A crude, whole-body extract of female heartworms was administered IV to 10 dogs with and 13 dogs without heartworm (HW) infection. Shock developed in 8 of 10 infected dogs and 11 of 13 non-infected dogs, and blood coagulopathy was observed in 12 of 19 dogs with shock. Prevalence and severity of blood coagulopathy were proportionate to prevalence and severity of shock. Platelet count decreased in all dogs with shock with or without blood coagulopathy; thus, the decrease in platelet count might be related to shock. In 4 dogs, activated partial thromboplastin time (APTT) was prolonged--192.0 seconds at 30 minutes after HW injection--and prothrombin time (PT) was increased--13.8 seconds at initial collapse. In 8 dogs, APTT was increased--200 seconds for 2 hours after HW injection--and PT was increased--200 seconds at 30 minutes after the injection. The APTT prolongation might have been caused mainly by decreases in activities of factors VIII, IX, XI, and XII of the intrinsic blood coagulation pathway. In dogs with severely prolonged PT, plasma fibrinogen concentration and factor II activity decreased slightly. Prolonged PT was corrected in vitro by addition of normal plasma at high concentration (> 80%), but prolonged APTT could not be corrected in vitro by addition of 80% normal plasma. Serum fibrin degradation products concentration was < 10 microgram/ml, and soluble fibrin monomer complex was negative in all dogs. Thrombi were not found in blood vessels of any organ at necropsy and after histologic study. Therefore, it was suggested that blood coagulopathy resulting from inhibition of coagulation factor activities might develop in shock induced by HW extract.

The effect of mimicking prepartum concentration of estradiol-17 beta on the inflammatory response to endotoxin in gilts was studied. The study was performed in a split-litter design and comprised 5 pairs of littermates. A catheter was inserted into the jugular vein 2 days prior to the start of the study. In each pair, 1 littermate was treated IM with 2.5 mg of estradiol-17 beta/75 kg of body weight, and the other littermate was given peanut oil IM as a control. The day after treatment, all gilts were challenge-exposed with a Salmonella typhimurium-derived endotoxin (1 microgram/kg, IV) and the inflammatory response to challenge exposure was monitored. There was no effect of estradiol treatment on the transient clinical signs of endotoxemia or on the increase in rectal temperature. The increase in blood concentrations of prostaglandin F2 alpha, metabolite and cortisol after endotoxin challenge exposure was not affected by estradiol. Decrease in number of circulating blood mononuclear cells and polymorphonuclear leukocytes was not changed by estradiol treatment. Taken together, mimicking prepartum concentration of estradiol did not affect either the magnitude or the kinetics of the inflammatory response to endotoxin in gilts. Relevance of these findings to development of endotoxin-mediated diseases, such as the postpartum agalactia syndrome, needs further study.

A crude, whole-body extract of female or male heartworms was injected IV into 28 dogs with and 22 dogs without heartworm (HW) infection. The female HW extract caused shock in 22 of 24 dogs with and 12 of 20 dogs without HW infection. The male HW extract induced shock in 4 of 4 dogs with and 1 of 2 dogs without HW infection. Prevalence of shock caused by female HW extract was significantly (P < 0.05) higher in dogs with than without HW infection; shock developed 5 to 30 minutes after HW injection. These signs were observed: marked decrease in blood pressure; collapse (initial collapse); paleness of mucous membranes; weak heart sounds; dyspnea; skin coldness; intestinal hyperperistalsis, and defecation; increases in RBC count, serum total protein concentration, serum osmolality, serum Na and blood glucose concentrations; and decreases in neutrophil, eosinophil, and platelet counts. Alanine transaminase, alkaline phosphatase, and lactate dehydrogenase activities increased substantially from the time of initial collapse to 24 hours after HW injection. Of 39 dogs with shock, 29 recovered from initial collapse, but 5 of the 29 subsequently collapsed again (secondary collapse), with bloody diarrhea followed by death. Of these 39 dogs, 6 died during initial collapse without bloody diarrhea, and 4 were euthanatized during initial collapse. It was confirmed that HW extract had, in fact, induced shock. These clinical, hematologic, and biochemical findings were fundamentally similar to those associated with shock resulting from administration of drugs, such as diethylcarbamazine and milbemycin D, in microfilaremic dogs with HW infection.

Sheep given powdered Ferula communis variety brevifolia at dosage of 2.5 g/kg of body weight/d for 15 days developed classical clinical signs of intoxication: anorexia, somnolence, apparent weakness, and hemorrhage. Marked reduction of vitamin K-dependent coagulation factors and prolongation of prothrombin time and activated partial thromboplastin time were consistent with presence of ferulenol, a toxic coumarinic factor in the plant. Changes induced in the coagulation system developed by the second day of plant administration and were normal within 4 days after dosing was stopped. There was no evidence of primary liver damage or platelet malfunction. Of 6 intoxicated sheep, 2 died with only minimal evidence of hemorrhage.

A total of 21 calves were inoculated IV with 1 of the following isolates of bovine viral diarrhea virus (BVDV); CD87 (n = 10), NY-1 (n = 3), NADL (n = 5), or were sham-inoculated with virus-free medium (n = 3). Subsequent to inoculation, platelet counts were monitored to detect differences between noncytopathic (CD87, NY-1) and cytopathic (NADL) isolates in their ability to induce thrombocytopenia. Platelet count decrease throughout infection was statistically analyzed by comparing the slope of the line drawn from the count on the day of infection to the lowest count achieved by that calf. Significant difference was observed in the CD87-inoculated calves and in the NY-1-inoculated calves, compared with those of the same control group. Significant difference was not observed in the slope of platelet count decrease between the cytopathic NADL-infected calves and control-group calves. The data indicate that noncytopathic BVDV isolates may more easily induce thrombocytopenia than do cytopathic isolates in immune-naive, immunocompetent calves; acute infection with 1 cytopathic BVDV isolate (NADL) did not induce thrombocytopenia. In addition, although each calf seroconverted, virus was rarely isolated from mononuclear cells obtained from calves with cytopathic infections. At some point after infection, virus was always isolated from each of the calves undergoing noncytopathic infections, and occasionally, transient association of noncytopathic BVDV antigen with platelets was observed during these infections.

The neutrophil plasma membrane has a major role in migration, phagocytosis, and destruction of microorganisms. Neutrophils isolated from blood and mammary secretions were homogenized, and the plasma membrane fraction was isolated on discontinuous sucrose gradient (20, 32, and 50%). Purity of plasma membrane preparation was determined by use of marker enzyme analysis. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the membrane proteins was performed under reducing conditions for polypeptide characterization. The membrane proteins were also labeled with 125I externally, using 1,3,4,6-tetrachloro-3 alpha-6 alpha-diphenylglycouril, and proteins were separated by SDS-PAGE and autoradiographed. Compared with whole cell homogenate, the plasma membrane fraction obtained at the 20/32% interface was enriched for the marker enzymes, 5'-nucleotidase (16-fold), alkaline phosphatase (5.5-fold), and total phosphatase (26-fold). The membrane fraction had minimal specific activity for beta-glucuronidase (0.4-fold), compared with whole cell homogenate. Plasma membrane protein yield was about 500 micrograms/ 10(9) bovine blood neutrophils. The SDS-PAGE of plasma membrane proteins revealed 25 protein bands, of which 13 were major bands. There were 3 distinct bands (18, 36, and 65 kd) in the plasma membrane-enriched fraction (20/32 interface) that were not seen in other fractions (30/50% and pellet). Further, 125I-labeling identified 5 distinct protein bands (205, 140, 65, 35, and 30 kd). Blood and mammary neutrophils had similar polypeptide patterns, except that 36- and 65-kd bands were more prominent for blood neutrophils than for mammary neutrophils.

High serum alkaline phosphatase (ALP) activity is considered a sensitive marker of cholestasis in most mammalian species, including dogs. Induction of high serum ALP activity in association with cholestasis is dependent on high hepatic bile acids concentrations. Treatment of dogs with glucocorticoids also results in high serum ALP activity. The possible causal relation between serum ALP activity and bile acids concentration was investigated in dogs treated with glucocorticoids. The relation of glucocorticoid treatment to changes in the activity of individual ALP isoenzymes, alanine transaminase (ALT) and gamma-glutamyltransferase (GGT) also was investigated. Eight conditioned dogs were given 4 mg of prednisone/kg of body weight, IM, daily for 10 days. Blood samples were taken prior to treatment and on treatment days 3, 5, 7, and 10. Liver tissue was then taken from each dog. Serum total ALP activity was significantly (P < 0.05) high at day 3 in prednisone-treated dogs. Isoenzyme analysis indicated that this increase was attributable to an increase in the liver ALP isoenzyme (LALP). Significant increases in serum corticosteroid-induced ALP (CALP) and bone ALP were first observed on days 7 and 10, respectively. Serum ALT and GGT activities were significantly increased by day 5. Increased serum or hepatic tissue bile acids concentrations were not observed in prednisone-treated dogs, compared with values in 8 clinically normal (control) dogs, but were high in 3 dogs with complete bile duct ligation. Hepatic activities of LALP, CALP, and GGT were higher in prednisone-treated dogs than values in controls, indicating probable increased hepatic synthesis of these enzymes. Hepatic ALT activity was not increased. The ratio of serum to tissue LALP activity was increased in prednisone-treated dogs, compared with values in controls, indicating that LALP may have been preferentially released into serum. There was no difference in the ratio of serum to liver GGT activity between prednisone-treated dogs and controls. The LALP and GGT ratios were increased in bile duct-obstruction dogs. It was concluded that, although LALP is the principal ALP isoenzyme in serum during the first 10 days of prednisone treatment, hepatic bile acid concentrations are not increased and, therefore, are not likely to be responsible for induction and release of ALP into serum. Prednisone may, therefore, be directly responsible for induction of ALP activity in dogs treated thusly.

Parenchymal cells were isolated from the liver of male calves, and monolayer cultures formed were treated with glucocorticoids to examine whether haptoglobin, appearance of which is associated with hepatic lipidosis (fatty liver) in cattle, is induced by steroid hormones. Without addition of dexamethasone, only trace amounts of haptoglobin were detected in culture medium. With addition of dexamethasone (10(-12) to 10(-4)M), considerable amounts of haptoglobin were released into the medium. Maximal release was observed at concentrations of 10(-8) to 10(-6)M dexamethasone. Haptoglobin release was similarly induced by cortisol, although the effect was less potent than that of dexamethasone. Actinomycin D (a known protein synthesis inhibitor) dose-dependently reduced amounts of haptoglobin released in response to 10(-8)M dexamethasone. Dexamethazone also induced annexin I, which is known to be synthesized in response to glucocorticoids. Dexamethasone treatment resulted in reduced protein kinase C activity in the cell cytosol, which has been shown to be an early event in dexamethasone-treated cells. Other than glucocorticoids, estradiol induced haptoglobin release, whereas progesterone was less effective. The association of haptoglobin with hepatic lipidosis can be reasonably explained by the fact that haptoglobin production by the liver is induced by glucocorticoids and estradiol, and these steroid hormones are triggers for development of hepatic lipidosis in cattle.

Effects of dietary aflatoxin (AF) and supplemental vitamin E (d-alpha-tocopherol) were evaluated in growing crossbred pigs. Nine barrows (3 replicates of 3 each, mean body weight, 14.0 kg) per group were assigned to 1 of 4 treatment groups (for a total of 36 barrows): 0 IU of supplemental vitamin E and 0 mg of AF/kg of feed (control); 2,400 IU of vitamin E divided into equal doses and administered IM on days 1 and 16; 2.5 mg of AF/kg of feed; or 2.5 mg of AF/kg of feed plus 2,400 IU of vitamin E administered similarly to treatment 2. Barrows were administered their respective treatment for 32 days. Evaluations were made for group production performance and for serum biochemical, immunologic, hematologic, pathologic, serum and tissue tocopherol, and serum retinol variables. Body weight was reduced by AF-alone and AF plus vitamin E treatments, compared with control and vitamin E-alone treatments. Liver weight was increased for the AF alone-treated and the AF plus vitamin E-treated barrows, compared with control barrows. The AF alone-treated barrows had alterations in: serum values of alkaline phosphatase, gamma-glutamyltransferase, albumin, glucose, phosphorus, calcium, cholesterol, total iron, unsaturated iron-binding capacity, total iron-binding capacity, and urea nitrogen; RBC numbers, hematocrit, hemoglobin concentration, and prothrombin time; and mitogen-induced lymphoblastogenic responses. With the exception of some slight ameliorating effects on hematologic measurements, supplemental treatment with vitamin E did not prove beneficial against the toxicosis-associated AF treatment. The AF alone-treated barrows had decreased serum tocopherol and retinol concentrations, compared with control and pretest values, and decreased tocopherol concentration in cardiac tissue. High parenterally administered doses of vitamin E did not have sparing effect on Af-induced reductions of serum tocopherol or retinol concentration; however, compared with pretest values, serum tocopherol concentration was increased by vitamin E-alone treatment. Tocopherol concentration in cardiac tissue of the AF plus vitamin E-treated barrows was increased over that of the AF alone-treated barrows, indicating an ameliorating effect on AF-induced tissue concentrations reductions. These data indicate that vitamin E may not have a sparing effect on AF-induced toxicosis and that AF may reduce serum retinol and serum and tissue tocopherol concentrations.