropsy, histopathology, and bacterial culture findings are summarized. Mortality was highest in young birds (<6 mo) and embryos. Husbandry- and gastrointestinal-related diseases were the most common causes of mortality.

Belgian Waterslager canaries are afflicted by Scheibe's-like dysplasia.

Behavioral investigations of Belgian Waterslager canaries (BWCs) have demonstrated a congenital hearing impairment that primarily affects high frequencies. Research into the surface anatomy of the basilar papilla of these birds has pointed to the hair cells as the site of the lesion. Given that the basilar papilla and the vestibular organs both develop from the otocyst, we were interested in ascertaining whether the vestibular sensory epithelia also displayed abnormal hair cells. The inner ear of adult BWCs was examined by scanning electron microscopy. As expected, hair cells in the basilar papilla of BWCs were abnormal. As for the vestibular parenchyma, abnormal hair cells were detected in only one structure: the sacculus. Morphological abnormalities of the cochlea and sacculus are pathognomonic signs of Scheibe's dysplasia, the most common inner ear defect associated with congenital hearing loss. Our results suggest that BWCs are afflicted by this genetic disorder.

Congenital extra-hepatic biliary cyst in a Congo African Grey Parrot (Psittacus erithacus erithacus).

An 8-week-old Congo African Grey Parrot (Psittacus erithacus erithacus) was presented with a history of abdominal enlargement since hatch. Trans-illumination of the abdomen suggested that the enlargement was due to marked hepatomegaly. This was supported by radiographic and ultrasonic examination. Postmortem examination revealed an extra-hepatic biliary cyst 4 cm in diameter.

Morphology of congenital microphthalmia in chicks (Gallus gallus).

This study examines the morphology of sporadic congenital microphthalmia in 1-day-old chicks, with particular emphasis on the neural retina. On the basis of the size of the eyeball it is possible to classify microphthalmia into two groups, severe and mild. In severe microphthalmia (less than 5 mm in equatorial diameter), the eyeball is severely malformed, but in most cases it shows evidence of an organized neural retina. Although ganglion cells and an optic nerve head are present in a small proportion of these retinae, we could not trace an optic nerve projection to the brain. These results indicate that some ganglion cells are able to be sustained after the period of naturally occurring cell death, suggesting either that those ganglion cells have established some contact with the central nervous system or that the presence of their axons in a rudimentary optic nerve is adequate for survival. In mild microphthalmia (greater than 5 mm in equatorial diameter), the most consistent abnormality is a defect in the pecten, which together with other abnormalities such as orbital cysts and colobomas indicates that the major abnormality occurs in the region of the choroid fissure. Associated with these defects are abnormalities within the ganglion cell layer. In some cases the number of ganglion cells was reduced, and in others the numbers of both ganglion and displaced amacrine cells were reduced. Unexpectedly, there were localized regions completely devoid of cells in the ganglion cell layer. The timing of the congenital defect may provide some clue as to the presence of a critical period in which displaced amacrine cells are formed or are sensitive to events related to ganglion cell loss.

Developmental ocular disease of raptors.

Sixteen raptors, including one eagle, two falcons, five hawks and eight owls, were found to have developmental ocular lesions. The most common lesion was microphthalmia. Other findings included cataract, microphakia, retinal dysplasia, malformation of the ciliary body, choroid and pecten, and lentoid formation. Specific causes for these lesions could not be determined. It is hypothesized that developmental ocular disease probably is more common than available reports indicate.

Skull deformity in a herring gull chick (Larus argentatus).

A skull deformity resulting in death of a herring gull chick (Larus argentatus) is described in detail. The bones of the skull and upper jaw were twisted, asymmetrical and of unusual size or absent. The lower jaw had an almost "spoon-like" external appearance and lacked normal articular surfaces.

Persistent right oviduct in ring-necked pheasant.

1. A right oviduct, approximately two-thirds the length of the left oviduct, and with a separate opening into the cloaca was observed in a female Ring-necked pheasant. 2. It is suggested that interference of the synthesis of Müllerian inhibiting factor from the gonads may have allowed its development.