Influence of 17-α-Methyltestosterone on Red Tilapia Under Two Thermal Regimes

Fingerling red tilapia ( Oreochromis mossambicus ± O. niloticus ) were orally administered 17-α-methyltestosterone (MT) under a warmwater (27.0 ± 0.5 C) and coolwater (21.5 ± 0.5 C) thermal regime. In the warmwater experiment, fish received either 0, 1, 5, 10, 30, 60, or 100 mg MT/kg feed for 75 days. In the coolwater experiment, fish received 0, 10, or 60 mg MT/kg feed for 75 days followed by a 34 day withdrawal period. After 75 days, fish receiving 60 mg MT/kg feed (best treatment) in the warmwater and coolwater experiments exhibited significantly higher growth rates than controls by 35.3 and 45.8%, respectively. Likewise, feed conversion among groups receiving 60 mg MT/kg feed in the warmwater and coolwater experiments were significantly better than the controls (1.14 versus 1.30 and 1.44 versus 1.77, respectively). During the withdrawal period, no significant differences in growth rates or feed conversion were observed between the control and treatment groups. MT treatment significantly affected the body composition (whole body and empty carcass) of the red tilapia in both experiments, elevating percent moisture and protein values, but depressing percent fat values. Results demonstrated that incorporation of MT into fingerling diets offers potential for extending the period when tilapias actively feed and grow in temperate climates.     

Use of a condylar screw plate for repair of a Salter-Harris type-III fracture of the femur in a 2-year-old horse

A 2-year-old sexually intact male Paint horse weighing 427 kg (940 lb) was admitted for examination and treatment of intermittent non-weight-bearing lameness of the right hind limb of 1 week's duration. Radiography revealed a displaced Salter-Harris type-III fracture of the right femoral condyle with the sagittal component of the fracture line located in the intercondylar space and the transverse component exiting on the medial aspect of the femur. The fracture was repaired with a condylar screw plate designed for repair of femoral condylar fractures in humans. The owner reported by telephone 9 months after surgery that the horse was sound. To our knowledge, use of this particular implant system for fixation of a Salter-Harris type-III fracture on the medial side of the femur in a horse has not been described. Results in this horse suggest that this implant can be successfully used for repair of femoral condylar fractures in selected adult horses.     

Serum total and ionized magnesium concentrations and urinary fractional excretion of magnesium in cats with diabetes mellitus and diabetic ketoacidosis

OBJECTIVE: To determine magnesium (Mg) status in cats with naturally acquired diabetes mellitus (DM) and diabetic ketoacidosis (DKA), evaluate changes in Mg status after treatment for DKA, and correlate Mg status with systemic blood pressure and degree of glycemic control. DESIGN: Case series and cohort study. ANIMALS: 12 healthy cats (controls), 21 cats with DM, and 7 cats with DKA. PROCEDURE: Serum total magnesium (tMg) and ionized magnesium (iMg) concentrations and spot urinary fractional excretion of magnesium (FEmg) were determined, using serum and urine samples obtained from all cats when they were entered in the study and from cats with DKA 12, 24, and 48 hours after initiating treatment. Indirect blood pressure and degree of glycemic control were determined in 10 and 21 cats with DM, respectively. RESULTS: Initially, 2 and 13 cats with DM and 1 and 4 cats with DKA had serum tMg and iMg concentrations, respectively, less than the low reference limit (mean-2 SD) determined for controls. In cats with DKA, serum tMg concentration decreased significantly over time after initiating treatment. Urinary FEmg was significantly higher in cats with DM or DKA, compared with controls. Systemic hypertension was not detected nor was there a correlation between Mg status and degree of glycemic control in cats with DM. CONCLUSIONS AND CLINICAL RELEVANCE: Hypomagnesemia was a common finding in cats with DM and DKA and was more readily identified by measuring serum iMg concentration than tMg concentration. The clinical ramifications of hypomagnesemia in such cats remain to be determined.     

Mermithid nematode infection in a colony of blue-winged grasshoppers (Tropidacris collaris)

A die-off occurred in a captive colony of blue-winged grasshoppers (Tropidacris collaris) at the Toronto Zoo. One fourth of the colony died within a year due to infection with worms initially mistaken for nematomorphs but later identified as nematodes belonging to the Mermithidae, genus Mermis. Mortality persisted and the grasshopper population dwindled over the following years. Mermithid larvae developed in the hemocoel of the insects until they eventually emerged from a hollowed-out exoskeleton. Circumstantial evidence suggests that the parasites were introduced with raspberry browse that was grown on site and contaminated with mermithid eggs.     

THE FIRST TWENTY-ONE YEARS OF VETERINARY DIAGNOSTIC ULTRASOUND

The veterinary literature of 1966–1986 was searched for articles and books related to the use of diagnostic ultrasound in animals. There were 492 references, categorized as follows: general, 30; small animal applications, 169; large animal applications, 248; blood pressure measurement, 23; ultrasound-guided biopsy, 4; miscellaneous, 18.     

Assessment of the metabolic effects of hydrocortisone on llamas before and after feed restriction

OBJECTIVE: To evaluate the effects of administration of hydrocortisone on plasma concentration of insulin and serum concentrations of glucose, triglyceride, and nonesterified fatty acids (NEFAs) in llamas before and after feed restriction. ANIMALS: 9 adult female llamas. PROCEDURE: Feed was withheld from llamas for 8 hours. Blood samples were collected before (0 minutes) and 120, 180, 240, and 300 minutes after IV injection of hydrocortisone sodium succinate (1 mg/kg) for determination of plasma insulin concentration and serum concentrations of glucose, triglyceride, and NEFAs. The llamas were then fed a limited diet (grass hay, 0.25% of body weight daily) for 21 days, after which the experimental procedures were repeated. RESULTS: Compared with llamas that were not feed-restricted, llamas after feed restriction had significantly higher plasma insulin concentration and serum concentrations of triglycerides and NEFAs. Feed-restricted llamas after hydrocortisone injection had a significantly smaller increase in serum glucose concentration, a decrease (rather than an increase) in serum concentration of NEFAs, and no change in blood concentrations of insulin or triglycerides. CONCLUSIONS AND CLINICAL RELEVANCE: Short-acting glucocorticoid hormones did not appear to increase blood lipid concentrations in healthy llamas, regardless of ongoing fat mobilization. Thus, these hormones appear unlikely to be major direct contributors to diseases such as hepatic lipidosis or hyperlipemia. Although administration of hydrocortisone reduced serum concentration of fatty acids in feed-restricted llamas, its use has not been evaluated in sick camelids and cannot be considered therapeutically useful.     

Assessing the efficacy of perioperative oral carprofen after cranial cruciate surgery using noninvasive, objective pressure platform gait analysis

OBJECTIVE: To document, using pressure platform gait analysis, the effect of perioperative oral carprofen on limb function and pain after cranial cruciate ligament surgery in dogs. STUDY DESIGN: Blinded, prospective clinical investigation. ANIMALS: Twenty dogs with naturally occurring unilateral cranial cruciate disease. PROCEDURE: Physiologic indices, subjective pain scoring, and pressure platform gait analyses were performed before and 24, 48, and 72 hours after surgery. Correlations were assessed between methods of evaluation and the data was compared across treatment groups. RESULTS: No strong correlations were noted between physiologic data, subjective scoring systems, or gait analysis data at a walk or stance. Although average measures of limb function were nearly twice as large in dogs treated with carprofen, no significant differences between groups over time were identified. No significant differences were noted in any other measure of pain or limb function. Power analysis of peak vertical force at a walk indicated that significant difference would have been detected had the number of dogs in each group been increased to 35. CONCLUSION: When limb function was assessed with pressure platform gait analysis no statistical difference was noted between groups with respect to PVF and VI at a walk or stance, although average ground reaction forces for dogs in the carprofen group were greater than the traditional pain management group at all time points. CLINICAL RELEVANCE: Oral carprofen appears to provide some benefit for the treatment of postoperative orthopedic pain.     

Management of twin pregnancy and perinatal concerns in a Beluga (Delphinapterus leucas)

A 22-yr-old multiparous beluga, Delphinapterus leucas, with consistently elevated serum progesterone concentrations post-artificial insemination was diagnosed with viable twins at 149 days postconception. Twins were of similar size at least until day 264, the last point when ultrasound measurements of both twins were made. However, ultrasound was used to determine the viability of both fetuses on days 365, 393, and 400. After 90% of normal gestation, or 434 days, steroids were administered to encourage fetal lung maturation. Seven days later a 40.9-kg live female calf was delivered headfirst. A second 22.7-kg stillborn calf was delivered in fluke-first presentation 8 hr later. Immediately after birth, the live calf was administered surfactant intratracheally. The next day, it was given beluga immunoglobulin intramuscularly, and started on oral antibiotics and provided nutritional support via an oral gastric tube. The calf started nursing voluntarily on day 3. Antibiotic and nutritional support was discontinued on day 10. Bimonthly weight and length measurements demonstrated that after an initial increased growth rate, the calf has grown within normal parameters after birth. This calf represents the first known successful surviving twin of any cetacean species and sets an important precedent for treatment modalities that may be available to assist the premature cetacean neonate.     

Economically Optimal Stocking Rates: A Bioeconomic Grazing Model

A dynamic bioeconomic model that examines economically optimal stocking rate decisions while taking into account changes in forage availability is presented. The model presented here focuses on economically optimal stocking decisions while taking into account changes in the forage resource. The model is parameterized for a stocker operation in central Wyoming. Regardless of the scenario analyzed, the general rule of 50% utilization is determined to be an economically sound management strategy. The factors most heavily influencing economically optimal stocking rate decisions are forage growth rates and the Michaelis Constant. Both grain prices and cattle prices impact financial returns yet do not directly impact optimal stocking decisions by cattle producers.