FIV vaccine development and its importance to veterinary and human medicine: a review FIV vaccine 2002 update and review.

Feline immunodeficiency virus (FIV) is a natural infection of domestic cats that results in acquired immunodeficiency syndrome resembling human immunodeficiency virus (HIV) infection in humans. The worldwide prevalence of FIV infection in domestic cats has been reported to range from 1 to 28%. Hence, an effective FIV vaccine will have an important impact on veterinary medicine in addition to being used as a small animal AIDS model for humans. Since the discovery of FIV reported in 1987, FIV vaccine research has pursued both molecular and conventional vaccine approaches toward the development of a commercial product. Published FIV vaccine trial results from 1998 to the present have been compiled to update the veterinary clinical and research communities on the immunologic and experimental efficacy status of these vaccines. A brief report is included on the outcome of the 10 years of collaborative work between industry and academia which led to recent USDA approval of the first animal lentivirus vaccine, the dual-subtype FIV vaccine. The immunogenicity and efficacy of the experimental prototype, dual-subtype FIV vaccine and the efficacy of the currently approved commercial, dual-subtype FIV vaccine (Fel-O-Vax FIV) are discussed. Potential cross-reactivity complications between commercial FIV diagnostic tests, Idexx Snap Combo Test and Western blot assays, and sera from previously vaccinated cats are also discussed. Finally, recommendations are made for unbiased critical testing of new FIV vaccines, the currently USDA approved vaccine, and future vaccines in development.

Renal effects of carprofen administered to healthy dogs anesthetized with propofol and isoflurane.

OBJECTIVE: To evaluate renal effects of carprofen in healthy dogs following general anesthesia. DESIGN: Randomized clinical trial. ANIMALS: 10 English hound dogs (6 females and 4 males). PROCEDURE: Dogs were randomly assigned to control (n = 5) or carprofen (5) groups. Anesthesia was induced with propofol (6 to 8 mg/kg [2.7 to 3.6 mg/lb] of body weight, i.v.) and maintained with isoflurane (end-tidal concentration, 2.0%). Each dog underwent two 60-minute anesthetic episodes with 1 week between episodes, and mean arterial blood pressure was maintained between 60 and 90 mm Hg during each episode. Dogs in the carprofen group received carprofen (2.2 mg/kg [1 mg/lb], p.o.) at 9:00 AM and 6:00 PM the day before and at 7:00 AM the day of the second anesthetic episode. Glomerular filtration rates (GFR) were determined during each anesthetic episode by use of renal scintigraphy. Serum creatinine and BUN concentrations and the urine gamma-glutamyltransferase-to-creatinine concentration (urine GGT:creatinine) ratio were determined daily for 2 days before and 5 days after general anesthesia. RESULTS: Significant differences were not detected in BUN and serum creatinine concentrations, urine GGT:creatinine ratio, and GFR either between or within treatment groups over time. CONCLUSIONS AND CLINICAL RELEVANCE: Carprofen did not significantly alter renal function in healthy dogs anesthetized with propofol and isoflurane. These results suggest that carprofen may be safe to use for preemptive perioperative analgesia, provided that normal cardiorespiratory function is maintained.

Comparison of sedative and cardiorespiratory effects of diazepam, acepromazine, and xylazine in ferrets.

The sedative and cardiorespiratory effects of an intramuscular injection of diazepam (3 mg/kg body weight), acepromazine (0.1 mg/kg body weight), or xylazine (2 mg/kg body weight) in ferrets (n = 10, crossover design) was evaluated. Time from injection to assuming lateral recumbency was not significantly different between the three drugs. Duration of recumbency expressed as mean+/-standard deviation was significantly longer with xylazine (68.3+/-20.8 min) than with diazepam (43.2+/-8.2 min) or acepromazine (49.8+/-11.2 min). Sedation was graded to be the best in the xylazine-treated ferrets and worst in the diazepam-treated ferrets. Analgesia was judged only to be present following xylazine injection. Systolic blood pressure, oxyhemoglobin saturation, and end-expired carbon dioxide (CO2) were similar with all three drugs. It was concluded that, at the doses administered, xylazine provided better chemical restraint in the healthy ferret than either acepromazine or diazepam.

Evaluation of the sedative and cardiorespiratory effects of medetomidine, medetomidine-butorphanol, medetomidine-ketamine, and medetomidine-butorphanol-ketamine in ferrets.

Ten ferrets were used in a crossover study to determine the anesthetic effects of intramuscular (I.M.) medetomidine (80 microg/kg body weight), medetomidine (80 microg/kg body weight)-butorphanol (0.1 mg/kg body weight), medetomidine (80 microg/kg body weight)-ketamine (5 mg/kg body weight), and medetomidine (80 microg/kg body weight)-butorphanol (0.1 mg/kg body weight)-ketamine (5 mg/kg body weight). All ferrets assumed lateral recumbency within four minutes and remained dorsally recumbent for 100 minutes, until atipamezole (400 microg/kg body weight, I.M.) administration. All four anesthetic combinations were effective for chemical restraint, with the most respiratory depression occurring in the medetomidine-butorphanol-ketamine group. The addition of butorphanol or ketamine to medetomidine significantly increased the duration of analgesia. The addition of ketamine to medetomidine-butorphanol expedited endotracheal intubation.

Effects of three sedative protocols on glomerular filtration rate in clinically normal dogs.

OBJECTIVE: To determine the effects of 3 sedative protocols (butorphanol and diazepam [BD] IV; acepromazine and butorphanol [AB] IV; diazepam and ketamine [DK] IV) on glomerular filtration rate (GFR) as measured by 99mTc DTPA nuclear scintigraphy and to compare them with GFR measured without sedation. Cardiovascular, respiratory, and sedative effects of each protocol also were measured. ANIMALS: 12 adult male Walker Hounds. PROCEDURE: Systolic, diastolic, and mean arterial blood pressures and heart and respiratory rates were measured before, during, and after scintigraphic measurement of GFR. RESULTS: Difference in GFR was not significant between any of the sedative regimens and the control. The DK protocol caused significant increases in systolic, diastolic, and mean arterial blood pressure; compared with the AB and BD protocols, it caused significant increases in heart rate versus all protocols, and was associated with the lowest mean GFR (2.80 ml/min/kg of body weight). The AB protocol caused significant decreases in systolic, diastolic, and mean arterial blood pressures, compared with DK and the nonsedation protocols. Mean GFR for the BD protocol was 2.94 ml/min/kg, and was 3.13 ml/min/kg for the AB and the nonsedation protocols. The AB protocol provided the best sedation with minimal additional restraint required. The BD and nonsedation protocols often were associated with substantial dog movement. The DK protocol induced inadequate duration of immobilization (< 10 minutes) in some dogs and excitement in others. CONCLUSION: GFR measurements obtained with any of the sedative protocols were not significantly different, compared with measurements in awake dogs. The AB protocol provides the best sedative effects and was associated with GFR values identical to those in awake dogs. Systemic hypotension caused by acepromazine did not decrease GFR in clinically normal dogs.

Mercury distribution in American alligators (Alligator mississippiensis) in Florida.

Thirty American alligators (Alligator mississippiensis), including 24 wild-caught and six control captive farm-raised alligators, were analyzed for whole body mercury contamination. Wild-caught animals were collected from Water Conservation Area 3 in the Everglades ecosystem (n = 12) and from Alachua, Brevard, and Collier counties outside the Everglades (n = 12). Using cold-vapor atomic absorption spectrophotometry, samples of brain, cervical spinal cord, liver, paired kidneys, paired testes, paired ovaries, paired oviducts, heart, lungs, spleen, bile, tail and leg muscle, and tail and leg scales were analyzed on a wet weight basis to determine mercury concentration. Mercury was consistently detected in all specimens except for bile. Farm-raised alligators, fed a commercially prepared diet, contained very low mercury concentrations in all tissues analyzed. In comparison with alligators from outside the Everglades, Everglades alligators had significantly elevated concentrations of mercury in all tissues analyzed except ovaries, oviduct, bile, tail scales, and leg scales (paired two-sample Student's tau-test, P < 0.05). Muscle concentrations exceeded state (0.50-1.50 ppm) and federal (1.00 ppm) allowances for safe human consumption in alligators collected in the Everglades. No clinical signs of neurologic, hepatic, or renal toxicosis were detected. Because of the alligator's ability to bioaccumulate mercury, this species might be useful as a bio-monitor for environmental mercury contamination.

Comparison of sedative and cardiorespiratory effects of medetomidine and medetomidine-butorphanol combination in dogs.

OBJECTIVE: Sedative, cardiorespiratory, and analgesic effects of intramuscular administration of medetomidine (40 micrograms/kg of body weight)-glycopyrrolate (0.01 mg/kg) and medetomidine (10 micrograms/kg)-butorphanol (0.2 mg/kg)-glycopyrrolate (0.01 mg/kg) combinations were compared. Additional evaluations were done on reversal of medetomidine, using atipamezole (200 micrograms/kg. IV), after 90 minutes of medetomidine-induced sedation. DESIGN: Crossover study, with each dog receiving each drug combination at 1-week intervals. ANIMALS: Six 2-year-old English hound-type dogs. PROCEDURE: Arterial blood pressure, ECG, respiratory rate, tidal volume, minute volume, arterial blood gas tensions, and serum biochemical variables were measured before, during, and after sedation. Analgesia was evaluated by needle prick on the skin and tail clamp. RESULTS: Heart rate decreased significantly from 100 beats/min to < 40 beats/min within 3 minutes of injection of medetomidine and medetomidine and butorphanol (MB). Mean arterial blood pressure in both groups were maintained above 100 mm of Hg throughout the recording period. There was no significant difference between medetomidine and MB in respiratory rate, tidal volume, and minute ventilation. Hypoxemia (PaO2 < 60 mm of Hg) was observed at 10 and 20 minutes in 2 dogs given MB. Atipamezole administration in the dogs given medetomidine significantly increased PaO2, and returned the values to baseline. Needle prick analgesia duration was longer in the medetomidine (80 +/- 7.7 minutes) than MB (56.0 +/- 19.2 minutes) group. Tail pinch analgesia was variable in both groups. Duration of lateral recumbency was longer after medetomidine (90 +/- 0 minutes) than MB (73.5 +/- 19.0 minutes). CONCLUSION: Medetomidine and MB were effective combination for mildly invasive procedures. CLINICAL RELEVANCE: MB induced a shorter period of analgesia and recumbency than did medetomidine.

Intraocular pressure variation associated with body length in young American alligators (Alligator mississippiensis).

Using an applanation tonometer, 5 replicate intraocular pressure (IOP) measurements were obtained from each eye of 12 young clinically normal, American alligators. Alligator length ranged from 46 to 117 cm, measured from snout to tail tip. All IOP were recorded by a single observer at an ambient temperature of approximately 25 C, and ranged from 5 to 35 mm of Hg. Observer reliability was excellent (intraclass r = 0.93), and IOP did not change over the ordered sequence of 5 replicate measurements/eye. Replicate IOP) measurements were, therefore, averaged in each eye for comparison between eyes of the same alligator. Left and right eve IOP were highly correlated within individual alligators (r = 0.92), whereas the mean within animal difference between left and right eye IOP was not statistically significant (95% confidence interval [CI] for the left eye-right eye mean difference, - 1.9 to 1.3 min of Hg). Mean IOP determined for 5 confirmed females and 3 confirmed males did not differ significantly between the sexes (95% CI for the male-female difference in means, -2.1 to 3.7 mm of Hg). Mean +/- SEM IOP of 23.7 + 2.1 mm of Hg determined for 4 alligators < -50 cm long was significantly (P = 0.009) greater than mean IOP of 11.6 + 0.5 mm of Hg determined for 8 alligators > 50 cm long (95% CI for the difference in means, 8.5 to 15.7 mm of Hg). In young alligators, the relation between body length and IOP appears to be nonlinear, possibly with a negative exponent.

Effects of carbon dioxide arterial infusion on hepatic biochemistry and histology in a rabbit model.

RATIONALE AND OBJECTIVES: The objective of this study was to determine the effect of carbon dioxide (CO2) infusion on hepatic biochemistry and histology in a rabbit model. METHODS: The study population consisted of 24 anesthetized rabbits that received hepatic infusion of either CO2 or saline (control) at doses of 10 mL/kg, comparable with those doses used in human clinical trials. Blood for clinical chemistry analysis was collected at baseline, 1 hour, 24 hours, and 168 hours (7 days) postprocedure. The rabbits were killed at 7 days postprocedure and the liver examined histologically for hepatic damage. RESULTS: There were no significant differences between the CO2 and the control groups in dorsal, ventral, and dorsal/ventral scores. Increases in alanine, an important indicator of hepatocellular membrane injury, in the CO2 group were significantly greater at 1 hour and 24 hours posttreatment (P = 0.037 and 0.013). However, the mean levels at 168 hours (7 days) were not significantly different (P = 0.22). The increases at 1 and 24 hours were small, transient, and considered clinically insignificant. CONCLUSION: No long-term hepatic effects in these animals were suggested by biochemical and histological examinations.