Mystery swine disease in The Netherlands: the isolation of Lelystad virus.   总被引：115，自引：0，他引：115  

G Wensvoort  C Terpstra  J M Pol  E A ter Laak  M Bloemraad  E P de Kluyver  C Kragten  L van Buiten  A den Besten  F Wagenaar 《The Veterinary quarterly》1991,13(3):121-130

In early 1991, the Dutch pig-industry was struck by the so-called mystery swine disease. Large-scale laboratory investigations were undertaken to search for the etiological agent. We focused on isolating viruses and mycoplasmas, and we tested paired sera of affected sows for antibodies against ten known pig viruses. The mycoplasmas M. hyosynoviae, M. hyopneumoniae, and Acholeplasma laidlawii, and the viruses encephalomyocarditis virus and porcine enterovirus types 2 and 7 were isolated from individual pigs. An unknown agent, however, was isolated from 16 of 20 piglets and from 41 of 63 sows. This agent was characterised as a virus and designated Lelystad virus. No relationship between this virus and other viruses has yet been established. Of 165 sows reportedly afflicted by the disease, 123 (75 per cent) seroconverted to Lelystad virus, whereas less than 10 per cent seroconverted to any of the other virus isolates or to the known viral pathogens. Antibodies directed against Lelystad virus were also found in pigs with mystery swine disease in England, Germany, and in the United States. We conclude that infection with Lelystad virus is the likely cause of mystery swine disease.  相似文献   

The prevalence and identity of Sarcocystis cysts in cattle in Belgium     

J Vercruysse  J Fransen  M van Goubergen 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1989,36(2):148-153

Muscle tissue from the oesophagus, diaphragm and heart of 100 cattle slaughtered in Belgium was examined for Sarcocystis infection by microscopic examination of tissue and artificial digestion. Intact sarcocysts or cystozoietes were recovered from 97% of the cattle examined. There was a difference in sensitivity between the method (digestion or histology) used and the muscle processed. The digestion of the oesophagus muscle resulted in the highest number of positive animals whereas the heart muscles contained most cysts during histological examination. Thin-walled cysts were recovered from all positive animals especially in the heart and they were indistinguishable from those of S. cruzi. Thick-walled cysts were recovered from 56% of animals but these could not be identified as S. hirsuta and/or S. hominis on morphological grounds. A correlation between pathological changes and the infection grade could not be proved.  相似文献   

Alteration of nitrogen metabolism by alpha-ketoglutarate administration in growing lambs fed high nonprotein nitrogen-containing diets   总被引：1，自引：0，他引：1  

J W van der Veen  J A Boling  L D Bunting 《Journal of animal science》1989,67(9):2386-2392

Two completely randomized design experiments were conducted, using either 10, 38-kg (Exp. 1) or 10, 26-kg (Exp. 2) Hampshire x Western wether lambs, to study the effects of alpha-ketoglutarate (AKG) administration on N metabolism. Lambs were fed 890 and 885 g DM/d in Exp. 1 and 2, respectively, of corn-cottonseed hull basal diets with urea added to attain CP levels of 10.6 and 10.5% in Exp. 1 and 2, respectively. Experiments consisted of 10 d of adaptation followed by 7 d of infusion and excreta collection. Lambs were infused continuously either i.v. (Exp. 1) or abomasally (Exp. 2) with control solutions (CON) or solutions containing 41.3 g AKG/d (AKG). In Exp. 1, fecal and urinary N excretion and N retention were not affected (P greater than .10) by treatment. Compared to CON in Exp. 2, AKG infusion increased (P less than .10) fecal N output (6.6 vs 5.9 g N/d) but did not affect (P greater than .10) the amount of N retained (4.4 vs 3.5 g N/d). Compared to CON, AKG increased (P less than .10) urinary NH3 N excretion in Exp. 1. Serum urea N was lower (P greater than .10) for AKG than for CON in Exp. 1 but was not affected (P greater than .10) by treatment in Exp. 2. In Exp. 1, AKG appeared to reduce activities of several serum enzymes that function in amino N metabolism. In Exp. 1, compared to CON, AKG decreased (P less than .10) aspartate but increased (P less than .10) asparagine in serum.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Hepatic lipidosis in pregnant cows on a dairy farm.     

G H Wentink  S van Dijk  S A Goedegebuure  J Vos  T Wensing 《The Veterinary quarterly》1992,14(4):159-160

A syndrome very similar to hepatic lipidosis is described in dairy cows during the dry period. After being sent to pasture the animals did not eat well for undetermined reasons. The disease phenomena were mainly observed in animals carrying twins. At post mortem examination severe falty infiltration was found in the 3 animals made available for post mortem examination. Increase of the energy supply to the dry cows by addition of maize silage to the ration prevented new cases.  相似文献   

Quantitative Aspects of Thyroid Scintigraphy With Pertechnetate (^99mTcO₄) in Cats     

Ariana M.P. Nap  Yvonne W.E.A. Pollak  Walter E. van den  Brom Ad Rijnberk DVM  PhD 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1994,8(4):302-303

Thyroidal ^99mTcO₄(pertechnetate) uptake percentages were determined in unanesthetized euthyroid (n = 13) and hyperthyroid (n = 18) cats. Maximal uptakes were observed 60 minutes after IV injection of the radionuclide and ranged from 0.3 to 3.9% of the dose in euthyroid cats (median 2.23%) and from 5.2% to 23.9% of the dose in hyperthyroid cats (median 14.8%) ( P < .05). There were no overlaps in pertechnetate uptake percentages during any of the intervals evaluated. It is concluded that the optimal time for visualization of the thyroid by ^99mTcO₄-scanning is 60 minutes after IV injection of the radionuclide. Calculation of the percentage uptake is of additional diagnostic value.  相似文献   

Aerosol transmission of arthropathic and amyloidogenic Enterococcus faecalis.     

W J Landman  K T Veldman  D J Mevius  J H van Eck 《Avian diseases》2001,45(4):1014-1023

One-day-old brown layer chicks were exposed to an aerosol of an arthropathic and amyloidogenic Enterococcus faecalis strain alone or after being subjected to treatment with formaldehyde gas (100-200 ppm). Four-day-old chicks were also treated with the same aerosol but after treatment with a Newcastle disease vaccine virus (NDVV) aerosol or intramuscular injection with methylprednisolon at day 1. The same E. faecalis strain was inoculated intramuscularly in day-old chicks as positive control. Bacteremia with time showed that 24 hr after the aerosol the day-old exposed chicks had the highest rate of positive blood cultures (70%-80%). Lower numbers of bacteremic birds at this point in time were found in the chicks treated with E. faecalis aerosol at day 4 (3/10 in the methylprednisolon-treated group and 0/10 in the NDVV-treated group) and the E. faecalis intramuscular-injected group at day 1 (2/10). Formaldehyde gas treatment did not favor the occurrence of bacteremia. NDVV aerosol exposure or injection with corticosteroids did not favor the occurrence of bacteremia 24 hr after E. faecalis aerosol exposure at day 4 either, although 66 days after aerosol, one bird (1/14) treated with NDVV showed bacteremia. A few bacteremic birds were found 10 days after aerosol in the NDVV- and methylprednisolon-treated groups, whereas at 14 days after aerosol, one bacteremic bird was seen in the group subjected to E. faecalis aerosol at day 1, indicating the occurrence of chronic bacteremia. In contrast to the E. faecalis intramuscular-inoculated birds, no joint pathology was seen in the aerosol-exposed groups in spite of the occurrence of chronic bacteremia.  相似文献   

Dietary protein for young grazing sheep: Interactions with gastrointestinal parasitism   总被引：1，自引：0，他引：1  

M. F. J. van Houtert  I. A. Barger  J. W. Steel 《Veterinary parasitology》1995,60(3-4):283-295

Effects of protein supplementation and of nematode control on production responses in young grazing sheep and on nematode population dynamics were assessed. Young Merino wether sheep (n = 270) were allocated to one of three supplementation (Su) treatments and one of three regimes of nematode control (drench, Dr) in a factorial design. Each of the nine treatments was replicated three times in a randomised complete block. Animals received no supplement (SuO) or were given supplements at a level equivalent to 200 g day⁻¹, fed three times a week. The supplements contained 25% lucerne meal with either 75% sunflower meal (Su1) or 75% formaldehyde-treated sunflower meal (Su2). Nematode control regimes were: not drenched unless survival of individual animals was threatened (DrO); drenched according to a strategic drenching programme (Dr1); treatment with a controlled-release albendazole capsule (Dr2). Infections with Haemonchus contortus were suppressed by use of closantel. Due to drought conditions and lack of pasture growth, lucerne hay was fed to all sheep from Week 14 onwards (350 g per head per day, fed twice a week). Supplementation reduced the need for ‘survival drenching’ in Dr0 sheep considerably. Live-weight gain was increased significantly by supplementation with Su1 or Su2 during the 36-week experiment. Undrenched animals given Su1 or Su2 tended to grow faster than unsupplemented animals in the Dr1 and Dr2 groups. Greasy wool production and fibre diameter were increased by supplementation and anthelmintic treatment. Faecal worm egg counts (FEC) in undrenched sheep were significantly lower for Su1 and Su2 sheep than for Su0 sheep. There were no effects of supplementation on FEC in Dr1 or Dr2 sheep. Worm burden was generally unaffected by supplementation, while the drenching treatments Dr1 and Dr2 reduced worm burden at Week 16 and to a lesser extent at Week 27. Trichostrongylus colubriformis was the predominant nematode species, with smaller numbers of Nematodirus spp., Trichostrongylus vitrinus, Trichostrongylus axei and Ostertagia circumcincta also present. It was concluded that supplementary feeding with protein meal substantially reduced production losses attributable to nematode infections in young grazing sheep. This appears to be due to an enhanced resilience of the host, rather than any major changes in development of protective immunity.  相似文献   

Further studies of the clinical pathology of sweating sickness in cattle     

S R van Amstel  F Reyers  P T Oberem  O Matthee 《The Onderstepoort journal of veterinary research》1987,54(1):45-48

Experimentally-induced cases of sweating sickness in calves were used in an effort to correlate the blood chemistry with some of the known pathological changes. Results showed that the "sweating" associated with necrotic dermatitis did not alter blood electrolyte levels. Laboratory evidence of a disseminated intravascular coagulopathy was found which correlated with the microthrombi described in cases of sweating sickness. A high blood cortisol level was found in one of the animals that died from the disease and could possibly be used as a prognostic indicator in clinical cases. Recommendations are made with regard to the supportive treatment based on the clinical pathological findings.  相似文献   

Covalently protein-bound bilirubin conjugates in cholestatic disease of dogs     

J Rothuizen  T van den Ingh 《American journal of veterinary research》1988,49(5):702-704

We investigated the occurrence of covalently protein-bound bilirubins in the plasma of dogs with hyperbilirubinemia attributable to hepatobiliary diseases or Coombs test-positive hemolysis. The bilirubins in plasma were measured with the conventional Van den Bergh reaction, by treatment with diazotized p-iodoaniline, and by high-performance liquid chromatography of bilirubin and its methylesters after alkaline methanolysis. All but one dog had covalently protein-bound bilirubin conjugates. The concentration and the fraction of total bilirubins varied in all diseases investigated, but they tended to be low in primary hemolysis. The "biliprotein" complex accounted for 2 to 94% of total plasma bilirubins. Because biliprotein usually is not cleared by the liver, but has a half-life comparable with that of albumin, it prevents the evaluation of the actual state of the underlying disease. Measurement of the total bilirubin concentration exclusively with the Van den Bergh reaction, therefore, is clinically useless. Other methods should be introduced for routine bilirubin assays, permitting the measurement of noncovalently bound pigment as a meaningful estimate of the course of the disease.  相似文献   

The histological appearance of peroral gastric biopsies in clinically healthy and vomiting dogs.   总被引：1，自引：1，他引：0       下载免费PDF全文

I van der Gaag 《Canadian journal of veterinary research》1988,52(1):67-74

A survey of the histology of gastric biopsies in 501 dogs, consisting of 19 clinically healthy dogs and 482 vomiting dogs is presented. Whole stomachs of four young clinically healthy laboratory dogs were used as controls. Eleven percent of forceps biopsies were unsuitable for examination; all suction biopsies were of good quality. Slight to severe gastritis was found in 168 vomiting dogs (35%), whereas five dogs (26%) of the clinically healthy group showed a mainly slight gastritis. Superficial and diffuse gastritis were the most prominent findings in the 168 dogs with gastritis. A single type of gastritis was found in 114 dogs, a combination of different types in 54 dogs. Gastric atrophy was seen in 23 (5%) vomiting dogs and in three (15%) clinically healthy dogs, atrophy with a slight to severe fibrosis in 21 (4%) vomiting dogs, and in 84 (17%) vomiting dogs and two (11%) healthy dogs, gastric fibrosis was present. Carcinomas were seen in 26 vomiting dogs, of which 17 also had gastritis. A differential diagnosis of granulomatous gastritis/carcinoma had to be made in one case. Seven dogs showed a lymphosarcoma, and in six other dogs a differential diagnosis of lymphosarcoma and/or gastritis was made. One adenomatous polyp was seen. In one clinically healthy dog an adenomyoma was diagnosed. Ulceration was found in 24 dogs, but only five of these lacked other lesions. Other biopsy findings were pseudopyloric metaplasia, hyperplasia, cysts, calcification and edema. Some dogs showed "antralization".  相似文献