Curing experimental Bryophyllum tubiflorum poisoning of cattle with activated carbon, electrolyte replacement solution and antiarrhythmic drugs

A slurry of activated carbon (activated charcoal) in electrolyte replacement solution given by stomach tube and antiarrhythmic drugs given parenterally cured 9 of 11 calves dosed 7 to 24 h previously with a lethal amount (20g/kg) of Bryophyllum tubiflorum flower heads. Two of another 4 calves treated 26 to 36 h after dosing with flowers survived. B. tubiflorum toxins are bufadienolides (cardiac glycosides). Activated carbon was effective at a single dose of 5 g/kg. Calves were rehydrated with oral electrolyte replacement solution at 150 ml/kg in divided doses over 24 h. Tachycardia was treated with intravenous lignocaine (200 mg doses) or propranolol (5 mg doses) and atrioventricular block with atropine (0.5 mg/kg).     

Role of bentonite in prevention of T-2 toxicosis in rats

Experiments were conducted to determine the effect of bentonite and nonnutritive dietary polymers on toxicity and metabolism of T-2 toxin in rats. Male weanling rats were fed diets containing 5% bentonite, anion exchange resin, cation exchange resin or vermiculite-hydrobiotite. Each diet was fed with and without 3 micrograms T-2 toxin/g of feed for 2 wk. Bentonite and anion exchange resin were the treatments most successful at overcoming growth depression and feed refusal caused by T-2 toxin. Subsequent experiments tested bentonite and anion exchange resin at 0, 2.5, 5.0, 7.5 and 10% of the diet. Bentonite fed at 10% was the most effective treatment at overcoming feed refusal and growth depression. Rats were fed 0, 5, 7.5 or 10% bentonite for 2 wk and then dosed with [3H] T-2 toxin. Urine and feces were collected for 21 h after dosing and tissues were excised for determination of residual 3H. Feeding bentonite had little effect on the fraction of the dose excreted in the urine. Significant increases in fecal excretion of 3H were shown, when the feeding of 5, 7.5 or 10% bentonite was compared with the casein-based, semi-purified control diet. Dietary bentonite had no effect on residual 3H in liver or kidney, but all concentrations of bentonite tested reduced residual 3H in muscle. More 3H was found in the digesta in the small intestine and in the wall of the intestinal tissue when rats fed 5% bentonite were compared with the controls. Intestinal transit time for rats fed bentonite diets was reduced compared with that of the controls as indicated by chromic oxide marker studies.(ABSTRACT TRUNCATED AT 250 WORDS)     

An evaluation of the effect of repeated doses of oral activated charcoal on the depletion of enrofloxacin residual levels in chicken breast muscles

The purpose of this study was to determine whether concurrent oral administration of activated charcoal has an affect on the depletion of the residual concentrations of enrofloxacin (ENRO) in chicken breast muscles. Sixty-four broiler chickens were divided into four groups (n = 16 per group), one given a daily oral dose of enrofloxacin with feed at a dose of 10 mg/kg for 5 consecutive days (control group) and the others given the same dose of enrofloxacin simultaneously with activated charcoal at a dose rate of 0.5, 1, and 2 % of daily feed for 5 days (treatment groups). At the end of treatment, 2 hens were sacrificed at each of the sampling time points (6,12, 18,48, 72,96,120 and 144 h after completion of dosing), breast muscles were collected and analyzed. Supercritical fluid extraction and high-performance liquid chromatography methods were used to determine the enrofloxacin residue levels in chicken breast muscles.The limit of quantification (LOQ) 16.5 microg/kg, was lower than the maximum residue levels (MRL) fixed by the Commission of the European Union. For all the time periods, charcoal treatment did not affect enrofloxacin tissue concentrations except at 12 and 48 h post treatment.To our knowledge, no studies on the depletion of enrofloxacin in the presence and absence of activated charcoal in chicken muscles have been performed. Although our current understanding is incomplete, multiple dose activated charcoals may play a role in the therapy of overdose.To prove this, further investigation is warranted.     

Effect of sodium bicarbonate and sodium bentonite on digestion, solid and liquid flow, and ruminal fermentation characteristics of forage sorghum silage-based diets fed to steers

Six ruminally cannulated steers, five Holsteins and one Hereford (250 to 295 kg), were fed 84% forage sorghum silage plus 16% supplement or 50% forage sorghum silage plus concentrate and supplement diets containing either no addition (controls), 1% sodium bicarbonate (NaHCO3) or 2% sodium bentonite in a 2 X 3 factorial arrangement of treatments in a 6 X 6 Latin-square experiment with 3-wk periods. Sodium bicarbonate increased dry matter (DM) intake when concentrate was included, but neither compound affected intake of the 84% silage diet. Bentonite lowered DM, neutral detergent fiber (NDF), and acid detergent fiber (ADF) digestibilities, but NDF disappearance from nylon bags was unchanged. Ruminal pH, osmolality and L(+) and D(-) lactate were not affected by treatment. Both NaHCO3 and bentonite tended to lower ruminal NH3-N concentrations. Bentonite lowered the molar proportion of isobutyrate in ruminal fluid relative to controls, but proportions of other volatile fatty acids (VFA) and total VFA concentrations were unchanged. Neither NaHCO3 nor bentonite affected ruminal liquid or solid volumes, dilution rate constants or ruminal outflow rates. Markers overestimated volumes, but correction with measured volumes did not change interpretation of treatment effects. It was concluded that control diets had sufficiently high baseline values of pH, dilution rate and acetate proportion to preclude changes induced by either compound, especially at 1 or 2% of DM intake. An effect on palatibility through neutralization of silage acids may have been responsible for the intake response to NaHCO3.     

Experimentally induced Cassia roemeriana poisoning in cattle and goats

The dried, ground aerial portions of the plant Cassia roemeriana were administered to each of seven calves at a dosage of 10 g/kg of body weight/day for 2 to 10.5 days and to each of six goats at a dosage of 10 g/kg/day for 5 days or 5 or 7 g/kg/day for 23 to 25 days. Experimentally induced C roemeriana poisoning in both species resulted in hepatopathic poisoning characterized by a brief survival period (3.9 to 7.9 days), moderate-to-severe hepatocellular damage, and little or no evidence of injury to skeletal muscle or resulted in myopathic poisoning characterized by a longer period of survival, mild-to-severe skeletal myopathy, and mild hepatocellular injury. The minimal dosage that induced hepatopathic poisoning (also the minimal lethal dosage) was 10 g/kg/day for 3 days in calves and for 5 days in goats. The minimal dosage that induced the myopathic syndrome (as determined by the earliest increase in serum creatine kinase activity) was 10 g/kg/day for 6 days for calves and 5 g/kg/day for 10 to 16 days for goats.     

Acute lead poisoning in calves: clinical, pathological and toxicological findings]

We present a case of acute lead poisoning in 10 calves. All calves died with few or no clinical signs prior to death. The clinical signs included neurologic and gastrointestinal symptoms but were of an unspecific nature. Several painted iron girders, stored on a field close to the farm, were determined as the source of the poisoning. Postmortem findings were minimal. Some animals presented acid-fast, intranuclear inclusion bodies in the renal tubules. A chemical analysis of some frozen parts of the liver and kidney revealed levels of lead as high as 12 ppm in the liver and 63 ppm in the kidney on a wet-weight basis. This article discusses the etiology, clinical signs, postmortem findings and diagnosis of lead poisoning in calves with special emphasis on the chemical analysis.     

Pluronic poisoning in a herd of dairy calves

Of 32 calves given an unknown amount of a pluronic bloat mixture with their milk, 28 died in convulsions over 24 hours. Supportive therapy was unsuccessful. Concentrations of pluronic present in abomasal and rumenal contents supported a diagnosis of pluronic poisoning.     

Efficacy of salinomycin in treatment of experimental Eimeria bovis infections in calves

The efficacy of salinomycin for treatment of experimental Eimeria bovis infections was evaluated. In experiment 1, 18 calves were placed into four groups. Group 1 calves were nonmedicated controls; groups 2, 3, and 4 calves were given salinomycin (0.33, 0.66, and 1.00 mg/kg of body weight, respectively) in daily oral divided doses starting 2 or 3 days prior to E bovis inoculations and continuing until postinoculation day (PID) 21. Calves treated with 0.66 and 1.00 mg/kg (groups 3 and 4) passed substantially fewer oocysts than did control calves (group 1) or calves treated with 0.33 mg/kg (group 2). Group 1 control calves had typical signs of severe E bovis infections, whereas signs of infection in medicated calves were almost nonexistant. Experiment 2 was conducted as before, with 15 calves. Group 5 calves were nonmedicated controls; groups 6, 7, and 8 calves were treated with 0.5, 1.0, and 2.0 mg/kg, respectively. All group 8 calves and three of four group 7 calves had nearly complete suppression of oocyst excretions. The severity of the disease in the group 5 control calves was not as extensive as it was in group 1 control calves. In experiment 3, 16 calves were used. Group 9 calves were nonmedicated controls, whereas other calves were given salinomycin (2.0 mg/kg) during PID 3 to 7 (group 10), PID 8 to 12 (group 11), and PID 13 to 17 (group 12). Salinomycin therapy in group 2 calves resulted in substantial reductions in oocyst excretions and clinical signs.     

Effects of noncytopathic type 2 Bovine viral diarrhea virus on the proliferation of bone marrow progenitor cells

The purpose of this study was to investigate the effects of isolates of noncytopathic type 2 Bovine viral diarrhea virus (ncpBVDV-2) of high and low virulence on the proliferation of bone marrow progenitor cells. Holstein calves 6 to 7 mo old and BVDV-na?ve were inoculated intranasally with a BVDV isolate of high virulence (HV24515), a BVDV isolate of low virulence (LV11Q), or uninfected cell culture medium. Serial bone marrow and peripheral blood samples were collected before and after inoculation. Bone marrow mononuclear cells (BMMCs) were isolated and cultured for 5 d, and the mean number of colony-forming unit-granulocyte-macrophage (CFU-GM) colonies was determined. Tritiated (3H)-thymidine uptake by BMMCs was determined to indicate overall proliferative capacity. Virus isolation was done on concurrent samples of BMMCs and peripheral blood. Virus was isolated from BMMCs and peripheral blood buffy-coat cells as early as day 2 or 3 after inoculation. Neutropenia developed in both groups inoculated with a BVDV isolate. However, in the calves given LV11Q, neutrophil counts rebounded earlier in response to increased proliferation of BMMCs, whereas the response was delayed in calves given HV24515. Thymidine uptake was significantly increased (P = 0.0047) in BMMCs after inoculation compared with before inoculation in the calves given LV11Q but not in those given HV24515 or in the control calves. The median number of CFU-GM colonies was significantly decreased (P = 0.0164) after inoculation compared with before inoculation in the calves given HV24515, whereas there was no significant difference in the calves given LV11Q or in the control calves. The data support the hypothesis that the prolonged neutropenia observed in calves given HV24515 results at least in part from decreased proliferative capacity of bone marrow progenitor cells.     

Evaluation of age-dependent susceptibility in calves infected with two doses of Mycobacterium avium subspecies paratuberculosis using pathology and tissue culture

The longstanding assumption that calves of more than 6 months of age are more resistant to Mycobacterium avium subspecies paratuberculosis (MAP) infection has recently been challenged. In order to elucidate this, a challenge experiment was performed to evaluate age- and dose-dependent susceptibility to MAP infection in dairy calves. Fifty-six calves from MAP-negative dams were randomly allocated to 10 MAP challenge groups (5 animals per group) and a negative control group (6 calves). Calves were inoculated orally on 2 consecutive days at 5 ages: 2 weeks and 3, 6, 9 or 12 months. Within each age group 5 calves received either a high – or low – dose of 5 × 10⁹ CFU or 5 × 10⁷ CFU, respectively. All calves were euthanized at 17 months of age. Macroscopic and histological lesions were assessed and bacterial culture was done on numerous tissue samples. Within all 5 age groups, calves were successfully infected with either dose of MAP. Calves inoculated at < 6 months usually had more culture-positive tissue locations and higher histological lesion scores. Furthermore, those infected with a high dose had more severe scores for histologic and macroscopic lesions as well as more culture-positive tissue locations compared to calves infected with a low dose. In conclusion, calves to 1 year of age were susceptible to MAP infection and a high infection dose produced more severe lesions than a low dose.     

Treatment rationale for dogs poisoned with aldicarb (carbamate pesticide)

The treatment rationale for dogs poisoned by aldicarb is reviewed from a pharmacological perspective. The illegal use of aldicarb to maliciously poison dogs is a major problem in some parts of the world. In South Africa, it is probably the most common canine poisoning treated by companion animal veterinarians. Aldicarb poisoning is an emergency and veterinarians need to be able to diagnose it and start with effective treatment immediately to ensure a reasonable prognosis. Successful treatment depends on the timely use of an anti-muscarinic drug (e.g. atropine). Additional supportive treatment options, including fluid therapy, diphenhydramine, benzodiazepines and the prevention of further absorption (activated charcoal) should also be considered. Possible complications after treatment are also briefly discussed.     

Effect of a trainer cow on health, behavior, and performance of newly weaned beef calves

Experiments were conducted to investigate the effects of the presence of a trainer cow on behavior, performance, health, and feeding patterns of newly weaned beef calves. In Exp. 1,252 weaned calves (270+/-18 kg) were allocated to 22 pens (11 to 15 calves per pen). A trainer cow was randomly assigned to each of 11 pens. Calves were weighed prior to feeding on d 0, 3, 7, 14, 21, and 28. Rectal temperatures were taken on each of these days (except d 28) and blood samples were collected on d 0, 3, and 7 and subsequently analyzed for serum haptoglobin and leukotoxin antibody titers. Instantaneous scan observations of calf behavior were made at 10-min intervals between 0730 and 1730 on d 1, 2, 4, 5, and 6. A similar protocol was used in Exp. 2, in which 297 calves (258+/-17 kg) were allocated to 24 pens. Blood analyses included haptoglobin, white blood cell counts (WBC), and neutrophil:lymphocyte (NL) ratios. In Exp. 3, the above protocol was followed and patterns of feed bunk attendance of individual calves were also monitored using radio frequency identification by passive transponder ear tags. Trainer cows did not influence (P > .10) calf rectal temperatures, requirements for antibiotic therapy, WBC, NL ratios, or leukotoxin antibody titers. Pooled across treatments, NL ratios were lower (P < .01) on d 0 (.31) than on d 3 (.36) or d 7 (.39). Although differences in weight gain were detected in some periods within the three experiments, there were no differences (P > .10) overall (d 0 to 28). Trainer cows did not affect (P > .05) frequency or duration of bunk visits by the calves. Averaged across treatments, frequency and duration of bunk visits increased (P < .001) from 9.6 visits/d and 56.7 min/d between d 0 and 3 to 12.3 visits/d and 108.9 min/d between d 15 and 21. The number of calves observed eating during scan sampling observations also increased from 16.4% on d 1 to 25% on d 4 (P < .10) and 29% on d 5 and 6 (P < .05). More (P < .05) calves were observed lying on d 1 (41.7%) and d 2 (45.3%) than on d 4 (37.5%), d 5 (34.8%), or d 6 (36.2%). With a trainer cow present, fewer (36.7% vs 41.5%; P < .001) calves were observed lying and more (11.7% vs 10.2%; P = .08) were observed walking than when no cow was present. Trainer cows did not improve calf health, time spent at the feed bunk, or performance of newly weaned calves.     

Endotoxin-induced changes in the hemostatic system in neonatal calves: the effect of antiserum to a mutant Escherichia coli (J-5)

Changes in the hemostatic system were studied in 22 neonatal calves given a small dosage of Escherichia coli endotoxin (0.5 microgram/kg) by slow (5-hour) IV infusion. The effect of pretreatment with an antiserum to mutant of E coli O111:B4 (J-5) was evaluated. The platelet count, plasma fibrinogen concentration, prothrombin time, and activated partial thromboplastin time changed significantly from base line during and after endotoxin infusions in all calves. The mean platelet count was significantly decreased from 1 through 24 hours after endotoxin infusion was started. Mean plasma fibrinogen was decreased 2 through 12 hours after endotoxin infusion was started. The mean prothrombin time and activated partial thromboplastin time were significantly greater than base line at 3 to 6 hours and 3 to 12 hours, respectively, after endotoxin infusion was started. Serum concentration of fibrinolytic degradation products remained less than 10 micrograms/ml. Bovine J-5 antiserum did not prevent the endotoxin-induced changes in the hemostatic system of these neonatal calves.     

Influence of macronutrients and activated charcoal on intake of sagebrush by sheep and goats

We determined if supplemental macronutrients or activated charcoal influenced intake of sagebrush, a shrub that contains terpenes. Sheep (lambs 3 mo age, 33 kg) and goats (kids 5 mo age, 28 kg) were fed supplements high in energy, high in protein, or offered a choice between the two supplements before and after receiving sagebrush for 4 h/d. The effect of activated charcoal, a compound that reduces bioavailability of toxins, was assessed by offering charcoal mixed with a carrier or the carrier alone while animals consumed sagebrush for 4 h/d. The effects of supplemental macronutirents were tested before and after charcoal supplementation. Activated charcoal did not increase intake of sagebrush by sheep or goats (P > 0.05), but supplemental macronutrients influenced intake of sagebrush by both species (P < 0.05). Intake of sage-brush was markedly higher for animals fed the high-protein supplement than for animals fed the high-energy supplement (P < 0.05). Lambs (before and after charcoal supplementation) and kids (after charcoal supplementation) offered a choice between the two supplements used sagebrush at levels comparable to animals supplemented with protein. They consumed more CP than animals fed the high-energy supplement and more ME than lambs fed the high-protein supplement (P < 0.05). Thus, providing a choice between supplements enhanced intake of sagebrush and enabled animals to achieve a more balanced intake of macronutrients. Preference for supplement and sagebrush also depended on an animal's immediate past history with a supplement. Sheep and goats previously fed the high-energy or the high-protein supplement preferred, respectively, the high-protein or the high-energy supplement when given a choice (P < 0.05). The changes in preference for supplement caused a decreased intake of sagebrush by groups that preferred the energy concentrate, and an increased intake of sagebrush by groups that preferred the protein concentrate. Thus, supplements of different energy and protein densities consistently altered intake of sagebrush by sheep and goats.     

Use of febantel or ivermectin for treatment of calves with experimentally induced Bunostomum phlebotomum infection

In the first of 2 separate trials, the efficacy of febantel, given at a dosage of 5 mg/kg of body weight, was assessed in calves with 60-day experimentally induced Bunostomum phlebotomum infection. Ten calves were given febantel paste, and 10 were given the vehicle only. All 20 calves were necropsied 7 days after cessation of treatment. Compared with untreated calves, febantel-treated calves harbored 99.4% fewer nematodes. In the second trial, the efficacy of ivermectin, given as a paste formulation at a dosage of 0.2 mg/kg, was assessed in calves with experimentally induced B phlebotomum infection. Ivermectin was given at 18 (n = 6) and 60 (n = 6) days after infection. At each treatment date, 3 additional calves were given vehicle only. At 67 days after infection, all calves were euthanatized. Efficacies of ivermectin against 18- and 60-day infections were 100 and 99.8%, respectively. Both anthelmintic preparations were easily administered, and adverse reactions were not observed.     

An Appraisal of the Bentonite Flocculation Test in the Detection of Bovine Tuberculosis

In this further study, an exhaustive investigation into the value of the bentonite flocculation test in detecting tuberculosis in cattle was made on a group of 358 cattle, with known intradermal (ID) tuberculin reactions and with or without tuberculosis lesions. Bentonite sensitized with human old tuberculin (OT) and a purified BCG carbohydrate fraction (BCG-F1) were used.

In the group of 126 cows with tuberculosis lesions, 113 were positive to the tuberculin ID test and there were also 113 positive reactions to the flocculation test using OT sensitized bentonite. Only 62 were positive using the BCG-F1 sensitized bentonite.

Out of the 232 animals with no visible lesions, 114 reacted positively to the tuberculin ID test, 148 had a titer to the flocculation test using OT sensitized bentonite and 70 were positive when using BCG-F1 sensitized bentonite.

     

THE ORAL TOXICITY FOR SHEEP OF TRITERPENE ACIDS ISOLATED FROM LANTANA CAMARA

SUMMARY Toxic Lantana camara taxa growing in Queensland all contain the triterpene acids lantadene A, reduced lantadene A and lantadene B. These when dosed as pure compounds orally to sheep were similarly toxic at 65 to 75, 42 to 80 and 200 to 300 mg/kg body weight respectively, causing jaundice, photosensitisation, kidney and liver lesions typical of natural and experimental lantana poisoning. Because of its comparative toxicity and abundance lantadene A is the most significant toxic principle in the plant. Reduced lantadene A because of its low concentration in the leaves (5% of lantadene A) and lantadene B because of its significantly lower toxicity are thus unlikely to be of much importance in the poisoning of ruminants following consumption of the plant. In addition, the structural features of both lantadene A and B molecules given to sheep by the oral route do not conform to the chemical structures previously reported to be required for liver damaging action of the verbenaceous triterpenes administered to rabbits by the intraperitoneal route.     

Salmonella dublin experimental infection in calves: protection after oral immunization with an auxotrophic aroA live vaccine

Salmonella dublin strain SL5631, which is auxotrophic for p-amino-benzoic acid and 2,3-dihydroxybenzoate because of a deleted aroA gene, was given orally in a dose of 10(10) live bacteria to 6 calves 5-7 weeks old. The calves tolerated the strain well, had a transient mucoid diarrhea and sacrificed animals showed a moderate acute inflammation in the ileum on day 2. The salmonella strain was seen lining the mucosal epithelium using immunohistopathology. Already in calves sacrificed on day 6 the damage was less pronounced and signs of regeneration were obvious. The healing process was more accentuated in calves sacrificed on day 14. The results demonstrated the attenuating effect of the deleted aroA gene. Groups of 5-7 weeks old calves (n = 25) orally immunized with 10(8), 10(9) and 10(10) S. dublin SL5631 at weekly intervals were challenged 2, 6 or 15 weeks after the immunization. All calves were protected against oral challenge with 10(10) bacteria of the virulent S. dublin strain, which equals 1,000 LD50 doses. At autopsy, calves were sacrificed 3 weeks after challenge, all calves had normal intestinal findings with only slightly enlarged mesenteric lymph nodes. The protective effect is surmised to involve cell-mediated as well as humoral defense mechanisms.     

Control of bovine coccidiosis with monensin: in nonresistant newborn calves

Newborn Holstein male calves were purchased within 3 days after birth and were removed from the local farms to the Dixon Springs Agricultural Research Center. They were hand-fed for 7 weeks and then weaned to a prepared feed. Eight groups, each of 4 calves, were housed in separate pens. In each of 4 pens (pens 2 to 5), 1 calf was inoculated with sporulated oocysts of Eimeria bovis (and was not medicated); 1 calf was inoculated and given feed with added monensin at the dosage level of 10 g/906 kg of feed; and 2 calves were inoculated and given medicated feed with added monensin at the dosage level of 20 g/906 kg or 30 g/906 kg. In the 4 other pens (6 to 9), the calves were inoculated with E zuernii and otherwise were given feed without or with added monensin as in pens 2 through 5. Another group of 5 calves (all kept in 1 pen), served as noninoculated, nonmedicated controls. At 14 days after inoculations with E bovis, the single calves in each of the 4 pens that were given the nonmedicated feed began to show clinical signs of coccidiosis and discharged increasing numbers of oocysts. The other inoculated calves (given monensin) had fewer clinical signs and discharged fewer oocysts in the feces as the level of medication in the feed increased. The calves inoculated with E zuernii developed only moderately severe infections when compared with those inoculated with E bovis. Inoculated (with E bovis) nonmedicated calves had severe reductions in feed consumption and weight, and 3 of 4 died.(ABSTRACT TRUNCATED AT 250 WORDS)     

Current ideas on the pathophysiology and treatment of lantana poisoning of ruminants

Lantana poisoning in ruminants results from the ingestion of toxic varieties of the plant Lantana camara, which contain the triterpene acids lantadene A and lantadene B. Poisoning results in intrahepatic cholestasis and the consequences of the liver injury include jaundice, photosensitisation and ruminal stasis. The decreased ruminal motility causes toxic material to be retained in the rumen and continuous absorption of toxins from the rumen maintains the disease. Lantana poisoning can best be treated by preventing further absorption of toxins. This can be achieved by giving a large quantity of activated charcoal into the rumen together with a large volume of a multiple electrolyte solution to stimulate ruminal motility and rehydrate the animal. Treatment for photosensitive dermatitis should also be given.