tilmicosin and Body-Weight

The effect of tilmicosin on the incidence of clinical mastitis and subsequent lamb performance was studied in 9 sheep flocks in Ontario. Ewes were treated randomly with either tilmicosin or placebo approximately one month prior to lambing. Outcome was assessed by comparing rates of clinical mastitis, palpable udder abnormalities, and preweaning (50-day) lamb weights between the 2 treatment groups, while controlling for other important variables. Lambs raised by multiparous ewes treated with tilmicosin were significantly heavier than lambs from placebo-treated multiparous ewes at 50 days. Lambs from tilmicosin-treated ewes were on average 0.52 kg heavier than lambs in the placebo group. There was no difference between treatment groups in the weight of lambs from first parity ewes. Tilmicosin treatment resulted in a 43% decrease in palpable udder abnormalities. Incidence of clinical mastitis did not differ between experimental groups. The administration of tilmicosin prelambing, at the time of routine clostridial disease vaccination, may be a beneficial and convenient way to reduce mastitis infection and improve the preweaning gain of lambs.

Topics: Animals; Animals, Newborn; Anti-Bacterial Agents; Body Weight; Female; Incidence; Macrolides; Mammary Glands, Animal; Mastitis; Sheep; Sheep Diseases; Tylosin

A field trial was performed under commercial feedlot conditions in western Canada to compare the efficacy of florfenicol and tilmicosin for the treatment of undifferentiated fever (UF) in calves that received metaphylactic tilmicosin upon arrival at the feedlot. One thousand and eighty recently weaned, auction market derived, crossbred beef calves suffering from UF were allocated to one of 2 experimental groups as follows: florfenicol, which was intramuscular (i.m.) florfenicol administered at the rate of 20 mg/kg body weight (BW) at the time of allocation (Day 0) and again 48 h later, or tilmicosin, which was subcutaneous (s.c.) tilmicosin administered once at the rate of 10 mg/kg BW on day 0. Five hundred and forty-four animals were allocated to the florfenicol group and 536 animals were allocated to the tilmicosin group. The chronicity, wastage, overall mortality, and bovine respiratory disease (BRD) mortality rates were significantly (P < 0.05) lower in the florfenicol group than in the tilmicosin group. There were no significant (P > or = 0.05) differences in first UF relapse, second UF relapse, hemophilosis mortality, or miscellaneous mortality rates between the florfenicol and tilmicosin groups. Average daily gain (ADG) from arrival at the feedlot to the time of implanting and ADG from allocation to the time of implanting were significantly (P < 0.05) lower in the florfenicol group as compared with the tilmicosin group. There were no significant (P > or = 0.05) differences in arrival weight, allocation weight, implanting weight, or ADG from arrival to allocation between the experimental groups. In the economic analysis, there was an advantage of $18.83 CDN per animal in the florfenicol group. The results of this study indicate that florfenicol is superior to tilmicosin for the treatment of UF because of lower chronicity, wastage, overall mortality, and BRD mortality rates. However, interpretation of these observations must take into consideration the fact that these calves received meta-phylactic tilmicosin upon arrival at the feedlot, which is a standard, cost-effective, management procedure utilized by feedlots in western Canada.

Topics: Animals; Anti-Bacterial Agents; Body Weight; Canada; Cattle; Drug Administration Schedule; Macrolides; Male; Pasteurellosis, Pneumonic; Risk; Thiamphenicol; Tylosin; Weight Gain

The intravenous pharmacokinetic profile of tilmicosin is yet to be achieved because of the cardiovascular effects of tilmicosin. This study summarizes two pharmacokinetic studies that provided complete pharmacokinetic profile of tilmicosin in cattle. The first study was a pharmacokinetic study of tilmicosin in beef calves dosed by i.v. infusion over 5 h. The second study was a subcutaneous (s.c.) pharmacokinetic study comparing the pharmacokinetic profile of tilmicosin in light (approximately 170 kg) and heavy (approximately 335 kg) beef cattle and comparing the labeled dose range of 10 or 20 mg/kg dose. The data from the two different studies were used to calculate bioavailability values, which support the assumption that tilmicosin is 100% bioavailable in cattle. The results from the second study showed that the weight of an animal when administered tilmicosin does not have a significant effect on exposure, but did demonstrate that doubling the dose of tilmicosin administered doubles the systemic exposure to tilmicosin.

Topics: Animals; Anti-Bacterial Agents; Biological Availability; Body Weight; Cattle; Chromatography, High Pressure Liquid; Dose-Response Relationship, Drug; Female; Infusions, Intravenous; Injections, Subcutaneous; Tandem Mass Spectrometry; Tylosin

Our previous studies demonstrated that tilmicosin-loaded hydrogenated castor oil solid lipid nanoparticles (Til-HCO-SLN) are a promising formulation for enhanced pharmacological activity and therapeutic efficacy in veterinary use. The purpose of this work was to evaluate the acute toxicity of Til-HCO-SLN.. Two nanoparticle doses were used for the study in ICR mice. The low dose (766 mg/kg.bw) with tilmicosin 7.5 times of the clinic dosage and below the median lethal dose (LD(50)) was subcutaneously administered twice on the first and 7th day. The single high dose (5 g/kg.bw) was the practical upper limit in an acute toxicity study and was administered subcutaneously on the first day. Blank HCO-SLN, native tilmicosin, and saline solution were included as controls. After medication, animals were monitored over 14 days, and then necropsied. Signs of toxicity were evaluated via mortality, symptoms of treatment effect, gross and microscopic pathology, and hematologic and biochemical parameters.. After administration of native tilmicosin, all mice died within 2 h in the high dose group, in the low dose group 3 died after the first and 2 died after the second injections. The surviving mice in the tilmicosin low dose group showed hypoactivity, accelerated breath, gloomy spirit and lethargy. In contrast, all mice in Til-HCO-SLN and blank HCO-SLN groups survived at both low and high doses. The high nanoparticle dose induced transient clinical symptoms of treatment effect such as transient reversible action retardation, anorexy and gloomy spirit, increased spleen and liver coefficients and decreased heart coefficients, microscopic pathological changes of liver, spleen and heart, and minor changes in hematologic and biochemical parameters, but no adverse effects were observed in the nanoparticle low dose group.. The results revealed that the LD50 of Til-HCO-SLN and blank HCO-SLN exceeded 5 g/kg.bw and thus the nanoparticles are considered low toxic according to the toxicity categories of chemicals. Moreover, HCO-SLN significantly decreased the toxicity of tilmicosin. Normal clinic dosage of Til-HCO-SLN is safe as evaluated by acute toxicity.

Topics: Animals; Anti-Bacterial Agents; Body Weight; Castor Oil; Drinking; Drug Carriers; Eating; Female; Heart; Hydrogenation; Lethal Dose 50; Lipids; Liver; Longevity; Male; Mice; Mice, Inbred ICR; Myocardium; Nanoparticles; Particle Size; Spleen; Toxicity Tests, Acute; Tylosin

Many compounds have been screened for their potential anti-cryptosporidial activity in ruminants but none of them has been totally efficient in controlling the disease. Macrolide antibiotics have demonstrated some activity against Cryptosporidium spp. in humans. Tilmicosin is a macrolide antibiotic, available in France in an oral form (Pulmotil AC, Lilly France). The preventive efficacy of tilmicosin was evaluated in a goat farm experiencing severe clinical cryptosporidiosis in kids. Twenty-two kids were separated from their dams just after birth and placed in a separated pen. They were divided into 3 groups: an untreated group (10 kids), group 1 (6 kids) receiving tilmicosin at 25mg/kg BW/day and group 2 (6 kids) receiving tilmicosin at 50mg/kg BW/day. Tilmicosin was individually given by oral route from day 2 of age for 10 days. Three times a week, individual faecal samples were performed to assess the oocyst output. Clinical data, i.e. diarrhea and mortality, were recorded. In control kids, the highest prevalence and intensity of excretion were observed between day 6 and day 16 of age and mortality reached 90%. Excretion dynamic and clinical consequences were similar in both treated kid groups. Finally, tilmicosin did not demonstrate any activity against severe kid cryptosporidiosis in field conditions.

Topics: Administration, Oral; Animals; Animals, Newborn; Anti-Bacterial Agents; Body Weight; Cryptosporidiosis; Cryptosporidium parvum; Feces; Goat Diseases; Goats; Parasite Egg Count; Random Allocation; Statistics, Nonparametric; Tylosin

The efficacy of an injectable formulation of florfenicol (300 mg/mL) as metaphylactic control of naturally occurring bovine respiratory disease (BRD) was evaluated in two double-blind randomly controlled field studies on two Dutch veal calf herds (A and B). Cattle aged not older than 3 months and in the direct presence of calves with clinical respiratory disease were randomly allocated to treatment with 40 mg/kg florfenicol subcutaneously (s.c.) a positive control treatment (12.5 mg/kg tilmicosin p.o. twice daily for five consecutive days in herd A, and 12.5 mg/kg doxycycline p.o. twice daily for five consecutive days in herd B), or a negative control (one placebo saline s.c. administration on D0). The predominant respiratory pathogens present in pretreatment respiratory samples from affected animals were Mycoplasma bovis and Pasteurella multocida in outbreaks A and B, respectively. Metaphylactic administration of florfenicol resulted in a statistically significant weight gain, decreased rectal temperature for five consecutive days after treatment and decreased metaphylactic failure percentages compared with both positive and negative control groups. In summary, these studies demonstrated that a single s.c. injection of florfenicol is effective and practical for control of the bacterial component of BRD in veal calves.

Topics: Animals; Anti-Bacterial Agents; Body Temperature; Body Weight; Cattle; Cattle Diseases; Disease Outbreaks; Male; Mycoplasma bovis; Mycoplasma Infections; Netherlands; Pasteurella Infections; Pasteurella multocida; Respiratory Tract Infections; Thiamphenicol; Tylosin

Two replicated-pen field studies were performed under commercial feedlot conditions in western Canada to compare the administration of long-acting oxytetracycline at 30 mg/kg body weight (BW) versus tilmicosin at 10 mg/kg BW to feedlot calves upon arrival at the feedlot. Ten thousand nine hundred and eighty-nine, recently weaned, auction market derived, crossbred beef steer and bull calves were randomly allocated upon arrival at the feedlot to one of 2 experimental groups as follows: oxytetracycline, which received intramuscular long-acting oxytetracycline (300 mg/mL formulation) at a rate of 30 mg/kg BW; or tilmicosin, which received subcutaneous tilmicosin (300 mg/mL formulation) at a rate of 10 mg/kg BW. There were 20 pens in each experimental group. In Study 1 and in the combined analysis, the initial undifferentiated fever (UF) treatment rate was significantly (P < 0.05) higher in the oxytetracycline group as compared with the tilmicosin group. There were no significant (P > or = 0.05) differences in first UF relapse, second UF relapse, third UF relapse, overall chronicity, overall rail, overall mortality, bovine respiratory disease (BRD) mortality, hemophilosis mortality, arthritis mortality, or miscellaneous mortality rates between the experimental groups in either study or in the combined analysis. In addition, there were no significant (P > or = 0.05) differences in initial weight, final weight, weight gain, days on feed, daily dry matter intake, average daily gain, or the dry matter intake to gain ratio between the experimental groups in either study or in the combined analyses. In the economic analysis, there was a net economic advantage of $5.22 CDN per animal in the oxytetracycline group, due to a lower prophylactic cost, even though the UF therapeutic cost was higher.

Topics: Animals; Anti-Bacterial Agents; Body Weight; Cattle; Cattle Diseases; Costs and Cost Analysis; Injections, Intramuscular; Injections, Subcutaneous; Macrolides; Male; Oxytetracycline; Random Allocation; Treatment Outcome; Tylosin

Our objective was to determine the effects of preshipping (PRE) vs. arrival (ARR) medication with tilmicosin phosphate (MIC; Exp. 1 and 2) and feeding chlortetracycline (CTC; 22 mg/kg of BW from d 5 to 9; Exp. 2) on health and performance of beef calves received in the feedlot. Ninety-six steers (Exp. 1; pay weight 236 kg) and 240 (Exp. 2; average pay weight 188 kg) steer and bull calves were used. For Exp. 1, treatments included no MIC (CON), PRE, and ARR. For Exp. 2, treatments were arranged in a 3x2 factorial. Treatments included CON, PRE, and ARR, either with CTC or without CTC. For Exp. 2, serum concentrations of immunoglobulin (Ig)G and alpha-1-acid glycoprotein (AGP) were determined on samples collected on d 0, 5, 10, and 28 and d 0, 5, and 10, respectively. No MIC x CTC interactions were observed. No differences were noted among MIC or CTC treatments in any of the experiments for ADG, daily DMI, or gain:feed ratio for the overall receiving periods. For Exp. 1, percentage of steers treated for bovine respiratory disease (BRD) was decreased (P<.05) for MIC-treated animals vs CON (71.9, 45.2, and 46.9 for CON, PRE, and ARR, respectively), and the week that calves were treated for BRD differed (P<.10) among treatments. For Exp. 2, the number of calves treated for BRD was decreased (P<.01) for MIC-treated steers vs CON and decreased (P<.05) for ARR vs. PRE (40.0, 18.7, and 7.5% for CON, PRE, and ARR, respectively). Averaged across days, serum IgG was decreased (P<.05) for MIC-treated steers vs. CON, with no differences noted among treatments for AGP. Results suggest that preshipping medication programs are no more effective than arrival medication programs using tilmicosin phosphate.

Topics: Animals; Anti-Bacterial Agents; Body Weight; Cattle; Chlortetracycline; Immunoglobulin G; Macrolides; Male; Orosomucoid; Transportation; Tylosin