Clinical value of blood glucose measurement in 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.

Radiological and laboratory prognostic parameters for gastric dilation in rabbits (Oryctolagus cuniculus)

BACKGROUND

The aim of this study was to evaluate the radiographical and laboratory findings in pet rabbits with gastric dilation (GD) and identify prognostic parameters.

METHODS

One hundred and fifty-five rabbits with GD were included for the radiographical analyses and 75 for the laboratory analyses. A vertebral stomach score (VSS) was established to determine the extension of the stomach on lateral radiographs. In addition, the caudal limit of gastric distention and the extension and position of gas accumulation in the stomach were recorded.

RESULTS

The VSS was significantly higher in rabbits with GD than in healthy rabbits (p = 0.001). Extensive amounts of gas accumulation in the stomach (p = 0.001) and a ventral or central location of gas accumulation (p = 0.023) were associated with significantly increased mortality. Azotemia (51%), hyperglycaemia (44%) and hyponatraemia (37%) were the most frequent biochemical alterations in rabbits with GD.

LIMITATIONS

Due to the retrospective nature of the data, the cause of GD could not be determined in all animals.

CONCLUSION

Rabbits with GD and severe alterations in glucose, creatinine and sodium concentrations, ventral or central gas accumulations and a large amount of gas in the stomach had a poor prognosis.

Pregnancy Complications and Feto-Maternal Monitoring in Rabbits

Rabbit production holds significant relevance in modern agriculture due to its potential as a sustainable source of high-quality protein and efficient feed conversion, contributing to food security and economic diversification. Nevertheless, studies incorporating feto-maternal monitoring in this species are uncommon. This review gathers research on the monitoring and evaluation of factors affecting rabbit gestation, providing a better understanding of the causes of prenatal development abnormalities. These include studies regarding how chronic maternal hypertension, gestational diabetes, maternal stress, ectopic gestation, maternal uterine ischemia and fetal hypoxia, intrauterine growth restriction, superfetation, maternal age, maternal nutritional status, maternal physical condition, maternal and embryonic genotype, and the intrauterine location of rabbit fetuses can potentially impact rabbits' reproduction and maternal and fetal health. Among other monitoring techniques, ultrasonography, considered one of the best tools for diagnosing pregnancy and conducting follow-up, is also reviewed. Details on measurable fetal-development parameters in rabbits and precautions to be considered before and during the examination are also provided. Additional studies are required to understand why some events occur and their consequences throughout gestation, allowing the determination of new biomarkers or cut-offs that can be helpful for early diagnosis and improve reproductive efficiency.

Clinicopathological and radiographic indicators for orogastric decompression in rabbits presenting with intestinal obstruction at a referral hospital (2015-2018)

BACKGROUND

Orogastric decompression is regularly recommended as a part of both medical and pre-surgical treatment for small intestinal obstruction in rabbits. However, guidelines as to when orogastric decompression is indicated are sparse.

METHODS

The medical records of 35 rabbits diagnosed with gastrointestinal obstruction over a 3-year period were examined. Differences in presentation, clinicopathological and radiographic examination findings, treatments and outcome were evaluated.

RESULTS

Approximately 49% of the cases evaluated were considered to have non-life-threatening disease, while 51% were considered to have life-threatening disease. The severity of gastric obstruction was correlated with the severity of hyperglycaemia (average 25.7 mmol/L; 463 mg/dl) and corresponding hyponatraemia (Na < 138 mmol/L; 138 mEq/L). These patients were treated with orogastric decompression and medical management only.

LIMITATIONS

This is a retrospective study and there are inherent limitations involving the quality of the data and data collection. Additional studies should be completed that strive for larger sample sizes to compare the differences in outcome between surgical and medical management, as well as investigate the outcomes of rabbits with hyperglycaemia and hyponatraemia that did not have an orogastric decompression performed.

CONCLUSIONS

Blood glucose and sodium concentrations, in combination with radiographic findings, may aid clinicians in determining if orogastric decompression is indicated to stabilise rabbits with small intestinal obstructive disorders.

Quantitative measurement of blood glucose influenced by multiple factors via photoacoustic technique combined with optimized wavelet neural networks

In this work, the photoacoustic (PA) quantitative measurement of blood glucose concentration (BGC) influenced by multiple factors was firstly investigated. A set of PA detection system of blood glucose considering the comprehensive influence of five factors was established. The PA signals and peak-to-peak values (PPVs) of 625 rabbit whole blood were obtained under 625 influence combinations. Due to the accurate measurement of BGC limited by the overlap PA signals, wavelet neural network (WNN) was utilized to train the PPVs of blood glucose for 500 rabbit blood. The mean square error (MSE) of BGC for 125 testing blood was approximately 6.5782 mmol/L. To decrease the MSE, the parameters of WNN were optimized by particle swarm optimization (PSO), that is, PSO-WNN algorithm was employed. Under the optimal parameters, MSE of BGC was decreased to approximately 0.48005 mmol/L. To further improve the prediction accuracy of BGC, an improved nonlinear dynamic inertia weight (NDIW) strategy of PSO was proposed, and compared with other two kinds of dynamic inertia weight strategies. Under the optimal parameters, the MSE of BGC was decreased to approximately 0.2635 mmol/L. The comparison of nine algorithms demonstrate that the PA technique combined with PSO-WNN and the improved NDIW strategy is significant in the quantitative measurement of blood glucose influenced by multiple factors.

Pain Recognition in Ferrets

Recognition and accurate assessment of the severity of pain can be challenging in ferrets as they are unable to verbally communicate, and often hide their pain. Pain assessment relies on the assessment of behavioral, physiologic, and other clinical parameters that serve as indirect indicators of pain. Assessment of physiologic and clinical parameters requires handling, which results in changes in these parameters. Behavioral parameters can be assessed less invasively by observing the patient. Due to their nonspecificity, correct interpretation may be challenging. Just as in other species, a grimace scale seems to be the most helpful tool in recognizing pain in ferrets.

Effects of Buprenorphine and Carprofen on Appetite in New Zealand White Rabbits (Oryctolagus cuniculus)

Rabbits are especially susceptible to adverse effects related to surgery, which can lead to inappetence and gastrointestinal (GI) stasis. However, these adverse effects may be related to discomfort from the procedure, anesthesia, the analgesics used, and the stress of restraint for analgesic administration. Opioid and NSAID analgesics which are frequently used in rabbits, can contribute to these adverse effects. This study compared the clinical GI side effects of buprenorphine and carprofen to saline controls in New Zealand White rabbits after a nonsurgical anesthetic event. Nine rabbits (3 females and 6 males, aged 8 to 20 mo) were randomly rotated through 5 treatment groups with a 7-d washout period between treatments: anesthesia control (no treatment), buprenorphine (0.05 mg/kg SC every 12 h for 72 h), carprofen (5 mg/kg SC every 24 h for 72 h), twice daily saline control (equivalent volume to buprenorphine SC every 12 h for 72 h), and once daily saline control (equivalent volume to carprofen SC every 24 h for 72 h). All rabbits were anesthetized 5 times and received initial treatments on the day of anesthesia. Generalized linear mixed models were used to assess food intake, water intake, and fecal output score for 7 days after anesthesia. Analysis showed that buprenorphine-treated rabbits had a significant 4-d decrease in food intake and a 3-d decrease in fecal output score compared with baseline. None of the other treatment groups showed any changes in food intake or fecal output score compared with baseline. These findings demonstrate that in the absence of pain, buprenorphine significantly depresses food intake in rabbits and that restraint and injections have minimal effect on food intake despite the possibility of increased stress.

Endocrine Diagnostics for Exotic Animals

Endocrine disease in exotic species is less common than in small animals. Nevertheless, the diagnostic principles used in small animals can be adapted to evaluate endocrine disease in many of the exotic species although species-specific aspects need to be considered. This article covers important diseases such as thyroid dysfunction in reptiles and birds, hyperthyroidism in guinea pigs, and hyperadrenocorticism in ferrets. Glucose metabolism in neoplasms affecting normal physiology, such as insulinoma in ferrets and gastric neuroendocrine carcinoma in bearded dragons, is discussed. Calcium abnormalities, including metabolic bone disease in reptiles and hypocalcemia in birds, are also covered.

[Studies on the use of iodine-containing contrast agent diatrizoate in rabbits (Oryctolagus cuniculus)]

OBJECTIVE

The use of the iodine-containing contrast agent diatrizoate was investigated in healthy rabbits and in rabbits with gastric dilatation and intestinal obstruction. For this purpose, transit times through the gastrointestinal tract and clinical use were investigated during a one year period. In addition, a possible influence on thyroid hormone levels was evaluated.

MATERIAL AND METHODS

Transit times of contrast agent through the different intestinal sections were examined radiographically in 14 healthy rabbits. For this purpose, 7 ml/kg of a 300 mg iodine/ml and 600 mg diatrizoate/ml containing solution were administered. Radiographs were obtained at different time intervals. Three different doses (D1 2 ml/kg, D2 7 ml/kg, D3 10 ml/kg) were administered, and blood samples were collected at two time points (60 min, 24 h) to analyze thyroid hormone levels (TT4, fT4, TSH). In addition, 70 rabbits that had received the contrast agent diatrizoate because of gastric dilatation and suspected intestinal obstruction were retrospectively evaluated during a period of one year. Focus was placed on arrival of the contrast agent in the cecum, laboratory changes, and mortalities.

RESULTS

In all healthy rabbits, contrast medium was detectable in the cecum after a mean of 45-60 min. In the animals suffering from gastrointestinal obstruction, this was delayed to a mean of 121.2 min. These animals showed hypothermia in 92.4 % and hyperglycemia in 45.9 %. 56.1 % exhibited an increase in urea and 33.9 % an increase in creatinine. In 71.4 % of cases, medical treatment was possible, however 12 % of these individuals succumbed to the disease. 28.6 % of the cases were managed surgically which was associated with a mortality of 50 %. TT4, fT4, and TSH levels displayed significant alterations among the three contrast agent doses (p < 0.05). These changes were found to be transient when follow-up was performed two weeks later.

CONCLUSION AND CLINICAL RELEVANCE

When ileus is suspected in rabbits, diatrizoate may be helpful in evaluating the progression of the disease in addition to the use of native radiographs. Sufficient hydration and monitoring of renal function are advisable. Transient changes in thyroid hormones were evident but lacked clinical relevance.

Glucose and Lactate Reference Intervals for White Sturgeon and Evaluation of Two Point-of-Care Devices in Sturgeon Infected with Veronaea botryosa

White Sturgeon Acipenser transmontanus are cultured for human consumption as well as for conservation purposes. In this study, two commercially available portable devices for measuring glucose and lactate were compared to a benchtop analyzer and blood reference intervals were generated using heparin plasma collected from 43 healthy White Sturgeon yearlings. The generated normal ranges were used to compare plasma values collected from Veronaea botryosa-infected White Sturgeon at 10, 20, and 30 d postchallenge (dpc). In the 43 healthy yearlings, significantly different glucose and lactate values were obtained when comparing the portable devices to the benchtop analyzer. In the portable devices, blood glucose showed a consistent bias of 12.3 mg/dL and blood lactate showed a proportional bias. The detected blood glucose values in infected sturgeon were significantly different from those in noninfected controls when using the benchtop analyzer at 20 and 30 dpc and when using the portable device at 20 dpc. However, blood glucose in infected individuals and controls was within the reference interval on either device. No significant difference was noted for lactate measurements in infected sturgeon. The results of this study indicate that portable devices for blood glucose and blood lactate evaluation in White Sturgeon may be useful in a setting where relative values are an acceptable approximation of absolute values.

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.

Case Report: Spontaneous Appendicitis With Suspected Involvement of Klebsiella variicola in Two Pet Rabbits

Although laboratory rabbits are commonly used as models of appendicitis in man, spontaneous appendicitis was only described ante-mortem in one pet rabbit with an acute abdomen. The aim of this article is to describe two spontaneous cases of appendicitis in pet rabbits, to describe therapeutic appendectomy, and to discuss the microbial flora of the inflamed appendix. A 5-month-old intact female and a 16-month-old, neutered male were presented to the veterinary clinic with restlessness, anorexia, and reduced faecal output. The main clinical findings were restlessness, severe discomfort on abdominal palpation, a mid-abdominal palpable tubulous mass and an elevated rectal temperature. Blood analyses showed lymphocytosis, monocytosis, and hyperglycaemia. Radiography was inconclusive. Abdominal ultrasound revealed a presence of a tubular structure with wall thicknesses of 4.2 and 3.7 mm in the two rabbits, respectively. The tubular structure had a rounded, closed end, and a multilayered wall, suggestive of appendicitis. Due to metabolic acidosis and poor prognosis, the first rabbit was euthanized. In the 16-month-old rabbit, appendectomy was performed. Recovery was uneventful, and 4 h after surgery, the rabbit started to become normally active. Postoperative care consisted of fluid therapy, multimodal analgesia, supportive care and prokinetics. Follow-up examinations at 10 days, 1 month, and at 11 months after the surgery did not show any abnormal clinical or laboratory findings. Histopathological examination of appendices from both rabbits showed gangrenous appendicitis. Aerobic cultivation showed the presence of pure culture of Klebsiella variicola sensitive to enrofloxacin, marbofloxacin, tetracycline, cefuroxime, trimethoprim sulphonamide, neomycin, and gentamicin. Restlessness associated with anorexia, abdominal pain, palpable abdominal mass, hyperglycaemia, lymphocytosis, and elevated rectal temperature may be indicative of inflammation within the gastrointestinal tract. Abdominal ultrasound is recommended in rabbits with showing these clinical signs because radiography can be inconclusive. Appendicitis is a life-threatening condition, which should be included into the list of differential diagnoses; for the rabbit, an acute abdomen and gastrointestinal stasis syndrome and must be treated immediately. K. variicola may be associated with appendicitis in rabbits as a causative agent or in association with appendix intraluminal dysmicrobia.

Sonochemically engineered nano-enabled zinc oxide/amylase coatings prevent the occurrence of catheter-associated urinary tract infections

Catheter-associated urinary tract infections (CAUTIs), caused by biofilms, are the most frequent health-care associated infections. Novel antibiofilm coatings are needed to increase the urinary catheters' life-span, decrease the prevalence of CAUTIs and reduce the development of antimicrobial resistance. Herein, antibacterial zinc oxide nanoparticles (ZnO NPs) were decorated with a biofilm matrix-degrading enzyme amylase (AM) and simultaneously deposited onto silicone urinary catheters in a one-step sonochemical process. The obtained nano-enabled coatings inhibited the biofilm formation of Escherichia coli and Staphylococcus aureus by 80% and 60%, respectively, for up to 7 days in vitro in a model of catheterized bladder with recirculation of artificial urine due to the complementary mode of antibacterial and antibiofilm action provided by the NPs and the enzyme. Over this period, the coatings did not induce toxicity to mammalian cell lines. In vivo, the nano-engineered ZnO@AM coated catheters demonstrated lower incidence of bacteriuria and prevent the early onset of CAUTIs in a rabbit model, compared to the animals treated with pristine silicone devices. The nano-functionalization of catheters with hybrid ZnO@AM coatings appears as a promising strategy for prevention and control of CAUTIs in the clinic.

Rabbit Sedation and Anesthesia

With the increasing frequency of rabbits as veterinary patients, the expectation for high-quality, intensive veterinary care, and resultantly an understanding of anesthesia has been increasing. Sedation and general anesthesia are commonly required for many routine and emergency procedures in rabbits, and this results in the need for a strong awareness of anesthetic principles, knowledge of limitations of anesthesia, and maintenance of high standards of anesthesia.

Rectal temperature is a prognostic indicator in client-owned guinea pigs

OBJECTIVES

To determine whether rectal temperature was associated with patient mortality in client-owned guinea pigs upon presentation to a veterinary hospital.

MATERIALS AND METHODS

The medical record database at a veterinary teaching hospital was searched for records of guinea pigs from January 2016 through June 2019. Guinea pigs were included in the study if a rectal temperature was measured at presentation and there was data on survival status 7 days post-presentation. If survivor status was not documented in the medical record, follow-up information was obtained from the client via telephone or email. The data was ultimately collected from 201 client-owned guinea pigs who presented for 388 independent examinations. Univariable, multivariable and sensitivity analyses were performed.

RESULTS

Guinea pigs with hypothermia (<37.9°C) at presentation had a relative risk of mortality within 7 days of presentation almost 3 times greater than guinea pigs without hypothermia (relative risk: 2.88; 95% confidence interval: 1.86 to 4.48). For each 0.55°C decrease in rectal temperature, the odds of death increased 1.6 times (odds ratio: 1.64; 95% confidence interval: 1.42 to 2.89). Sensitivity analyses confirmed the robustness of the finding.

CLINICAL SIGNIFICANCE

Rectal temperature was a predictor of death for guinea pigs presenting for care at a veterinary hospital. Obtaining a rectal temperature recording should be considered for patient guinea pigs.

Prognostic value of packed cell volume and blood glucose concentration in 954 client-owned chelonians

OBJECTIVE

To evaluate the prognostic value of PCV and blood glucose concentration in chelonians presented for veterinary care and to develop risk categories on the basis of the interaction of these analytes.

ANIMALS

954 client-owned chelonians (34 genera).

PROCEDURES

Medical records of 1,059 client-owned chelonians presented to 2 veterinary institutions between 2014 and 2018 were reviewed. Logistic regression models were developed to evaluate factors associated with death, including PCV and blood glucose concentrations.

RESULTS

There were 954 chelonians (34 genera) for which the data required to be included in the analysis were available. Both PCV and blood glucose concentration were significant prognostic indicators of death. Odds of death for chelonians with severe anemia (PCV, < 10%) and moderate anemia (PCV, 11% to 20%) were 6.8 times (adjusted odds ratio [aOR], 6.8; 95% CI, 3.8 to 12.3) and 1.6 times (aOR, 1.6; 95% CI, 1.01 to 2.7), respectively, the odds of death for chelonians with PCV within reference range. Odds of death for chelonians with severe hypoglycemia (< 30 mg/dL), moderate hyperglycemia (91 to 150 mg/dL), and severe hyperglycemia (> 181 mg/dL) were 5.3 times (aOR, 5.3; 95% CI; 2.4 to 11.4), 3 times (aOR, 3.0;95% CI, 1.4 to 6.3), and 4.3 times (aOR, 4.3; 95% CI, 2.4 to 7.6), respectively, the odds of death for chelonians with blood glucose concentration within reference range. Five risk categories were identified on the basis of PCV and blood glucose concentration.

CONCLUSIONS AND CLINICAL RELEVANCE

Derangements in PCV and blood glucose concentration in client-owned chelonians were associated with increased odds of death. On the basis of these results, more aggressive diagnostic testing and treatments may be indicated in chelonians with similar alterations.

Associations between biochemical parameters and referral centre in pet rabbits with urolithiasis

OBJECTIVES

To determine the association between signalment, selected haematologic and biochemical parameters and referral centre in pet rabbits with imaging evidence of urolithiasis presented to two veterinary teaching hospitals in North America.

MATERIALS AND METHODS

The medical record database of two veterinary teaching hospitals was searched from 2009 to 2019 for records of pet rabbits that received both imaging studies and plasma biochemistry profiles. Information regarding signalment, bodyweight, packed cell volume, total solids, and plasma biochemistry profiles was obtained. Univariable and multivariable logistic regression models were performed to identify statistically significant parameters associated with imaging evidence of urolithiasis.

RESULTS

Of the 324 examined rabbits, 33 (10.2%) had confirmed evidence of urolithiasis on imaging. Increasing plasma calcium and sodium concentrations and referral centre were significantly associated with the presence of urolithiasis on the univariable logistic regression model. However, only plasma calcium concentration and the referral centre demonstrated significant associations on the multivariable logistic regression model.

CLINICAL SIGNIFICANCE

Results indicate that urolithiasis in pet rabbits that receive imaging is associated with mildly increasing plasma calcium concentration and referral centre. The association with referral centre may indicate there are geographic influences on urolithiasis or on imaging. However, the identified associations have low predictive value for the diagnosis of urolithiasis, indicating the need for additional diagnostic modalities.

Comparison of 2 portable human glucometers for the measurement of blood glucose concentration in White New Zealand rabbits

We compared measurements of blood glucose concentrations in 30 healthy adult White New Zealand rabbits using 2 commercial portable glucometers (PGM1 and PGM2) and a laboratory chemical analyzer. Results were analyzed with Pearson correlation, Passing-Bablok regression analysis, Bland-Altman analysis, and a modified error grid. Measurements with PGM1 were significantly correlated (r = 0.37) with those obtained from the laboratory reference method (RM); Bland-Altman and Passing-Bablok analyses indicated no significant systematic or proportional differences (mean difference of -0.26, 95% CI of mean difference of -0.54 to 0.01, and LOA of -1.70 to 1.17); and error grid resulted in 100% of measurements in zone A. No significant correlation (r = -0.05) was detected between PGM2 and RM; Bland-Altman and Passing-Bablok analyses results indicated a mean difference of 2.14, 95% CI of mean difference of 1.67-2.60, and limit of agreement of -0.32 to 4.59, which overestimated blood glucose concentration, with 53% of glucose measurements in error grid zone A and 47% in zone B. PGM1 was considered accurate in normoglycemic rabbits, whereas the use of PGM2 could result in overestimations of glycemia.

Investigation for correction formulas on the basis of packed cell volume for blood glucose concentration measurements obtained with portable glucometers when used in rabbits

OBJECTIVE

To determine effects of PCV on blood glucose (BG) concentration measurements obtained with a human portable blood glucometer (HPBG) and a veterinary portable blood glucometer (VPBG) on canine (cVPBG) and feline (fVPBG) settings (test methods) when used in rabbits and to develop correction formulas to mitigate effects of PCV on such measurements.

SAMPLE

48 resuspended blood samples with known PVCs (range, 0% [plasma] to 92% [plasma and packed RBCs]) from 6 healthy research rabbits (experimental sample set) and 252 historic measurements of BG concentration and PCV in 84 client-owned rabbits evaluated at a veterinary hospital (validation data set).

PROCEDURES

Duplicate measurements of BG concentration with each test method and of PCV were obtained for each sample in the experimental sample set, and the mean results for each variable for each test method and sample were compared with results from a clinical laboratory analyzer (reference method) used to determine the true BG concentration for each sample. Mean ± SD differences in measurements between the reference and test methods were calculated. Linear regression and modified Clarke error grid analysis were used to develop correction formulas for the test methods given known PCVs, and these formulas were evaluated on the validation data set with linear regression and a modified Clarke error grid.

RESULTS

Blood glucose concentrations were falsely low for cVPBG and fVPBG used on samples with PCV < 31% and were falsely high for all test methods used on samples with PCV > 43%. Compared with original measurements, formula-corrected measurements overall had better agreement with reference method measurements for the experimental sample set; however, only the formula-corrected HPBG measurements had improved agreement for the validation data set.

CONCLUSIONS AND CLINICAL RELEVANCE

Findings indicated that, in rabbits, HPBG measurements had improved accuracy with the use of the correction formula HPBG measurement of BG concentration + ([0.75 × PCV] - 15); however, the correction formulas did not improve the accuracy of VPBG measurements, and we believe that neither the cVPBG nor fVPBG should be used in rabbits.

Clinical characteristics and short-term outcomes for rabbits with signs of gastrointestinal tract dysfunction: 117 cases (2014-2016)

OBJECTIVE

To describe the clinical findings and short-term outcomes for rabbits with signs of gastrointestinal tract dysfunction or rabbit gastrointestinal syndrome (RGIS).

ANIMALS

117 client-owned rabbits.

PROCEDURES

The electronic medical records database of a veterinary teaching hospital was searched to identify rabbits that were examined because of altered or absent food intake and decreased or absent fecal output between June 1, 2014, and June 30, 2016. For each rabbit, information extracted from the record included history of prior episodes of gastrointestinal tract dysfunction, signalment, physical examination and diagnostic test results, and outcome.

RESULTS

117 of the 484 (24%) rabbits examined at the hospital during the study period met the inclusion criteria and were enrolled in the study. Fifty-nine and 58 rabbits were managed on an inpatient and outpatient basis, respectively. Gastrointestinal stasis without overt obstruction was diagnosed for 43 rabbits on the basis of abdominal radiographic, ultrasonographic, or necropsy results. Many rabbits had concurrent disease and biochemical abnormalities. Fifteen, 18, and 84 rabbits died, were euthanized, and survived to hospital discharge, respectively. Rabbits that were hypothermic (rectal temperature, ≤ 36.6°C [97.9°F]) during the initial examination were 5 times as likely to die or be euthanized as were euthermic rabbits, after controlling for potential confounders.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that the prognosis was generally good for rabbits with signs of RGIS unless they were hypothermic during initial examination. Prospective studies are warranted to further elucidate and characterize RGIS and assess the efficacy of various treatments and outcomes for affected rabbits.

Evaluation of blood urea nitrogen concentration and anorexia as predictors of nonsurvival in client-owned rabbits evaluated at a veterinary referral center

OBJECTIVE To determine the prognostic relevance of BUN concentration in client-owned rabbits evaluated at a veterinary referral center. ANIMALS 246 healthy or clinically ill client-owned rabbits with BUN concentrations measured at a veterinary referral center. PROCEDURES In a retrospective cohort study design, medical records of rabbits were retrieved, and data were collected on BUN concentration (exposure variable of interest) and other variables, including outcome (survival status at 15 days after BUN concentration measurement). Univariate, multivariate, and subgroup analyses were performed to identify variables associated with outcome. RESULTS BUN concentrations ranged from 6.5 to 251.1 mg/dL (median, 18.7 mg/dL). Univariate analysis revealed that the risk of nonsurvival over the 15-day period for rabbits with a high BUN concentration (≥ 23.3 mg/dL) was 33% higher (relative risk, 1.33; 95% confidence interval [CI], 1.06 to 1.69) than that for rabbits with unremarkable BUN values. Subgroup analysis revealed that for rabbits with anorexia, a high (vs unremarkable) BUN concentration was associated with an increased risk of nonsurvival (relative risk, 1.69; 95% CI, 1.05 to 2.71). In the final multivariate model that controlled for age, sex, and appetite (anorexia vs no anorexia), the odds of nonsurvival for rabbits with BUN values > 24.74 mg/dL were 3 times that for rabbits with BUN values < 14.00 mg/dL (OR, 2.92; 95% CI, 1.29 to 6.58). CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that a high BUN concentration increased the risk of nonsurvival over a 15-day period for client-owned rabbits, particularly those with anorexia. Blood urea nitrogen concentration should be used together with other clinical indicators to provide prognostic information for rabbits receiving veterinary care.

PROGNOSTIC INDICATORS FOR SURVIVAL OF ORPHANED NEONATAL AND JUVENILE EASTERN COTTONTAIL RABBITS (SYLVILAGUS FLORIDANUS): 1,256 CASES (2012-17)

Orphaned eastern cottontail rabbits (ECRs; Sylvilagus floridanus) often present to wildlife clinics within their geographic range and require considerable dedication of time and resources. The objective of this analytical cross-sectional study was to assess initial examination findings to be used as prognostic indicators for orphaned neonatal and juvenile ECRs. The medical records of the University of Illinois Wildlife Medical Clinic were searched for ECRs presenting between 2012 and 2018. This criterion identified 1,256 ECRs that were then classified as survivors (survived and released) or as nonsurvivors (euthanized or natural death) within 72 h of admission. Presenting weight, body system abnormalities, hydration status, intervention prior to presentation, and singleton versus group presentation were categorically recorded for each individual ECR. The data were modeled using a series of logistic regression models fitted using the general linear model. Individuals were significantly more likely to be nonsurvivors if they presented as singletons (P<0.0001), presented with moderate/severe (P<0.001) or mild integumentary signs (P=0.0261), presented with multi-organ disease (P<0.001), presented with neurologic signs (P<0.0003), or had treatment provided prior to presentation (P=0.031). Factors that did not predict survival status in ECRs included body weight (P=0.210), presence of respiratory signs (P=0.674), and presence of dehydration (P=0.356). These findings may be used at wildlife medical clinics to make triage criteria for euthanasia as well as dedicate limited funds and labor to cases with the best prognosis for survival.

Gastrointestinal Diseases of Rabbits

Gastrointestinal stasis syndrome is a very common presentation of an ill rabbit to the veterinarian. The causes involved in this syndrome are often multifactorial, and an inappropriate diet puts the rabbit at a greater risk of developing this syndrome. Complications of this disorder can lead to gastrointestinal obstruction, a life-threatening condition that necessitates aggressive medical and in some case surgical therapy. Rabbits may also be presented with signs of diarrhea. However, abnormal cecotrophs must be differentiated from true intestinal diarrhea. The common causes, diagnosis and management of diarrhea including dysbiosis and enteritis are discussed. Other important causes of gastrointestinal disease are infectious disease and liver lobe torsion. Rabbit hemorrhagic disease virus has a new variant that has been identified in mainland Europe, the United Kingdom, and Australia. Subclinical infection of intestinal coccidiosis is a common cause of weight loss in adult rabbits. Liver lobe torsion is a challenging condition to diagnose in rabbits; this chapter discusses the presenting signs, diagnostic techniques, and therapeutic options.

Postanaesthetic effects of ketamine-midazolam and ketamine-medetomidine on gastrointestinal transit time in rabbits anaesthetised with isoflurane

BACKGROUND

Gastrointestinal stasis is a common perianaesthetic complication in rabbits. The objective of this study was to assess the impact on gastrointestinal transit time of ketamine-midazolam (KMZ) versus ketamine-medetomidine (later antagonised by atipamezole) (KMT-A) in rabbits anaesthetised with isoflurane.

METHODS

This was a cross-over, randomised, single-blinded, controlled, experimental trial. Seven healthy adult New Zealand White rabbits were used. Gastrointestinal transit time was assessed by contrast radiography in awake rabbits. Presence of contrast medium in the small intestine (gastric transit time), in the caecum (small intestinal transit time) and in faeces in the colon was assessed. One week later, 55 minutes isoflurane anaesthesia was induced with ketamine (15 mg/kg) and either midazolam (3 mg/kg) or medetomidine (0.25 mg/kg) by intramuscular injection. Thirty minutes after discontinuation of isoflurane, atipamezole (0.5 mg/kg) was administered only to rabbits in KMT-A treatment. Gastrointestinal transit time was then assessed in both treatment groups, beginning 30 minutes after cessation of isoflurane administration. Two weeks later, the treatment groups were interchanged.

RESULTS

Gastric and small intestinal transit times were significantly longer with KMT-A (92±109 minutes and 214±119 minutes, respectively) than with KMZ (1±0 minutes and 103±6 minutes, respectively) and in the awake state (7±7 minutes and 94±32 minutes, respectively).

CONCLUSION

Clinicians should therefore be aware of the potential gastrointestinal side effects of KMT-A, particularly in rabbits at risk for gastrointestinal stasis.

Radiographic diagnosis of small intestinal obstruction in pet rabbits (Oryctolagus cuniculus): 63 cases

OBJECTIVES

To identify radiographic features that can be used to aid in the diagnosis of small intestinal obstruction in pet rabbits.

MATERIALS AND METHODS

Retrospective study comparing radiographic features of 63 cases of confirmed intestinal obstruction with 50 abdominal radiographs taken of rabbits without gastrointestinal disease. Abdominal radiographs were examined for gastric size, gastric contents, small intestinal dilatation and gas within the large intestine and caecum.

RESULTS

Gastric size, gastric contents, small intestinal dilatation and gas within the large intestine and caecum were all features that differed between rabbits with small intestinal obstruction and rabbits without gastrointestinal disease. Radiographic features associated with small intestinal obstruction included severe gastric dilation, gastric contents primarily consisting of liquid and gas, small intestinal dilation and absence of large amounts of gas in the caecum and large intestine.

CLINICAL SIGNIFICANCE

Observation on gastric size, small intestinal dilatation and gas within the large intestine and caecum aid in radiological diagnosis of small intestinal obstruction in rabbits and so can guide appropriate treatment.

Effects of vagotomy on cardiovascular and heart rate variability alterations following chronic normobaric hypoxia in adult rabbits

BACKGROUND

chronic hypoxia increases basal ventilation and pulmonary vascular resistance, with variable changes in arterial blood pressure and heart rate, but it's impact on heart rate variability and autonomic regulation have been less well examined. We studied changes in arterial blood pressure, heart rate and heart rate variability (HRV) in rabbits subjected to chronic normobaric hypoxia (CNH; PB ~ 719 mmHg; F_IO₂ ~ 9.2%) for 14 days and assess the effect of autonomic control by acute bilateral vagal denervation.

RESULTS

exposure to CNH stalled animal weight gain and increased the hematocrit, without affecting heart rate or arterial blood pressure. Nevertheless, Poincaré plots of the electrocardiographic R-R intervals showed a reduced distribution parallel to the line of identity, which interpreted as reduced long-term HRV. In the frequency domain, CNH reduced the very-low- (< 0.2 Hz) and high-frequency components (> 0.8 Hz) of the R-R spectrograms and produced a prominent component in the low-frequency component (0.2-0.5 Hz) of the power spectrum. In control and CNH exposed rabbits, bilateral vagotomy had no apparent effect on the short- and long-term HRV in the Poincaré plots. However, bilateral vagotomy differentially affected higher-frequency components (> 0.8 Hz); reducing it in control animals without modifying it in CNH-exposed rabbits.

CONCLUSIONS

These results suggest that CNH exposure shifts the autonomic balance of heart rate towards a sympathetic predominance without modifying resting heart rate or arterial blood pressure.

Convergence in reduced body size, head size, and blood glucose in three island reptiles

Many oceanic islands harbor diverse species that differ markedly from their mainland relatives with respect to morphology, behavior, and physiology. A particularly common morphological change exhibited by a wide range of species on islands worldwide involves either a reduction in body size, termed island dwarfism, or an increase in body size, termed island gigantism. While numerous instances of dwarfism and gigantism have been well documented, documentation of other morphological changes on islands remains limited. Furthermore, we lack a basic understanding of the physiological mechanisms that underlie these changes, and whether they are convergent. A major hypothesis for the repeated evolution of dwarfism posits selection for smaller, more efficient body sizes in the context of low resource availability. Under this hypothesis, we would expect the physiological mechanisms known to be downregulated in model organisms exhibiting small body sizes due to dietary restriction or artificial selection would also be downregulated in wild species exhibiting dwarfism on islands. We measured body size, relative head size, and circulating blood glucose in three species of reptiles-two snakes and one lizard-in the California Channel Islands relative to mainland populations. Collating data from 6 years of study, we found that relative to mainland population the island populations had smaller body size (i.e., island dwarfism), smaller head sizes relative to body size, and lower levels of blood glucose, although with some variation by sex and year. These findings suggest that the island populations of these three species have independently evolved convergent physiological changes (lower glucose set point) corresponding to convergent changes in morphology that are consistent with a scenario of reduced resource availability and/or changes in prey size on the islands. This provides a powerful system to further investigate ecological, physiological, and genetic variables to elucidate the mechanisms underlying convergent changes in life history on islands.

Evidence-Based Advances in Rabbit Medicine

Rabbit medicine has been continuously evolving over time with increasing popularity and demand. Tremendous advances have been made in rabbit medicine over the past 5 years, including the use of imaging tools for otitis and dental disease management, the development of laboratory testing for encephalitozoonosis, or determination of prognosis in rabbits. Recent pharmacokinetic studies have been published, providing additional information on commonly used antibiotics and motility-enhancer drugs, as well as benzimidazole toxicosis. This article presents a review of evidence-based advances for liver lobe torsions, thymoma, and dental disease in rabbits and controversial and new future promising areas in rabbit medicine.

Physiological values of some blood indicators in selected dwarf rabbit breeds

<p>The aim of the present study was to evaluate the effect of breed on haematological and biochemical indicators in 3 dwarf rabbit breeds. In the experiment, 30 sexually intact dwarf rabbit females aged 6 mo were used. With the sole exception of white blood cells and haematocrit value, breed had the most significant effect on the majority of haematological indicators monitored. The red blood cell count was higher in the Dwarf Lop compared to the Netherland Dwarf (+1.91×10¹² cells/L; P&lt;0.05) and also the Teddy Dwarf (+1.32×10¹² cells/L; P&lt;0.05). For haemoglobin concentration, a higher value was found in the Netherland Dwarf than in the Teddy Dwarf (+39.29 g/L; P&lt;0.05) and the Dwarf Lop (+26.36 g/L; P&lt;0.05). For erythrocytic indicators, the highest values of mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration were found in the Netherland Dwarf. The breed had a significant effect on the urea and potassium values. A higher value of urea was recorded in the Dwarf Lop compared to the Teddy Dwarf (+1.56 mmol/L; P&lt;0.05). For potassium, a higher value was found in the Netherland Dwarf compared to the Teddy Dwarf (+0.85 mmol/L; P&lt;0.05). In addition, a significantly positive correlation (P&lt;0.05) was found between the live weight of dwarf females and values of haematocrit (0.49), albumin (0.54), alanine aminotransferase (0.51), and aspartate aminotransferase (0.41), while a significantly negative correlation (P&lt;0.05) was found between their live weight and values of triacylglycerols (–0.44), alkaline phosphatase (–0.38) and inorganic phosphorus (–0.52). </p>

Assessment and Care of the Critically Ill Rabbit

Rabbits have the ability to hide their signs and often present in a state of decompensatory shock. Handling can increase susceptibility to stress-induced cardiomyopathy and specific hemodynamic changes. Careful monitoring with a specific reference range is important to detect early decompensation, change the therapeutic plan in a timely manner, and assess prognostic indicators. Fluid requirements are higher in rabbits than in other small domestic mammals and can be corrected both enterally and parenterally. Critical care in rabbits can be extrapolated to many hindgut fermenters, but a specific reference range and dosage regimen need to be determined.

Proximal duodenoileal anastomosis for treatment of small intestinal obstruction and volvulus in a green iguana (Iguana iguana)

CASE DESCRIPTION A 13-year-old female green iguana (Iguana iguana) was examined because of a 6-day history of vomiting, anorexia, and lethargy and a 4-day history of decreased fecal and urate output. CLINICAL FINDINGS Physical examination revealed a distended abdomen, signs of depression, pallor, tachycardia, harsh lung sounds, and vomiting. Abdominal radiographs revealed gas distention of the stomach and small intestine with fluid lines evident on the lateral view. Plasma biochemical analysis indicated hypochloremic metabolic alkalosis, hyperglycemia, and hyperuricemia. TREATMENT AND OUTCOME Exploratory laparotomy confirmed a diagnosis of small intestinal entrapment and 170° volvulus involving approximately 80% (20 to 30 cm) of the small intestine. The portion of the small intestine extending from the middle portion of the duodenum to the caudal extent of the ileum was resected, and end-to-end anastomosis of the remaining small intestine was performed. The iguana recovered without apparent complications and was reportedly doing well 1 year after surgery. CLINICAL RELEVANCE Findings suggested that iguanas, as hindgut fermenters, may tolerate > 70% resection of the small intestine with a good outcome and no clinical evidence of residual gastrointestinal dysfunction.

Construction and Characterization of Protein-Encapsulated Electrospun Fibermats Prepared from a Silica/Poly(γ-glutamate) Hybrid

Protein-encapsulated fibermats are an attractive platform for protein-based bioactive materials. However, the choice of methods is still limited and not applicable to a wide range of proteins. In this study, we studied new polymeric materials for constructing protein-encapsulated fibermats, in which protein molecules are encapsulated within the nanofibers of fibermats without causing deleterious changes to protein structure or function. We constructed a protein-encapsulated fibermat using the poly(γ-glutamate) (PGA)/(3-glycidyloxypropyl)-trimethoxysilane (GPTMS) hybrid as a precursor for electrospinning. Because the PGA/GPTMS hybrid is water-soluble, protein molecules can be added to the precursor in an aqueous solution, significantly enhancing protein stability. Polycondensation during electrospinning (in-flight polycondensation) makes the obtained fibermats water-insoluble, which stabilizes the fibermat structure such that it is resistant to degradation in aqueous buffer. The molecular structure of the PGA/GPTMS hybrid gives rise to unique molecular permeability, which alters the selectivity and specificity of biochemical reactions involving the encapsulated enzymes; lower molecular-weight (MW) substrates can permeate the nanofibers, promoting enzyme activity, but higher MW substrates such as inhibitor peptides cannot permeate the nanofibers, suppressing enzyme activity. We present an effective method of encapsulating bioactive molecules while maintaining their structure and function, increasing the versatility of electrospun fibermats for constructing various bioactive materials.

Rabbit Soft Tissue Surgery

This article summarizes the available information on different soft tissue surgical procedures in rabbits, based on the literature and the authors' experiences, emphasizing the differences between rabbits and the more familiar dogs and cats. The major surgical principles in rabbits are discussed, and common surgical procedures, such as abdominal exploration, gastrotomy, enterotomy, liver lobectomy, nephrectomy, cystotomy, cystectomy, ovariohysterectomy, ovariectomy, orchidectomy, are described.

Cutaneous lesions in pet rabbits following subcutaneous administration of a novel bivalent vaccine against myxomatosis and rabbit haemorrhagic disease

BACKGROUND

A novel bivalent vaccine to protect against myxomatosis and rabbit haemorrhagic disease is commercially available for pet rabbits.

HYPOTHESIS/OBJECTIVES

To describe the appearance of cutaneous lesions arising in pet rabbits positive for myxoma virus (MV) by RT-PCR evaluation shortly after vaccination.

ANIMALS

Four pet rabbits presenting with papular, crusting skin lesions ~10 days after vaccination.

METHODS

Histological evaluation of formalin-fixed skin biopsies obtained from lesional skin (case 1). Real-time polymerase chain reaction (RT-PCR) evaluation of paraffin-embedded tissue from skin biopsies (case 1) and crusts obtained from the lesion surface (cases 2-4) for myxoma virus are reported as cycle threshold (Ct ) values.

RESULTS

Lesions affecting the ear pinna, dorsal aspect of the nose, vulva and/or conjunctiva are reported. Histopathological findings included severe ulcerative, necrotizing dermatitis and intralesional cytoplasmic inclusion bodies in myxoma cells. DNA was amplified from all the paraffin-embedded skin biopsies (Ct  = 34-35) and crusts (Ct  = 20-24).

CONCLUSIONS AND CLINICAL IMPORTANCE

Although a wild virus challenge cannot be definitively excluded, veterinarians and pet-owners should be aware that cutaneous lesions have been observed after vaccination with this novel vaccine in low numbers of rabbits.

Point-of-Care Blood Gases, Electrolytes, Chemistries, Hemoglobin, and Hematocrit Measurement in Venous Samples from Pet Rabbits

Point-of-care testing is an attractive option in rabbit medicine, because it permits rapid analysis of a panel of electrolytes, chemistries, blood gases, hemoglobin, and hematocrit, requiring only 65 μL of blood. The purpose of this study was to evaluate the performance of a portable clinical analyzer for measurement of pH, partial pressure of CO2, Na, chloride, potassium, blood urea nitrogen, glucose, hematocrit, and hemoglobin in healthy and diseased rabbits. Blood samples obtained from 30 pet rabbits were analyzed immediately after collection by the portable clinical analyzer (PCA) and immediately thereafter (time &lt;20 sec) by a reference analyzer. Bland-Altman plots and Passing-Bablok regression analysis were used to compare the results. Limits of agreement were wide for all the variables studied, with the exception of pH. Most variables presented significant proportional and/or constant bias. The current study provides sufficient evidence that the PCA presents reliability for pH, although its low agreement with a reference analyzer for the other variables does not support their interchangeability. Limits of agreement provided for each variable allow researchers to evaluate if the PCA is reliable enough for their scope. To the authors’ knowledge, the present is the first report evaluating a PCA in the rabbit.

Gastrointestinal Disease in Exotic Small Mammals

Exotic small mammal medicine is a relatively new specialty area within veterinary medicine. Ferrets, rabbits, and rodents have long been used as animal models in human medical research investigations, resulting in a body of basic anatomic and physiologic information that can be used by veterinarians treating these species. Unfortunately, there is a paucity of veterinary articles that describe clinical presentation, diagnosis, and treatment options of gastrointestinal (GI) disease as it affects exotic small mammals. Although there is little reference material relating to exotic small mammal GI disease, patients are commonly presented to veterinary hospitals with digestive tract disorders. This article provides the latest information available for GI disease in ferrets (Helicobacter mustelae gastritis, inflammatory bowel disease [IBD], GI lymphoma, systemic coronavirus, coccidiosis, and liver disease), rabbits (GI motility disorders, liver lobe torsion, astrovirus, and coccidiosis), guinea pigs (gastric dilatation volvulus [GDV]), rats (Taenia taeniaeformis), and hamsters (Clostridium difficile). Both noninfectious diseases and emerging infectious diseases are reviewed as well as the most up-to-date diagnostics and treatment options.