Clinical diagnosis and outcome of cervicofacial cellulitis in pyrexic rabbits: six cases (2014-2021).

OBJECTIVES: To assess the signalment, history, exam findings, diagnostics, treatment and outcome of rabbits diagnosed with pyrexia and concurrent cervicofacial cellulitis. MATERIALS AND METHODS: Retrospective evaluation of medical records of rabbits diagnosed with cervicofacial cellulitis and pyrexia based on physical exam, contrast-enhanced CT, clinicopathology and microbiology findings. RESULTS: Six out of 1588 rabbits met the study inclusion criteria. Rabbits presented with a median age of 6 years (range, 8 months to 8 years) with a presenting complaint of anorexia or hyporexia. All rabbits had a rectal temperature >40.2°C (104.4°F). Physical exam and contrast-enhanced CT revealed unilateral submandibular and ipsilateral cervical diffuse soft tissue swelling in five of six rabbits. No antemortem evidence of periodontal or dental disease was found on physical exam or CT. Leucopenia was present in five of six rabbits. A left shift with marked toxic changes was present in all four rabbits, for which blood smears were reviewed. Bacterial cultures of the aspirated subcutaneous soft tissue swelling cultured Escherichia coli, Pasteurella multocida, Granulicatella adiacens, Streptococcus species, Haemophilus species and Bacteroides species. Treatment was pursued in five rabbits, where all rabbits received supportive care and four of five rabbits received systemic antibiotics. One rabbit was euthanased following a diagnosis of cervicofacial cellulitis. Three out of five rabbits continued to decline clinically despite medical management, and thus, euthanasia was pursued within 24 hours of starting treatment. Two rabbits responded to initial treatment and developed subsequent multi-focal abscessation. One rabbit was euthanased due to client cost constraints, and one rabbit died shortly after achieving clinical resolution of cervicofacial cellulitis. CLINICAL SIGNIFICANCE: Cervicofacial cellulitis should be considered a differential diagnosis in pyrexic rabbits with facial or cervical swelling with medical and surgical management pursued for therapy.

Effects of commercial metronidazole and metronidazole benzoate suspensions on food intake in chinchillas.

OBJECTIVES: To evaluate if commercially available metronidazole and metronidazole benzoate suspensions cause a reduction in food intake in healthy chinchillas and if the reduction in food intake is dose-dependent. MATERIALS AND METHODS: Twelve chinchillas were used in a randomised, controlled, blinded, complete-crossover study. All treatments were administered orally every 12 hours for 3 days. Metronidazole (125 mg/mL) was administered at 20 mg/kg and metronidazole benzoate (25 mg/mL) was administered at 20 and 10 mg/kg. Food intake was recorded daily. The washout period between treatments was at least 14 days. RESULTS: At 20 mg/kg PO q12h administration of both commercial suspensions resulted in a significant reduction of food intake. The greatest mean reduction in food intake occurred after 2 to 3 days of drug administration (metronidazole: -54 ± 25%; metronidazole benzoate: -44 ± 36%). After administration of metronidazole benzoate at 10 mg/kg PO q12h, the reduction in food intake was significantly less pronounced (-24 ± 36%), suggesting that negative effect of metronidazole on food intake in chinchillas is dose-dependent. Variation in metronidazole-induced food intake reduction differed widely between individual chinchillas. CLINICAL SIGNIFICANCE: The oral administration of commercial metronidazole and metronidazole benzoate suspensions results in a dose-dependent clinically relevant reduction in food intake in chinchillas. Metronidazole should be used cautiously in this species and food intake should be monitored during treatment. Future studies are needed in order to determine if metronidazole at 10 mg/kg q12h is an effective therapeutic dosage in chinchillas.

Aortocavitary fistula secondary to vegetative endocarditis in a rabbit.

A 4-year-old intact male mini lop rabbit (Oryctolagus cuniculus) was presented with a 2-week history of severe progressive lethargy. A right parasternal continuous heart murmur and an irregular rhythm were detected on physical examination. Echocardiography identified vegetative aortic and tricuspid valve (TV) endocarditis. There was an aortocavitary fistula between the right sinus of Valsalva into the right ventricle, creating a left-to-right intracardiac shunt. Based on the echocardiographic findings, it was suspected that the infection originated in the aortic valve, eroded through the periannular tissue, and secondarily infected the TV. Pleural and peritoneal effusion secondary to right-sided congestive heart failure was also found during the echocardiogram. Atrial fibrillation, conducted with a left bundle branch block morphology, was identified using electrocardiography. Necropsy findings directly correlated with the echocardiographic diagnosis; marked periodontal disease was also identified. Aerobic culture of the aortic and tricuspid vegetations resulted in significant growth of Haemophilus parainfluenzae. Haemophilus spp. belong to a group of similar gram-negative coccobacillus bacteria (HACEK group), which can act as an uncommon cause of endocarditis in humans. HACEK endocarditis is most commonly associated with oral infection and/or dental procedures in people. This is the first case report of a rabbit with periannular complications of infective endocarditis. It remains unknown whether dental disease resulted in endocarditis in this patient.

Effect of injection site on alfaxalone-induced sedation in ball pythons (Python regius).

OBJECTIVES: To evaluate the sedative and cardiorespiratory effects of alfaxalone in ball pythons following subcutaneous administration in the cranial versus caudal third of the body. MATERIALS AND METHODS: In a prospective, randomised, blinded, complete crossover study, eight ball pythons ( Python regius ) received alfaxalone in the cranial or caudal third of the body. Sedative and cardiorespiratory parameters were recorded. RESULTS: Administration of alfaxalone in the cranial third of the body resulted in significantly deeper and longer sedation compared with administration in the caudal third of the body. Righting reflex was lost in five of eight snakes following cranial injection compared with one of eight snakes after caudal injection. Jaw tone was lost in all snakes following cranial injection and intubation was successfully performed in seven. In contrast, snakes did not lose jaw tone and intubation was not possible following caudal injection. Heart rate and respiratory rate were significantly decreased following administration of alfaxalone in the cranial third of the body. CLINICAL SIGNIFICANCE: Administration of drugs that undergo hepatic metabolism or excretion should not be performed in the caudal third of the body in snakes, because it can result in significantly reduced drug efficacy. A hepatic first-pass effect is assumed to be the most likely underlying cause for the observed effect because part of the venous return from the caudal body flows directly to the liver.

Vertebral heart size in chinchillas (Chinchilla lanigera) usingradiography and CT.

OBJECTIVE: To determine the vertebral heart size in chinchillas using right and left lateral radiographic views and CT images. To evaluate the agreement between radiographic and CT modalities. METHODS: Twenty-one clinically healthy chinchillas and seven chinchillas with cardiovascular abnormalities underwent cardiovascular examination before thoracic radiographs and thoracic CT obtained under dexmedetomidine-ketamine anaesthesia. Two observers calculated vertebral heart size for radiographic and CT studies. Reference intervals were calculated with the robust method. Agreement between radiographic and CT-derived vertebral heart size was evaluated with Bland-Altman plots and Deming regression. RESULTS: Mean ±sd vertebral heart size for lateral radiographs was 8·9 ±0·62 (reference interval: 7·5 to 10·2) and for CT-derived vertebral heart size was 8·2 ±0·55 (reference interval: 7·1 to 9·4). CT significantly underestimated the radiographic vertebral heart size by 0·66 vertebrae. There was no significant difference between vertebral heart size for right and left lateral radiographic views, or between female and male chinchillas. CLINICAL SIGNIFICANCE: Radiographic vertebral heart size for chinchillas is larger than that reported for similar rodents. Vertebral heart size can be calculated using radiography or CT in chinchillas, but these techniques are not interchangeable.

Epidemiology of bacterial conjunctivitis in chinchillas (Chinchilla lanigera): 49 cases (2005 to 2015).

OBJECTIVES: To evaluate the anamnesis, clinical signs, diagnostic test results, treatment and outcome of chinchillas diagnosed with bacterial conjunctivitis. METHODS: Medical records of 49 chinchillas diagnosed with bacterial conjunctivitis were retrospectively reviewed. Association between clinical signs and type of bacteria involved was determined by means of univariate logistic regression. RESULTS: 61·5% of the isolated bacteria were Gram-negative, and the most common bacterial species was Pseudomonas aeruginosa (50%), followed by Staphylococcus species (26·9%). Chinchillas with acute conjunctivitis (1 to 3 days) were much more commonly affected by Gram-negative organisms. The majority of chinchillas that presented with concurrent respiratory signs were diagnosed with P. aeruginosa. Clinical resolution of conjunctivitis was reported in 87·8% chinchillas with a median time to clinical resolution of 17·5 days. Susceptibility of P. aeruginosa isolates to potentiated sulphonamides, enrofloxacin, ciprofloxacin, gentamicin, amikacin and polymyxin B was 8·3, 36, 62·5, 88·5, 100 and 100%, respectively. CLINICAL SIGNIFICANCE: P. aeruginosa is the predominant bacterial species associated with bacterial conjunctivitis in chinchillas. With the exception of duration of clinical signs, information on the anamnesis or physical examination findings cannot aid in distinguishing conjunctivitis caused by P. aeruginosa or other Gram-negative bacteria from the ones caused by Gram-positive bacteria. Gentamicin- or polymyxin B-containing antibiotic formulations are recommended for empirical topical therapy.

Urolithiasis in chinchillas: 15 cases (2007 to 2011).

OBJECTIVE: To evaluate the signalment, history, clinical signs, diagnostic test results, treatment and outcome of chinchillas diagnosed with urolithiasis. METHODS: Medical records of 15 chinchillas diagnosed with urolithiasis were retrospectively reviewed. RESULTS: All animals were male with a median age of 30 months (range: 11 to 132 months). Haematuria, pollakiuria and stranguria were the most common presenting complaints. Of 15 animals, 12 had abnormal physical abdominal examination, including pain and palpable cystic calculi. Uroliths were diagnosed in the urinary bladder, urethra or both. Nine animals had cystic calculi only. Four out of 6 chinchillas with urethral calculi were euthanased within 1 day of diagnosis. There was recurrence of cystic calculi following cystotomy in 5/10 animals and median time to recurrence was 68 days (range: 19 to 440 days). Median survival time in chinchilla with urolith recurrence was 391 days (range: 74 to 1074 days) following initial diagnosis. Disease-free follow-up time in 5/10 chinchillas without urolith recurrence following surgical removal was 2204 days (range: 1914 to 2535 days). CLINICAL SIGNIFICANCE: Cystic uroliths in male chinchillas carry a better prognosis than urethral uroliths. Recurrence of urolithiasis is common.

Angiofibroma in a cockatiel (Nymphicus hollandicus).

Human angiofibromas are rare and arise typically in the nasopharynx. In veterinary medicine they have only been described in the dog. Microscopically, angiofibromas consist of irregular groups of blood vessels within a stroma of connective tissue, with oedema and secondary inflammation often present. A cockatiel (Nymphicus hollandicus) was presented with an oral mass that consisted of aggregates of blood vessels surrounded by a connective tissue stroma, with the presence of oedema and secondary inflammation. Tumours of the oral cavity are uncommon in birds and to the authors' knowledge this is the first case of avian angiofibroma.

Subspectacular nematodiasis caused by a novel Serpentirhabdias species in ball pythons (Python regius).

Subspectacular nematodiasis was diagnosed in three captive-bred juvenile ball pythons (Python regius) from two unrelated facilities within a 6-month period. The snakes were presented with similar lesions, including swelling of facial, periocular and oral tissues. Bilaterally, the subspectacular spaces were distended and filled with an opaque fluid, which contained nematodes and eggs. Histopathology showed nematodes throughout the periocular tissue, subspectacular space and subcutaneous tissue of the head. The nematodes from both facilities were morphologically indistinguishable and most closely resembled Serpentirhabdias species. Morphological characterization and genetic sequencing indicate this is a previously undescribed rhabdiasid nematode.

Diagnosis and management of oviductal disease in three red-eared slider turtles (Trachemys scripta elegans).

Three mature, female, red-eared slider turtles (Trachemys scripta elegans) were individually, and separately, diagnosed with different forms of oviductal disease. Case 1 presented with acute cloacal bleeding and was diagnosed with acute oviductal rupture and ectopic eggs in the coelom. Case 2 presented for repeated scratching in the direction of the cloaca and was diagnosed with chronic oviductal impaction and coelomitis. Both cases were treated successfully by endoscopy-assisted complete ovariosalpingectomy via a bilateral prefemoral approach. Case 3 presented with a reduced appetite and signs of nesting behaviour and was diagnosed with obstructive dystocia associated with bacterial salpingitis. Successful treatment consisted of transcloacal egg removal and systemic antibiotics. Complete recovery was achieved in all three turtles, which remained disease-free 23 to 33 months later. Oviductal disease can present with a variety of clinical signs, and an accurate diagnosis can be made based on a thorough history, physical examination and appropriate diagnostic techniques.

History dependence of circadian pacemaker period in the cockroach.

The freerunning period of circadian clocks in constant environmental conditions can be history-dependent, and one effect of entrainment of circadian clocks by light cycles is to cause long-lasting changes in the freerunning period that are termed after-effects. We have studied after-effects of entrainment to 22-h (LD 8:14) and 26-h (LD 8:18) light cycles in the cockroach Leucophaea maderae. We find that in cockroaches, the freerunning period of the locomotor activity rhythm, measured in constant darkness (DD), is 0.7h less after entrainment to T22 than after entrainment to T26. Induction of after-effects requires several days (>1 week) entrainment, and after induction, after-effects will persist in DD for over 40 days. Further after-effects are unaltered by phase-resetting of up to 12h caused by exposure to low-temperature pulses (7 degrees C) of 24 or 48h duration. After-effects also persist through re-entrainment for 2 weeks to 24-h light cycles. These results indicate that after-effects arise from stable changes in the circadian system that are likely to be independent of phase relationships among oscillators within the circadian system. We also show that entrainment to temperature cycles does not generate after-effects indicating that light may be unique in its ability to generate lasting changes in pacemaker period.