Effect of the injection site on the pharmacokinetics of procaine penicillin G in horses     

E C Firth  J F Nouws  F Driessens  P Schmaetz  K Peperkamp  W R Klein 《American journal of veterinary research》1986,47(11):2380-2384

The plasma penicillin concentrations were determined in 5 horses given an IV injection of sodium penicillin G; plasma penicillin concentrations were also determined in a crossover experiment, where animals were given procaine penicillin G subcutaneously at 1 site and IM at 4 sites. The mean penicillin plasma peak concentration and bioavailability were highest after the drug was injected in the neck and biceps musculature. Injections in the gluteal muscle and in the subcutaneous sites resulted in similar, but lower, more persistent penicillin plasma concentrations and a lower bioavailability than were obtained with injection in the neck and biceps musculature. The pharmacokinetic data obtained after penicillin was administered via the pectoral muscle route exhibited an intermediate position. Therapeutic implications of the routes of administration with respect to hemolytic streptococcal infections are discussed.  相似文献   

An induced synovitis disease model in ponies     

E C Firth  T Wensing  F Seuren 《The Cornell veterinarian》1987,77(2):107-118

The effects of intra-articular injection of small amounts of E. coli lipopolysaccharide (LPS) into the intercarpal joint of 5 ponies were studied. The LPS induced predictable changes all of which were analogous to acute bacterial infection, except that the development of signs occurred sooner after the LPS injection, and subsided within 36 hours. Fever was monophasic and peaked at 5-7 hours. The ponies exhibited depression, reduced or absent appetite, increased pulse and respiration rates, and lameness. The lameness became evident between 1 and 2 hours after injection, at which time warmth, articular effusion, and resentment to palpation of joint flexion were evident. Hematological changes included neutrophilic leucocytosis, and changes in copper, iron and zinc serum concentrations. The synovial fluid total protein, leucocyte, and alkaline phosphatase levels increased within 2 hours. The mucin precipitation, total protein and leucocyte counts in synovial fluid remained elevated long after clinical and hematological changes had subsided. The model is useful for the study of some aspects of infectious joint disease.  相似文献   

Susceptibility of freshly-mulesed lambs to flystrike and the effectiveness of propetamphos as a wound dressing     

SA HARRINGTON  EC STEINER 《Australian veterinary journal》1993,70(5):190-191

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Comparison of the effects of morphine administered by constant-rate intravenous infusion or intermittent intramuscular injection in dogs     

Lucas AN  Firth AM  Anderson GA  Vine JH  Edwards GA 《Journal of the American Veterinary Medical Association》2001,218(6):884-891

OBJECTIVE: To compare physiologic and analgesic effects of morphine when given by IV constant-rate infusion or by IM injection to dogs undergoing laparotomy and to determine pharmacokinetics of morphine in dogs following IV constant-rate infusion. DESIGN: Prospective randomized controlled trial. ANIMALS: 20 dogs. PROCEDURE: Dogs undergoing laparotomy were treated with morphine beginning at the time of anesthetic induction. Morphine was administered by IV infusion (0.12 mg/kg/h [0.05 mg/lb/h] of body weight) or by IM injection (1 mg/kg [0.45 mg/lb]) at induction and extubation and every 4 hours thereafter. Treatments continued for 24 hours after extubation. RESULTS: Blood gas values did not indicate clinically significant respiratory depression in either group, and degree of analgesia (determined as the University of Melbourne Pain Scale score) and incidence of adverse effects (panting, vomiting, defecation, and dysphoria) were not significantly different between groups. Dogs in both groups had significant decreases in mean heart rate, rectal temperature, and serum sodium and potassium concentrations, compared with preoperative values. Mean +/- SEM total body clearance of morphine was 68 +/- 6 ml/min/kg (31 +/- 3 ml/min/lb). Mean steady-state serum morphine concentration in dogs receiving morphine by constant-rate infusion was 30 +/- 2 ng/ml. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that administration of morphine as a constant-rate IV infusion at a dose of 0.12 mg/kg/h induced effects similar to those obtained with administration at a dose of 1 mg/kg, IM, every 4 hours in dogs undergoing laparotomy. Panting was attributed to an opioid-induced resetting of the hypothalamic temperature set point, rather than respiratory depression.  相似文献   

Effects of exercise on tenocyte cellularity and tenocyte nuclear morphology in immature and mature equine digital tendons     

Stanley RL  Goodship AE  Edwards B  Firth EC  Patterson-Kane JC 《Equine veterinary journal》2008,40(2):141-146

REASON FOR PERFORMING STUDY: The injury-prone, energy-storing equine superficial digital flexor tendon (SDFT) of the mature performance horse has a limited ability to respond to exercise in contrast with the noninjury-prone, anatomically opposing common digital extensor tendon (CDET). Previous studies have indicated low levels of cellular activity in the mature SDFT, but in foal tendons the tenocytes may still have the ability to adapt positively to increased exercise. OBJECTIVES: To measure tenocyte densities and types in histological sections from the SDFT and CDET of horses from controlled long-term, short-term and foal exercise studies. METHODS: Specimens were collected from mid-metacarpal segments of the CDET and SDFT for each horse and processed for histology; central and peripheral regions of the SDFT cross-section were analysed separately (SDFTc, SDFTp). Tenocyte nuclei were counted in a total area of 1.59 mm(2) for each tendon region in each horse. Each nucleus was classified as type 1 (elongate and thin), type 2 (ovoid and plump) or type 3 (chondrocyte-like); type 1 cells are proposed to be less synthetically active than type 2 cells. RESULTS: No significant differences were noted between exercise and control groups in any of the studies, with the exception of an exercise-related reduction in the proportion of type 1 tenocytes for all tendons combined in the long-term study. There were tendon- and site-specific differences in tenocyte densities and proportions of type 1 and 2 cells in all 3 studies. CONCLUSIONS AND POTENTIAL RELEVANCE: There was no indication that exercise increased tenocyte density or proportions of the (theoretically) more active type 2 cells in immature horses (short-term and foal studies), perhaps because the training regimens did not achieve certain threshold strain levels. In the foal study these findings can still be interpreted positively as evidence that the training regimen did not induce subclinical damage.  相似文献   

A cross-sectional survey of Thoroughbred stud farm management in the North Island of New Zealand     

Rogers CW  Gee EK  Firth EC 《New Zealand veterinary journal》2007,55(6):302-307

AIM: To obtain initial baseline data on the management of Thoroughbred stud farms in the North Island of New Zealand. METHODS: Data on the management of Thoroughbred stud farms were collected from a sample of 22 stud farms located in the south Auckland/Waikato region (n=15) and lower North Island (n=7) of New Zealand, using a face-to-face survey. The studmaster provided information on the size, scope and management of the farms during the 2004/2005 breeding season. Analysis was based on the location of the farm and size of the breeding operation (number of resident mares). RESULTS: Effective farm size ranged from 20 to 526 ha and averaged 167 (standard error (SE) 36) and 88 (SE 49) ha in the south Auckland/Waikato and lower North Island areas, respectively. Some farms in the Auckland/Waikato region stood shuttle stallions. The median number of stallions per farm was three (range 0-9), and the median mare-to-stallion ratio was 43 (range 10-250). The farms had a mean of 50 (range 7-180) wet mares and 21 (range 0-100) dry mares. The number of mares per breeding stallion increased with increasing size of breeding operation (p=0.04), being 28 (95% confidence interval (CI) = 10-56) vs 40 (95% CI=16-74) vs 74 (95% CI=44-113) for moderate (or=200 mares in total) operations, respectively. Seventy-one percent of farms aimed to breed dry mares early in the breeding season, and used a combination of lights, hormone therapy, and rising plane of nutrition to achieve this. Foaling took place in foaling paddocks monitored using a night foaling attendant (17/22) or with foaling alarms (5/22). At birth, 17/22 studmasters routinely administered antibiotics, 14/22 administered tetanus antitoxin, 9/22 administered an enema to foals, and 2/22 did not routinely administer prophylactic treatments. Weaning occurred at 5 (range 3.7-7) months of age, and foals were confined to a box for 1-2 weeks on 16/22 farms. Weaned foals were drenched with anthelmintics every 7 (range 4-9) weeks, and were fed 2.9 (range 1-6) kg of concentrate feed while at pasture until intensive management associated with preparation of the horses for auction began 13 (range 6-20) weeks before the yearling sales. Eight farms weighed the weanlings, at least monthly, to monitor growth. CONCLUSIONS AND CLINICAL RELEVANCE: The management of Thoroughbred horses was relatively consistent throughout the regions surveyed. Utilisation of breeding stallions tended to be more efficient on the larger stud farms in the south Auckland/Waikato region. Even though foals are grown at pasture they are often provided with large quantities of concentrate feed.  相似文献   

Osteochondrosis and copper: histology of articular cartilage from foals out of copper supplemented and non-supplemented dams     

Gee E  Davies M  Firth E  Jeffcott L  Fennessy P  Mogg T 《Veterinary journal (London, England : 1997)》2007,173(1):109-117

Copper (Cu) supplementation of dams in late gestation may be protective against articular cartilage abnormalities in foals. Articular cartilage was harvested from 22 Thoroughbred foals at 160 days of age, at sites predisposed to osteochondrosis (OC), and examined for evidence of early cartilage abnormalities and established dyschondroplastic (DCP) lesions to determine if there were any significant differences due to mare Cu supplementation by injection during late gestation, or foal liver Cu concentration. Cu supplemented mares received calcium Cu edetate injections in late gestation (250 mg at around 220, 248, 276 and 304 days gestation, then every two weeks until foaling). Foals were euthanased at 160 days of age and articular cartilage was harvested from four defined sites. Samples were examined for histological appearance of chondrocytes after staining with haematoxylin and eosin, and were also stained with toluidine blue to indicate proteoglycan content. Alkaline phosphatase (ALP) activity was detected by histochemistry, and histocytochemical techniques were used to determine the expression of cathepsin B. Cu supplementation of the dam, or liver Cu concentration of the foal at birth or 160 days of age had no statistically significant effect on the frequency of cartilage irregularities observed grossly, or abnormalities detected histologically at four defined sites. ALP expression was similar in all samples. Cathepsin B expression varied between sites, and was seen in chondrocyte clusters. The intensity of toludine blue staining varied between sites. Minor histological cartilage abnormalities were observed in cartilage from clinically normal animals. These abnormalities might be 'early' dyschondroplastic lesions, which could resolve or progress. The role of Cu in the development, resolution or progression of dyschondroplastic lesions is poorly understood.  相似文献   

Prevalence of exon 11 internal tandem duplications in the C‐KIT proto‐oncogene in Australian canine mast cell tumours          下载免费PDF全文

VS Tamlin  AE Kessell  RJ Mccoy  EC Dobson  TS Smith  M Hebart  L Brown  D Mitrovic  AE Peaston 《Australian veterinary journal》2017,95(10):386-391

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Evidence for new sources of NOX in the lower atmosphere     

EC Zipf  SS Prasad 《Science (New York, N.Y.)》1998,279(5348):211-213

Laboratory studies show that the reaction of short-lived O2(B3Sigmau) molecules (lifetime approximately 10 picoseconds) with N2 and the photodissociation of the N2:O2 dimer produce NOx in the stratosphere at a rate comparable to the oxidation of N2O by O(1D). This finding implies the existence of unidentified NOX sinks in the stratosphere. The NO2 observed in this experiment is isotopically heavy with a large 15N/14N enhancement. However, photodissociation of this NO2 unexpectedly produced NO molecules with a low 15N/14N ratio. The diurnal odd-nitrogen cycle in the stratosphere will be marked by a complex isotope signature that will be imprinted on the halogen and HOX catalytic cycles.  相似文献