Gross anatomy of the pancreatic lobes and ducts in six breeds of domestic ducks and six species of wild ducks in China

Characterization of the pancreas of common pheasant (Phasianus colchicus): A light and transmission electron microscope study

The present work was carried out to investigate the structure and ultra structure of the pancreas in the common pheasant (Phasianus colchicus). Totally, five healthy adult pheasant were used. The pancreas was assessed using histochemistry and transmission electron microscopy (TEM). The pancreas was composed of four lobes: dorsal, ventral, third, and splenic lobes. These lobes emptied into ascending duodenum through three excretory ducts as: ventral duct, splenic duct, and a common duct for dorsal and third lobes. The exocrine pancreas was constituted of pyramidal-shaped acinar cells with aggregation of zymogen granules at their apical cytoplasm. The endocrine pancreas was identified as large islet of Langerhans as α islets and small islets as β ones. No mixed islet was observed. At the level of TEM, two types of acinar cells were distinguished: Dark cells with electron dense cytoplasm, and indented nucleus, Light cells with electron lucent cytoplasm, and regular nucleus. The α islets were mainly constituted by A and D cells, whereas the β islets principally contained B cells and a few A cells. No D cells were identified in β islets. B cells were characterized by their polymorphic granules which were surrounded by a narrow halo zone. The granules of D cells were quite different. These cells contained large spherical granules with lower density as compared to the A or B granules surrounded by a limiting membrane. In conclusion, the pancreas of the common pheasant has a species-specific feature which must be considered in phylogenic studies. RESEARCH HIGHLIGHTS: The common pheasant's pancreas was composed of four lobes as dorsal, ventral, third, and splenic lobe. There were three excretory ducts. Ventral duct for ventral lobe, a common duct for both dorsal and third lobes, and a distinct splenic duct for splenic lobe. The exocrine acini were composed of two distinct types of cells: dark cells and light cells. The large alpha islets were composed of alpha cells and a few numbers of delta cells and small beta islets were composed of beta cells and a few numbers of alpha cells.

Comparative anatomy of the hepatobiliary systems in quail and pigeon, with a perspective for the gallbladder-loss

Although the gallbladder is one of the characteristic component of the vertebrate body, it has been independently lost in several lineages of mammals and birds. Gallbladder loss is a widely reported phenomenon; however, there have been few descriptive comparisons of entire hepatobiliary structures between birds with and without a gallbladder. Here, we discuss the evolution of avian hepatobiliary morphology by describing the gross anatomy of the hepatobiliary system in the quail and pigeon. Quails have two major extrahepatic bile ducts: the right cystic-enteric duct, which has a gallbladder, and the left hepatic-enteric duct, which does not. Together with two pancreatic ducts, they share one opening to the ascending part of duodenum. Pigeons lack a gallbladder, but also have two extrahepatic ducts similar to those of quails. However, the hepatic-enteric duct opens solely to the descending part of the duodenum close to the stomach. The pancreatic duct opens to the very posterior part of the duodenum independent from the biliary tracts, giving rise to three separate openings in the duodenum. The hepatobiliary anatomy of the pigeon represents a highly derived condition not only because of gallbladder loss. Avian gallbladder loss may be related to remodeling of the entire hepatobiliary system, and may have occurred via a different mechanism from that of mammals, which can be explained simply by the disappearance of the gallbladder primordium.

Disseminated pancreatic adenocarcinoma in an eclectus parrot (Eclectus roratus)

CASE DESCRIPTION

A 15-year-old 0.412-kg (0.906-lb) sexually intact male eclectus parrot (Eclectus roratus) was evaluated because its owners found it lethargic and dyspneic at the bottom of its cage.

CLINICAL FINDINGS

The parrot was thin and had generalized muscle wasting, diffuse feather loss, pale mucous membranes, and melena. The coelomic cavity was distended and soft on palpation, with coelomic effusion suspected. Results of a CBC indicated leukocytosis with left shift heterophilia, including toxic heterophils, lymphopenia, and anemia. Plasma biochemical analyses revealed severe hyperamylasemia.

TREATMENT AND OUTCOME

Radiography revealed no evidence of a metallic foreign body but severe loss of coelomic detail, suggestive of a coelomic mass, coelomic effusion with coelomitis, or both. Ultrasonography and CT revealed severe accumulation of coelomic fluid; a large, heterogeneous, irregularly marginated, and moderately vascularized mass in the caudal aspect of the coelomic cavity; and multiple hepatic, coelomic, and pulmonary nodules. On the basis of a poor prognosis, the parrot was euthanized. Necropsy results confirmed exocrine pancreatic adenocarcinoma, with disseminated metastases in the liver, gastrointestinal tract, coelomic cavity, and lungs.

CLINICAL RELEVANCE

In birds, pancreatic adenocarcinoma is rarely reported but should be considered a differential diagnosis for hyperamylasemia, coelomic mass, coelomic effusion, or abnormal gastrointestinal signs, alone or in combination. Ultrasonography and CT can be useful in further evaluating such patients and should be considered in the diagnostic plan.

Intestinal mucosal immune response in ducklings following oral immunisation with an attenuated Duck enteritis virus vaccine

To investigate the intestinal mucosal immune responses in ducklings orally inoculated with attenuated Duck enteritis virus (DEV), the kinetics of the viral load, the specific humoral immune responses, and the distribution of immunoglobulin (Ig)A-secreting cells in the intestine were evaluated. Oral inoculation with attenuated DEV stimulated an IgA-dominant response in intestinal secretions and a IgY-dominant response in the serum. The dramatic increase in virus-specific mucosal IgA 15 days after inoculation was accompanied by reductions in the DEV intestinal load, suggesting that the IgA response has a role in controlling viral replication. The kinetics of virus-specific IgA production closely correlated with the presence of IgA+ plasma cells in the intestinal lamina propria.

Intestinal mucosal immune response against virulent duck enteritis virus infection in ducklings

Duck virus enteritis (DVE) is an acute and contagious herpes virus infection of duck, geese and swans with high morbidity and mortality. The development of specific mucosal immune system against duck enteritis virus (DEV) infection for ducks has been hindered by a lack of knowledge concerning the purification of immunoglobulin A (IgA) of duck. In the present work, the method for purification of duck immunoglobulin A was developed, and the induction of intestinal mucosal immune responses against DEV was studied by orally infected ducklings with virulent DEV. The results showed that a continuous increased DEV DNA levels were observed in blood and various organs examined of orally infected ducklings throughout the infection, which was accompanied by the development of infection in ducklings from mild progressed to severe pathological lesions. Furthermore, a marked increased level of DEV-specific IgA and IgG antibodies in bile, serum and the intestinal tract, as well as the density of IgA(+) cells in intestine were detected between 1 and 12days p.i., followed by a drastic reduction of the antibody levels and the density of IgA(+) cells at 15days p.i. The results indicate that the DVE infection can stimulate both IgA-dominated antibody immune responses in the intestinal tract, and IgG-dominated antibody systemic immunity in the serum of ducklings orally inoculated with virulent DEV. The severe lesions of the villus epithelial cells and the lymphoid organs can suppress the intestinal mucosal immune responses.