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Abstract

OBJECTIVE To determine the pharmacokinetics of pergolide after IV administration to horses.

ANIMALS 8 healthy adult horses.

PROCEDURES Pergolide mesylate was administered IV at a dose of 20 μg/kg (equivalent to 15.2 μg of pergolide/kg) to each horse, and blood samples were collected over 48 hours. Pergolide concentrations in plasma were determined by means of high-performance liquid chromatography–tandem mass spectrometry, and pharmacokinetic parameters were determined on the basis of noncompartmental methods.

RESULTS After IV administration of pergolide, mean ± SD clearance, elimination half-life, and initial volume of distribution were 959 ± 492 mL/h/kg, 5.64 ± 2.36 hours, and 0.79 ± 0.32 L/kg, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE With an elimination half-life of approximately 6 hours, twice-daily dosing may be more appropriate than once-daily dosing to reduce peak-trough fluctuation in pergolide concentrations. Further pharmacodynamic and pharmacokinetic studies of pergolide and its metabolites will be necessary to determine plasma concentrations that correlate with clinical effectiveness to determine the therapeutic range for the treatment of pituitary pars intermedia dysfunction.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To establish a nonterminal semen collection method for use in captive Chilean rose tarantulas (Grammostola rosea) and to evaluate tools for investigating morphology and viability of spermatozoa.

Animals—7 mature male Chilean rose tarantulas.

Procedures—Each tarantula was anesthetized in a 500-mL induction chamber containing a cotton ball infused with 2 mL of isoflurane. Semen collection was performed by applying direct pressure to the palpal bulbs (sperm storage organs) located on the distal segment of the palpal limbs. Morphology of spermatozoa was examined by light microscopy and transmission and scanning electron microscopy. Propidium iodide and a fluorescent membrane-permeant nucleic acid dye were used to evaluate cell viability.

Results—Semen was collected successfully from all 7 tarantulas. Microscopic examination of semen samples revealed coenospermia (spherical capsules [mean ± SD diameter, 10.3 ± 1.6 μm] containing many nonmotile sperm cells [mean number of sperm cells/capsule, 18.5 ± 3.8]). Individual spermatozoa were characterized by a spiral-shaped cell body (mean length, 16.7 ± 1.4 μm; mean anterior diameter, 1.5 ± 0.14 μm). Each spermatozoon had no apparent flagellar structure. The fluorescent stains identified some viable sperm cells in the semen samples.

Conclusions and Clinical Relevance—The described technique allowed simple and repeatable collection of semen from Chilean rose tarantulas. Semen from this species was characterized by numerous spherical capsules containing many nonmotile spermatozoa in an apparently quiescent state. Fluorescent staining to distinguish live from dead spermatozoa appeared to be a useful tool for semen evaluation in this species.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine hip, stifle, and tarsal joint ranges of motion (ROM) and angular velocities during swimming and walking in healthy dogs and dogs with surgically corrected cranial cruciate ligament (CCL) rupture.

Design—Prospective clinical study.

Animals—13 healthy dogs and 7 dogs with CCL rupture.

Procedure—Dogs with CCL rupture were enrolled in a postoperative aquatic rehabilitation program and evaluated 21 to 35 days after surgery. Dogs were filmed while swimming in a pool and while walking at a fast (1.3 m/s) or slow (0.9 m/s) pace on a treadmill. Maximal angles of extension and flexion, ROM, and angular velocities were calculated.

Results—In healthy dogs, swimming resulted in a significantly greater ROM in the hip joint than did walking, but in dogs with CCL rupture, ROM of the hip joint did not vary with swimming versus walking. For dogs in both groups, swimming resulted in significantly greater ROM of the stifle and tarsal joints than did walking, primarily because of greater joint flexion. Stifle joint ROM was significantly lower in dogs with CCL rupture than in healthy dogs, regardless of whether dogs were swimming or walking.

Conclusions and Clinical Relevance—Results suggested that following surgical management of a ruptured CCL in dogs, swimming resulted in greater ROM of the stifle and tarsal joints than did walking. This suggests that if ROM is a factor in the rate or extent of return to function in these dogs, then aquatic rehabilitation would likely result in a better overall outcome than walking alone. (J Am Vet Med Assoc 2003;222:739–743)

Full access
in Journal of the American Veterinary Medical Association

Abstract

CASE DESCRIPTION

4 wild adult rat snakes (Pantherophis alleghaniensis) were evaluated after ingesting spherical or ovoid foreign bodies.

CLINICAL FINDINGS

Physical examination revealed a large, firm mass at the level of the stomach in each snake. Radiographic findings were consistent with ingestion of a golf ball (3 snakes) or an artificial egg (1 snake). Signs consistent with prolonged impaction included scale loss, dermal abrasions, and apparent loss of body condition in one snake and regional skin ulceration, dehydration, and generalized muscle atrophy in another.

TREATMENT AND OUTCOME

Nonsurgical removal of the foreign body was attempted in anesthetized or heavily sedated snakes by external manipulation in the orad direction. A golf ball was removed through the oral cavity without complications in 1 snake. In the other 3 snakes, tension caused by the advancing foreign body resulted in full-thickness skin rupture in the cervical region. The procedure was completed with the use of a balloon catheter to aid foreign body advancement for 1 of the 3 snakes, and the skin defect was closed. The procedure was converted to esophagotomy for the other 2 snakes. Three snakes recovered and were released; 1 died of complications from prolonged impaction and esophageal perforation.

CLINICAL RELEVANCE

The described nonsurgical techniques for removal of ingested round or ovoid foreign bodies were associated with substantial complications in 3 of 4 treated rat snakes. Although a nonsurgical method for removal of ingested objects such as golf balls could benefit snakes, the methods used for these patients did not appear to be more beneficial than traditional gastrotomy.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective

To determine effects of dietary protein and calories on progression of induced chronic renal failure in cats.

Animals

28 young adult female cats.

Procedure

Renal mass was reduced surgically, and glomerular filtration rate (GFR) was determined. Cats were allotted to 4 groups of 7 with similar mean GFR (1.52 to 1.55 ml/min/kg of body weight). Diets were formulated to provide: low protein and calorie (diet A), low protein and high calorie (diet B), high protein and low calorie (diet C), and high protein and calorie (diet D) intakes. Cats were fed their prescribed diet for 12 months, then blood and urine biochemical variables were measured, after which kidney specimens were examined microscopically.

Results

Protein intake by cats of groups C and D (9.0 g/d/kg) was substantially greater than that by cats of groups A and B (5.3 and 5.2 g/d/kg, respectively). Caloric intake by cats of groups B and D (73 and 71 calories/d/kg, respectively) was greater than that by cats of groups A and C (58 and 55 calories/d/kg, respectively). Renal glomerular lesions were mild and not affected by protein, calories, or their interactions. Nonglomerular lesions, though mild, were significantly influenced by calorie intake, but not by protein or calorie-protein interactions. The GFR did not decrease in any group. Urine protein-to-creatinine ratio increased significantly in all groups after reduction of renal mass, but values from all groups remained within the reference range (0 to 0.3).

Conclusions and Clinical Relevance

Diets replete in protein were not associated with increased severity of glomerular or nonglomerular renal lesions, increased proteinuria, or decreased GFR. Diets replete in calories were not associated with increased severity of glomerular lesions, but were associated with mild increase of nonglomerular lesions. Factors other than protein and calorie intake must be considered potential causes of progression of renal failure in cats. Results raise questions about the practice of restricting quantity of protein in the diet of cats with chronic renal failure, with the intention of ameliorating development of further renal damage. (Am J Vet Res 1998;59:575–582)

Free access
in American Journal of Veterinary Research

Objectives

To evaluate effects of tilmicosin when used in fever-based and metaphylactic treatment programs to attenuate acute undifferentiated bovine respiratory disease (BRD) in cattle that recently arrived at feedlots, and to evaluate the effects of tilmicosin for the treatment of BRD.

Design

Randomized-block controlled study.

Animals

1,639 calves from livestock auctions.

Procedures

Cattle were assigned to 3 groups. Cattle in the nonmedicated (control) group were not given antibiotics during processing. Cattle in the fever-based treatment group were given tilmicosin (10 mg/kg [4.5 mg/lb] of body weight, SC) during processing when their rectal temperature was ≥ 40 C (104 F). All cattle in the metaphylactic treatment group were given tilmicosin (10 mg/kg, SC) during processing. Calves with BRD were treated with tilmicosin (10 mg/kg, SC).

Results

Morbidity rates in the metaphylactic (30.4%) and fever-based (44.7%) treatment groups were less than that for the nonmedicated group (54.8%). Mortality rate for the metaphylactic group during the first 28 days (1.1%) and during the entire study (1.7%) was less than that for the nonmedicated group (3.3 and 4.6%, respectively). Differences were not observed in therapeutic response rates among calves with BRD that were treated.

Clinical Implications

Fever-based and metaphylactic treatment programs that used tilmicosin decreased the prevalence of BRD and improved growth of calves. Metaphylactic treatment decreased the number of fatalities caused by BRD in high-risk calves. Fever-based treatment was less effective than metaphylactic treatment for decreasing the prevalence of BRD in newly arrived cattle. (J Am Vet Med Assoc 1998,212:1919–1924)

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate whether immunosuppressive doses of cyclosporine (CsA) have an adverse effect on the liver, kidney, and pancreatic beta cells of pigs.

Animals—8 juvenile 8-week-old Landrace X Large White crossbred pigs.

Procedure—CsA (100 to 140 mg/kg) was administered orally to euglycemic pigs to reach whole blood trough concentrations of approximately 1500 ng/mL. To determine pancreatic beta cell function, plasma Cpeptide and insulin concentrations were measured in response to IV administration of glucose, glucagon, arginine, and oral administration of glucose. Effects on liver and kidney were determined by monitoring serum measurements of liver function and serum creatinine concentrations, respectively.

Results—Plasma concentrations of C-peptide were significantly lower in euglycemic CsA-treated pigs, compared with control pigs, following IV administration of glucose, glucagon, arginine, and oral administration of glucose. Furthermore, the glucose clearance rate was decreased in euglycemic CsA-treated pigs, compared with control pigs. Serum creatinine concentrations and 4 of 7 serum measurements of liver function were not adversely affected by CsA administration. Serum concentrations of bilirubin and albumin were significantly increased, and serum alanine aminotransferase activity was significantly decreased in CsA-treated pigs, compared with control pigs. Histologic evaluation of liver and kidney sections revealed no pathologic findings in CsA-treated or control pigs.

Conclusions and Clinical Relevance—In our study, immunosuppressive doses of CsA caused an impairment of porcine pancreatic beta cell function, but did not have toxic effects on the kidney. However, on the basis of changes in serum bilirubin and albumin concentrations and alanine aminotransferase activity, subclinical toxic effects on the liver did occur when immunosuppressive doses of CsA were administered. (Am J Vet Res 2002;63:1501–1506)

Full access
in American Journal of Veterinary Research

Abstract

CASE DESCRIPTION A 1-year-old reticulated python (Python reticulatus) was evaluated because of a 2-week history of wheezing and hissing.

CLINICAL FINDINGS Rostral facial cellulitis and deep gingival pockets associated with missing rostral maxillary teeth were evident. Tissues of the nares were swollen, resulting in an audible wheeze during respiration. Multiple scars and superficial facial wounds attributed to biting by live prey were apparent. Radiographic examination revealed bilateral, focal, rostral maxillary osteomyelitis.

TREATMENT AND OUTCOME Wound irrigation, antimicrobials, and anti-inflammatory drug treatment resulted in reduced cellulitis. A 3-week regimen that included empirical antimicrobial treatment and improved husbandry resulted in resolution of the respiratory sounds and partial healing of bite wounds, but radiographic evaluation revealed progressive maxillary osteomyelitis. Microbial culture of blood yielded scant gram-positive cocci and Bacillus spp, which were suspected sample contaminants. Bilateral partial maxillectomies were performed; microbial culture and histologic examination of resected bone confirmed osteomyelitis with gram-positive cocci. Treatment with trimethoprim-sulfamethoxazole was initiated on the basis of microbial susceptibility tests. Four months later, follow-up radiography revealed premaxillary osteomyelitis; surgery was declined, and treatment with trimethoprim-sulfamethoxazole was reinstituted. Eight months after surgery, the patient was reevaluated because of recurrent clinical signs; premaxillectomy was performed, and treatment with trimethoprim-sulfamethoxazole was prescribed on the basis of microbial culture of bone and microbial susceptibility testing. Resolution of osteomyelitis was confirmed by CT 11 months after the initial surgery.

CONCLUSIONS AND CLINICAL RELEVANCE Focal maxillectomies and premaxillectomy were successfully performed in a large python. Surgical management and appropriate antimicrobial treatment resulted in a good outcome.

Full access
in Journal of the American Veterinary Medical Association

Summary

Long-term follow-up information pertaining to 162 dogs with appendicular osteosarcoma treated by amputation alone was collected from 17 veterinary institutions. The majority (72.5%) of dogs died or were euthanatized because of problems documented to be related to metastases. The first clinically apparent sites of metastasis were the lungs (60.8% of total), the skeleton (5.2%), or both (4.6%). A Kaplan-Meier survivorship distribution was plotted on the basis of available survival time data in all 162 dogs. The mean and median survival times were estimated to be 19.8 and 19.2 weeks, respectively, and the 1- and 2-year survival rates were estimated to be 11.5 and 2.0% respectively.

Statistically significant relationships were not found between survival time and reporting institution, gender, site of primary tumor, whether the primary tumor was proximally or distally located, whether the primary tumor was located in the forelimb or hind limb, whether presurgical biopsy was performed, and whether death was tumor related. A significant (P < 0.01) quadratic relationship was found between age and survival time. Survival time was longest in dogs 7 to 10 years old and was shorter in older and younger dogs.

Free access
in Journal of the American Veterinary Medical Association