Steatitis in egrets and herons from Japan

More than 70 egrets and herons were found sick or dead at an agricultural water reservoir in Kanagawa Prefecture, Japan between September and October 2008. The birds showed weakness, lethargy, and inability to fly before death. Postmortem findings included large amounts of firm subcutaneous and cavitary fat comprised of necrotic adipose tissues with infiltrates of heterophils and macrophages. The birds were diagnosed with steatitis on the basis of the gross lesions and histopathology. Egrets with steatitis had low blood levels of vitamin E. High counts of cyanobacteria (Microcystis aeruginosa) were found in the reservoir concurrent with the outbreak of steatitis. No microcystin was detected in the reservoir water or the livers from the egrets. This is the first report of steatitis in wild birds in Japan.     

Isolation and Characterization of an Isolate (HN) of Marek's Disease Virus with Low Pathogenicity

A cytopathic agent was isolated and characterized as an isolate of Marek''s disease herpesvirus (MDHV) with low pathogenicity, and referred to as the HN isolate. This isolate of MDHV did not cause clinical Marek''s disease (MD) or death in a highly susceptible line of chickens within 5 weeks after exposure. Gross lesions of limited extent were noted in a few of the inoculated birds. Microscopic nerve lesions in the inoculated and contact-infected birds were invariably minimal, closely resembling C-type MD lesions.     

Capture myopathy in wild turkeys (Meleagris gallopavo) following trapping, handling and transportation in Colorado

Sixty wild turkeys were necropsied following trapping, transporting and handling during the winters of 1980-1981, 1981-1982, and 1982-1983 in order to determine the incidence of subclinical capture myopathy. Gross lesions characterized by small to large patchy, pale white streaked areas within skeletal muscle were found in 13 of 27 birds trapped with a drop net in the winter of 1982-1983. Microscopic lesions within myocardium characterized by irregular areas of coagulative necrosis, collapse of intercellular stroma and myocardial nuclear proliferation were found in two of 14 birds in 1980-1981, five of 19 birds in 1981-1982 and 11 of 27 birds in 1982-1983. Microscopic lesions within skeletal muscle characterized by rhabdomyolysis were found in 16 of 19 birds in 1981-1982 and 25 of 27 birds in 1982-1983. These findings suggest that wild turkeys are susceptible to capture myopathy and particular caution should be exercised in capturing and handling these birds.     

N tau methyl histidine excretion and [U-14C]amino acid oxidation in fully chickens from two lines selected for high and low body fat contents

Protein turnover and amino acid oxidation were examined in two lines of domestic broiler chicken selected for high (fat) and low (lean) plasma very low density lipoprotein levels. Protein turnover was assessed by comparing N tau methyl histidine excretion in two lines. No differences between the fat and lean birds were found. Oxidation of [U-14C]amino acids in vivo was measured in birds of both lines which had been fed ad lib. The lean birds oxidized significantly less of the administered [U-14C]amino acids to 14CO2 than their fat counterparts during the first 90 min following administration. Lean birds also excreted significantly less 14C than fat birds from [U-14C]amino acids.     

Isolation and Characterization of an Isolate (HN) of Marek''s Disease Virus with Low Pathogenicity

A cytopathic agent was isolated and characterized as an isolate of Marek's disease herpesvirus (MDHV) with low pathogenicity, and referred to as the HN isolate. This isolate of MDHV did not cause clinical Marek's disease (MD) or death in a highly susceptible line of chickens within 5 weeks after exposure. Gross lesions of limited extent were noted in a few of the inoculated birds. Microscopic nerve lesions in the inoculated and contact-infected birds were invariably minimal, closely resembling C-type MD lesions.     

Effects of high dietary levels of soybean meal and its constituents (potassium,oligosaccharides) on foot pad dermatitis in growing turkeys housed on dry and wet litter

Soybean meal (SBM) is the main protein source in diets for turkeys. High dietary levels of SBM are thought to increase the incidence of foot pad dermatitis (FPD). Therefore, this study was conducted to test potential effects of high SBM and to elucidate which constituents in SBM might be associated with the development of FPD. Two week-old female turkeys were allotted to four groups of 29 birds each, and housed on dry wood shavings in floor pens over a period of three weeks. Four different diets were fed: control, high SBM, high potassium (K) or high oligosaccharide (OL) diet. Additionally, for only 8 h/d half of the animals in each group were exposed to wet litter (27% DM) in adjacent separate boxes. The foot pads of all birds were assessed on days 0, 7, 14 and 21 for external lesions. For the histopathology of the foot pads, on day 0 three birds from each group, and on days 7 and 14 six birds per feeding group were selected. The remaining birds in each group were sacrificed on day 21 and their pads were evaluated histologically. High dietary levels of SBM, potassium or oligosaccharides did not influence the severity of FPD on dry litter, but slightly increased the severity on wet litter. However, there were no histopathological differences in FPD severity between these dietary treatments within each litter form compared to the control. Nevertheless, the FPD severity was in general higher on wet litter. Thus, litter moisture appears to be one of the most important factors involved in FPD in turkeys. In addition, all nutritional factors which increase water intake and excreta or litter moisture may contribute to an increased development and severity of FPD in turkeys.     

Effects of high dietary levels of soybean meal and its constituents (potassium, oligosaccharides) on foot pad dermatitis in growing turkeys housed on dry and wet litter

Soybean meal (SBM) is the main protein source in diets for turkeys. High dietary levels of SBM are thought to increase the incidence of foot pad dermatitis (FPD). Therefore, this study was conducted to test potential effects of high SBM and to elucidate which constituents in SBM might be associated with the development of FPD. Two week-old female turkeys were allotted to four groups of 29 birds each, and housed on dry wood shavings in floor pens over a period of three weeks. Four different diets were fed: control, high SBM, high potassium (K) or high oligosaccharide (OL) diet. Additionally, for only 8 h/d half of the animals in each group were exposed to wet litter (27% DM) in adjacent separate boxes. The foot pads of all birds were assessed on days 0, 7, 14 and 21 for external lesions. For the histopathology of the foot pads, on day 0 three birds from each group, and on days 7 and 14 six birds per feeding group were selected. The remaining birds in each group were sacrificed on day 21 and their pads were evaluated histologically. High dietary levels of SBM, potassium or oligosaccharides did not influence the severity of FPD on dry litter, but slightly increased the severity on wet litter. However, there were no histopathological differences in FPD severity between these dietary treatments within each litter form compared to the control. Nevertheless, the FPD severity was in general higher on wet litter. Thus, litter moisture appears to be one of the most important factors involved in FPD in turkeys. In addition, all nutritional factors which increase water intake and excreta or litter moisture may contribute to an increased development and severity of FPD in turkeys.     

Effects on Turkey Poults of Rations Containing Corn Invaded by Fusarium tricinctum (Cda.) Sny. & Hans

Consumption of an otherwise balanced ration containing 1% of corn invaded by Fusarium tricinctum isolate 2061-C resulted in the death of 13% of turkey poults within 35 days, in decreased feed efficiency and weight gain, and moderate development of bilateral necrotic lesions at angles of the mouth, especially in those that succumbed. Consumption of a ration with 2% of corn invaded by F. tricinctum resulted in death of 60 to 83% of the birds, in greatly reduced growth and feed efficiency in the survivors, and in development of severe mouth lesions. Consumption of rations containing 5, 10, and 20% of corn invaded by the fungus resulted in death of all birds in 5 to 15 days.     

Avipox sp. in a colony of gray-crowned rosy finches (Leucosticte tephrocotis)

Members of a wild-caught colony of 16 gray-crowned rosy finches (Leucosticte tephrocotis) were presented with dermal and mucosal lesions, anorexia, emaciation, lethargy, and sudden death. Lesions included dermatitis, conjunctivitis, and glossitis. Skin scrapings from and bacterial culture of dermal lesions yielded Staphylococcus aureus and Candida albicans. Necropsy and histologic examination revealed characteristic epidermal and mucosal pox lesions, with the presence of characteristic Bollinger body intracellular inclusions. Electron microscopy (EM) provided confirmation of pox virus infection. This epornitic resulted in the death or euthanasia of 12 birds (75% morbidity and associated mortality) and was brought to conclusion through culling of affected birds. The source of infection remains unknown, although multiple modes of introduction exist. Similar epornitics may be prevented through indoor, species-specific housing, and quarantine. Vaccination and antiparasitic treatment may reduce the risk of disease spread.     

Necrotizing lesions in the intestine, gizzard, and liver in captive capercaillies (Tetrao urogallus) associated with Clostridium perfringens.

During the period from 1982 to 1991, 863 captive and 32 wild capercaillies (Tetrao urogallus) were necropsied. The most common cause of death in captive capercaillies was necrotizing enteritis, diagnosed in 110 (13%) birds. Of these, 31 (28%) birds also had necrotizing lesions in the liver. Necrotizing gastritis occurred in 29 birds, two of which had concurrent necrotizing enteritis. In the capercaillies with necrotizing enteritis, Clostridium perfringens type A was isolated more frequently and in larger numbers than in birds which died from other causes. Thus, Clostridium perfringens type A may be of etiological importance in necrotizing enteritis. Necrotizing enteritis was not diagnosed in wild capercaillies.     

Fetal proteinuria in diagnosis of congenital nephrosis detected by raised alpha-fetoprotein in maternal serum.

High concentrations of alpha-fetoprotein (alpha-FP) were found at 14, 19, and 21 weeks gestation in the serum of a woman with a history of unexplained fetal death in her previous pregnancies. The alpha-FP concentration of the liquor also was high at 21 weeks and the pregnancy was terminated. Though the fetus was macroscopically normal, measurement of albumin, alpha-FP, IgG, and alpha2-macroglobulin in the fetal urine showed a selective proteinuria, and congenital nephrosis was diagnosed after examination of the fetal kidneys by electron microscopy. Possibly some fetuses reported to be "false-positive for neural tube defect" may have had renal lesions of this nature. Examination of fetal urine may be the simplest initial diagnostic procedure in any future case.     

A histochemical study of cervical motor neurons and the posterior latissimus dorsi muscle in normal and dystropic chickens.

A chromatolysis study, 14 to 21 days following denervation, showed the spinal cord representation of the nerve to the posterior latissimus dorsi muscle to be in the ventrolateral cell column between cervical ganglia 14 and 15. to characterize cevical neruos nt undergoing chromatolysis, histochemical stuies were done the cords of additional nondenervated animals. Staining reactions for beta-hydrocybutyrate dehydrogenase, succinic dehydrogenase and cholinesterase did not reveal any quantitative differences between motor neurons in cervical segments 14 and 15 of normal and dystrophic birds. Motor neurons are positive for beta-hydroxybutyrate dehydrogenase and succinic dehydrogenase, but the surrounding neuropil is positive for the latter only. No pseudocholinesterase activity is found in the ventral horn cells, but true cholinesterase is present in most of the neurons...     

Effect of age and growth rate on myocardial irritability in broiler chickens

Young broiler chickens are undergoing a period of extremely rapid growth and may be expected to be in a state of extreme endocrine and biochemical flux. These birds are also subject to a sudden death syndrome of unknown etiology. We hypothesized that an increased myocardial sensitivity in birds exhibiting early rapid growth may contribute to this syndrome. The objective of the current study was to investigate the interaction between early growth rate and age on myocardial irritability in young broiler chickens. This study utilized 74 male broiler chickens between 3 (Group A, 21-24 days) and 6 (Group B, 43-47 days) weeks of age exhibiting rapid (heavy weight, greater than 425 g at 2 weeks) and slow (low weight, less than 350 g at 2 weeks) early growth. Physiologic parameters such as blood pressure, heart rate, and arterial blood gases in the awake, restrained birds were essentially unchanged across these groups. Myocardial irritability of the anesthetized bird (pentobarbital) as measured by the threshold to electrical fibrillation was significantly increased only in the Group A HW birds. The results of this study suggest an increased myocardial irritability in large young broilers (3 weeks of age) that is no longer present in a similar group of older birds (6 weeks of age). These findings are consistent with the hypothesis that there is an increased myocardial sensitivity in birds succumbing to sudden death syndrome, with death due to myocardial fibrillation. Further research is needed to determine the mechanisms involve.     

Haemoproteus and Leucocytozoon infections in birds of the Oklahoma City Zoo

A total of 222 birds, captive or free-flying in the Oklahoma City Zoo, were examined for blood parasites; 31 (14%) harbored Haemoproteus and/or Leucocytozoon. While 21% of the indigenous avifauna were infected, only 8% of the exotic bird species harbored haemoproteids and these parasites were also exotic to North America. There was no evidence to indicate that exotic infections were transmitted to native birds or vice versa.     

Auditory stimulation of reproductive function in male Rufous-winged Sparrows, Aimophila carpalis

Prolonged exposure to conspecific song stimulates gonadal function and reproductive hormone secretion in female birds but few studies have investigated the physiological effects of conspecific song exposure on males outside of short-term, aggressive interactions. We exposed male Rufous-winged Sparrows, Aimophila carpalis, either to conspecific song (CS Song), to heterospecific song (Black-throated Sparrow, Amphispiza bilineata; HS Song), or to no recorded song (No Song) for 59 consecutive days (two h per day). Birds were exposed to short days (8L:16D) for the first 21 days of treatment and were then transferred to long days (13L:11D) for the remaining 38 days. During long day exposure, CS Song birds experienced faster growth of testes than HS Song and No Song birds. HS Song birds also grew their testes faster than No Song birds. Plasma luteinizing hormone (LH) and testosterone did not differ between CS Song and No Song birds. However, plasma LH was higher in HS Song birds compared to other groups. There were no differences in hypothalamic immunocytochemical labeling for gonadotropin-releasing hormone, its precursor proGnRH, or gonadotropin-inhibitory hormone, nor were there differences in two song control nuclei volumes (HVC and RA) between CS Song and No Song treatment groups. Furthermore, we found no effect of heterospecific song on free-living Rufous-winged Sparrow aggressive behaviors. These data indicate that long-term exposure to auditory stimuli, such as song, can influence the reproductive system of male songbirds and different types of auditory stimuli can have differential effects on reproductive function.     

Experimental candidiasis in Japanese quail: Pathological changes

Candidiasis was experimentally produced in young Japanese quail by oral administration ofCandida albicans cells. Lesions were confined to upper digestive tract with most characteristic changes occurring on the mucosa of crop. No lesions were observed in other tissues of the body. The initial changes in the crop were characterized by thickening and yellowish-white necrotic plaques on the mucosa. From 10th day onwards, there was marked thickening and corrugations of the crop mucosa giving it a typical turkish towel appearance. Varying degree of mucosal swelling was also observed in the oesophagus and proventriculus. Two of the infected birds also revealed yellowish-white necrotic plaques on the tongue at 7th and 10th day post-infection. The prominent microscopic lesions in the crop and tongue consisted of hyperkeratosis and parakeratosis with congestion of the subepithelial tissues. Varying degree of parakeratosis and epithelial hyperplasia coupled with subepithelial oedema and hypertrophy of glands was observed in the oesophagus. The proventriculus and small intestine revealed congestion, oedema, mild to marked goblet cell hyperplasia and focal epithelial sloughing. Fungal elements could be demonstrated in the sections of tongue upto 10 days while in crop upto 14 days post-infection. Reisolation of the fungus was consistently achieved from the crop of infected birds throughout the duration of the experiment.     

Toxicity of sodium chloride to house sparrows (Passer domesticus)

Sodium chloride (NaCl) is widely used as a deicing agent on roadways. There are numerous anecdotal reports of poisoning of passerine birds by road salt in the United States and Canada, but little is known about the toxicity of NaCl to songbirds. The objectives of this study were to determine the lethal dose range for NaCl in a representative passerine species (house sparrow [Passer domesticus]); to determine the clinical, physiologic, and pathologic effects of sublethal and lethal oral NaCl exposure; and to assess the potential for recovery after exposure to granular salt or highly concentrated salt solutions. The up-and-down method was used in a pilot study to estimate the lethal oral dose of granular NaCl in wild caught house sparrows. The toxicity of highly concentrated NaCl solution also was investigated. This was followed by an acute dose response study in which house sparrows were dosed orally with granular NaCl at 0, 500, 1,500, 2,500, or 3,500 mg/kg. Sparrows were deprived of water for 6 hr postexposure (PE) in an attempt to mimic specific winter conditions. Groups of three birds at each dose were euthanized at 1, 3, 6, and 12 hr PE, and samples were collected for histopathology and brain and plasma electrolyte analyses. Results indicated an approximate mean lethal dose (LD50) of 3,000-3,500 mg/kg in water-deprived birds, which is similar to mammalian values. House sparrows dosed with a concentrated solution of NaCl generally died at doses of 8,000 mg/kg. Clinical signs observed at >or=1,500 mg/kg included rapid onset (<30 min) of depression (indicated by reduced activity and reduced response to visual and auditory stimuli), ataxia, inability to fly or perch, and death in as little as 45 min. Birds that survived for 6 hr usually recovered. Plasma Na concentrations >200 mmol/l were consistently associated with clinical signs. Pathologic lesions consisted of edema and distension of the caudoventral thin muscled region of the gizzard and were observed 1 hr PE in most birds dosed with >or=500 mg/kg. Brain Na concentrations in clinically ill sparrows and those that died of NaCl toxicity ranged from 1,297 to 1,615 (mean=1,450; SD=115) ppm wet weight or 5,603 to 6,958 (mean=6,367; SD=454) ppm dry weight, which differed significantly from control birds. No histologic lesions were observed in brain sections of exposed birds, likely reflecting the acute nature of the exposure. However, fluid accumulation beneath the koilin layer of the gizzard was observed in the majority of birds at high dosage levels. These results indicate that passerines ingesting relatively small numbers of road salt granules or small quantities of highly concentrated NaCl solutions are at risk of sodium poisoning.     

Repercussions of anterior hypothalamic lesions on nycthemeral variations of plasma thyroxine and corticosterone in the pigeon

Plasma thyroxine and corticosterone levels were determined by competitive protein binding assay, at 3 hr intervals, throughout the photoperiod. Pigeons were kept in controlled environment (21 +/- 1 degree C; 14L6-20: 10D). Intact controls exhibited low thyroxine (T4) and corticosterone (B) levels for the light phase of the photoperiod. Values were rising during the night, up to a peak at 03 hr. Electrolytic lesions were placed bilaterally in either the nucleus anterior medialis hypothalami or the n. preopticus, or the n. supraopticus. Circadian rhythms of both T4 and B were markedly altered in all lesioned pigeons, with a shift of very high T4 values to the morning times and a complete disorganization of B patterns, with very heterogeneous values. The possibility is raised that anterior hypothalamic formations participate in the endogenous oscillator circuitry in birds.     

Pathological features in marine birds affected by the prestige's oil spill in the north of Spain

A total of 2,465 seabirds, mainly common murres (Uria aalge), razorbills (Alca torda), and puffins (Fratercula arctica) that beached in the northwestern part of Spain after the "Prestige" oil spill on 19 November 2002 were examined by pathological methods. Birds were divided into three groups: dead birds with the body covered (group 1) or uncovered (group 2) by oil and birds recovered alive but which died after being treated at a rescue center (group 3). The main gross lesions were severe dehydration and emaciation. Microscopically, hemosiderin deposits, related to cachexia and/or hemolytic anemia, were observed in those birds harboring oil in the intestine. Severe aspergillosis and ulcers in the ventriculus were found only in group 3 birds, probably because of stress associated with attempted rehabilitation at the rescue center. The mild character of the pathological changes suggests that petroleum oil toxicosis causes multiple sublethal changes that have an effect on the ability of the birds to survive at sea, especially weak and young, inexperienced animals. Dehydration and exhaustion seem to be the most likely cause of death.     

Cyclopiazonic acid production by Aspergillus flavus and its effects on broiler chickens

Cyclopiazonic acid (CPA) was purified from cultures of Aspergillus flavus, and ca. 14 g of the toxin was collected for use in feeding studies. Chicken rations were artificially contaminated with purified CPA at concentrations of 10, 50, and 100 ppm (microgram/g) and fed ad libitum to eight groups of chickens for 7 weeks. Chickens receiving feed with 100 ppm of CPA had high mortality, decreased weight gain, and poor feed conversion when compared with birds receiving other doses. Postmortem examination showed that chickens fed the two greatest doses of CPA had proventricular lesions characterized by mucosal erosion and hyperemia (100 ppm) and by thick mucosa and dilated proventricular lumens (50 ppm). Birds given 100 ppm of CPA in feed also had numerous yellow foci in their livers and spleens. Microscopic examination of tissues of birds that received 100 ppm of CPA revealed ulcerative proventriculitis, mucosal necrosis in the gizzard, and hepatic and splenic necrosis and inflammation. Birds given 50 ppm of CPA had hyperplasia of the proventricular mucosal epithelium. Birds given 10 ppm of CPA and control birds had no significant treatment-related lesions.