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.

CLINICAL AND PATHOLOGIC FINDINGS IN IGUANIDS WITH SODIUM URATE CHOLELITHIASIS

Four green iguanas (Iguana iguana) and one blue iguana (Cyclura lewisi) from five facilities were diagnosed with sodium urate cholelithiasis. One case was diagnosed antemortem via ultrasonography, and the iguana underwent a choledochotomy for treatment. The other four cases were identified at necropsy. Pathologic hepatic and biliary changes were present in four of the five cases at necropsy. Histologically, four iguanas had hepatic fibrosis, three had bile duct hyperplasia, and one had cholangiohepatitis and pancreaticocholedochitis. Two iguanas had pathologic renal changes. This is the first report of sodium urate cholelithiasis in reptiles. This case series highlights the potential significant clinical disease caused by sodium urate cholelithiasis and the importance of biliary system evaluation. Further investigation is recommended to explore the pathogenesis of reptilian sodium urate cholelith formation.

Multifocal Hepatocellular Carcinoma in a Malayan Wreathed Hornbill (Rhyticeros undulatus)

A 30-year-old female intact Malayan wreathed hornbill (Rhyticeros undulatus) was presented for presumed nesting behavior, progressive anorexia, dropping food, and coelomic distension. A complete blood count and plasma biochemistry analysis revealed marked inflammation, severe electrolyte abnormalities, elevated liver enzyme activities and bile acids, and normal plasma iron concentrations. Radiographic images of the patient were consistent with hepatomegaly and loss of serosal detail in the coelomic cavity. A computed tomography study revealed multiple poorly contrast-enhancing hepatic nodules, hepatoperitoneal and intestinal peritoneal fluid and gas, and a contrast-enhancing mass in the ventral coelom. Cytologic samples of the liver were consistent with necrosis, and the coelomic effusion was characterized as an aseptic suppurative exudate. An exploratory coeliotomy was performed and biopsy samples of the liver and a mesenteric mass were histologically interpreted as a tubular carcinoma with metastasis to the liver and secondary portal hepatitis. Euthanasia was elected and multiple liver masses and a peripancreatic mass were identified on necropsy. Histopathological samples collected during the postmortem gross examination showed multiple well-demarcated hepatic masses consisting of neoplastic hepatocytes encapsulated by fibrous tissue and proliferation of dysplastic biliary ductules, as well as a peripancreatic heterophilic granuloma with adjacent pancreatic atrophy and ductular proliferation. Ultimately, the patient was diagnosed with multifocal hepatocellular carcinoma and chronic granulomatous and heterophilic pancreatitis, steatitis, and coelomitis with intralesional bacteria. Malignant hepatobiliary neoplasia has been poorly documented in hornbills despite high anecdotal incidence in this and other avian species predisposed to iron storage disease. This report illustrates clinical and pathological information, including advanced imaging, which could aid in the diagnosis of this condition in hornbills and other avian species.

Treatment of Pain in Rats, Mice, and Prairie Dogs

Recent myomorph and scuiromorph rodent analgesia studies are reviewed and evaluated for potential clinical application. Differences between laboratory animal studies and clinical use in diseased animals are discussed. Analgesia classes reviewed include local anesthetics, nonsteroidal anti-inflammatories, acetaminophen, opioids, and adjuvants such as anticonvulsants. Routes of administration including sustained-release mechanisms are discussed, as are reversal agents. Drug interactions are reviewed in the context of beneficial multimodal analgesia as well as potential adverse effects. Dosage recommendations for clinical patients are explored.

Neurological examination in healthy adult inland bearded dragons (Pogona vitticeps)

OBJECTIVE

To evaluate neurological tests and expected results in inland bearded dragons (Pogona vitticeps) and generate recommendations for bearded dragon-specific neurological examination.

ANIMALS

26 healthy adult inland bearded dragons.

PROCEDURES

A complete neurological examination utilizing tests described in both mammals and reptiles was performed on each lizard, and test feasibility and outcome were recorded.

RESULTS

Tests with poor feasibility included oculocardiac reflex (successfully completed in 62% [16/26] of animals) and voluntary ambulation and swallowing by use of a food item (0% [0/26] of animals). Tests with outcomes considered abnormal in mammals but attributable to normal bearded dragon behavior included head position (head tilt present in 12% [3/26]) and head movement (head bob present in 4% [1/26]). Many tests had absent or inconsistent outcomes, including menace response (present in 19% [5/26]), proprioceptive positioning (present in 4% [1/26] in the thoracic limbs and 0% [0/26] in the pelvic limbs), vent reflex (present in 27% [7/26]), and myotatic reflexes (biceps present in 8% [2/26]; patellar, gastrocnemius, and triceps present in 0% [0/26]). Extensor postural thrust was absent in all successfully tested animals, but a novel reflex termed the caudal thoracic extensor reflex was noted instead in all observed animals (100% [21/21]).

CLINICAL RELEVANCE

Tests with poor feasibility or inconsistent outcomes should have low priority or be excluded from neurological examinations of inland bearded dragons. Normal behaviors should be considered for head position and movement. A bearded dragon-specific neurological examination protocol derived from these findings is described and recommended in order to decrease stress and improve neurolocalization.

Gelatinous transformation of bone marrow in a rabbit

A 9-y-old, spayed female rabbit was presented for evaluation of hypoglycemia and lateral recumbency. The patient was hypothermic and had diffuse muscle wasting; weight loss since a previous visit was also noted. Hematologic abnormalities included progressive nonregenerative anemia and severe heteropenia. Evaluation of a bone marrow aspirate sample revealed active hematopoiesis with abundant pink matrix. The matrix material stained positively with periodic acid-Schiff and alcian blue, and a diagnosis of gelatinous transformation of the bone marrow (GTBM, serous atrophy of fat) was made. Although its precise prevalence remains to be determined, GTBM should be suspected in rabbits with persistent cytopenias following prolonged starvation or gastrointestinal disease.

Persistent infection and pancytopenia associated with ferret systemic coronaviral disease in a domestic ferret

Ferret systemic coronaviral disease (FSCD) is a well-established cause of mortality in domestic ferrets. We describe herein novel findings in a case of FSCD that was diagnosed and medically managed following virus detection by immunohistochemical (IHC) staining of surgical biopsy samples. Hematologic changes in this ferret suggested spread of the virus to the bone marrow, which was confirmed by IHC staining of a postmortem sample. Genotyping of the virus indicated that the virus grouped with alphacoronaviruses and was most closely related to ferret enteric coronavirus (FRECV) MSU-2. Our clinical case demonstrates that a FRECV MSU-2-like ferret coronavirus associated previously with the enteric pathotype may cause systemic disease, including bone marrow involvement causing persistent pancytopenia.

A novel surgical technique for enucleation in rabbits to reduce the risk of intra- and post-operative orbital hemorrhage

A 10-year-old male castrated Holland Lop rabbit (Oryctolagus cuniculus) was presented for severe ulcerative stromal keratitis of the right eye and a luxated hypermature cataract and glaucoma of the left eye. Staged bilateral enucleation was elected. A LigaSure™ electrosurgical bipolar vessel-sealing device was used as a means to minimize intraoperative and post-operative hemorrhage, especially that associated with the orbital venous plexus. The LigaSure™ was used to ligate and transect all extraocular muscles, the optic nerve bundle, and the base of the third eyelid with no complications encountered. Overall, the LigaSure™ was easy to use, resulted in minimal hemorrhage, and reduced surgery time. This is the first report of the use of a LigaSure™ to aid in the enucleation of a rabbit. Although only positive results were achieved as an alternative to conventional methodologies, its use in clinical practice should be that of caution until a larger study evaluating the long-term results is performed.