Pharmacodynamic effects of serotonin (5-HT) receptor ligands in pigs: stimulation of 5-HT2 receptors induces malignant hyperthermia.

In pigs, the serotonin-2 (5-HT2) receptor agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), 0.8 mg/kg, induced "psychotic" behaviour (e.g., grimacing, backward locomotion, blank stare) and a muscular syndrome, which is known as malignant hyperthermia (MH) in pigs and humans. This syndrome is characterized by generalized skeletal muscle rigidity, leading to an increase in body temperature, marked acidosis, hyperkaliaemia, cyanosis and elevation of lactate, carbon dioxide and the muscle enzyme creatine kinase (CK) in plasma. In pigs which were selectively bred for susceptibility to MH induction by known triggering agents, such as halothane, the administration of DOI was fatal in 3 out of 5 animals. In genetically susceptible pigs, MH was also induced by 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), 0.5-1.8 mg/kg, and D-lysergic acid diethylamide (LSD), 60-110 micrograms/kg. Furthermore, 5-MeO-DMT and LSD induced head shakes in the animals, which had not been observed after DOI and could not be blocked by 5-HT2-antagonists, ketanserin (0.5-5 mg/kg) and ritanserin (1-2.5 mg/kg). The psychotomimetic effects of 5-MeO-DMT could be blocked by ketanserin or ritanserin, which, depending on the dose, also reduced or totally prevented the hyperthermia and metabolic changes induced by 5-MeO-DMT in pigs. Administration of 5-MeO-DMT, 1.8 mg/kg, was fatal in 4 of 5 MH-susceptible pigs, whereas pigs injected with this dosage after pretreatment with ketanserin (0.5-5 mg/kg) or ritanserin (1-2.5 mg/kg) did not die. In pigs from MH-resistant littermates, administration of 5-MeO-DMT was not fatal. Comparison of metabolic changes in susceptible and non-susceptible pigs suggested that the marked increase in plasma potassium, which arises principally from damaged muscle cells, is primarily responsible for the fatal effect of DOI and 5-MeO-DMT in genetically susceptible individuals. In MH-susceptible pigs, which were anesthetized, relaxed and artificially ventilated, 5-MeO-DMT did not induce hyperthermia, thus substantiating that the marked hyperthermia observed in conscious pigs was a result of muscle activation and not due to effects on thermoregulation or blood pressure. The results indicate that hallucinogenic drugs with 5-HT2 agonistic effects trigger a life-threatening syndrome, MH, in genetically susceptible pigs. 5-HT2 antagonists, such as ketanserin or ritanserin, are capable of counteracting the fatality of this syndrome.

The effects of Sarcocystis miescheriana infections on blood enzymes and weight gain of stress-sensitive and stress-insensitive pigs.

The effects of mild Sarcocystis miescheriana infection on blood enzymes and body weight were compared in stress-sensitive (halothane positive) and in stress-insensitive (halothane negative) pigs. Ten halothane-positive pigs (Group A) and ten halothane-negative pigs (Group C) with a mean body weight of 36 kg were each inoculated orally with 50,000 sporocysts of S. miescheriana. Twelve halothane-positive pigs (Group B) and ten halothane-negative pigs (Group D) served as non-infected controls. Five days before infection (a.i.) and 58 days post infection (p.i.) all pigs were myostress challenged (creatine kinase test). During the whole period of the experiment (3 weeks a.i. to 13 weeks p.i.) body weights were determined and blood samples taken at weekly intervals. Creatine kinase (CK), aspartate aminotransferase (ASAT) and Sarcocystis antibody titres were determined. The infection induced slightly elevated temperatures (max. 42.8 degrees C) and transient reduced food intake during the 2nd and 3rd week p.i. The CK values of the infected pigs in Groups A and C increased from Day 28 p.i. onwards, and were significantly higher than those of the pigs of the non-infected controls (Days 35-77 p.i.). The ASAT values of the infected groups (A and C) increased from Day 21 p.i. onwards, and were significantly higher than those of the non-infected controls from Days 28-77 p.i. The myostress injection at 5 days a.i. (1st CK test) resulted in significantly higher CK and ASAT values in stress-sensitive pigs.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of bleeding procedure and some environmental conditions on stress-dependent blood constituents of laboratory rats.

The influence of experimental conditions on 10 haematological and blood chemical constituents were investigated in male Han:Wistar rats. Significant differences existed between values of haematological and chemical constituents of blood, sampled within 10 s, between 10 and 30, or between 30 and 60 s after decapitation respectively, The leucocyte count decreased quickly but the lactate concentration rose after decapitation. The interindividual coefficient of variance for the majority of the blood constituents was reduced markedly if blood was sampled within 10 s of decapitation. Significant differences in plasma protein and blood lactate concentrations existed between 2 rats kept in one cage, when the first rat was decapitated 20 s before the second one. Plasma protein concentrations differed significantly between rats bled at 9.00 am and 11.00 am. Significant differences in blood glucose and lactate concentrations existed between rats bled on 5 different days within a period of 10 days. Packed cell volume, eosinophilic granulocytes and plasma protein concentration differed significantly between rats kept in a room with a 12:12 light: darkness (LD) cycle and those living in a room with a 2.3:2.3 LD cycle.

[Diagnostic value of total plasma levels of bile acids and ammonia in liver diseases in sheep]. / Zur diagnostischen Bedeutung der Plasmakonzentration von Gesamtgallensäuren und Ammoniak bei Lebererkrankungen des Schafes.

For the estimation of the diagnostic value of plasma concentrations of total bile acids and ammonia in liver disease healthy controls (n = 23) as well as animals sick with different diseases were examined. The reference values for total bile acids and ammonia in the plasma of sheep range from 18-166 mumol/l and 15-64 mumol/l, respectively. While animals with chronic copper poisoning (n = 18), vitamin E/selenium deficiency (n = 15) and with diseases not affecting the liver (n = 8) did not show significant differences in concentrations of total bile acids and ammonia from those of the healthy controls, this could be proven for animals with severe hepatopathy or hepatoencephalopathy. Furthermore, some of the latter group showed increased ammonia concentrations in the liquor cerebrospinalis and multifocal vacuolation of the central nervous system. The determination of total bile acids and ammonia in the diagnosis of liver disease in sheep would also be useful. The hepatoencephalic syndrome should therefore be considered as possible differential diagnosis in animals showing neurological signs.

[Clinical studies of kidney function in sheep. II. Effect of pregnancy, lactation and feed restriction and metabolic diseases on kidney function]. / Klinische Nierenfunktionsuntersuchungen bei Schafen. II. Einfluss von Gravidität, Laktation und Futterentzug sowie von Stoffwechselerkrankungen auf die Nierenfunktion.

Investigations of renal function have been done in healthy ewes in different stages of reproduction, and after food restriction, as well as in ewes sick with ketosis, hypocalcemia, rumen acidosis and different nephropathies. The determination was based on the estimated weight dependent endogenous creatinine excretion (E). A reference population of 56 healthy non or early pregnant ewes (before day 120 of pregnancy) was used as control. Late pregnancy (121.-149. day, n = 14) and lactation (n = 14) lead to higher renal creatinine-clearance (approximately GFR). Food restriction in all stages of pregnancy was followed by lower plasma concentrations of potassium, calcium, magnesium and glucose, and a reduced fractional excretion of potassium, calcium and magnesium. Pregnancy and especially food restriction caused a marked rise of the 3-OH-hydroxybutyrate values in the plasma and a significant acetonuria. After withdrawal of feed in lactating sheep, in opposition to pregnant sheep, the plasma values of phosphate were higher. In ketotic sheep (n = 43) a failure of renal function could not be demonstrated, the pronounced acetonuria could be explained by acetonemia. In hypocalcemia (n = 23) disturbance of creatinine-clearance and tubular reabsorption of sodium, potassium, glucose and 3-OH-butyrate could be seen. Glucosuria and acetonuria were caused by increased plasma concentrations and reduced tubular reabsorption. In rumen acidosis (n = 10) disturbances of low degree of GFR and reabsorption could be seen, glucosuria was mainly due to hyperglycemia.(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinical studies of kidney function in sheep. I. Methods and reference values of healthy animals]. / Klinische Nierenfunktionsuntersuchungen bei Schafen. I. Methodik und Referenzwerte gesunder Tiere.

Investigations of renal function have been done on the basis of renal clearance (Clr) and excretion (E) of endogenous creatinine in health sheep of different body weight (89 female, 19 male). Creatinine-E was negatively correlated with body weight in female sheep, it can be calculated from body weight. The Creatinine-Clr in ewes ranged from 1.1 to 2.3 ml/min/kg and was highly correlated with inulin-Clr (r = 0.88, p < 0.001). Fractional excretion (FE) of creatinine, determined by inulin-Clr was 118%. That demonstrate a tubular secretion of 15% of the total excretion. Therefore the creatinine-Clr may be considered representative enough for the glomerular filtration rate (GFR). Urea-FE was 24-50%, and urea-Clr about 50% of the inulin-Clr, that points to a high tubular urea absorption (50-75%). For that reason urea is not appropriate for the characterization of kidney functions. Water, sodium, glucose, L-lactate and 3-OH-hydroxybutyrate were absorbed in the renal tubules nearly completely (FE < 2%). So they are suitable as endogenous markers for insufficient tubular absorption. Calcium, phosphate, magnesium and potassium are reabsorbed incompletely, depending on the supply of these substances (FE 0-15%, potassium 5-100%). A method for clinical determination of kidney function by measurement of concentrations of metabolites and electrolytes in blood plasma and spontaneous urine is described and evaluated. The method is based on the calculation of the creatinine-excretion, depending on sex and body weight, and especially allows the examination of male and sick animals without quantitative sampling of urine.(ABSTRACT TRUNCATED AT 250 WORDS)

[Elimination kinetics of several clinically relevant enzymes in the blood plasma of cattle after intravenous bolus infusion of homologous preparations]. / Eliminationskinetiken einiger klinisch relevanter Enzyme im Blutplasma von Rindern nach intravenöser Bolus-infusion homologer Präparate.

Extracts of homologous organs (liver, muscle) and of colostrum were infused intravenously in cattle of two different age groups: heifers (n = 9, each preparation was infused in 3 animals) and calves (n = 6, preparations from liver and muscle were infused in 3 animals each). Parameters of elimination kinetics were determined for some clinically relevant enzymes. Enzyme elimination was quicker in the younger animals. The volume of enzyme distribution was comparable to plasma volume. Biological half-lives in calves and heifers respectively were: CK from muscle 3.46 +/- 0.65 h and 8.27 +/- 3.27 h, AST from muscle 9.74 +/- 1.38 h and 33.48 +/- 3.74 h, AST from liver 14.99 +/- 0.81 h and 16.71 +/- 0.58 h, GLDH from liver 14.61 +/- 1.88 h and 25.09 +/- 4.13 h, SDH from liver 13.95 +/- 2.25 h and 17.68 +/- 0.81 h, GGT from colostrum 1.69 +/- 0.95 h (only heifers).

[Kidney function tests in horses--methods and reference values in healthy animals]. / Nierenfunktionsuntersuchungen bei Pferden--Methodik und Referenzwerte bei gesunden Tieren.

Investigations of renal function have been done on the basis of renal clearance (Clr) and excretion (E) of endogenous creatinine in healthy horses of different body weight (23 female, 7 male). Creatinine was measured by enzymatic PAP-method. Creatinine-E of female horses was poor positively correlated with body weight. The creatinine-Clr was highly correlated with the inulin-Clr (r = 0,896, p < 0,001). The excretion of creatinine was 35% higher than the filtration of creatinine, determined by inulin-Clr. That demonstrate a tubular net secretion of 26% of the total creatinine excretion. However the creatinine-Clr may be considered representative enough for the glomerular filtration rate (GFR). Water, sodium, glucose and L-lactate were absorbed in the renal tubules nearly completely, with a fractional excretion (FE) lower 2%. So they are suitable as endogenous markers for insufficient tubular absorption. Other electrolytes were absorbed incompletely depending on the supply of these substances (calcium-FE and magnesium-FE: 1-50%, potassium-FE: 10-120%, phosphate-FE: 0-5%). An extremely variable part of the filtered urea was reabsorbed in the tubuli (urea-FE 8-85%). For that reason urea is not appropriate for the diagnostic of disturbances of renal functions. A method for clinical determination of renal function by measurement of concentrations of metabolites and electrolytes in blood plasma and spontaneous urine is described and evaluated. The method is based on the supposed constant excretion of the creatinine (0,17 mumol/min/kg) and allows especially the examination of male and sick animals without quantitative sampling of urine. Reference-values for the renal excretion of electrolytes and metabolites of healthy horses are given.

[Demonstration of tissue lesions after intramuscular injection by determination of creatine kinase in blood]. / Zum Nachweis von Gewebsläsionen nach intramuskulärer Injektion durch Bestimmung der Creatinkinase-Aktivität im Blutplasma.

Local muscle tissue damage by Terramycin-LA (20 mg/kg BM) injected at the neckmuscle was tested with seven pigs prepared with veneous catheters. Four of the pigs were used as the control group and were treated with an intramuscular injection of 0.9% NaCl-solution into the opposite neckmuscle later on. The tissue damage was clinically, pathologically and enzymatically examined. A significant rise of creatinkinase (CK) in bloodplasma up to 48 hours after intramuscular injection of Terramycin-LA proves to be a good indicator of local muscle damage. Based on enzymekinetic calculations it was possible to estimate the amount of muscle laesions after intramuscular injection of Terramycin-LA up to 13 g/100 kg BM and of NaCl-solution up to 0.5 g/100 kg BM respectively. The difference is significant.

[Clinical findings and differential diagnosis in ketosis and hypocalcemia in sheep]. / Klinische Befunde und Differentialdiagnose bei Ketose und Hypocalcämie der Schafe.

Clinical and laboratory examinations were carried out in a prospective study from 1978 to 1998 on 454 spontaneously diseased sheep of different breeds aged 2-8 years. Three groups of sheep were defined by plasma concentrations of 3-hydroxybutyrate (3-OHB) and calcium. 214 ewes suffered from ketosis (pregnancy toxaemia, 3-OHB > 1.6 mmol/l), 195 ewes and 5 rams suffered from hypocalcaemia (Ca < 2.0 mmol/l), and 40 ewes were sick with booth diseases simultaneously. Clinical findings differ only slightly in all three groups. In ketosis the time until the onset of clinical signs and the duration of the disease is somewhat longer, while locomotion disturbances are less severe than in hypocalcaemia and in the combination of both. In individual cases a differential diagnosis is not possible on the basis of clinical findings, and also acetonuria is not a reliable criterion. Therefore, a therapy is suggested to treat all three possible forms of disease: daily oral application of Na-propionate, Ca-lactate and K-chloride, and additional subcutanous injection of Ca-borogluconate, vitamin D3, alpha-Tocopherol and selenium at the beginning of the disease. Pathogenesis of both diseases are discussed, recommendations for feeding management are given.

[The contributions of the hormones insulin, cortisol, somatotropin and total estrogen to the pathogenesis of sheep ketosis]. / Zur Mitwirkung der Hormone Insulin, Cortisol, Somatotropin und Gesamtöstrogen an der Pathogenese der Schafketose.

The concentrations of hormones, metabolites and electrolytes in plasma of 45 ewes have been examined repeatedly during gestation (day 80 to 149) and at the third day of lactation. Healthy single pregnant (n = 8) and twin pregnant ewes (n = 12) have been compared with ewes sick with subclinical (3-hydroxybutyrate > 1,0 mmol/l, n = 6) and clinical (3-hydroxybutyrate > 1,6 mmol/l, n = 19) pregnancy ketosis. The concentration of 3-hydroxybutyrate, glucose, calcium, sodium and growth hormone in the plasma of the healthy animals were higher post partum than ante partum, while the concentrations of inorganic phosphorus, cortisol and total oestrogen were lower post partum than during pregnancy. In the pregnant ewes the concentrations of 3-hydroxybutyrate, bilirubin, total oestrogen and growth hormone in the plasma increased, while the concentration of insulin decreased with raising number of fetuses. In comparison with the healthy twin pregnant ewes the animals with subclinical and clinical pregnancy ketosis showed increased values of bilirubin, glutamate-dehydrogenase, growth hormone, total oestrogen, cortisol and cortisol/insulin ratios as well as decreased values of glucose, insulin and potassium. Individual differences of the animals within their groups were observed for the examined hormones as well as for glucose, calcium, sodium and potassium (analysis of variance). Beside multiple pregnancy low insulin values and high cortisol/insulin ratios, which are obviously due to individual disposition, influence enhanced ketogenesis and disorder of glucostasis.

[Crystalluria in sows]. / Untersuchungen zur Kristallurie bei Sauen.

In 12 breeding sows the influence of high feed levels of calcium (Ca 16.0 mg/kg, P 5.9 mg/kg, Ca/P ratio 2.71:1), of a mineral feed mixture (Ca 13.8 mg/kg, P 8.3 mg/kg, Ca/P ratio 1,66:1) and of phosphorus (Ca 7.0 mg/kg, P 11.0 mg/kg, Ca/P ratio 0.64:1) on blood concentrations and renal excretion of minerals (Ca, P, Mg), electrolytes (Na, K) as well as development of urine concrements (crystalluria) was investigated in comparison to a control feed (Ca 7.3 mg/kg, P 6.0 mg/kg, Ca/P ratio 1.23:1). Besides the effect of water supply on formation of crystalluria was tested. Studies showed that especially high levels of phosphorus in the feed are responsible for excretion of urinary crystals. Sediment consisted of Ca phosphates mainly, which could be detected as amorphous crystals microscopically. Alkaline pH values in urine and an insufficient water supply supported development of crystalluria, but formation of crystals differed greatly between individuals. Cystoscopic investigations demonstrated inflammatory alterations of the bladder mucosa in sows with crystalluria. Therefore crystalluria in sows has to be considered as a risk factor for urinary tract infections.

[Clinical kidney function studies in sheep. III. Pathologic function changes in nephropathies of sheep and in urolithiasis of rams and billy goats]. / Klinische Nierenfunktionsuntersuchungen bei Schafen. III. Pathologische Funktionsänderungen bei Nephropathien der Schafe sowie bei der Urolithiasis der Schaf- und Ziegenböcke.

Examination of renal function have been carried out in sheep with acute prerenal (n = 6), renal (n = 15) or postrenal failure (n = 3), pyelocystitis (n = 4), and in cases of urolithiasis in rams (n = 16) and billy goats (n = 11) respectively. The calculation of parameters was done on the basis of the estimated weight dependent endogenous creatinine excretion. A control group of 56 healthy non pregnant or early pregnant (< 120th day of pregnancy) ewes have been used. The renal creatinine clearance was reduced and the absolute as well as the fractional renal water excretion was enhanced in all groups of sick animals. An elevated fractional excretion of sodium and phosphate could be seen as well. Functional disturbances could be observed in urolithiasis in like manner as in acute renal failure. There was proteinuria, glucosuria, excessive potassium excretion and often decreased plasma concentration of potassium in both syndromes. A hyperkalemia occurred only in the final state of urolithiasis. No clinical outcome of chronic nephropathies could be seen. Mortality of the described acute nephropathies was about 76%. The results of examination were suitable to control the course and restitution of renal function. They were not helpful for differential diagnosis and prognosis of acute renal failure.

[Photometric determination of copper content in the liver during experimental chronic copper poisoning in sheep]. / Photometrische Bestimmung der Kupfergehalte in der Leber bei experimenteller chronischer Kupfervergiftung des Schafes.

15 castrated rams were exposed to an oral copper-dosage of 3.64 mg/d/kg body weight for 84 days. The control group consisted of 11 rams with a copper intake of 0.14 mg/d/kg bodyweight. Liver biopsies were taken percutaneously (100 samples), under laparoscopic control (53 samples) or post mortem (14 samples) before, during and up to 200 days after the controlled copper intake. Analysis of copper concentration in the liver tissue was done by a modified photometrical Bathocuproin-method after cold extraction with hydrochloric and trichloracetic acid. By using a parallel specimen blank with added EDTA, disturbing factors of the sample matrix were eliminated. The method was evaluated by the atom-absorption-spectroscopy after wet incineration as well as by standard addition of copper titrisol. The correlation with the reference method was very good (r > 0.99); the recovery rate after standard addition was 95 +/- 5.4%. The maximum copper concentrations in the liver were reached after the completion of the copper dosage. Blackheaded sheep showed significantly higher values (480 +/- 173 mg/kg wet tissue weight) than Merino sheep (338 +/- 103). The values of the control animals were 36 +/- 18 mg/kg. In the copper dosed rams the course of copper storage in the liver tissue could be described by an multiple regression with an accuracy of r2 > 0.75. The half-life of the copper concentration in the liver after exceeding maximum levels was 175 +/- 91 days. The pathogenetic role of the copper retention in the dosed animals was proven by regularly increased values of the hepatocellular enzyme glutamate dehydrogenase in the plasma.

[Investigations on manifestations of vitamin E and selenium deficiency in sheep and goats]. / Untersuchungen zur Manifestation von Vitamin E- und Selen-Mangel bei Schafen und Ziegen.

In a prospective study from 1991-1998 plasma concentrations of alpha-Tocopherole (VitE) and Selenium (Se) were analysed in 125 sheep and 32 goats with generalised motor disturbances or elevated plasma-activities of Creatine-Kinase (CK). VitE-values < 1.0 mg/l and Se-values < 0.08 mg/l were regarded as deficiency. Diagnosis of pathological manifestations was based on blood enzyme values. CK-values in plasma > 300 U/l or Aspatate-Amino-Transferase (ASAT) > 150 U/l were regarded as myopathy, Glutamat-Dehydrogenase-values > 25 U/l indicated a hepatopathy. 92 (74%) sheep and 10 (31%) goats showed VitE and/or Se deficiency. There were no principal differences in the frequencies of myopathies (67%) and hepatopathies (46%) between pure VitE deficiencies or pure Se deficiencies or combinations of both deficiencies. In VitE deficiency and in the combinations of VitE and Se deficiency the elevations of the enzyme activities were more pronounced than in Se deficiency. The lethality was significantly higher in combined VitE + Se deficiencies (73%) than in pure VitE or Se deficiencies (35%). Combined VitE + Se deficiencies occurred more frequent in lambs (53%) and was often accompanied by anaemia (29%) and hypoproteinaemia (32%). The diagnostic reliability of ASAT and GLDH for the detection of VitE and Se deficiency was better than CK. Diagnostic and therapeutic strategies in flock diseases are discussed.

[Investigations on the dependence of hematologic and blood chemical parameters on the age of health lambs--a contribution to the definition of reference values in sheep]. / Untersuchungen zur Altersabhängigkeit hämatologischer und blutchemischer Messgrössen bei gesunden Schaflämmern--ein Beitrag zur Definition von Referenzwerten beim Schaf.

Haematological and biochemical examinations were carried out in 284 clinically healthy lambs aged from birth to nine month. The 122 male and 164 female animals belonged to the following breeds: German blackheaded mutton sheep (n = 114), Merino (n = 21), Frisian milksheep (n = 98), Texel (n = 31), Bentheimer landrace (n = 16) and Leine sheep (n = 5). The lambs were selected from a larger number of probationers by use of outlier tests. No differences were found between sexes for any of examined parameters. For the period from two to eight weeks of age breed differences could be proven for glutamate dehydrogenase and creatinin. Many parameters showed a strong dependence on the age of the lambs in a linear or polynomial function. While lymphocytes, protein, urea, creatinin, 3-hydroxybutyrate and copper increased, bilirubin, glucose, calcium, inorganic phosphate and the activities of alkaline phosphatase and gamma-glutamyl-transferase decreased with age. Body weight had no influence on any examined parameter within the age dependence. Reference values (limits) are defined for healthy lambs and for healthy ewes, summarized from former studies.

[Fetal heart rate measurement and sonographic fetometry for determination of fetal age in sheep]. / Fetale Herzfrequenzmessung und sonographische Fetometrie zur Bestimmung des Trächtigkeitsstadiums beim Schaf.

Fetal heart rate was repeatedly measured in 84 ewes of different breeds during gestation. The Doppler system (83 measurements) and the real-time M-Mode ultrasound system (221 measurements) were used. Furthermore the following fetometric parameters were ascertained in 13 pregnant ewes sonographically once a week: crown-rump-length, width of the head, inter-eye distance, height of the lateral thorax in the region of the cardial septum and caudal of the sternum, as well as the diameter of the thorax and abdomen in each case latero-lateral and ventro-dorsal. The following influencing factors were tested by means of group regression analyses and multiple regression analysis: days before parturition, method of examination, litter size and later birth weight of lams, and heart rate, breeds and diseases of the ewes. A significant regression exists between the days before parturition (d.b.p.) and fetal heart rate (fhr): y (fhr) = 139 + 0.94 x (d.b.p.); r = 0.781 p < 0.001; n = 304. No significant influence was proved for the birth weight, litter size, maternal heart rate, method of examination, breed and health state of the ewes on the fetal heart rate. All fetometric parameters were significantly correlated with the days before parturition. This regression was most evident for the measured value of the ventro-dorsal abdomen (abd. vd., mm): y (abd. vd) = 114.2 -0.966 x (d.b.p.); r = -0.958; p < 0.001, n = 128. The litter size influenced the regression with a significance of p < 0.05. The fetometry is more appropriate for the determination of gestational age and the prediction of parturition than the measurement of the fetal heart rate.

Classical swine fever in wild boar (Sus scrofa)--experimental infections and viral persistence.

A pregnant wild boar and two wild boar weaners were inoculated intranasally with a field isolate of classical swine fever virus (CSFV) recently derived from a diseased domestic pig. The clinical, pathological and haematological findings noted in the young wild boars were comparable to those in domestic weaner pigs inoculated with the same virus isolate. Both wild boars showed the acute haemorrhagic form of CSF, one animal died 18 days post inoculation (p. i.) and the second one had to be euthanized when moribund two days later. The wild boar sow did not show any signs of illness p. i. but seroconversion was noticed. Twenty-eight days p. i. birth was given to six clinically healthy offsprings. One of the newborn proved to be viraemic until death when 39 days of age. Except for poor growth no other symptoms were noticed in this piglet. The non-viraemic litter mates remained healthy, although they had close contact to the persistently infected piglet. High titres of neutralizing antibodies against CSFV were measured in the serum samples of these offsprings. All findings were more or less in accordance with observations previously made in domestic pigs when infected with CSFV around 85 to 90 days of gestation. The wild boar was calculated to have been inoculated at about 87 to 92 days of gestation.