This study sought to determine if sheep suffer neurological symptoms when fed Acacia angustissima leaves, and whether an equivalent amount of 70% acetone extract would have the same effect. In addition, the study tried to determine if treatment of leaves with 70% acetone would destroy the activity of A. angustissima toxins, and whether extraction with 70% aqueous acetone extract would separate two components of a toxic system. Twenty-five Menz lambs were randomly assigned to one of five treatments (1) A angustissima leaves as half the diet, 2) dried extract (70% aqueous acetone) of the same quantity of leaves, 3) a corresponding amount of residues, 4) a recombination of the dried extract and dried residue, or (5) a control diet containing no A angustissima leaves or extract fractions. All animals fed the leaves and the recombined fractions died or were euthanized when they were observed to be dying of severe neurological derangement. None of the other animals showed any neurological signs of impairement. The results of this study indicate that healthy, well-fed sheep can be poisoned by A angustissima, that the toxins are not destroyed by acetone or oven drying, and that severe neurological intoxication requires two components, which can be separated by acetone extraction.

A high-performance liquid chromatographic–diode array detector (HPLC-DAD) method for the determination of amoxicillin in medicated feedingstuffs was developed and validated. The method was used to investigate the quality requirements of animal feedingstuffs (declared content of active substance and feed homogeneity). Two-gram samples were extracted by potassium phosphate buffer solution. Extracts were filtered and directly analysed by HPLC-DAD without further clean-up. Amoxicillin was separated by acetonitrile and 0.01M phosphate buffer (pH 5.0) on a Phenomenex Luna C18 column. This method provided average recoveries of 76.1 to 81.6% with coefficients of variation (CV, %) for repeatability and reproducibility in the ranges of 3.7–7.2% and 5.3–7.6%, respectively. The limit of detection was 51.2 mg/kg and limit of quantification was 103.0 mg/kg. The method was successfully validated and proved to be efficient, precise, and useful for quantification of amoxicillin in medicated feedingstuffs.

Bovine mastitis is an inflammatory disease of the udder that causes important economic losses in the animal breeding and dairy product industries. Nowadays, the conventional livestock antibiotic treatments are slowly being replaced by alternative treatments. In this context, the main aim of this study was to evaluate the efficacy of natural products in alternative treatment of bovine mastitis. Two natural formulations with previously suggested in vitro antimicrobial effect were tested in vivo on mastitic cows. Animals with a positive diagnosis for mastitis (n = 20) were divided into three treatment groups: two groups (n = 8) were administered formulations of propolis, alcoholic extracts of Brewers Gold and Perle hops, plum lichen, common mallow, marigold, absinthe wormwood, black poplar buds, lemon balm, and essential oils of oregano, lavender, and rosemary designated R4 and R7 (differing only in the latter being more concentrated) and one group (n = 4) a conventional antibiotic mixture. In vivo efficacy of treatments was evaluated by somatic cell and standard plate counts, the treatment being considered efficacious when both parameters were under the maximum limit. R7 was effective in the most cases, being therapeutically bactericidal in six out of eight cows, while R4 gave good results in three out of eight cows, and conventional antibiotics cured one out of four. These results suggest the possible therapeutic potential of these natural products in bovine mastitis.

Resistance to antibiotics is a problem all over the world, and this problem also is so extended in veterinary fields. Therefore, this study aimed to find out the antibacterial substances from natural medicinal herbs against bovine mastitis pathogens, especially methicillin-resistant Staphylococcus aureus (MRSA). Among seventy two medicinal herbs, Terminaliae chebula extract showed antimicrobial effect against MRSA isolated from mastitis milk in cow and patient in human. However, Terminaliae chebula extract didn't show antibacterial effects on various strains including other contagious and environmental pathogens related with mastitis of dairy cows.

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.

The purpose of this in vitro study was to determine whether Pasteurella haemolytica capsular extract (CE) damages bovine pulmonary endothelial cells (EC) directly or through neutrophil-mediated mechanisms. Chromium 51-labeled EC were treated with the following variables: CE (1, 10, and 100 ng of protein/ml), CE and bovine neutrophils (10(6) cells/well), and CE and polymyxin B (500 U/ml). Although only minimal damage to EC occurred by 5 hours after treatment, by 22 hours after treatment, the 10-ng and 100-ng CE dose produced severe damage to EC, as indicated by 51Cr release, cellular detachment, and loss of monolayer confluency. The component in the CE that was toxic to the EC was lipopolysaccharide, evidenced by effective neutralization of the toxic effect with polymyxin B. Neutrophils inhibited the CE-mediated EC toxicity and were activated, as indicated by shape change and adhesion to EC monolayers. We concluded that the lipopolysaccharide component of CE causes direct damage to EC, which can be attenuated by neutrophils and polymyxin B.

The chemotactic activity of turkey peritoneal macrophages in response to an atherosclerotic plaque extract from a hypertensive strain of turkeys was determined. Atherosclerotic plaque extract stimulated macrophage chemotaxis, whereas normal aortic extract did not stimulate macrophage chemotaxis. However, differences were not revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis of extracts of atherosclerotic plaque and normal aorta. Chemotactic activity was diminished with pronase treatment, suggesting the chemoattractant is a protein. Seemingly, atherosclerotic plaque of turkeys contains a macrophage chemotaxin.

Fifteen dogs were given doxorubicin, IV, at a dosage of 30 mg/m(2) of body surface. A commercially available biological extract of Serratia marcescens (BESM) was administered sc to 9 of these dogs (0.04 mg/kg of body weight every third day, n = 2; 0.08 mg/kg every other day, n = 2; and 0.08 mg/kg daily, n = 5), beginning the day after administration of doxorubicin, in an attempt to find an optimal dosage and schedule of administration of BESM to reduce the duration and severity of chemotherapy-induced myelosuppression. Nine additional dogs were randomized into 3 groups of 3 dogs to receive 1 of the following dosages of BESM SC: 0.08, 0.16, and 0.32 mg/kg. Serum was harvested immediately prior to treatment and at 2, 4, 6, 8, 12, 24, 48, and 72 hours from this latter group of dogs for subsequent analysis of canine granulocyte colony-stimulating factor (G-CSF) by enzyme immunoassay. Increasing the dosage and schedule of administration of BESM reduced the duration and severity of doxorubicininduced myelosuppression. Neutrophil counts of the group of dogs given BESM daily at a dosage of 0.08 mg/kg and the controls were evaluated statistically. The neutrophil count increased significantly (P < 0.05) above pretreatment values in BESM-treated dogs after day 7. Median neutrophil counts of the BESM-treated dogs were never significantly lower than pretreatment values, whereas the median counts of the dogs treated with doxorubicin alone were significantly below normal for 6 days (days 7-12). The median counts decreased below normal (< 3,000 cells/microl) for 1 day in the dogs given BESM and doxorubicin, and for 3 days in the dogs that were given only doxorubicin. Four of the 6 dogs not treated with BESM and none of those given BESM developed serious neutropenia (< 1,500/microl). There was an increase in canine G-CSF 4 to 6 hours after BESM was administered to dogs at dosages of 0.16 and 0.32 mg/kg. These findings demonstrate that BESM is capable of reducing the duration and severity of doxorubincin-induced myelosuppression, and that this may be at least partially mediated by G-CSF.

Dialyzable lymph node extracts (DLE) containing transfer factor prepared from calves sensitized to Mycobacterium paratuberculosis and keyhole-limpet hemocyanin (KLH) were administered to 4 adult cows with chronic paratuberculosis. Cutaneous delayed hypersensitivity, lymphocyte blastogenesis, monocyte migration-inhibition, and lymphoblast proliferative capacity as a reflection of interleukin-2 (IL-2) activity were measured in response to M bovis purified protein derivative, johnin, and KLH before and after treatment with DLE. Change in cutaneous delayed hypersensitivity was not evident after DLE treatment. Alterations in histologic features of pre- and posttreatment sections of ileum and mesenteric lymph nodes were not detected. Lymph node extract treatment significantly (P < 0.05) increased IL-2 activity and migration-inhibition in response to johnin and KLH in vitro. Treatment had no effect on lymphocyte blastogenesis. The data indicate that cattle with chronic paratuberculosis may benefit from DLE treatment, by virtue of increased IL-2 activity, and that effects of DLE are at least partially mediated by an increase in IL-2 activity.

An aqueous extract was made from black walnut (Juglans nigra) heartwood obtained in the fall of the year. Ten hours after nasogastric administration of 5 L of the extract, a 550-kg, 13-yr-old Quarter Horse gelding experienced Obel grade-3 laminitis. The effect of aqueous extract of black walnut on vascular contractility was then tested, using isolated equine digital arteries and veins. The vessels were maintained in Krebs bicarbonate buffer with 95% oxygen at 37 C. The extract did not induce a direct contractile effect. It did, however, reversibly enhance the vasoconstriction induced in the isolated vessels by administration of epinephrine potentiated with hydrocortisone. In contrast, aqueous extracts made, using the same techniques, from the shavings of eastern white pine (Pinus strobus), eastern red cedar (Juniperus virginiana), and pin oak (Quercus palustrus) had no effect on epinephrine-induced digital vessel contractions.