Major crossmatch compatibility of rabbit blood with rabbit, canine, and feline blood.

OBJECTIVE: To evaluate the major crossmatch compatibility between rabbit recipients, rabbit donors, and the major canine and feline blood types. DESIGN: Prospective in vitro study in December 2021. SETTING: Academic veterinary teaching hospital. ANIMALS: Whole blood samples were collected from 11 healthy New Zealand White rabbits (Oryctolagus cuniculus) with no previous transfusion history. Three pigtail segments were acquired from dog erythrocyte antigen (DEA)-1-positive, DEA-1-negative, and feline type A blood units. Whole blood was collected from a healthy type B blood donor cat. INTERVENTIONS: Blood from each rabbit recipient underwent a major crossmatch using standard tube crossmatch methodology with itself and the following donor blood types: rabbit, DEA-1-positive, DEA-1-negative, feline type A, and feline type B. MEASUREMENTS AND MAIN RESULTS: Self-crossmatches and crossmatches between rabbit recipients and conspecific donors were negative for hemolysis and agglutination. Crossmatches between rabbit recipients and canine and feline donors yielded no hemolysis but produced varying degrees of macroscopic and microscopic agglutination. Rabbit recipients had 1.4 (95% confidence interval: 1.1-1.8) times the risk of macroscopic agglutination when major crossmatched with canine blood compared to feline blood. No significant difference in agglutination was found between DEA-1-positive and DEA-1-negative or feline type A and type B donors. CONCLUSIONS: These findings support allogeneic blood transfusions between rabbits being highly compatible and suggest rabbits have naturally occurring alloantibodies against both canine and feline red blood cells. However, feline red blood cells had a lower rate of in vitro incompatibility on major crossmatch, suggesting potentially higher in vivo compatibility if an emergency xenotransfusion is needed. Further prospective research is needed to determine if xenotransfusion is associated with a higher incidence of acute and delayed transfusion reactions in rabbits than allogeneic transfusions.

Cardiovascular disease in central bearded dragons (Pogona vitticeps): 54 cases (2007-2022).

OBJECTIVE: To describe the clinical features, histopathologic lesions, and outcome of cardiovascular disease in central bearded dragons. ANIMALS: 54 bearded dragons. METHODS: Retrospective evaluation of captive bearded dragons with antemortem imaging or postmortem diagnosis of cardiovascular disease from 2007 to 2022 from 6 hospitals. RESULTS: The total prevalence of cardiovascular disease was 3.3% (54/1,655). Physical examination findings were available in 46 cases with change in mentation being the most common finding (n = 28/46 [60.9%]), followed by dehydration (17/46 [37%]), palpable coelomic mass (13/46 [28.3%]), dyspnea (10/46 [21.7%]), and sunken eyes (10/46 [21.7%)]. Doppler auscultation revealed an arrhythmia in 5/34 (14.7%) animals. Diagnostic imaging was only performed on 21 animals, and 10 (47.6%) had cardiovascular abnormalities described. In total, 84 cardiovascular diagnoses were found in 54 animals. The most common diagnosis was myocarditis (n = 14) followed by aneurysms (11), pericardial effusion (9), atherosclerosis (7), epicarditis (7), and myocardial degeneration/necrosis (7). Overall, 62 causes of death were identified in 52 cases, with cardiovascular disease being the most common (n = 18/52 [34.5%]). Only 3/54 animals were diagnosed with congestive heart failure. Animals with aneurysms were more likely to die to due cardiovascular disease compared to other types of cardiovascular diagnoses (OR, 43.75; 95% CI, 4.88 to 392.65; P < .001). CLINICAL RELEVANCE: Diagnosis of cardiovascular disease in bearded dragons is challenging given the inconsistent clinical presentation; however, it should remain a differential in animals with nonspecific signs of illness. Antemortem diagnostics are recommended in suspected cases, including diagnostic imaging. Of the cardiovascular diseases described, aneurysms most often contributed to clinical demise.

Osteosarcoma of the wing in a sulfur-crested cockatoo.

A 26-year-old female sulfur-crested cockatoo (Cacatua galerita) was evaluated for vocalizing through the night and extending her right wing. Physical examination revealed a large, firm mass extending from the humerus to the distal aspect of the elbow. Computed tomography confirmed a large aggressive mass of the right distal humerus with a large soft tissue component, severe osteolysis, and adjacent periosteal proliferation. Fine-needle aspirates of the mass were most compatible with sarcoma, and osteosarcoma was prioritized. An unstained slide was treated with nitroblue tetrazolium chloride/5-bromo-4-chloro-3-indolyl phosphate toluidine salt-phosphatase (NBT/BCIP) substrate for ALP detection and was strongly positive, confirming a diagnosis of osteosarcoma. A month later, the patient underwent wing amputation and arrested during recovery from anesthesia. Post-mortem examination and histopathology were consistent with osteosarcoma. This case report highlights a rare occurrence of osteosarcoma in a cockatoo as well as its cytologic and histologic features. Additionally, this report provides support for NBT/BCIP application in ALP-expressing tumors, a cytochemical stain that has been minimally investigated in avian species.

Rabbit Pediatrics.

Rabbits encompass roles spanning from companion animals, wildlife species to laboratory animal models. Pediatric care of these species therefore may extend to various disciplines of veterinary medicine. Rabbits are born altricial but have a unique perinatal relationship between kit and doe with infrequent nursing. Nursing is immunologically protective to the kit and close contact with the doe allows for colonization of their gastrointestinal tract with bacterial flora. The most common diseases that pediatric rabbits are faced with are gastrointestinal in nature with orphaned and hand-reared rabbits at higher risk due to the aforementioned effects on their immune system.

The clinical features and treatment of fishhook injuries in freshwater turtles: 126 cases from 1997-2022.

OBJECTIVE: To describe the clinical features, treatment, and outcomes of wild freshwater turtles with fishing hook injuries. ANIMALS: 126 wild turtles residing in central North Carolina that were presented to a wildlife rescue clinic. METHODS: Medical records from July 1997 to July 2022 were reviewed, and data were collected and analyzed. RESULTS: The most common species presenting for a fishhook injury was the yellow-bellied slider (Trachemys scripta scripta) (n = 69/126 [54.8%]; 95% CI, 45.7 to 63.6). The most common location identified was the oral cavity (n = 77/140 [55%]; 95% CI, 46.4 to 63.4) and the most common removal method was retrograde removal after cutting the barb off of the hook (76/120 [63.3%]; 95% CI, 54.1 to 71.9). Fishhooks embedded in the esophagus had a significantly higher chance of complications affecting recovery (OR estimate, 3.49; 95% CI, 1.07 to 11.38). There was no significant increase in mortality associated with the location of the injury; however, there was a significant increase in mortality in patients that experienced complications (P < 0.001). The time in care ranged from 1 to 150 days (median, 16 days). Of the turtles evaluated, 10.8% (n = 12/111; 95% CI, 5.7 to 18.1) were euthanized or died after treatment and 89.2% (99/111; 95% CI, 81.9 to 94.3) were released. CLINICAL RELEVANCE: These findings describe various successful techniques to remove fishhooks from turtles. While no superior treatment was identified, considerations should be taken to provide patient comfort, decrease injury-associated complications, and shorten recovery time by using minimally invasive techniques. Overall, freshwater turtles with fishhook injuries have a high release rate even when the injuries are severe.

ULTRASONOGRAPHIC EVALUATION OF COELOMIC FLUID IN HEALTHY CORN SNAKES (PANTHEROPHIS GUTTATUS).

Free coelomic fluid can be a physiologic or pathologic finding in snakes. In this study, ultrasonography was used to assess the presence, volume, and type of coelomic fluid in 18 (16 females, 2 males) clinically healthy corn snakes (Pantherophis guttatus) using a semiquantitative scoring system. Each snake was divided into five equal regions (R1-R5) by length (from rostrum to vent) and fluid volume was scored on a scale of 0 to 4. Coelomic fluid was sampled when possible and cytologic analysis was performed. The majority of snakes (16/18) were found to have some degree of free coelomic fluid. The coelomic fluid samples that were collected (n= 6) were classified as transudates, acellular or primarily lymphocytic. Fluid was most likely to be found in R3 compared with all other regions and least likely to be found in R1 compared with R2, R3, and R4. A higher score of volume was found in R3 compared with R1 and R5. This study describes the distribution and abundance of coelomic fluid in snakes, as well as a method for point of care ultrasound (POCUS) in this species.

Treatment of Pain in Rabbits.

Rabbits occupy facets of veterinary medicine spanning from companion mammals, wildlife medicine, zoologic species, and research models. Therefore, analgesia is required for a variety of conditions in rabbits and is a critical component of patient care. Considerations when selecting an analgesic protocol in rabbits include timing of administration, route of administration, degree or anticipated pain, ability to access or use controlled drugs, systemic health, and any potential side effects. This review focuses on pharmacologic and locoregional management of pain in rabbits and emphasizes the need for further studies on pain management in this species.

Imaging Diagnosis: Thoracic radiographic features of toxoplasmosis in a 14-month-old Red Kangaroo (Macropus rufus).

A privately owned 14-month-old intact female red kangaroo (Macropus rufus) was presented for acute onset respiratory distress and lethargy. On presentation, the kangaroo was laterally recumbent, tachypneic, dyspneic, lethargic, and obtunded. Thoracic radiographs revealed a severe diffuse mixed pulmonary pattern (alveolar pattern superimposed on a bronchial pattern) and subjective mild generalized cardiomegaly. Due to the severity of clinical signs and grave prognosis, euthanasia was elected. Postmortem examination was consistent with systemic toxoplasmosis. Histopathology and immunohistochemistry staining on infected tissues confirmed Toxoplasma gondii. This is the first published report of radiographic findings for confirmed toxoplasmosis in a red kangaroo or marsupial.

Clinicopathological findings in and prognostic factors for domestic rabbits with liver lobe torsion: 82 cases (2010-2020).

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.

Pharmacokinetics of pimobendan following oral administration to New Zealand White rabbits (Oryctolagus cuniculus).

OBJECTIVE: To determine the pharmacokinetics and potential adverse effects of pimobendan after oral administration in New Zealand White rabbits (Ocytolagus cuniculi). ANIMALS: 10 adult sexually intact (5 males and 5 females) rabbits. PROCEDURES: 2 pilot studies were performed with a pimobendan suspension or oral tablets. Eight rabbits received 7.5 mg of pimobendan (mean 2.08 mg/kg) suspended in a critical care feeding formula. Plasma concentrations of pimobendan and O-demethylpimobendan (ODMP) were measured, and pharmacokinetic parameters were calculated for pimobendan by noncompartmental analysis. Body weight, food and water consumption, mentation, urine, and fecal output were monitored. RESULTS: Mean ± SD maximum concentration following pimobendan administration was 15.7 ± 7.54 ng/mL and was detected at 2.79 ± 1.25 hours. The half-life was 3.54 ± 1.32 hours. Plasma concentrations of pimobendan were detectable for up to 24 hours. The active metabolite, ODMP, was detected in rabbits for 24 to 36 hours. An adverse event occurred following administration of pimobendan in tablet form in 1 pilot study, resulting in death secondary to aspiration. No other adverse events occurred. CLINICAL RELEVANCE: Plasma concentrations of pimobendan were lower than previously reported for dogs and cats, despite administration of higher doses, and had longer time to maximum concentration and half-life. Based on this study, 2 mg/kg of pimobendan in a critical care feeding formulation should maintain above a target plasma concentration for 12 to 24 hours. However, further studies evaluating multiple-dose administration as well as pharmacodynamic studies and clinical trials in rabbits with congestive heart failure are needed to determine accurate dose and frequency recommendations.

Clinical and pathological findings in rabbits with cardiovascular disease: 59 cases (2001-2018).

OBJECTIVE: To determine epidemiological features of cardiovascular disease in rabbits examined at a veterinary teaching hospital and characterize clinical and pathological findings. ANIMALS: 59 rabbits. PROCEDURES: Medical records from 2001 to 2018 were reviewed, and data were collected. Echocardiographic images and histologic diagnoses were reviewed. RESULTS: The prevalence of cardiovascular disease was 2.6% (59/2,249). Clinical signs related to cardiac disease included heart murmur (n = 25 rabbits), arrhythmia (22), tachypnea or dyspnea (13), hyporexia or anorexia (13), and muscle wasting (9). Radiographic (n = 39) abnormalities included cardiomegaly (19) and peritoneal (12) and pleural (11) effusion. Common echocardiographic (n = 37) diagnoses included degenerative valve disease (15), dilated cardiomyopathy (7), unclassified cardiomyopathy (4), restrictive cardiomyopathy (3), and hypertrophic cardiomyopathy (2). On ECG (n = 19), supraventricular arrhythmias (16) were more common than ventricular arrhythmias (12). Thirty-five necropsy reports were available, and diagnoses included cardiomyopathy (n = 14), myocarditis (10), and arteriosclerosis (9). Medical management (n = 20) included a wide range of drugs and dosages with few adverse effects. Survival times (n = 36 rabbits) ranged from 1 to 2,353 days with a median cardiac disease-specific survival time of 306 days. CONCLUSIONS AND CLINICAL RELEVANCE: The findings provided information on the prevalence of cardiovascular disease in rabbits and survival times for affected rabbits. Right-sided, left-sided, and biventricular congestive heart failure occurred equally. Median survival time was lower than that reported for other species. Further research on the diagnosis and treatment of cardiovascular disease in rabbits is needed.

NEOURETEROCYSTOSTOMY AND URETHRAL STENT PLACEMENT IN A BLACK-HANDED SPIDER MONKEY (ATELES GEOFFROYI).

A 27-y-old female black-handed spider monkey (Ateles geoffroyi) was evaluated 13 d after an ovariohysterectomy because of abdominal distension, anorexia, and absent urination. The animal was diagnosed with a uroabdomen and urethral obstruction from computed tomographic findings and fluid creatinine levels. During exploratory laparotomy, a defect in the right ureter was confirmed as the source of the uroabdomen. Utilizing intraoperative fluoroscopy, a urethral obstruction with an irregular luminal filling defect was evident. A self-expanding nitinol urethral stent was placed, and a ureteral transposition was performed. Two months after the procedure, the animal developed dysuria, a urinary tract infection, recurrent bladder distension and a partial urethral obstruction. Treatment with prazosin 1 mg/kg PO q12h improved urination. Reobstruction of the urethra occurred 17 mo postsurgery, and the animal was euthanatized. On postmortem examination, the animal had ingrowth into the stent with proliferative granulation tissue, detrusor muscle degeneration, pelvic adhesions, cystitis, pyelonephritis, and hydronephrosis.

Pharmacokinetics of maropitant citrate in New Zealand White rabbits (Oryctolagus cuniculus).

OBJECTIVE: To determine the pharmacokinetics and adverse effects of maropitant citrate after IV and SC administration to New Zealand White rabbits (Oryctolagus cuniculus). ANIMALS: 11 sexually intact (3 males and 8 females) adult rabbits. PROCEDURES: Each rabbit received maropitant citrate (1 mg/kg) IV or SC. Blood samples were collected at 9 (SC) or 10 (IV) time points over 48 hours. After a 2-week washout period, rabbits received maropitant by the alternate administration route. Pharmacokinetic parameters were calculated. Body weight, food and water consumption, injection site, mentation, and urine and fecal output were monitored. RESULTS: Mean ± SD maximum concentration after SC administration was 14.4 ± 10.9 ng/mL and was detected at 1.25 ± 0.89 hours. Terminal half-life after IV and SC administration was 10.4 ± 1.6 hours and 13.1 ± 2.44 hours, respectively. Bioavailability after SC administration was 58.9 ± 13.3%. Plasma concentration at 24 hours was 2.87 ± 1.69 ng/mL after IV administration and 3.4 ± 1.2 ng/mL after SC administration. Four rabbits developed local dermal reactions at the injection site after SC injection. Increased fecal production was detected on the day of treatment and 1 day after treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Plasma concentrations of rabbits 24 hours after SC and IV administration of maropitant citrate (1 mg/kg) were similar to those of dogs at 24 hours. Reactions at the SC injection site were the most common adverse effect detected. Increased fecal output may suggest an effect on gastrointestinal motility. Additional pharmacodynamic and multidose studies are needed.

Acremonium and trichosporon fungal keratoconjunctivitis in a Leopard Gecko (Eublepharis macularius).

A 6-year-old male leopard gecko (Eublepharis macularius) was presented with a 2-year history of recurrent dysecdysis involving the ocular surface of both eyes. Ophthalmic examination revealed ocular surface desiccation and multifocal superficial ulcerative keratitis with patchy remnants of retained shed. Other abnormalities included stomatitis and mandibular and maxillary osteomyelitis. Topical and systemic antibiotic therapy, oral vitamin A, and improved husbandry conditions resolved the stomatitis and osteomyelitis but did not improve the ocular surface. Corneal cytology collected with a cytobrush revealed branching hyphae and budding yeast consistent with fungal keratitis. Fungal culture grew Acremonium sp. and Trichosporon sp. The addition of topical antifungal therapy improved the ocular surface health, but the patient was euthanized 7 weeks after initial presentation for persistent vomiting and dyspnea. Necropsy was declined. This case describes the first case of fungal keratitis caused by Acremonium sp. and Trichosporon sp. in a reptile.

Comparison of rectal and tympanic thermometry in chinchillas (Chinchilla lanigera).

OBJECTIVE To evaluate the effects of restraint time and thermometer insertion depth on rectal temperature measurements in chinchillas and determine the extent of agreement between temperatures measured with 2 tympanic and a rectal thermometer. DESIGN Prospective method comparison study. ANIMALS 47 healthy chinchillas. PROCEDURES Effects of 1- and 2-cm rectal thermometer insertion depths and the effect of manual restraint for up to 5 minutes were evaluated. Near simultaneous temperature measurements were obtained with a human tympanic, a veterinary tympanic, and a rectal thermometer by 2 observers. Duplicate temperature measurements were obtained for each method, and the sequence of measurements was randomized for each animal. RESULTS Rectal temperature readings obtained at a depth of 2 cm were significantly higher (mean ± SD, 1.14 ± 0.77°C [2.05° ± 1.39°F]) than those obtained at 1 cm. After 3 minutes, manual restraint had a significant effect on rectal temperature. The reference interval for rectal temperature in chinchillas with a 2-cm thermometer insertion depth was calculated as 34.9° to 37.9°C (94.8° to 100.2°F). Both tympanic infrared thermometers had significant systematic bias (0.42 ± 0.12°C [0.76° ± 0.22°F]) and proportional bias (0.88 ± 0.14°C [1.58° ± 0.25°F]). The coefficients of reliability for the rectal thermometer, the human tympanic thermometer, and the veterinary tympanic thermometer were 0.86, 0.85, and 0.69, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Rectal thermometer insertion depth and duration of manual restraint had a significant effect on rectal temperature measurements in chinchillas. Because of significant systematic and proportional bias, tympanic thermometry was not considered a suitable replacement for rectal thermometry in chinchillas.

Stifle Disarticulation as a Pelvic Limb Amputation Technique in a Cockatiel ( Nymphicus hollandicus ) and a Northern Cardinal ( Cardinalis cardinalis ).

This clinical report describes the use of stifle disarticulation in 2 avian patients as an alternative to transfemoral limb amputation. A northern cardinal ( Cardinalis cardinalis ) was presented for soft tissue swelling and a traumatic fracture of the third digit of the left limb, with secondary bacterial infection and necrosis. A 25-year-old cockatiel ( Nymphicus hollandicus ) was diagnosed with distal extremity necrosis after a nonunion of a closed tibiotarsal fracture. In both cases amputation was recommended due to the poor prognosis for healing and because both birds were poor surgical candidates for traditional methods of amputation due to patient size or age. Therefore, stifle disarticulation surgery for amputation of the pelvic limb was performed successfully in both cases and recovery was unremarkable. The outcomes of these 2 cases suggest that stifle disarticulation may be used as an alternative to transfemoral amputation in birds where prolonged surgery, anesthesia, or patient size precludes traditional amputation techniques.