Nutritional Secondary Hyperparathyroidism and Fibrous Osteodystrophy in a Captive African Penguin (Spheniscus demersus) Similar to Osteomalacia in Poultry.

A 9-yr-old female black-footed African penguin (Spheniscus demersus) was presented for necropsy after a history of reproductive abnormalities, paresis of limbs, weakness, and sudden death. Postmortem examination revealed soft keel, collapsed rib cage with beading of the ribs, and bilateral parathyroid enlargement. Classic histologic lesions of fibrous osteodystrophy with osteomalacia were observed in the ribs, vertebrae, and to a lesser extent in the femur and tibiotarsus associated with hyperplasia of parathyroid glands. This represents the first report of nutritional secondary hyperparathyroidism in birds of the order Spheniciformes, most likely caused by low levels of calcium supplementation during egg laying. The reproductive abnormalities observed in this penguin and others from the same group (asynchronous egg-laying cycles, abnormal breeding behavior) were most likely exacerbated by the lack of an adequate photoperiod mimicking the natural daylight pattern.

Reporte de caso­Hiperparatiroidismo secundario nutricional y osteodistrofia fibrosa en un pingüino africano (Spheniscus demersus) en cautiverio similar a la osteomalacia observada en de aves de corral. Una hembra de pingüino africano de patas negras (Spheniscus demersus) de nueve años fue sometida a necropsia después de un historial de anomalías reproductivas, paresia de extremidades, debilidad y muerte súbita. El examen post mortem reveló que la quilla del esternón estaba blanda, la caja torácica colapsada, se observaron "perlas raquíticas" en las costillas y agrandamiento bilateral de las paratiroides. Se observaron lesiones histológicas clásicas de osteodistrofia fibrosa con osteomalacia en las costillas, vértebras y en menor medida, en el fémur y tibiotarsus asociadas con hiperplasia de glándulas paratiroides. Esto representa el primer informe de hiperparatiroidismo secundario nutricional en un ave del orden Spheniciformes, muy probablemente causado por un bajo nivel de suplementos de calcio durante la producción de huevos. Las anomalías reproductivas observadas en este pingüino y otros del mismo grupo (ciclos de puesta de huevos asincrónicos, comportamiento de reproducción anormal) probablemente se vieron exacerbadas por la falta de un fotoperíodo adecuado que imitara el patrón de luz natural.

An outbreak of thyroid hyperplasia (goiter) with high mortality in budgerigars (Melopsittacus undulatus).

An outbreak of goiter with high morbidity and mortality in a flock of budgerigars (Melopsittacus undulatus) in California is described. Forty-five out of 400 adult birds exhibited signs of illness, weight loss, and enlargement in the crop area; 15 of the 45 birds died over a 2-3-month period. Diet consisted of a commercial mixture with the addition of broccoli, whole oats, and carrots, but no minerals or supplements. Six budgerigars were subjected to necropsy; all 6 birds had severely enlarged thyroid glands. Thyroid follicular hyperplasia was histologically observed in all birds examined, while granulomatous thyroiditis and microfollicular adenoma were observed in 2 birds, respectively. Virological, bacteriological, parasitological, and heavy metal analyses were negative or within normal limits. The total iodine in the thyroid glands of affected birds was measured by inductively coupled plasma-mass spectrometry. Following iodine supplementation and removal of broccoli from the diet, the owner reported weight gain and a reduced death rate among clinically affected birds; no additional birds became sick. The presence of broccoli with its iodine-binding ability and the complete lack of added minerals in the diet of these animals were thought to be the predisposing factors for the outbreak in the present study. Outbreaks of goiter accompanied by high mortality are rare in any species and, to the best of the authors' knowledge, have not been described previously in any avian species. Recognition of this condition may help improve medical, welfare, and trade standards concerning this species.

Interaction of ionophore and vitamin E in knockdown syndrome of turkeys.

Monensin and vitamin E concentrations, as well as histopathology of skeletal muscles and myocardium, were evaluated in broad-breasted white turkeys kept in commercial facilities. Turkeys with knockdown syndrome had myopathy of skeletal muscles, but no lesions in the myocardium. Generally, concentration of monensin in serum was highest in turkeys diagnosed with knockdown syndrome given more than 90 mg/kg of monensin in the diet, followed by turkeys diagnosed with knockdown syndrome given <90 mg/kg of monensin in the diet, healthy turkeys fed a diet that contained <90 mg/kg of monensin, and finally healthy turkeys fed a diet free of monensin (not detectable). However, the concentration of monensin was highly variable within each group, and the median was lower than the average. Vitamin E concentrations in the livers varied from low-normal to below normal and were statistically higher in healthy turkeys fed a diet free of monensin than in the livers of birds from the 3 groups exposed to monensin. This suggests that the concentration of monensin in serum positively correlates to the severity of clinical signs and pathology and to the amount of monensin in the feed. Although the methodology developed to detect serum monensin concentrations is beneficial and accurate for case investigations, it is recommended that several samples from each flock be evaluated because of variation within a flock. The current study also suggests that monensin in the feed could induce lower concentrations of vitamin E in the liver of turkeys and can predispose the turkeys to knockdown syndrome.

Microstructure and mineral content of femora in male turkeys with and without fractures.

Microscopic and radiographic observations, as well as ash, calcium, phosphorus, copper, manganese, and zinc concentrations, were evaluated from femora of 32- to 35-wk-old male turkeys from two different farms (A and B). Turkeys from Farm A were divided into birds with femoral fracture (AF) and without femoral fracture (ANF). Turkeys from Farm B did not have femoral fractures (BNF). In the mid-diaphyseal cortex of turkeys without femoral fractures, collagen fibers were evenly distributed parallel to the transverse plane of bone surface. In contrast, collagen fibers were disorganized and the cortex was osteoporotic in turkeys with femoral fractures. Each turkey with femoral fractures also had callus on the mediocaudal region of the femoral middiaphysis. The periosteal callus was interrupted at the insertion of the puboischiofemoralis muscle. Muscle attachment to the bone might have interfered with the formation of periosteal callus. The concentration of calcium was lower in the cortex of turkeys in group AF compared to turkeys in groups ANF and BNF. The focal nature of the callus, along with the low levels of calcium, is indicative of a local repair response with alteration in cortical structure and altered concentrations of minerals in the cortex. These changes in the bone and the routine handling of the birds might have predisposed the turkeys to complete fractures of the femur.