OBJECTIVE To use CT-derived measurements to create a ferret-specific formula for body surface area (BSA) to improve chemotherapeutic dosing.
ANIMALS 25 adult ferrets (19 live and 6 cadavers).
PROCEDURES Live subjects were weighed, and body measurements were obtained by each of 3 observers while ferrets were awake and anesthetized. Computed tomography was performed, and a 3-D surface model was constructed with open-source imaging software, from which BSA was estimated. The CT-derived values were compared with BSA calculated on the basis of the traditional tape method for 6 cadavers. To further validate CT analysis software, 11 geometric shapes were scanned and their CT-derived values compared with those calculated directly via geometric formulas. Agreement between methods of surface area estimation was assessed with linear regression. Ferret-specific formulas for BSA were determined with nonlinear regression models.
RESULTS Repeatability among the 3 observers was good for all measurements, but some measurements differed significantly between awake and anesthetized ferrets. Excellent agreement was found between measured versus CT-derived surface area of shapes, traditional tape– versus CT-derived BSA of ferret cadavers, and CT-derived BSA of cadavers with and without monitoring equipment. All surface area formulas performed relatively similarly.
CONCLUSIONS AND CLINICAL RELEVANCE CT-derived BSA measurements of ferrets obtained via open-source imaging software were reliable. On the basis of study results, the recommended formula for BSA in ferrets would be 9.94 × (body weight)2/3; however, this represented a relatively minor difference from the feline-derived formula currently used by most practitioners and would result in little practical change in drug doses.
Objective—To determine the degree of agreement between 3 commercially available point-of-care blood glucose meters and a laboratory analyzer for measurement of blood glucose concentrations in Hispaniolan Amazon parrots (Amazona ventralis).
Procedures—A 26-gauge needle and 3-mL syringe were used to obtain a blood sample (approx 0.5 mL) from a jugular vein of each parrot. Small volumes of blood (0.6 to 1.5 μL) were used to operate each of the blood glucose meters, and the remainder was placed into lithium heparin microtubes and centrifuged. Plasma was harvested and frozen at −30°C. Within 5 days after collection, plasma samples were thawed and plasma glucose concen-trations were measured by means of the laboratory analyzer. Agreement between pairs of blood glucose meters and between each blood glucose meter and the laboratory analyzer was evaluated by means of the Bland-Altman method, and limits of agreement (LOA) were calculated.
Results—None of the results of the 3 blood glucose meters agreed with results of the laboratory analyzer. Each point-of-care blood glucose meter underestimated the blood glucose concentration, and the degree of negative bias was not consistent (meter A bias, −94.9 mg/dL [LOA, −148.0 to −41.7 mg/dL]; meter B bias, −52 mg/dL [LOA, −107.5 to 3.5 mg/dL]; and meter C bias, −78.9 mg/dL [LOA, −137.2 to −20.6 mg/dL]).
Conclusions and Clinical Relevance—On the basis of these results, use of handheld blood glucose meters in the diagnosis or treatment of Hispaniolan Amazon parrots and other psittacines cannot be recommended.
Objective—To assess the effects of dopamine and dobutamine on the blood pressure of isoflurane-anesthetized Hispaniolan Amazon parrots (Amazona ventralis).
Animals—8 Hispaniolan Amazon parrots.
Procedures—A randomized crossover study was conducted. Each bird was anesthetized (anesthesia maintained by administration of 2.5% isoflurane in oxygen) and received 3 doses of each drug during a treatment period of 20 min/dose. Treatments were constant rate infusions (CRIs) of dobutamine (5, 10, and 15 μg/kg/min) and dopamine (5, 7, and 10 μg/kg/min). Direct systolic, diastolic, and mean arterial pressure measurements, heart rate, esophageal temperature, and end-tidal partial pressure of CO2 were recorded throughout the treatment periods.
Results—Mean ± SD of the systolic, mean, and diastolic arterial blood pressures at time 0 (initiation of a CRI) were 132.9 ± 22.1 mm Hg, 116.9 ± 20.5 mm Hg, and 101.9 ± 22.0 mm Hg, respectively. Dopamine resulted in significantly higher values than did dobutamine for the measured variables, except for end-tidal partial pressure of CO2. Post hoc multiple comparisons revealed that the changes in arterial blood pressure were significantly different 4 to 7 minutes after initiation of a CRI. Overall, dopamine at rates of 7 and 10 μg/kg/min and dobutamine at a rate of 15 μg/kg/min caused the greatest increases in arterial blood pressure.
Conclusions and Clinical Relevance—Dobutamine CRI at 5, 10, and 15 μg/kg/min and dopamine CRI at 5, 7, and 10 μg/kg/min may be useful in correcting severe hypotension in Hispaniolan Amazon parrots caused by anesthesia maintained with 2.5% isoflurane.
To determine the pharmacokinetics of a solution containing cannabidiol (CBD) and cannabidiolic acid (CBDA), administered orally in 2 single-dose studies (with and without food), in the domestic rabbit (Oryctolagus cuniculus).
6 healthy New Zealand White rabbits.
In phase 1, 6 rabbits were administered 15 mg/kg CBD with 16.4 mg/kg CBDA orally in hemp oil. In phase 2, 6 rabbits were administered the same dose orally in hemp oil followed by a food slurry. Blood samples were collected for 24 hours to determine the pharmacokinetics of CBD and CBDA. Quantification of plasma CBD and CBDA concentrations was determined using a validated liquid chromatography–mass spectrometry (LC-MS) assay. Pharmacokinetics were determined using noncompartmental analysis.
For CBD, the area under the curve extrapolated to infinity (AUC)0–∞ was 179.8 and 102 hours X ng/mL, the maximum plasma concentration (Cmax) was 30.4 and 15 ng/mL, the time to Cmax (tmax) was 3.78 and 3.25 hours, and the terminal half-life (t1/2λ) was 7.12 and 3.8 hours in phase 1 and phase 2, respectively. For CBDA, the AUC0–∞ was 12,286 and 6,176 hours X ng/mL, Cmax was 2,573 and 1,196 ng/mL, tmax was 1.07 and 1.12 hours, and t1/2λ was 3.26 and 3.49 hours in phase 1 and phase 2, respectively. Adverse effects were not observed in any rabbit.
CBD and CBDA reached a greater Cmax and had a longer t1/2λ in phase 1 (without food) compared with phase 2 (with food). CBDA reached a greater Cmax but had a shorter t1/2λ than CBD both in phase 1 and phase 2. These data may be useful in determining appropriate dosing of cannabinoids in the domestic rabbit.
CASE DESCRIPTION An adult sexually intact female Harris hawk (Parabuteo unicinctus) housed at a wildlife hospital was evaluated because of acute collapse during an educational exhibition.
CLINICAL FINDINGS Physical examination and hematologic analysis revealed no abnormalities; radiography revealed findings consistent with a previous tibiotarsal fracture. Coelioscopy with histologic examination and fungal culture of lung and air sac samples revealed anthracosis but no fungal infection. The hawk was discharged and temporarily removed from the education program; 1 month later, upon reintroduction into the program, it collapsed again. Physical examination and hematologic findings were similar to those after the first episode. Transcoelomic and transesophageal echocardiography and CT angiocardiography findings were consistent with cardiomyopathy.
TREATMENT AND OUTCOME Initial cardiac treatment included furosemide (0.5 mg/kg [0.23 mg/lb], PO, q 24 h) and pimobendan (10 mg/kg [4.5 mg/lb], PO, q 12 h). After 10 days of treatment, peak and trough plasma concentrations of pimobendan were measured at 25, 196 and 715.97 ng/mL, respectively; the dosage was decreased to 0.25 mg/kg (0.11 mg/lb), PO, every 12 hours. No overt signs of toxicosis were detected. A sample was collected to reevaluate plasma pimobendan concentration after 30 days of treatment; results were not obtained prior to the patient's death but revealed a peak concentration of 16.8 ng/mL, with an undetectable trough concentration. The hawk was found dead 6 months after initial evaluation. Necropsy revealed cardiomegaly, but histologic examination did not reveal an inciting cause of cardiac dysfunction.
CLINICAL RELEVANCE Cardiac disease in raptors may be underreported. Transcoelomic and transesophageal echocardiography and CT angiography provided useful information for the diagnosis of cardiac disease in the hawk of this report.
Objective—To estimate the prevalence of clinically relevant atherosclerotic lesions in birds and identify epidemiological variables and illness types associated with development of atherosclerosis.
Design—Retrospective case-control study.
Sample—Records of 7683 psittacine birds, including 525 with advanced atherosclerosis.
Procedures—5 pathology centers provided databases and access to histopathology slides. Age and sex were collected for all birds of the Amazona, Ara, Cacatua, Nymphicus, and Psittacus genera. Databases were searched for atherosclerosis cases, and slides were reviewed for the presence of type IV through VI atherosclerotic lesions. Results were used to build several multiple logistic models to define the association between advanced atherosclerosis and age, sex, genus, illness type, and specific lesions. Prevalence was reported as a function of age, sex, and genus.
Results—In the first model including 7683 birds, age, female sex, and the genera Psittacus, Amazona, and Nymphicus were significantly associated with clinically relevant atherosclerosis detected via necropsy. Subsequent models of 1,050 cases revealed further associations with reproductive disease, hepatic disease, and myocardial fibrosis, controlling for age, sex, and genus.
Conclusions and Clinical Relevance—Age, female sex, and 3 genera appeared to be positively associated with the presence of advanced atherosclerotic lesions in psittacine birds. This information may be useful in clinical assessment of the cardiovascular system and patient management. Reproductive diseases were the only potentially modifiable risk factor identified and could be a target for prevention in captive psittacine birds.