Macroscopic lesions of the ventriculus of Rhea americana , Linnaeus, 1758 (Aves: Rheidae) naturally infected by Sicarius uncinipenis (Molin, 1860) (Nematoda: Habronematidae).

There are few studies concerning the parasites of rheas. However, parasitism is the major cause of the limited success in captive breeding of these birds. Deletrocephalus dimidiatus, Deletrocephalus cesarpintoi, Paradeletrocephalus minor, and Sicarius uncinipenis are the most prevalent nematode species affecting these birds, but the lesions caused by these parasites have not been previously reported. Four adult rheas were necropsied to determine the presence or absence of gross lesions within the gastrointestinal tract, associated with parasitic infection. Two rheas parasitized by S. uncinipenis had ulcers on the koilin layer or had parasites penetrating this layer, resulting in widespread necrosis and hemorrhagic areas, whereas the 2 nonparasitized birds did not present lesions. The degree of injury was proportional to the parasitic load found in the birds. Thus, high parasitic loads can result in necrosis of the ventriculus, which may contribute to the death of birds, resulting in economic losses in the rural production of these birds.

Deoxynivalenol as a contaminant of broiler feed: intestinal development, absorptive functionality, and metabolism of the mycotoxin.

Deoxynivalenol (DON) has been recently documented to deteriorate intestinal morphology in chickens at dietary doses that are regarded as safe for this species. The present trial was conducted to explore the significance of these morphological changes in relation to intestinal absorptive functionality and DON metabolism. Ross broilers at 7 d of age were fed either a basal diet (0.265 ± 0.048 mg of DON/kg; 0.013 ± 0.001 mg of zearalenone/kg), a low DON diet (1.68 mg of DON/kg; 0.145 ± 0.007 mg of zearalenone/kg), or a high DON diet (12.209 ± 1.149 mg of DON/kg; 1.094 ± 0.244 mg of zearalenone/kg). The DON diets (to variable degrees) progressively decreased the relative density (weight:length) of the small intestine with increasing exposure length, which could be correlated with a decrease in villus height in the small intestine. Short circuit current of the jejunal epithelium, reflecting transport function of the epithelium per unit area, was reduced (P = 0.001) in the birds fed the high DON diet. The increasing dietary level of DON linearly (P = 0.035) increased the length of the jejunum in wk 4 of exposure, resulting in conservation of macronutrient retention. Upon challenging the birds with a fixed amount of DON after wk 5 of exposure, higher (P ≤ 0.033) amounts of DON and the detoxification metabolite (de-epoxy-DON) were found at 5 h postchallenge in the guts of birds raised on the DON diets. The increasing level of previous exposure to DON linearly (P = 0.040) decreased the plasma level of DON in the birds at 1 h postchallenge. The amounts of zearalenone and its analogs in the gut and plasma also followed a trend similar to that for DON. These data suggest that intestines in chickens may adapt to a chronic DON challenge by morphological and functional modifications. The birds having previous exposure to Fusarium mycotoxins showed moderate detoxification coupled with reduced transfer of the mycotoxins to systemic circulation. Some metabolites of zearalenone found in this study were previously unknown for chickens.

Ventricular diverticula formation in captive parakeet auklets (Aethia psittacula) secondary to foreign body ingestion.

A captive parakeet auklet at the North Carolina Zoo evaluated for weight loss, lethargy, and dyspnea had radiographic evidence of a distended, stone-filled ventriculus (bird 1). Multiple stones (n = 76) were removed surgically, but the bird died and a large ventricular diverticulum was diagnosed at necropsy. This bird and seven other parakeet auklets had been transferred 3 yr earlier from a zoo in Ohio. Radiographic investigation revealed that 6 of 7 Ohio birds had stones in their ventriculus (n= 2-26), but only 1 of 7 radiographed North Carolina Zoo auklets had one small stone. Further diagnostic imaging (survey and contrast radiographs, fluoroscopy, CT scans [n = 2]) of six Ohio and two North Carolina birds was conducted to determine if other birds had ventricular abnormalities (birds 2-9). No ventricular diverticula were diagnosed using imaging techniques, although two Ohio birds (birds 6 and 7) required surgical intervention to remove 12-26 stones. A small ventricular diverticulum was identified in bird 6 during surgery. That bird died of unrelated causes 11 mo after surgery, but bird 7 remains clinically normal more than 4 yr later, along with four other auklets with stones (n = 2-15; birds 2-5). It is possible that without surgical intervention, these birds may develop ventricular disease, presumably due to chronic mechanical trauma to the thin-walled ventriculus. It was hypothesized that the Ohio birds ingested stones in their previous exhibit, with a loose stone substrate, and retained them for at least 3 yr. Possible causes for stone ingestion include trituration (for grinding, mixing coarse ingesta), gastric parasite reduction, hunger suppression, accidental ingestion while feeding, or behavioral causes, but the underlying cause in these birds was not determined. Based on these results, parakeet auklets and other alcids should not be housed, or at least fed, on a loose stone substrate.

Oral lead bullet fragment exposure in northern bobwhite (Colinus virginianus).

Lead (Pb) is a worldwide environmental contaminant known to adversely affect multiple organ systems in both mammalian and avian species. In birds, a common route of exposure is via oral ingestion of lead particles. Data are currently lacking for the retention and clearance of Pb bullet fragments in gastrointestinal (GI) tract of birds while linking toxicity with blood Pb levels. In the present study, northern bobwhite quail fed a seed-based diet were orally gavaged with Pb bullet fragments (zero, one or five fragments/bird) and evaluated for rate of fragment clearance, and changes in peripheral blood, renal, immune, and gastrointestinal parameters. Based on radiographs, the majority of the birds cleared or absorbed the fragments by seven days, with the exception of one five-fragment bird which took between 7 and 14 days. Blood Pb levels were higher in males than females, which may be related to egg production in females. In males but not females, feed consumption, body weight gain, packed cell volume (PCV), plasma protein concentration, and δ-aminolevulinic acid dehydratase (δ-ALAD) activity were all adversely affected by five Pb fragments. Birds of both sexes that received a single Pb fragment displayed depressed δ-ALAD, suggesting altered hematologic function, while all birds dosed with five bullet fragments exhibited greater morbidity.

Distortion of the gizzard in Cyprus pigeons (Columba livia) associated with Hadjelia truncata infestation.

Hadjelia truncata is well recognised as an avian parasite but is rarely reported as pathogenic. This paper describes severe disease in pigeons due to this parasite and is the first to describe the condition in Cyprus. The morphology of the parasite and the associated lesions are described and illustrated and the pathogenesis of the condition is discussed.

Neuropathic gastric dilatation in psittaciformes.

Psittacine neuropathic gastric dilatation was studied in four cockatoos (Cacatua spp.). The birds died with characteristic clinical signs, and post-mortem examination revealed a highly distended proventriculus. Upon light microscopic examination, most of the ganglia of the gastric plexus and some of the duodenal myenteric plexus appeared destroyed and replaced by round cell accumulations; the same was true for the celiac ganglion. The neuronal perikaryon of the celiac ganglion and the myenteric plexus revealed intranuclear and extranuclear eosinophilic inclusion bodies. The electron microscope revealed virus-like particles outside and within those inclusions. These particles were similar to particles described and identified as paramyxovirus.

[Changes in chemical composition, biosynthesis and structure of secretion of intermediate area of chicken stomach with A-avitaminosis]. / Izmenenie khimicheskogo sostava, binsinteza i struktury sekreta promezhutochnoi zony zheludka tsypliat pri A-avitaminoze.

In the intermediate area of the chicken stomach with A-avitaminosis the amount of the secretion increases and its chemical composition changes sharply: the content of water, lipids, hexolamines and suphates lowers. By means of 14-C-acetate, 35S-methionine and 35S-sulphate it is established that renewal of the secretion is inhibited. The electron-microscopic examinations showed that the secret is homogenous in normalcy but with A-avitaminosis it acquires a honeycomb structure, its physicochemical properties being changed: it becomes rigid, cuticle-like. As a result there appear deep cracks reaching mucosa, which lead to formation of erosions and ulcers. An assumption is advanced that the initial disturbances of the secretion might be not related to protein component (as the ratio of amino acids in it's almost unchanged) and depend on the carbohydrate and lipid components. The hypothesis of de Luc et al. as to the transport and intermediatory function of vitamin A in biosynthesis of glycosamineglycanes, glycolipids and glycolipoproteins is questioned. Vitamin A may take part in these processes but not as an intermediator of metabolic systems but as the level of biological structures (for instance, the Golgi apparatus and others) which organize these systems and coordinate their function.