METHOD OF SEMEN COLLECTION AND ARTIFICIAL INSEMINATION IN SNAKES

This study focuses on the method for sperm extraction and artificial insemination in snakes. Ten adult healthy snakes (4.6) were included in the study (Pantherophis guttatus 1.3; Hydrodynastes gigas 1.1; Corallus hortulanus 1.1; and Sanzinia madagascariesis 1.1). Massage of the ventral aspect of the caudal third of the male snake body for 2 to 3 minutes was performed successfully for the semen collection. Both female and male P. guttatus and H. gigas were placed in brumation, with the female snakes being assessed for ovarian activity after emerging from dormancy. Only females showing ultrasonographic evidence of vitellogenic follicles were included in the study. S. madagascariensis and C. hortulanus were maintained at the same temperature through the year, and the ovarian activity was assessed ultrasonographically prior to artificially inseminating the animal. With the aid of a rigid endoscope, fresh semen was delivered through the cloaca and into the females’ oviducts using a catheter connected to the syringe. The technique failed in female S. madagascariensis and H. gigas. Two female P. guttatus laid eggs 2 months after artificial insemination, with hatchlings emerging following 2 months of development within the eggs. The third female corn snake did not lay an egg. The female C. hortulans produced eggs 4 months after insemination. The manual massage method of sperm collection in male snakes and endoscopy-assisted insemination in female snakes may be useful for conservation programs.     

Efficacies of fenbendazole and levamisole in the treatment of commercial turkeys for Ascaridia dissimilis infections

A field trial was conducted on a farm in Michigan with commercial turkeys naturally infected with Ascaridia dissimilis. The birds were treated at approximately 8 and 14 wk of age on a per-barn basis with fenbendazole (Safeguard) in the feed at 16 ppm for 6 d (1 barn), or with levamisole (Prohibit) in the water at 16 mg/kg of BW (2 barns). Six birds were obtained at random and sacrificed in each barn for worm burden determinations before treatments and again soon after treatments. Nematicidal efficacies for fenbendazole and levamisole were shown to be 99.3 to 99.9% and 54.6 to 85.8%, respectively. Despite the far greater reductions in worm burdens by fenbendazole as compared with levamisole, the burdens at the time of retreatment had equalized in all barns, illustrating the role of premunition regarding turkey ascaridiasis, and highlighting the overriding importance of reducing the challenge to provide long-term control of this parasitism.     

Body condition scoring (BCS) in corn snakes (Pantherophis guttatus) and comparison to pre-existing body condition index (BCI) for snakes

In the veterinary profession, the body condition score (BCS) plays an important role in the assessment of patients. It is a subjective, tactile method of evaluating body fat and muscle mass and is used in numerous species. Recognizing obesity (or the contrary, emaciation) is important for veterinarians treating reptiles and could be facilitated by a BCS. An existing form of body condition assessment already used is the body condition index (BCI), where the residuals from a regression of body mass on body length are calculated. Therefore, the goal of this study was to provide practitioners with a BCS system for corn snakes (Pantherophis guttatus) and to test it against the BCI. A total of 22 corn snakes (Pantherophis guttatus), stationed at the “Auffangstation für Reptilien” in Munich (reptile rescue centre, RRC), were subject of this study. Each had the following measurements taken: body weight (BW), snout–tail tip length (STL), snout–vent length (SVL) and circumference in the middle (C). Manual palpation of spine, area between vertebral spinous and transverse process, ribs and neck of each snake was performed by three veterinarians and assigned to specific scores by each examiner. A BCS (mean of examiners’ scores) was given to each snake according to manual palpation. The BCS system was chosen to be out of 5 in 0.5-point steps with 2.5 considered as ideal BCS. In the studied snakes, the BCS ranged from 1.5 to 3.5, with a median of 2.5. The median BW was 309 g (75–967 g), the median STL was 123 cm (79–153 cm), the median SVL was 104 cm (73–133 cm) and the median C was 7.5 cm (4.3–11 cm). BCS and BCI were positively correlated. A BCS includes a manual palpation of the animal and thus gives the examiner additional information to the objectively measured/calculated index.     

A fenbendazole oral drench in addition to an ivermectin pour-on reduces parasite burden and improves feedlot and carcass performance of finishing heifers compared with endectocides alone

Two studies utilizing 1,862 yearling heifers were conducted to determine the effects of a fenbendazole oral drench in addition to an ivermectin pour-on (SG+IVPO), compared with an ivermectin pour-on (IVPO) or a doramectin injectable (DMX) alone, on parasite burden, feedlot performance, and carcass merit of feedlot cattle. In the first study, heifers receiving the SG+IVPO had fewer (P = 0.02) cattle retreated for disease and 73% fewer (P = 0.06) worm eggs per fecal sample 98 d after treatment than heifers treated with IVPO. Heifers treated with SG+IVPO consumed more DM, had greater ADG, were heavier at slaughter, and had heavier carcasses than IVPO-treated heifers (P < 0.05). Heifers treated with SG+IVPO also had more (P = 0.07) carcasses grading USDA Prime or Choice than IVPO-treated heifers. In the second study, heifers treated with SG+IVPO had fewer (P < 0.01) worm eggs per fecal sample 35 d after treatment and had fewer numbers of adult and larval Cooperia and Trichostrongylus spp. in the small intestine at slaughter (P < 0.10) compared with heifers treated with DMX. Heifers treated with SG+IVPO consumed more DM, were heavier at slaughter, and had heavier carcasses than DMX-treated heifers (P < 0.01). The SG+IVPO-treated heifers also had greater ADG (P < 0.10). The broad-spectrum effectiveness of a combination of a fenbendazole oral drench and an ivermectin pour-on reduced parasite burden and increased feed intake, ADG, and carcass weight in feedlot heifers compared with treatment with an endectocide alone.     

A comparison of plasma metabolite levels in goats and sheep during continuous low-level administration of fenbendazole

Plasma levels of fenbendazole (FBZ) and its sulphoxide (OFZ) and sulphone (FBZ.SO₂) metabolites were measured in goats and sheep during low-level administration of FBZ given by intraruminal infusion or formulated into a urea-molasses feed supplement block (UMB). In experiment 1, 6 goats and 6 sheep were offered UMB containing 0.5 g FBZ/kg (MUMB) and individual block consumption was measured daily for 18 days. In experiment 2, some of the same animals (n=4 for each species) received FBZ by intraruminal infusion at 1, 1.5 and 3 mg/kg liveweight per day for 7 days at each dosage. FBZ, OFZ and FBZ.SO levels were determined in plasma collected every 3 days in experiment 1 and on days 4, 5 and²6 of each infusion period in experiment 2. In both experiments, higher equilibrium levels were observed for the three metabolites in sheep than in goats. Significant linear relationships were observed between the daily FBZ dosages and the plasma levels of the three metabolites in both species. The regression coefficients were significantly higher in sheep than in goats for FBZ and OFZ but not for FBZ.SO₂, and they were also significantly higher during MUMB administration than during infusion for all three metabolites in both species. FBZ is a suitable anthelmintic for incorporation into a MUMB formulation for use in livestock production systems where responses to molasses urea supplementation have been demonstrated and gastrointestinal parasitism impairs productivity. The results indicate that target dose rates for goats should be 0.75 mg/kg per day compared with 0.5 mg/kg per day for sheep.Abbreviations ANOVA analysis of variance - FBZ fenbendazole - FBZ.SO₂ fenbendazole sulphone - HPLC high-performance liquid chromatography - MUMB urea-molasses feed supplement block containing 0.5 g fenbendazole/kg - OFZ fenbendazole sulphoxide - UMB urea-molasses feed supplment block     

Control of ostertagiasis in young cattle under intensive grazing

The present communication is concerned with the effect of treatment with anthelmintics on animal performance in a system of beef production which was designed to make maximum use of grass and grass products. In the system under investigation a Leader/Follower system of grzing (i.e. Grazing calves in front of older cattle in the rotation) is adopted with conserved and grazing areas alternating during the season.Calves dosed with either levamisole or fenbendazole at time of change to aftergrass in mid-June performed significantly better than undosed controls. As judged by changes in serum persinogen levels (and liveweight gains in 1 year), dosing calces with fenbendazole at the end of the first grazing season was effective in removing inhibited larvae of Ostertagia ostertagi. Significant differences were found in both carcase weight and killing out percentage in the fenbendazole treated group.     

Productivity and Morphologic Traits of Thickspike Wheatgrass,Snake River Wheatgrass,and Their Interspecific Hybrids

Many rangeland restoration sites in the Intermountain West are environmentally challenging due to low precipitation and invasive species competition; thus, more effective native plant materials are needed. We aim to develop improved Snake River wheatgrass (Elymus wawawaiensis) germplasm through hybridization of this widely used bunchgrass with its nearest relative, the rhizomatous thickspike wheatgrass (E. lanceolatus), followed by backcrossing to Snake River wheatgrass. This approach can potentially introduce desirable adaptive traits from thickspike wheatgrass into Snake River wheatgrass. We measured shoot and root dry matter per plant (DMPP), specific leaf area, C:N ratio, and specific root length (SRL) of nine Elymus populations at two planting densities (25 and 7.8 plants m^? 2) in two repeated field experiments established from transplants in May 2005 and 2006, both at Millville, Utah. Populations included “Bannock” thickspike wheatgrass; “Secar,” “Discovery,” and three experimental Snake River wheatgrass populations; and three interspecific backcross hybrid populations. Compared with Snake River wheatgrass, the backcross hybrids displayed 10.4 ? 33.7% greater shoot DMPP (P < 0.0001) but 12.5 ? 16.5% lower root dry matter (DM) density (P < 0.05) across 6 and 2 comparisons, respectively, resulting in reduced root-to-shoot ratio. Compared with Snake River wheatgrass, Bannock displayed 38.6 ? 158.2% greater shoot DMPP (P < 0.0001) across six comparisons. In addition, Bannock displayed 22.4% lower SLA (P < 0.01) and 11.1% higher C:N ratio (P < 0.05) than Snake River wheatgrass and the backcross hybrids, traits suggestive of a low-nutrient growth strategy. These data suggest that Bannock achieved its consistently greater shoot DMPP during each growth period despite such a strategy. Hence, its greater productivity likely relates to a superior temporal and/or spatial ability to sequester resources that fuel growth. In this regard, Bannock displayed similar (P > 0.05) or 17% greater (P < 0.05) root DM density and 13.4% greater (P < 0.05) SRL than Snake River wheatgrass, as well as rhizomes.     

Urolithiasis in a Herd of Beef Cattle Associated with Oxalate Ingestion

An unusually high incidence of urinary calculi in a group of feeder cattle is described. Necropsy findings in one affected animal suggested that oxalates in the feed, specifically in fescue (Festuca spp.) seed screenings, may have been the cause. Low dietary calcium and decreased water intake by the cattle appear to have been predisposing factors. Control measures are discussed.     

Bioencapsulation of Fenbendazole in Adult Artemia

Fenbendazole was detected in adult brine shrimp tissue (bioencapsulation) after enrichment periods of 15 minutes, 30 minutes, 1 hour, 2 hours, 4 hours, 8 hours, 12 hours, and 24 hours in baths that contained 2-, 4-, and 8-g/L concentrations of fenbendazole. The assays were performed using high-performance liquid chromatography. A biphasic pattern of peak concentrations at 30 minutes or 1 hour and again at 8 or 12 hours was seen in the shrimp for all treatment concentrations. Percent of fenbendazole available that was incorporated in Artemia approached 100% for all treatment groups. Survival of shrimp was not affected by any of the fenbendazole concentrations, but animal deaths increased with time in all treatment concentrations. It can be concluded that fenbendazole can be successfully bioencapsulated in adult Artemia.     

Disposition of fenbendazole in the rabbit

The disposition of fenbendazole was studied in rabbits following either oral or intravenous administration. The major metabolites appearing in plasma were fenbendazole sulphoxide (oxfendazole) and fenbendazole sulphone. Calculation of the total urinary and faecal elimination of the drug and of its known metabolites showed that only 40 per cent of the dose was recovered after oral dosing; 29.7 per cent after an intravenous dose. The sulphoxide and sulphone were minor elimination products. The major excretory metabolite was p-hydroxyfenbendazole.     

Evaluating the efficacy of alfaxalone in corn snakes (Pantherophis guttatus)

ObjectiveAlfaxalone is a popular veterinary anesthetic; however, research on this anesthetic in snakes has been limited to ball pythons, garter snakes and several Australian species. The objective was to evaluate the anesthetic effects of alfaxalone in corn snakes (Pantherophis guttatus), a popular pet snake.Study designProspective, randomized crossover study.AnimalsA total of eight corn snakes.MethodsIn phase I, snakes were subcutaneously administered three doses of alfaxalone (5, 10 and 15 mg kg^–1) in the cranial third of the body to determine the most effective dose. In phase II, a dose of 15 mg kg^–1 was administered in the cranial and caudal thirds of the snakes to determine if injection site affected anesthesia duration. Heart rate (HR), respiratory rate (f_R), righting reflex, escape response, tail pinch, needle prick and tongue flick were monitored at baseline and 5 minute intervals until the snakes fully recovered.ResultsDuration of anesthesia differed significantly, with higher doses lasting longer than lower doses: 5 mg kg^–1 [23.8 ± 4.4 (15–30) minutes]; 10 mg kg^–1 [40.6 ± 9.4 (25–55) minutes]; and 15 mg kg^–1 [56.9 ± 8.4 (50–70) minutes], mean ± standard deviation (range). The tail pinch reflex was not completely lost in phase 1. There was a significant change in f_R over time, but this was not related to dose. HR was not different by time or dose. Duration of anesthesia was not different after administration of alfaxalone (15 mg kg^–1) in the cranial third versus the caudal third of the body; however, there was a significant decrease in HR and f_R at this dose, regardless of injection site.Conclusions and clinical relevanceBased on these results, alfaxalone (15 mg kg^–1) provides adequate anesthesia for brief procedures or intubation; however, additional analgesia is required for painful procedures.     

Susceptibility of fourth-stage Ascaris suum larvae to fenbendazole and to host response in the pig

Fenbendazole given at the rate of 2.5 g/kg of feed for 3 days had 100% efficacy against 4th-stage Ascaris suum larvae in 8 pigs. Eight control pigs had a total of 108 A suum. In 6 pigs infected 3 times with 3rd-stage A suum larvae and treated with fenbendazole after the larvae molted to the 4th stage, the challenge exposure-derived population was decreased by 64%. Similar sequential infections in 6 pigs similarly infected, but not treated with fenbendazole, decreased the challenge exposure-derived population by 98%; however, developing and/or adult worms from the vaccinating infections were present.     

Subclinical effects and fenbendazole treatment of turkey ascaridiasis under simulated field conditions

Under simulated natural conditions of bird production and parasite challenge, the effects of ascaridiasis and the effectiveness of fenbendazole treatment (6-day regimes in the feed at 16 ppm) were documented. Birds were artificially challenged with ascarid larvae on a daily basis from day 35 to 112, with bird grow out ending on day 119. Experimental groups, on a per pen basis, were infected control, treated with fenbendazole at days 63-69, treated with fenbendazole at days 63-69 and days 91-97, and uninfected control. In the same order as above, and on an experimental group mean bird basis, final weights were 13.34, 13.47, 13.59, and 13.78 kg, average daily gains from day 7 to day 119 were 117.8, 118.9, 120.1, and 121.8 g, and units gained per unit of feed consumed from day 7 to day 119 were 0.337, 0.341, 0.347, and 0.362. Infected control bird mean Ascaridia dissimilis burdens, with all stages combined, ranged from 351.1 on day 63 to 117.2 on day 91, levels seen commonly with naturally infected commercial turkeys. Trial data dearly indicated that moderate A. dissimilis burdens negatively impacted animal performance (average daily gains and feed efficiencies) and that these parasite burdens are effectively removed by fenbendazole treatment.     

Evaluation of three formulations of fenbendazole (10% suspension, 0.5% pellets, and 20% premix) against nematode infections in cattle

Anthelmintic efficacies of 3 formulations of fenbendazole were evaluated in cattle naturally parasitized with nematodes: a 10% oral suspension, 0.5% pellets as a top dressing on feed, and a 20% premix. All formulations of fenbendazole were greater than 99% effective in removing adults of Haemonchus contortus, Ostertagia spp, Cooperia spp, and Oesophagostomum radiatum. Fenbendazole was greater than 96% effective in removing adults of Strongyloides papillosus and greater than 85% effective in the removal of Trichuris sp. Fenbendazole was greater than 96% effective against immature nematodes, which were thought to be primarily Cooperia spp. Adverse reactions were not observed in calves treated with the 3 formulations of fenbendazole.     

Efficacy of dichlorvos, fenbendazole, and ivermectin in swine with induced intestinal nematode infections

Anthelmintic efficacies of dichlorvos, fenbendazole, and ivermectin were compared in specific-pathogen-free crossbred weanling pigs inoculated with Ascaris suum, Trichuris suis, and Oesophagostomum dentatum. On postinoculation day (PID) 50, 24 pigs in each treatment group were treated orally with 43 mg of dichlorvos/kg of body weight, 3 X 3 mg of fenbendazole/kg, or 300 micrograms of ivermectin/kg, SC. Twenty-four pigs were not treated. On posttreatment day 7 (PID 57), 12 pigs from each treatment group (phase I) were slaughtered, and the anthelmintic efficacy of each treatment was determined. Efficacies against A suum, T suis, and O dentatum, respectively, were: dichlorvos, 100%, 99.9%, and 100%; fenbendazole, 100%, 99.8%, and 100%; and ivermectin, 98.7%, 53.9%, and 87.6%. Weight gains and feed conversions of the remaining pigs were monitored until they reached market weight (phase II). The average weight gains (kg) and feed conversions (kg of feed/kg of gain) at posttreatment day 81 (PID 131), respectively, were: 73.6 and 3.44 for nontreated controls, 78.9 and 3.31 for dichlorvos-treated pigs, 72.1 and 3.36 for fenbendazole-treated pigs, and 74 and 3.48 for ivermectin-treated pigs. Differences in average weight gains and feed conversions were not significant (P greater than 0.05).     

Morphological changes in trichostrongylid eggs after treatment with fenbendazole

The influence of daily doses of 0.05–0.1 mg fenbendazole/kg body weight on egg development was tested in twenty-seven lambs artificially infected with Haemonchus contortus plus Trichostrongylus colubriformis or Ostertagia circumcincta, as well as in two additional sheep naturally infected with Nematodirus spp.Atypical eggs were detected before a reduction in the number of eggs. Atypical eggs had blastomeres of different sizes and shapes; knot-like, crater-like or bubble-like. In isolated cases eggs with atypical first larvae were recognizable. Morphologically changed eggs occurred in the reproductive organs of female O. circumcincta worms.None, or only a very small number of third stage larvae, could be cultured from the faeces of treated sheep.     

Strategic anthelmintic treatment of young cattle during summer in a Mediterranean-type climatic environment

A worm-control program utilising treatment of young grazing cattle with fenbendazole on two occasions during summer was tested in the Mediterranean-type climatic environment of south-west Western Australia. The grazing system aimed to produce steers by introducing three-month-old weaned calves to pasture in mid-winter until they were sold in early summer. Comparisons were made of the numbers of worm eggs passed on to plots by treated and untreated animals during autumn, the performances of treated and untreated cattle and the performances of calves introduced to the plots in mid-winter. The “tracer” calf technique was used to determine the availability of infective larvae on one untreated and one treated plot for each of the two years of the experiment.Treated animals deposited less Ostertagia spp. eggs on to pasture during autumn than did untreated animals in one of the two years. In both years they deposited less eggs of worm species other than Ostertagia spp. Less intestinal worms were acquired by “tracer” calves grazing treatment plots than those grazing no-treatment plots in both years, but there were no differences in the number of abomasal worms acquired.The reduction in availability of infective larvae of intestinal worms was insufficient to prevent the occurrence of parasitic gastroenteritis in calves introduced to the plots in mid-winter. The fenbendazole treatments did not confer any immediate body-weight advantage on treated animals.On both treatment and no-treatment plots, there were few infective larvae available to grazing cattle during early autumn, there was a rapid attainment of peak availability in winter and then a decline to low availability by mid-spring. In one year, infective larvae of intestinal worms (almost exclusively Cooperia spp.) increased in availability again in late spring and early summer. A high proportion of retarded worms was never a feature of the worm counts of “tracer” calves.It was concluded that the treatments may have been more effective had they been given during autumn.