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- Author or Editor: Olivia A. Petritz x
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Abstract
Objective—To determine the pharmacokinetics of buprenorphine hydrochloride after IM and IV administration to American kestrels (Falco sparverius).
Animals—13 healthy 3-year-old captive-bred American kestrels.
Procedures—Buprenorphine hydrochloride (0.6 mg/kg) was administered IM to all birds. Blood samples were collected at 9 times, ranging from 5 minutes to 9 hours after drug administration. Plasma buprenorphine concentrations were measured by use of tandem liquid chromatography–mass spectrometry. Pharmacokinetic parameters were determined by use of least squares linear regression and noncompartmental analysis of naïve pooled data. After a washout period of 2 weeks, the same dose of buprenorphine was administered IV to all birds and blood samples were collected at the same times after drug administration.
Results—Maximum plasma buprenorphine concentration was achieved within 5 minutes after IM administration. For IM administration, bioavailability was 94.8% and elimination half-life was 92.1 minutes. For IV administration, steady-state volume of distribution was 4,023.8 mL/kg, plasma clearance was 49.2 mL/min/kg, and elimination half-life was 105.5 minutes.
Conclusions and Clinical Relevance—Buprenorphine was rapidly absorbed, and bioavailability was good after IM administration to American kestrels. Plasma buprenorphine concentrations were > 1 ng/mL for 9 hours after both IM and IV administration. These results, in combination with those of a pharmacodynamic study, suggested that the analgesic effects of buprenorphine could last at least 6 to 9 hours in this species. Further investigations of the duration of analgesic effects, multiple-dose protocols, and potential adverse effects of buprenorphine are warranted in American kestrels and other raptors.
Abstract
Objective—To evaluate the stability of 3 extemporaneous oral suspensions of enrofloxacin mixed with readily available flavoring vehicles when stored at room temperature (approx 22°C).
Design—Evaluation study.
Samples—3 commonly compounded oral suspensions of enrofloxacin.
Procedures—On day 0, commercially available enrofloxacin tablets were compounded with a mixture of distilled water and corn syrup (formulation A) or cherry syrup (formulation B) flavoring vehicles to create suspensions with a nominal enrofloxacin concentration of 22.95 mg/mL, and 2.27% enrofloxacin injectable solution was compounded with a liquid sweetener (formulation C) to create a suspension with a nominal enrofloxacin concentration of 11.35 mg/mL. Preparations were stored in amber-colored vials at room temperature for 56 days. For each preparation, the enrofloxacin concentration was evaluated with high-performance liquid chromatography at prespecified intervals during the study. The pH, odor, and consistency for all suspensions were recorded at the start and completion of the study.
Results—Relative to the nominal enrofloxacin concentration, the enrofloxacin concentration strength ranged from 95.80% to 100.69% for formulation A, 108.44% to 111.06% for formulation B, and 100.99% to 103.28% for formulation C. A mild pH increase was detected in all 3 suspensions during the study.
Conclusions and Clinical Relevance—Results indicated that, when stored in amber-colored vials at room temperature for 56 days, the enrofloxacin concentration strength in all 3 formulations was retained within acceptance criteria of 90% to 110%. Subjectively, cherry syrup flavoring was better at masking the smell and taste of enrofloxacin than were the other mixing vehicles.
Abstract
Objective—To evaluate the effects of 4.7-mg deslorelin acetate implants on egg production and plasma concentrations of 17β-estradiol and androstenedione in Japanese quail (Coturnix coturnix japonica) over 180 days and assess safety of the implants in quail via gross and histologic examination.
Animals—20 female Japanese quail.
Procedures—Following a 7-day period of consistent egg laying, quail were anesthetized and received a 4.7-mg deslorelin implant (treatment group; n = 10) or identical placebo implant (control group; 10) SC between the scapulae. Egg production was monitored daily. Plasma concentrations of 17β-estradiol and androstenedione were measured on days 0 (immediately prior to implant injection), 14, 29, 62, 90, 120, 150, and 180 via radioimmunoassay. Birds were weighed periodically and euthanized at day 180 for complete necropsy.
Results—Egg production was significantly decreased in the treatment group, compared with the control group, from 2 to 12 weeks after implant injection. Egg production ceased in 6 of 10 quail in the treatment group (mean duration of cessation, 70 days). Plasma androstenedione and 17β-estradiol concentrations were significantly lower on day 29 in the treatment group than in the control group. Plama androstenedione and 17β-estradiol concentrations were significantly lower on day 29 in the treatment group then in the control group.
Conclusions and Clinical Relevance—4.7-mg deslorelin acetate implants reversibly decreased egg laying for approximately 70 days in most of the Japanese quail evaluated. Further studies evaluating implants containing different concentrations of the drug are needed in quail and other avian species.
Abstract
Objective—To evaluate agreement of 3 models of portable blood glucose meters (PBGMs; 2 designed for use with human samples and 1 designed for veterinary use) with a laboratory analyzer for measurement of blood glucose concentrations in ferrets (Mustela putorius furo).
Design—Evaluation study.
Animals—52 ferrets.
Procedures—Samples were analyzed with 4 PBGMs (whole blood) and a laboratory analyzer (plasma). Two PBGMs of the model designed for veterinary use were tested; each was set to a code corresponding to canine or feline sample analysis throughout the study. Agreement and bias between measurements obtained with the PBGMs and the laboratory analyzer were assessed with Bland-Altman plots. Linear regression analysis was performed to evaluate associations with venipuncture site by comparison of central (jugular) and peripheral (lateral saphenous or cephalic) venous blood samples.
Results—Plasma glucose concentrations measured with the laboratory analyzer ranged from 41 to 160 mg/dL. Results from the PBGM for veterinary use coded to test a canine blood sample had the greatest agreement with the laboratory analyzer (mean bias, 1.9 mg/dL); all other PBGMs significantly underestimated blood glucose concentrations. A PBGM designed for use with human samples had the least agreement with the laboratory analyzer (mean bias, −34.0 mg/dL). Blood glucose concentration was not significantly different between central and peripheral venous blood samples for any analyzer used.
Conclusions and Clinical Relevance—Significant underestimation of blood glucose concentrations as detected for 3 of the 4 PBGMs used in the study could have a substantial impact on clinical decision making. Verification of blood glucose concentrations in ferrets with a laboratory analyzer is highly recommended.
Abstract
OBJECTIVE To determine pharmacokinetics after oral administration of single and multiple doses and to assess the safety of zonisamide in Hispaniolan Amazon parrots (Amazona ventralis).
ANIMALS 12 adult Hispaniolan Amazon parrots.
PROCEDURES Zonisamide (30 mg/kg, PO) was administered once to 6 parrots in a single-dose trial. Six months later, a multiple-dose trial was performed in which 8 parrots received zonisamide (20 mg/kg, PO, q 12 h for 10 days) and 4 parrots served as control birds. Safety was assessed through monitoring of body weight, attitude, and urofeces and comparison of those variables and results of CBC and biochemical analyses between control and treatment groups.
RESULTS Mean ± SD maximum plasma concentration of zonisamide for the single- and multiple-dose trials was 21.19 ± 3.42 μg/mL at 4.75 hours and 25.11 ± 1.81 μg/mL at 2.25 hours after administration, respectively. Mean plasma elimination half-life for the single- and multiple-dose trials was 13.34 ± 2.10 hours and 9.76 ± 0.93 hours, respectively. Pharmacokinetic values supported accumulation in the multiple-dose trial. There were no significant differences in body weight, appearance of urofeces, or appetite between treated and control birds. Although treated birds had several significant differences in hematologic and biochemical variables, all variables remained within reference values for this species.
CONCLUSIONS AND CLINICAL RELEVANCE Twice-daily oral administration of zonisamide to Hispaniolan Amazon parrots resulted in plasma concentrations known to be therapeutic in dogs without evidence of adverse effects on body weight, attitude, and urofeces or clinically relevant changes to hematologic and biochemical variables.
Abstract
OBJECTIVE
To retrospectively evaluate the prevalence and clinical progression of wobbly hedgehog syndrome (WHS) and concurrent incidence of neoplasia in a cohort of African pygmy hedgehogs (Atelerix albiventris).
ANIMALS
49 hedgehogs.
CLINICAL PRESENTATION AND PROCEDURES
Medical records of hedgehogs from 7 institutions across the US over a 20-year period (2000 to 2020) were retrospectively reviewed. Inclusion criteria were hedgehogs of any sex or age with postmortem CNS histopathology consistent with WHS. Collected data included sex, age at onset and euthanasia, major histopathologic findings, reported neurologic clinical signs, and treatments administered.
RESULTS
24 males and 25 females were included. Fifteen of 49 (31%) individuals had subclinical WHS with no reported antemortem neurologic clinical signs. In neurologically affected (clinical) hedgehogs (n = 34), the mean ± SD age at onset was 3.3 ± 1.5 years with a median (range) time from onset to euthanasia of 51 days (1 to 319 days). In neurologically affected hedgehogs, the most commonly reported clinical signs were ataxia (n = 21) and pelvic limb paresis (16) and the most commonly administered treatment was meloxicam (13). Overall, 31 of 49 (63%) hedgehogs had a concurrent histopathologic diagnosis of neoplasia outside of the CNS.
CLINICAL RELEVANCE
The prognosis for hedgehogs with WHS is poor. No treatment had a significant effect on survival time, and neoplasia was a common comorbidity in the current cohort. A small but clinically relevant subset of neurologically normal hedgehogs had a histopathologic diagnosis of WHS.
Abstract
OBJECTIVE To determine the mydriatic effects of topical rocuronium bromide administration in Hispaniolan Amazon parrots (Amazona ventralis) and to identify any adverse effects associated with treatment.
DESIGN Randomized crossover study.
ANIMALS 8 healthy adult Hispaniolan Amazon parrots.
PROCEDURES Rocuronium bromide (20 μL/eye; 10 mg/mL) or saline (20 μL/eye; 0.9% NaCl) solution was administered in both eyes of each bird with a 26-day washout period. The birds were manually restrained in lateral recumbency with the apex of the cornea positioned upward for 2 minutes following administration in each eye. Infrared pupillometry and direct pupillary light reflex measurements were used to evaluate the mydriatic effects. Pupillary measurements were recorded prior to administration and every 20 minutes for 2 hours after administration, then hourly for a total of 7 hours. A brief physical examination was performed, direct pupillary light reflex was tested, and fluorescein staining was performed on each eye of each bird 24 hours after administration.
RESULTS A significant difference in pupillary diameter for the active versus control treatment group was noted from 20 to 360 minutes after drug administration, but not at 420 minutes. Minimal adverse effects were noted. Three birds had transient inferior eyelid paresis noted in both eyes after receiving rocuronium; 24 hours after the treatment, no differences in ocular measurements existed between the active and control treatments.
CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that topical rocuronium bromide administration may be safely used for pupillary dilation in Hispaniolan Amazon parrots and could be used for clinical evaluation, fundus imaging, and surgical interventions involving the lens and posterior segment in this species.
Abstract
OBJECTIVE
To document clinicopathologic findings in domestic rabbits with liver lobe torsion and identify prognostic factors.
ANIMALS
82 rabbits.
PROCEDURE
Medical records of 4 institutions were reviewed to identify rabbits with an antemortem diagnosis of liver lobe torsion that were examined between 2010 and 2020.
RESULTS
The prevalence of liver lobe torsion was 0.7% (82/11,402). In all 82 rabbits, the diagnosis was made by means of abdominal ultrasonography. Fifty (60.1%) rabbits underwent liver lobectomy, 23 (28%) received medical treatment alone, and 9 (10.9%) were euthanized or died on presentation. Overall, 32 (39%) rabbits died within 7 days of initial presentation and 50 (61%) survived. Seven-day survival rate did not differ significantly between medical treatment alone and surgical treatment. However, median survival time following medical treatment (530 days) was shorter than that following surgical treatment (1,452 days). Six of 14 rabbits had evidence of systemic inflammatory disease on necropsy. Rabbits with right liver lobe torsion were less likely to survive for 7 days than were those with caudate torsions (P = 0.046; OR, 3.27; 95% CI, 1.04 to 11.3). Rabbits with moderate to severe anemia were less likely to survive for 7 days than were rabbits that were not anemic or had mild anemia (P = 0.006; OR, 4.41; 95% CI, 1.55 to 12.51). Other factors associated with a decreased 7-day survival rate were high heart rate at admission (P = 0.013) and additional days without defecation after admission (P < 0.001). Use of tramadol was associated with an increased survival rate (P = 0.018).
CLINICAL RELEVANCE
The prognosis for rabbits with liver lobe torsions was more guarded than previously described. Rabbits that underwent liver lobectomy had a longer median survival time than did rabbits that only received medical treatment.
