The Educated Guess: Determining Drug Doses in Exotic Animals Using Evidence-Based Medicine

Comparison of subcutaneous sedation with alfaxalone or alfaxalone-midazolam in pet guinea pigs (Cavia porcellus) of three different age groups

OBJECTIVE

To compare the cardiorespiratory effects, quality and duration of sedation of 2 subcutaneous sedation protocols for noninvasive procedures in guinea pigs (GPs).

ANIMALS

24 pet GPs (15 females, 9 males) of 3 different age groups: infant (n = 8), juvenile (8), and adult (8).

PROCEDURES

The study design was a randomized, crossover, blinded, clinical trial with a washout period of at least 7 days between protocols. Guinea pigs were sedated SC with alfaxalone (5 mg/kg; group A) or alfaxalone (5 mg/kg) and midazolam (0.5 mg/kg; group A + M) to facilitate blood sampling, radiography, or abdominal ultrasonography. Vital parameters, hemoglobin saturation (SpO2), and sedation scores were recorded every 5 minutes.

RESULTS

Mean heart rate was lower in group A than group A + M (P = 0.001), and respiratory rate was significantly (P = 0.001) decreased relative to baseline during sedation in both groups. The SpO2 remained above 95% in both sedation groups. Rectal temperature was significantly (P = 0.001) lower during recovery versus baseline. Onset of sedation was shorter and the duration longer in group A + M than in group A. The duration and depth of the sedation was different between age groups (P = 0.001), being longer and deeper in adults. Bruxism, hectic movements, twitching, and some degree of hyperreactivity were observed during 41 of the 48 sedations.

CLINICAL RELEVANCE

Subcutaneous administration of alfaxalone provided reliable sedation for nonpainful procedures in GPs. When combined with midazolam, alfaxalone provided longer and deeper sedation that was more significant in adults than in younger patients.

Most veterinarians treating exotic animals use formularies to select drug dosages without consistently checking their sources

OBJECTIVE

To assess what information sources veterinarians use to select drug dosages for treating exotic animals and how they implement this information.

SAMPLE

936 veterinarians from Europe, Asia, Australia, Africa, and the Americas.

PROCEDURES

An anonymous, online survey was used to collect data on information sources used for dosage decisions by veterinarians treating exotic species. Logistic regression models were built to identify associations between individual characteristics and primary outcomes.

RESULTS

Respondents reported their single most common source for establishing drug dosages as formularies (682/936 [72.9%]), followed by scientific journals (96 [10.3%]), other textbooks (68 [7.3%]), colleagues (47 [5.0%]), or continuing education notes (38 [4.1%]). Over two-thirds of the respondents (645, 68.9%) consulted a specific exotic animal formulary for establishing drug dosages in most situations. Of the 936 respondents, 407 (43.5%) reported that they sometimes (318 [34.0%]) or never (89 [9.5%]) checked the source of a dosage in a textbook or a formulary, 503 (55.3%) reported that they sometimes (399 [42.6%]) or never (104 [11.1%]) searched the original publication on a dosage, and 486 (51.9%) reported that they would base their dosage decision on the abstract of an article if they had no access to the full-text. Several respondents' reported characteristics were significant predictors of primary outcomes.

CLINICAL RELEVANCE

Considering our findings, we recommend authors of formularies and textbooks should focus on evidence-based information and state clearly when information is anecdotal. Tailored strategies to educate veterinarians treating exotic animals on the importance of primary sources are also recommended.