A field survey of bovine anaplasmosis,babesiosis and tick vector prevalence in the eastern plains of Colombia     

D. E. Corrier  J. M. Cortes  K. C. Thompson  H. Riaño  E. Becerra  R. Rodriguez 《Tropical animal health and production》1978,10(1):91-92

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The recovery of Pasteurella haemolytica from the tonsils of adult sheep   总被引：3，自引：0，他引：3  

N J Gilmour  D A Thompson  J Fraser 《Research in veterinary science》1974,17(3):413-414

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A rapid method for the detection of leptospiraemia.     

C G Mackintosh  J C Thompson 《New Zealand veterinary journal》1979,27(10):224-225

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Use of the electronic computer in retrieval of veterinary pathologic data     

M W Castleberry  E D Jenkins  S W Thompson 《American journal of veterinary research》1966,27(118):824-829

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Effects of deslorelin acetate implants in horses: single implants in stallions and steroid-treated geldings and multiple implants in mares     

Johnson CA  Thompson DL  Cartmill JA 《Journal of animal science》2003,81(5):1300-1307

Three experiments were performed to test the following hypotheses: 1) stallions and/or progesterone-estradiol-treated geldings could serve as models for the effects of a single implant of the GnRH analog, deslorelin acetate, on LH and FSH secretion by mares; and 2) multiple implants of deslorelin acetate could be used as a means of inducing ovarian atrophy in mares for future study of the mechanisms involved in the atrophy observed in some mares after a single implant. In Exp. 1, nine light horse stallions received either a single deslorelin implant (n = 5) or a sham injection (n = 4) on d 0. In Exp. 2, 12 geldings received daily injections of progesterone on d -20 through -4, followed by twice-daily injections of estradiol on d -2 to 0. On the morning of d 0, geldings received either a single deslorelin implant (n = 6) or a sham injection (n = 6). Daily injections of progesterone were resumed on d 2 through 15. In Exp. 1, plasma LH and FSH were elevated (P < 0.05) in the treatment group relative to controls at 4, 8, and 12 h after implant insertion. In the treated stallions, FSH was decreased (P < 0.05) on d 3 to 13, and LH was decreased on d 6 to 13. In Exp. 2, plasma LH and FSH were elevated (P < 0.05) at 4,8, and 12 h after deslorelin implant insertion. Plasma LH was suppressed (P < 0.05) below controls on d 2 to 7, 9, and 11 to 15; plasma FSH was suppressed (P < 0.05) on d 4 to 15. In Exp. 3, 21 mares were used to determine whether multiple doses of deslorelin would cause ovarian atrophy. Mares received one of three treatments: 1) sham injections; 2) three implants on the first day; or 3) one implant per day for 3 d (n = 7 per group). Treatment with multiple implants increased (P < 0.05) the interovulatory interval by 14.8 d and suppressed (P < 0.01) LH and FSH concentrations for approximately 25 d; no mare exhibited ovarian atrophy. In conclusion, after an initial short-term increase in LH and FSH secretion, deslorelin implants caused long-term suppression of both gonadotropins in stallions as well as in geldings treated with progesterone and estradiol to mimic the estrous cycle. It is likely that either of these models may be useful for further study of this suppression in horses. Although multiple implants in mares suppressed gonadotropin secretion longer than a single implant, the lack of ovarian atrophy indicates that the atrophy observed after a single implant in previous experiments was likely due to the susceptibility of individual mares.  相似文献   

Chondrodysplasia of Texel sheep - a new disease of suspected genetic aetiology (abstract)     

Thompson KG  Blair HT  Linney LE  West DM 《New Zealand veterinary journal》2003,51(1):45

A chondrodysplasia characterised by dwarfism and varus deformity of the forelimbs has been recognised over four seasons in Texel and Texel-cross lambs on three related properties. Affected lambs appear normal at birth, but by 2 weeks of age have reduced growth rate, shortened neck and legs, varus forelimb deformities and a progressive reluctance to walk. Most die within the first 4 months of life. Some affected lambs have had normal co-twins. Post mortem examination of two severely affected 3-month-old lambs revealed extensive loss of articular cartilage and exposure of subchondral bone on the weight-bearing surfaces of the proximal humeri and femurs. Articular and physeal cartilages were thicker than normal, suggesting delayed or impaired endochondral ossification. Histopathologically, there was disorganisation of chondrocytes in articular and physeal cartilage of all bones examined. In addition, there were multiple foci of chondrolysis, which coalesced in some areas to form large clefts. The chondroid matrix surrounding chondrocytes had an abnormal fibrillar appearance. One lamb that exhibited early signs of the disease died of an unrelated cause at 3 weeks of age, and although there was no erosion of articular cartilage, characteristic microscopic lesions were present in articular and physeal cartilage. Although most of the affected lambs were born on a commercial property with a mix of different sheep breeds, all had Texel genes on both sire and dam sides of the pedigree. The farmer had been purchasing his Texel rams from the same flock for several seasons. Circumstantial evidence favours a genetic aetiology, characterised by either autosomal recessive inheritance or over dominance. Studies on the genetic and biochemical basis of the disease are continuing.  相似文献   

Brodifacoum toxicosis in two neonatal puppies     

Munday JS  Thompson LJ 《Veterinary pathology》2003,40(2):216-219

Eight out of a litter of 13 puppies were either born dead or died within 48 hours of birth. Three puppies that died shortly after birth were necropsied. Two puppies had hemorrhage in the thoracic and peritoneal cavities, intestinal serosa, and meninges. The third puppy was smaller than the other two puppies but did not have detectable hemorrhage. Brodifacoum, a second-generation coumarin anticoagulant, was detected in livers from the two puppies with hemorrhage. The dam did not have clinical signs of coagulopathy before or subsequent to whelping. The owners were confident that the dog had not been exposed to rodenticide for at least 4 weeks before whelping. A presumptive diagnosis of in utero brodifacoum toxicity was made. To the authors' knowledge this is the first time a second-generation coumarin anticoagulant has been detected in the liver of a newborn animal. This case is also unique because the dam was unaffected, suggesting that fetuses are more susceptible to brodifacoum toxicity than adult animals.  相似文献   

Comparison of anthelmintic activity of pyrantel, praziquantel, and nitazoxanide against Anoplocephala perfoliata in Horses     

Thomas M. Craig DVM  PhD  W.L. Scrutchfield DVM  MS  J.A. Thompson DVM  DVSc  E.E. Bass MS 《Journal of Equine Veterinary Science》2003,23(2):68

Three anthelmintics were compared for efficacy in reducing the egg production of Anoplocephala perfoliata in a herd of central Texas horses. Two trials were run, 1 in mares and the other in weanlings that were diagnosed as being infected with Anoplocephala by recovery of eggs in 5 g of feces with sugar centrifugation. Each animal was evaluated twice before treatment and again twice following treatment (at weeks 2 and 4 after treatment). The criteria for infection were the recovery of eggs on at least 1 occasion before treatment and the finding of eggs on 1 day following treatment. The mares were treated 1 time with either pyrantel pamoate at 13.2 mg/kg, nitazoxanide at 100 mg/kg, praziquantel at 1.23 mg/kg or remained as untreated controls. The weanlings were treated with pyrantel at 13.7 mg/kg nitazoxanide at 100 mg/kg or remained as untreated controls. The percentage reduction of patient infection in mares after treatment with pyrantel was 83%, with nitazoxanide was 78%, and with praziquantel was 83% and in controls was 17%. There was a 75% reduction of patient weanlings treated with pyrantel or nitazoxanide and a 17% reduction in untreated controls. The reduction of infection in all horses treated with any drug was significantly different from controls. All of the drugs were somewhat effective in the control of Anoplocephala, and there were no differences among the drugs in their effectiveness.

Introduction

Anoplocephala perfoliata, the lappeted tapeworm, is an inhabitant of the intestine of equids. Adult tapeworms attach to the intestinal mucosa at the ileocaecal valve and, when present in large numbers, cause edema and hypertrophy of the ileum. The disease manifest by this infection may be inapparent or may give rise to colic (abdominal pain) in the horse apparently from mechanical obstruction or intussusception of the small intestine into the caecocolon.^{1, 2, 3, 4, 5, 6, 7 and 8} The prevalence of infection is geographically variable^{9, 10, 11, 12 and 13} but appears to be increasing,¹⁴ with a much higher rate of infection found with necropsy as opposed to fecal observations. Horses become infected by the ingestion of infected orbatid mites in pastures. Orbatid mites, the intermediate hosts, are predatory and are found in decaying organic material, such as leaf litter. Horses of all ages are infected, but there are lower numbers of clinical cases in horses older than 4 years of age.⁴ The intensity of infection is highest in the late summer and autumn.^{8 and 12} Anthelmintics with reported efficacy against A perfoliata include pyrantel pamoate at 13.2 mg/kg,¹⁰ pyrantel tartrate at 2.6 mg/kg for 30 days,¹⁵ pyrantel embonate at 38 mg/kg,¹⁶ and praziquantel at 1 to 2 mg/kg.^{17 and 18} Nitazoxanide has not been evaluated for Anoplocephala but was included in the trial because of its effects against nematodes and tapeworms in humans.¹⁹ Because Anoplocephala infections may cause disease and there is a perception that current anthelmintics may not be as effective as in the past, a study was done to compare anthelmintics to lower the intensity of fecal egg counts in a herd of horses in central Texas.

Materials and methods

Quarter horse mares and weanlings from a single herd were evaluated with 5 g of feces with a sucrose double centrifugation test to determine whether eggs of Anoplocephala were present.²⁰ Feces from each individual horse were evaluated twice, once approximately 2 weeks before treatment and again on the day of treatment. If Anoplocephala eggs were found on either date, the horse was considered to have positive results. Within each group (mares or weanlings), the treatment selection was randomly allocated as the horses were restrained for treatment. Fecal samples were again evaluated at 14 and 28 days after treatment for the presence or absence of eggs on either day.The dose for each individual horse was determined by chest girth weight tape at the time of treatment. The treatments were as follows: pyrantel pamoate (Strongid-T, Pfizer Animal Health, Exton, Pa) at 13.7 mg/kg via nasogastric intubation (12 mares, 8 weanlings), nitazoxanide oral paste (Nitazoxanide, Idexx Laboratories, Westbrook, Me) at 100 mg/kg (9 mares, 8 weanlings), praziquantel (Droncet injectable, Bayer Corp, Shawnee Mission, Kan) at 1.23 mg/kg via nasogastric intubation (6 mares), and untreated controls (6 mares, 6 weanlings). A 1-tailed Fisher exact test was used to compare rates of infection before and after treatment. If a mare or foal did not have positive results before treatment, it was not evaluated in this study.

Results and discussion

No abnormal clinical signs were seen after treatment with any of the products. Treatment was administered to several additional animals with each product, but they were not included in the analysis if they did not have positive results on 1 of the 2 evaluations before treatment, hence, the different numbers of horses in treatment groups.None of the horses in the trial exhibited clinical signs associated with the infection of A perfoliata. However, before the trial, a mare from the infected herd exhibited signs of colic and Anoplocephala eggs were detected in the feces. Examination of the remainder of the herd gave impetus to the study.Mean egg counts before and after treatment are given in the Table.The presence of strongylate and Parascaris eggs in weanlings served as a control of the methodology of evaluation. The difficulty of finding Anoplocephala eggs has been recognized by several authors,^{5, 8, 13, 14 and 21} but the authors also recognize that when there were greater numbers of parasites there was increased egg production. Therefore, finding of eggs with fecal flotation indicated that there were 20 worms or more. However, there appears to be no correlation between the number of worms and egg counts once the detection threshold is reached,²² so the criterion for evaluation was the presence of eggs in the feces before treatment compared with after treatment. Although mean egg counts were not compared, the number of eggs in each infected horse was less after treatment in all groups compared with untreated controls (Table). The method of evaluation used in this study cannot be equated to those of critical^{10 and 16} or control¹⁴ studies in which horses are killed so that all worms are detected. However, the use of clinical studies to compare compounds is useful in detecting which anthelmintics are likely to be of value against geographically distinct populations of worms. Admittedly, more sampling may have increased the number of horses with positive results, both before and after treatment.  相似文献   

Evaluation of early fetal losses on four equine farms in central Kentucky: 73 cases (2001)     

Morehead JP  Blanchard TL  Thompson JA  Brinsko SP 《Journal of the American Veterinary Medical Association》2002,220(12):1828-1830

OBJECTIVE: To determine features of an early fetal loss (EFL) syndrome and evaluate potential risk factors for EFL in Thoroughbred broodmares on 4 farms in central Kentucky. DESIGN: Retrospective study. ANIMALS: 288 pregnant broodmares. PROCEDURE: Year-2001 breeding records for 288 Thoroughbred broodmares were examined. Early fetal loss was defined as loss of a fetus that was viable at > or = 40 days of gestation but was subsequently lost by 5 months of gestation. RESULTS: Overall 2001 EFL rate was 25% (73/288), median gestational age at time of fetal loss was 77 days, and median date of loss was May 7. Mares on 1 farm had significantly fewer fetal losses (5%) than mares on the other 3 farms (26 to 35%). Fetal losses were higher for maiden (42%) and barren (42%) mares than for foaling mares (18%). Fetal losses were greater in young than in older mares. Effects of broodmare farm, mare age, and reproductive status were all significant. Fetal losses were not associated with sire used for mating or stud farm. CONCLUSIONS AND CLINICAL RELEVANCE: Greatest risk for EFL occurred during the period from late April to May (ie, in mares bred during February through March). Higher incidence of EFL in maiden and barren mares and lower incidence of EFL on 1 farm suggest management or environmental influences may have affected outcome. Risk factors that should be investigated include environmental differences among farms and differences in management procedures used for lactating versus nonlactating mares.  相似文献   

Healthy People 2010--new opportunities for veterinary medicine in the 21st century     

Hendrix CM  McClelland CL  Kahn KL  Thompson I  Pence PA 《Journal of the American Veterinary Medical Association》2002,221(7):951-957

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