Laboratory reference intervals for systolic blood pressure, rectal temperature, haematology, biochemistry and venous blood gas and electrolytes in healthy pet rabbits

Computed tomographic diagnosis and clinical outcomes of small intestinal obstruction caused by trichobezoars in client-owned rabbits

Small intestinal obstruction in rabbits, although demonstrated to be common, is still poorly characterized. The objective of this study was to report features of small intestinal obstruction caused by trichobezoars in rabbits upon CT and their clinical outcomes. Rabbits with a diagnosis of intestinal obstruction that underwent CT scanning were included in this study. From each CT scan, obstruction location, appearance, Hounsfield units, size (mm), volume (mm3), distance from the stomach, and diameter of the small intestine proximal and distal to it, were extracted. Nine rabbits were included in the study. All rabbits presented for anorexia and had a distended or enlarged stomach (7) or abdomen (2). CT scan showed a non-contrast-enhancing, ovoid, smoothly marginated structure with a hyperattenuating rim, heterogeneous center, and variable amount of centrally located gas, in the duodenum (5), the jejunum (2), or the ileum (2). The density of the trichobezoars ranged from -156 to 58 HU (median, -44 HU) and volume ranged from 86.1 to 633.8 mm3 (median, 320.6 mm3). Three rabbits underwent medical management. Two of them survived, and one of them died. Six rabbits underwent surgery, of which three were successfully discharged from the hospital. CT proved to be a valuable imaging modality in rabbits with a suspected intestinal obstruction to provide the exact location of the obstruction and the characteristics of the obstructive material. The location and size of the trichobezoar may have relevant clinical implications.

Comparison of Venous Blood Gas and Biochemical Parameters in Sunda Pangolin (Manis javanica) and Chinese Pangolin (Manis pentadactyla) before and after Isoflurane Anesthesia

Venous blood gas analytes are commonly examined in animals, and the results may be important when evaluating the overall health status of an animal. Pangolins are critically endangered mammals, and there is limited information on their physiological reference values in the literature. The aim of this study was to analyze venous blood gas and biochemical parameters before and during isoflurane anesthesia in wild healthy Sunda and Chinese pangolins. The results obtained showed that the blood gas index trends of the two pangolin species before and after isoflurane anesthesia were the same. After anesthesia, the partial pressure of carbon dioxide (pCO2), partial pressure of oxygen (pO2), total carbon dioxide (CO2), mean blood bicarbonate (HCO3−), extracellular fluid compartment (BEecf) base excess and the mean blood glucose (Glu) levels of both pangolin species showed a significant increase compared to the pre-anesthesia period. In contrast, the mean blood potassium (K+), lactate (Lac) and mean blood pH levels were significantly lower. No significant differences in the mean blood sodium (Na+) or blood ionized calcium (iCa) levels were observed during anesthesia. This study is important for future comparisons and understanding the health status of this endangered species.

Hemostatic Testing in Companion Exotic Mammals

The mammalian hemostatic system is highly conserved, and companion exotic mammals are commonly used as biomedical models for normal and disordered hemostasis. Challenges associated with sample collection, test validation, and test interpretation have limited the use of these tests in clinical exotic animal practice. However, evaluation of platelet counts, coagulation screening times, and fibrin(ogen) degradation products can be valuable for monitoring exotic patients with a range of disease presentations including intoxications, anemia, systemic viral disease, hepatopathy, and endocrinopathy.

Clinical, surgical, and pathological findings in client-owned rabbits with histologically confirmed appendicitis: 19 cases (2015-2019)

OBJECTIVE

To report clinical, surgical, and pathological findings in client-owned rabbits with histologically confirmed appendicitis.

ANIMALS

19 rabbits.

PROCEDURES

Medical records for client-owned rabbits that had a histologic diagnosis of appendicitis were reviewed.

RESULTS

Median age of the rabbits at presentation was 24.0 months (range, 4 to 84 months). Seventeen cases occurred during the summer and fall seasons. Decreased appetite (17/19 rabbits), abnormal rectal temperature (hyperthermia, 9/16 rabbits; hypothermia, 4/16 rabbits), hypocalcemia (8/11 rabbits), and hypoglycemia (7/15 rabbits) were common signs. Abdominal ultrasonography and CT findings were suggestive of appendicitis in 6 of 8 rabbits and in 1 of 2 rabbits, respectively. Of the 6 rabbits that received medical treatment, 3 died at 48 hours, 1 died at 24 hours after hospitalization, and 1 died at 10 days after presentation; 1 rabbit was alive at 1,030 days after presentation. Of the 8 rabbits that underwent appendectomy, 3 died before discharge from the hospital and 1 died 113 days after surgery; 4 rabbits were alive at 315, 334, 1,433, and 1,473 days after presentation. The remaining 5 rabbits either died or were euthanized before treatment could be instituted. In each of the 19 rabbits, the appendix had evidence of severe inflammation with mucosal ulceration, heterophilic inflammation, and necrotic debris.

CLINICAL RELEVANCE

For rabbits with decreased appetite and an apparently painful abdomen, hyperthermia, hypocalcemia, or hypoglycemia, appendicitis should be considered as a differential diagnosis. Further comparisons of medical and surgical treatments are required to establish treatment recommendations for rabbits with appendicitis.

Safety verification for polysorbate 20, pharmaceutical excipient for intramuscular administration, in Sprague-Dawley rats and New Zealand White rabbits

Human serum albumin (HSA) has been widely used as a pharmaceutical excipient in Botulinum toxin serotype A (BoNT/A) products that are indicated for use in therapeutics and cosmetics. However, HSA as a human-derived material has some concerns, such as the potential risk of transmission of infectious agents, an insufficient supply, and difficulty in maintaining a certain quality. For those reasons, newly developed BoNT/A products (CORETOX^®, Medytox, Inc., Republic of Korea) contained polysorbate 20, a non-human-derived excipient, to replace the HSA. However, most safety studies of polysorbate 20 have been conducted with non-invasive routes of administration, and thus there are a few studies on the safety of polysorbate 20 when administered intramuscularly. To secure the in vivo safety profile of polysorbate 20, a four-week repeated intramuscular dose toxicity study (0.02, 0.1, and 0.4 mg/kg, one injection every two weeks for a total of three injections) was conducted in 66 Sprague-Dawley (SD) rats. An intradermal irritation study was further conducted with 18 New Zealand White (NZW) rabbits. The toxicological evaluation of HSA (0.06 and 0.12 mg/kg) was also carried out as a comparative substance. Systemic and local toxicities were not observed in any of the SD rats or NZW rabbits based on clinical signs, body weight, hematology, clinical biochemistry, macroscopic findings on necropsy, histopathology of the injection site, and allergic reactions. The current study suggested that intramuscular administration of polysorbate 20 was considered to be safe at a level similar to that of HSA, which has an in vivo safety profile accumulated over the years. This provided the basis for the in vivo safety profile of polysorbate 20 administered intramuscularly and the scientific reliability of the use of polysorbate 20 as an alternative to HSA, which is used as an excipient for various pharmaceuticals in terms of its safety.

Comparison between rectal and body surface temperature in dogs by the calibrated infrared thermometer

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Dogs poorly tolerate rectal temperature measurements with a contact thermometer.

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Existing alternative approaches used uncalibrated infrared thermometers.

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Gum and inguinal temperature are correlated moderately to rectal temperature.

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Hyperthermia was detected with sensitivity and specificity up to 90.0% and 78.6%.

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Future studies should include a calibrated thermometer and control external factors.

Because dogs tolerate conventional rectal temperature measurements poorly, a calibrated infrared thermometer was tested for assessing canine body surface temperature. Body surface temperature of 204 dogs was estimated on various sites (digit, snout, axilla, eye, gum, inguinal region, and anal verge). Having rectal temperature as the gold standard, temperature difference, Spearman's correlation coefficient, hyperthermia and hypothermia detection sensitivity and specificity, and stress response score was calculated for each measurement site. Although the canine body surface temperature was considerably lower than the rectal temperature, there was a moderate correlation between both temperatures. Spearman's coefficients were 0.60 (p < 0.001) for the inguinal region with a single operator and 0.50 (p < 0.001) for the gum with multiple operators. Measurement site on the gum additionally guaranteed hyperthermia detection sensitivity and specificity up to 90.0% (95% CI: [66.7 100]) and 78.6% (95% CI: [71.6 85.2]), respectively. Measurements with the infrared thermometer provoked a statistically significant lower stress response (mean stress scores between 1.89 and 2.48/5) compared to the contact rectal measurements (stress score of 3.06/5). To conclude, the correct body surface temperature measurement should include a calibrated thermometer, reliable sampling, and the control of external factors such as ambient temperature influence. The transformation of body surface temperature to the recognized rectal temperature interval allows more straightforward data interpretation. The gum temperature exhibited the best clinical potential since the differences to rectal temperatures were below 1°C, and hyperthermia was detected with the sensitivity of up to 90%.

Use of atracurium and its reversal with neostigmine in 14 pet rabbits undergoing ophthalmic surgery: a retrospective study

The objective of this retrospective study was to report the clinical use of atracurium and its reversal with neostigmine in pet rabbits. The medical records of 14 rabbits undergoing anaesthesia for ophthalmic surgery were located through a search of the hospital's database. Demographic data and data pertaining to the use of the neuromuscular blocker and its reversal were analysed. After intravenous administration of 0.44±0.4 mg/kg atracurium (total dose), 11 rabbits experienced at least one of the following cardiovascular responses: hypotension, defined as systolic arterial pressure less than 75 mmHg (n=6), hypotension with decreased heart rate (HR) (n=1), hypotension with increased HR (n=1), decreased arterial blood pressure (ABP) without hypotension (n=6), decreased ABP with decreased HR (n=1), or increased HR (n=2, ABP reading could not be taken). Two of these 11 rabbits also experienced severe intraoperative hypothermia. The neuromuscular block was monitored with a train-of-four nerve-stimulation pattern, and reversed, with intramuscular 0.01-0.045 mg/kg neostigmine and 0.01-0.02 mg/kg glycopyrronium, after the return of at least two out of four muscular twitches following nerve stimulation. Decrease in ABP and possibly hypothermia are likely intraoperative complications when clinical doses of atracurium are administered to pet rabbits. Measures should be taken to detect their occurrence in order to treat them promptly.