Infectious stunting syndrome associated with disturbances of mineral metabolism and bone development in broiler chickens

On a broiler farm with a rearing capacity of about 200,000 chickens, a disease characterised by growth retardation, variability in chick size, 'leg weakness', diarrhoea and increased mortality at 3 weeks of age occurred repeatedly, in several successive broiler flocks. Gross and histopathological findings were dominated by widening of the hypertrophic and ossification layers of the physes of long bones as well as by thickening, unevenness and defective calcification of the cartilage trabeculae. In the parathyroid gland, vacuolar degeneration of the cytoplasm of glandular epithelial cells, connective tissue proliferation and, here and there, cyst formation were seen. Additional findings included severe cerebellar oedema and neuronal degeneration. The pancreatic, myocardial and intestinal changes typical of infectious stunting syndrome (ISS) occurred only in a mild form. Four-week-old chickens exhibiting 'leg weakness' had significantly lower blood inorganic phosphate concentration and tibial ash content as compared to healthy chickens. The disease was successfully transmitted by oral administration of small intestinal homogenate from affected chickens. In a second experiment, however, the disease could not be transmitted with intestinal homogenate sterilized by irradiation. Large doses of vitamin D3reduced the rate of growth retardation and defective calcification of bones. The digestive enzyme activities of the pancreas and small intestinal mucosa of 'infected' chickens were decreased as is typical of ISS

Occurrence of porcine dermatitis and nephropathy syndrome in Hungary

In the past few years a characteristic, often fatal disease associated with cutaneous lesions and nephropathy has been observed in several large pig herds and household pig stocks of Hungary. In addition to general symptoms and slight fever in several cases, the disease was characterised by cutaneous lesions occurring mostly on the ventral part of the thorax and abdomen, on the extremities and ear pinnae, and in the nasal and perianal region. In the acute phase, circumscribed hyperaemic, confluent, crust-covered areas were seen. Histological examination revealed necrosis of the epithelial layer and lympho-histiocytic vasculitis in the corium, here and there accompanied by thrombosis and fibrinoid degeneration. The kidneys were pale brown and harder to tear, with cortical petechiae in most cases. By histopathological examination, intra- and extracapillary glomerulonephritis accompanied by fibrinoid exudation was seen. Some of the renal tubules were dilated, others were atrophied, and in advanced cases proliferation of the intertubular connective tissue and inflammatory cell infiltration also occurred. Necrotic vasculitis was also observed in some cases. By immunohistochemical examination IgA, IgG and IgM, and in a single case C3 belonging to the complement system were observed in the pathologically changed skin areas and kidneys. By polymerase chain reaction (PCR), porcine circovirus type 2 (PCV-2) was detected. Bacteriological and serological examinations did not reveal infections of aetiological importance

Massive goitre (Struma parenchymatosa) in geese

In a goose flock consisting of 2300 birds of 6 months of age severe goitre was diagnosed. To the best of our knowledge this is the first report of naturally occurring goitre in geese, which is not related to the feeding of rapeseed meal. The major pathological findings included retarded growth and plumage development, significantly (300%) increased relative thyroid weight, fat accumulation in the mesenteric and abdominal region, and lipid infiltration of liver and kidney cells. Subsequent hormone analysis showed undetectable thyroxine (T4) levels and a dramatic drop in triiodothyronine (T3) plasma levels of the diseased geese. Thy- roidal histology displayed the typical signs of struma parenchymatosa. In order to get more information about the possible causes of the goitre, 10 geese from the affected farm were transferred into the laboratories of the Central Veterinary Institute. The geese were allotted into two groups. Group I received iodine supplementation for 55 days, while the other group served as sick control (Group S). Iodine treatment caused a dramatic improvement in the birds clinical condition except in plumage growth in Group I, while the clinical and main pathological signs of goitre remained unchanged or worsened in the untreated Group S. Contrary to this, the serum levels of thyroid hormones and responsiveness to thyrotropin releasing hormone (TRH) improved not only in Group I but also in Group S. Almost euthyroid biochemical parameters were found after 55 days of iodine treatment in Group I and, surprisingly, a considerable improvement (especially in serum T3 levels) occurred also in Group S. These findings confirm the diagnosis of goitre but also call attention to the fact that iodine deficiency was not the only factor eliciting the disorder. The underlying possible goitrogenic substance could not be traced down

The pathological effect of the Bordetella dermonecrotic toxin in mice

The effect of dermonecrotic toxin (DNT) expression of Bordetella bronchiseptica was studied in mice by comparing the pathology induced by a wild type strain with that induced by an isogenic DNT- strain in which part of the structural gene has been replaced by an antibiotic resistance cassette. While extracts of strain B58 proved toxic in intravenously inoculated mice, similar extracts from strain B58GP had lost toxic activity. The parent (B58) and the mutant (B58GP) strains of B. bronchiseptica each possessed comparable virulence for mice. These findings confirmed that DNT production was successfully abolished in strain B58GP while other virulence characteristics required for pathogenicity in mice remained intact, at a comparable level to the parent strain. Turbinate atrophy was observed in mice infected with the DNT+ strain, but not in those infected with the DNT-strain. This indicates that DNT is the cause of turbinate atrophy in the mice and not other factors produced by phase I strains of B. bronchiseptica. B. bronchiseptica DNT showed a lienotoxic effect (lymphocyte depletion and a reduction in the intensity of extramedullar haemocytopoieis) that is considered to adversely alter the immune function of the host animal. In mice infected with strain B58GP, catarrhal pneumonia with characteristic lympho-histiocytic peribronchial and perivascular infiltration was noticed. In mice infected with strain B58, large necrotic areas were seen surrounded by an inflammatory reaction. The DNT appears to directly damage lung tissues, at least in mice. DNT production seems to enhance the establishment of B. bronchiseptica in the lungs, presumably by reducing the local resistance and causing severe local damage to the lung tissues

A 90-Day Oral Toxicological Evaluation of the Methylurate Purine Alkaloid Theacrine

A 90-day repeated-dose oral toxicological evaluation was conducted according to GLP and OECD guidelines on the methylurate purine alkaloid theacrine, which is found naturally in certain plants. Four groups of Hsd.Brl.Han Wistar rats (ten/sex/group) were administered theacrine by gavage doses of 0 (vehicle only), 180, 300, and 375 mg/kg bw/day. Two females and one male in the 300 and 375 mg/kg bw/day groups, respectively, died during the study. Histological examination revealed centrilobular hepatocellular necrosis as the probable cause of death. In 375 mg/kg bw/day males, slight reductions in body weight development, food consumption, and feed efficiency, decreased weight of the testes and epididymides and decreased intensity of spermatogenesis in the testes, lack or decreased amount of mature spermatozoa in the epididymides, and decreased amount of prostatic secretions were detected at the end of the three months. At 300 mg/kg bw/day, slight decreases in the weights of the testes and epididymides, along with decreased intensity of spermatogenesis in the testes, and lack or decreased amount of mature spermatozoa in the epididymides were detected in male animals. The NOAEL was considered to be 180 mg/kg bw/day, as at this dose there were no toxicologically relevant treatment-related findings in male or female animals

Pathogenicity of a bovine viral diarrhoea virus strain in pregnant sows: Short communication

The biological properties of bovine viral diarrhoea virus (BVDV) strain Oregon C24V were studied after intranasal and subcutaneous infection of pregnant sows. This virus strain is widely used in Hungary for immunising cattle against bovine viral diarrhoea (BVD). Based upon the results of the clinical, gross pathological, histopathological and virological examinations it can be established that the given strain caused asymptomatic infection and serological conversion in sows that were in the second third of gestation. The virus caused clinically apparent disease in some of the piglets born at term, which indicates that it had crossed the placenta. More than half (57%) of the live-born piglets died within 60 days of birth. The sows and their progeny did not shed the virus. BVDV infection has great differential diagnostic importance in pigs, as classical swine fever (CSF) virus strains of reduced virulence cause similar clinical symptoms and gross and histopathological changes

Study of soil-plant (potato and beetroot)-animal cycle of nutritive and hazardous minerals in a rabbit model

Potato and beetroot were grown on soils previously treated with heavy metal salts. Each particular microelement had a high concentration in both potato and beetroot [cadmium (Cd) 3.7 and 55.4, lead (Pb) 8.1 and 3.0, and mercury (Hg) 5.8 and 6.8 mg/kg dry matter, respectively]. In a metabolic balance trial 16 New Zealand White rabbits were fed 50 grams of basal diet and potato or beetroot ad libitum. The apparent digestibility of major nutrients and the accumulation of the microelements in different organs were investigated. Both potato and beetroot samples of high Pb and Hg content had the significantly (p < 0.05) lowest digestibility of organic matter and nitrogen-free extract. The Cd ingested from both potato and beetroot accumulated in the kidneys and liver (2.85 and 1.48 as well as 0.459 and 0.265 mg/kg, respectively). All the microelements (Cd, Pb and Hg) accumulated in the testicles (0.196, 0.32 and 0.199 mg/kg, respectively), reducing the rate of spermatogenesis. The tissue retention ofheavy metals depends not only on the element itself, but also upon the ‘carrier’ feedstuff

Study of the soil—plant (carrot)—animal cycle of nutritive and hazardous minerals in a rabbit model

Carrots were grown on soils polluted by heavy metal salts. Each particular microelement reached a high concentration [molybdenum (Mo) 39.00, cadmium (Cd) 2.30, lead (Pb) 4.01, mercury (Hg) 30.00, and selenium (Se) 36.20 mg/kg dry matter] in the carrot. In a metabolic balance trial conducted with 15 male and 15 female New Zealand White rabbits, the control animals (n = 5) were fed ad libitum with concentrate as basal diet, while the other rabbits received the basal diet and carrots containing the particular microelement. Blood samples were taken to determine the activity of serum enzymes. To investigate the metabolism of Mo, Cd, Pb, Hg and Se, samples were taken from the heart, liver, lungs, kidneys, spleen, ovaries/testicles, entire digestive tract, adipose tissue, femur, hair, faeces and urine. Carrot had significantly higher digestibility for all nutrients than the rabbit concentrate. Carrot samples of high Pb content had the lowest digestibility of crude protein. The microelements differed in their rate of accumulation in the organs examined: Mo and Cd accumulated in the kidneys, Pb in the kidneys, liver, bones and lungs, Hg in the kidneys and liver, while Se in the liver, kidneys and heart. The proportions of microelements eliminated from the body either via the faeces and urine (Mo 80.18% and Se 47.41%) or via the faeces (Cd 37.86%, Pb 66.39%, Hg 64.65%) were determined. Pathohistological examination revealed that the rate of spermatogenesis was reduced in the Mo, Cd, Pb and Hg groups compared to the control. Lead, Cd and Hg intake resulted in a considerable decrease in gamma-glutamyltransferase (GGT) and in an increase of alkaline phosphatase (ALP) activity because of damages to the kidneys and bones. All experimental treatments decreased the activity of cholinesterase (CHE) because of lesions in the liver