Case Description—3 hornbills (2 Papua hornbills [Aceros plicatus] and 1 longtailed hornbill [Tockus albocristatus]) were evaluated because of general listlessness and loss of feather glossiness.
Clinical Findings—Because hepatic iron storage disease was suspected, liver biopsy was performed and formalin-fixed liver samples were submitted for histologic examination and quantitative image analysis (QIA). Additional frozen liver samples were submitted for chemical analysis. Birds also underwent magnetic resonance imaging (MRI) under general anesthesia for noninvasive measurement of liver iron content. Serum biochemical analysis and analysis of feed were also performed. Results of diagnostic testing indicated that all 3 hornbills were affected with hepatic iron storage disease.
Treatment and Outcome—The iron chelator deferiprone was administered (75 mg/kg [34.1 mg/lb], PO, once daily for 90 days). During the treatment period, liver biopsy samples were obtained at regular intervals for QIA and chemical analysis of the liver iron content and follow-up MRI was performed. In all 3 hornbills, a rapid and large decrease in liver iron content was observed. All 3 methods for quantifying the liver iron content were able to verify the decrease in liver iron content.
Clinical Relevance—Orally administered deferiprone was found to effectively reduce the liver iron content in these 3 hornbills with iron storage disease. All 3 methods used to monitor the liver iron content (QIA, chemical analysis of liver biopsy samples, and MRI) had similar results, indicating that all of these methods should be considered for the diagnosis of iron storage disease and monitoring of liver iron content during treatment.
Case Description—A 4-year-old sexually intact male mixed-breed dog was evaluated because of clinical signs of acute-onset pelvic limb ataxia, rapidly progressing to paraplegia with severe spinal hyperesthesia.
Clinical Findings—General physical examination revealed pyrexia, tachycardia, and tachypnea. Neurologic examination demonstrated severe spinal hyperesthesia and paraplegia with decreased nociception. Magnetic resonance imaging revealed extradural spinal cord compression at T13-L1 and hyperintense lesions on T1- and T2-weighted images in the epaxial musculature and epidural space.
Treatment and Outcome—Decompressive surgery, consisting of a continuous dorsal laminectomy, with copious lavage of the vertebral canal was performed. Cultures of blood, urine, and surgical site samples were negative. Histologic examination results for samples obtained during surgery demonstrated suppurative myositis and steatitis. These findings confirmed a diagnosis of sterile idiopathic inflammation of the epidural fat and epaxial muscles with spinal cord compression. The dog's neurologic status started to improve 1 week after surgery. After surgery, the dog received supportive care including antimicrobials and NSAIDs. The dog was ambulatory 1 month after surgery and was fully ambulatory despite signs of mild bilateral pelvic limb ataxia 3 years after surgery.
Clinical Relevance—Although idiopathic sterile inflammation of adipose tissue, referred to as panniculitis, more commonly affects subcutaneous tissue, its presence in the vertebral canal is rare. Specific MRI findings described in this report may help in reaching a presumptive diagnosis of this neurologic disorder. A definitive diagnosis and successful long-term outcome in affected patients can be achieved by decompressive surgery and histologic examination of surgical biopsy samples.
Objective—To investigate the use of ultrasonography to assess nonunion of fractures in dogs and to compare results of ultrasonography, radiography, and histologic examination.
Sample Population—8 nonunion fractures in 6 dogs (1 each in 5 dogs and 3 in 1 dog); dogs ranged from 7 to 94 months of age and weighed 6 to 30 kg.
Procedures—Diagnostic assessment consisted of complete clinical and orthopedic examinations, radiography, B-mode (brightness mode) ultrasonography, and power Doppler ultrasonography. Biopsy samples were obtained during surgery for histologic examination. They were stained with H&E and immunolabeled by use of anti-CD31 antibodies. Correlations of power Doppler score, power Doppler count, vessel area, and radiographic prediction with the mean number of vessels counted per hpf were derived.
Results—Radiographically, 7 of 8 nonunion fractures were diagnosed as atrophic and were therefore estimated to be nonviable. Vascularity of nonunion fractures during power Doppler ultrasonography ranged from nonvascularized to highly vascularized. Absolute vessel count during histologic examination ranged from 0 to 63 vessels/hpf; 5 nonunion sites had a mean count of > 10 vessels/hpf. Vascularity during power Doppler ultrasonography was highly correlated with the number of vessels per hpf, whereas the correlation between the radiographic assessment and histologic evaluation was low.
Conclusions and Clinical Relevance—Radiographic prediction of the viability of nonunion fractures underestimated the histologically assessed vascularity of the tissue. Power Doppler ultrasonography provided a more accurate estimation of the viability of the tissue and therefore the necessity for debridement and autografts during revision surgery.
OBJECTIVE To evaluate lameness and morphological changes associated with an osteochondral fragment–groove procedure as a means of experimental induction of metacarpophalangeal (MCP) joint osteoarthritis within an 11-week period in horses.
ANIMALS 6 nonlame adult warmbloods.
PROCEDURES The right MCP joint of each horse underwent an osteochondral fragment–groove procedure (day 0). After 1 week of stall rest (ie, starting day 7), each horse was trained daily on a treadmill. Weekly, horses underwent visual and inertial sensor-based assessments of lameness. Both MCP joints were assessed radiographically on days 0 (before surgery), 1, 35, and 77. A synovial fluid sample was collected from the right MCP joint on days 0 (before surgery), 35, 36, 49, 63, and 77 for cytologic and biomarker analyses. On day 77, each horse was euthanized; both MCP joints were evaluated macroscopically and histologically.
RESULTS Right forelimb lameness was detected visually and by the inertial sensor system when horses were moving on a straight line after distal forelimb flexion or circling left on days 14 to 77. Compared with presurgical values, synovial fluid interleukin-6, prostaglandin E2, hyaluronic acid, and interleukin-1 receptor antagonist protein concentrations were increased at 2 or 3 time points, whereas tumor necrosis factor-α and interleukin-10 concentrations were decreased at 1 time point. Gross examination of all right MCP joints revealed synovitis and wear lines; synovitis was confirmed histologically.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that a combined osteochondral fragment–groove procedure can be used to induce clinically and grossly observable early MCP joint osteoarthritis during an 11-week period in horses.
Objective—To evaluate the impact of modulation of the membrane-bound efflux pump P-glycoprotein (P-gp) on plasma concentrations of orally administered prednisolone in dogs.
Animals—7 healthy adult Beagles.
Procedures—Each dog received 3 treatments (control [no treatment], rifampicin [100 mg/d, PO, for 21 days, as an inducer of P-gp], and ketoconazole [100 mg/d, PO, for 21 days, as an inhibitor of P-gp]). A single dose of prednisolone (1 mg/kg, PO) was administered on day 8 of each treatment period. There was a 7-day washout period between subsequent treatments. Plasma concentrations of prednisolone were determined by use of a validated liquid chromatography–tandem mass spectrometry method. Duodenum and colon biopsy specimens were obtained endoscopically from anesthetized dogs and assessed for P-gp protein labeling via immunohistochemical analysis and mRNA quantification via real-time PCR assay. Total fecal collection was performed for evaluation of effects of P-gp modulation on digestion of nutrients.
Results—Rifampicin treatment upregulated duodenal P-gp in dogs and significantly reduced the area under the plasma concentration-time curve of prednisolone. Ketoconazole typically downregulated expression of duodenal P-gp, with a subsequent increase in the area under the plasma concentration-time curve of prednisolone. There was a noticeable interindividual difference in response. Digestion of nutrients was not affected.
Conclusions and Clinical Relevance—Modulation of P-gp expression influenced plasma concentrations of prednisolone after oral administration in dogs. Thus, treatment response to prednisolone may be influenced by coadministration of P-gp–modulating medications or feed ingredients.