Iatrogenic ocular trauma associated with infraorbital block performed for rhinoscopy in a cat: case report and preliminary imaging findings.

OBJECTIVES: This paper describes a case of endophthalmitis in a feline patient caused by globe penetration during an infraorbital block performed to provide analgesia during rhinoscopy, and presents additional imaging and dissection data demonstrating risk of iatrogenic ocular trauma during infraorbital blocks in cats when the infraorbital canal is entered. METHODS: Case records and accompanying histopathologic reports were reviewed for the feline patient. Separately, two feline cadavers were imaged using CT following placement of 5/8" 25 G needles or 1" 22 G over the needle catheters in the infraorbital canal. Infraorbital blocks with injection of trypan blue dye followed by dissection were performed in two further feline cadavers to assess the potential for globe penetration and to provide preliminary information regarding the potential efficacy of infraorbital blocks for analgesia during rhinoscopy. RESULTS: Clinical and histopathologic findings support inadvertent globe penetration during infraorbital block as the cause for endophthalmitis in the feline patient described. CT imaging and dye injection studies further demonstrate the risks involved with this local anesthetic technique in cats. CONCLUSIONS AND RELEVANCE: Further study is needed to assess the safety and efficacy of infraorbital blocks performed for rhinoscopy in cats. Catheters may be safer anesthetic delivery devices than needles. Extreme caution should be used when entering the infraorbital canal in cats.

Esophageal dysfunction in dogs with idiopathic laryngeal paralysis: a controlled cohort study.

OBJECTIVES: To compare esophageal function in dogs with idiopathic laryngeal paralysis (ILP) to age and breed matched controls; to determine if dysfunction is associated with aspiration pneumonia over 1 year; and to compare clinical neurologic examination of dogs with ILP at enrollment and at 1 year. STUDY DESIGN: Prospective controlled cohort study. ANIMALS: Dogs with ILP (n=32) and 34 age and breed matched healthy dogs. METHODS: Mean esophageal score was determined for each phase of 3 phase esophagrams, analyzed blindly. After unilateral cricoarytenoid laryngoplasty, dogs with ILP were reexamined (including thoracic radiography) at 1, 3, 6, and 12 months. Neurologic status was recorded at enrollment, 6 and 12 months. RESULTS: Esophagram scores in dogs with ILP were significantly higher in each phase compared with controls, most notably with liquid (P<.0001). Dysfunction was more pronounced in the cervical and cranial thoracic esophagus. Five dogs that had aspiration pneumonia during the study had significantly higher esophagram scores than dogs that did not develop aspiration pneumonia (P<.02). Ten (31%) ILP dogs had generalized neurologic signs on enrollment and all ILP dogs developed neurologic signs by 1 year (P<.0001). Conclusions- Dogs with ILP also have esophageal dysfunction. Postoperative aspiration pneumonia is more likely in dogs with higher esophagram scores. Dogs with ILP will most likely develop generalized neuropathy over the course of 1 year. CLINICAL RELEVANCE: Esophagrams and neurologic examinations should be performed on all dogs with ILP.

Objective radiographic assessment of abdominal sand accumulation in horses.

Gastrointestinal sand accumulation is a common cause of equine colic. Subjective assessment of sand accumulation on abdominal radiographs has been used as a diagnostic aid; however, there is poor correlation between clinical, diagnostic, and surgical findings. The purpose of this study was to develop an objective method of assessing radiographic sand accumulation in order to improve the diagnostic utility of radiography for sand colic. Fifty-one equine abdominal radiographic examinations were reviewed, with approximately half of the imaged patients having a clinical diagnosis of sand colic. Initially, four observers independently reviewed these radiographic studies to subjectively decide whether or not sand accumulation was sufficient to cause colic. Subsequently, an objective scoring system was developed using various radiographic parameters that yielded a score ranging from one to 12 for quantity and apparent density of sand accumulation. Inter- and intraobserver results using the subjective scoring method had significant differences among all observers. Subjective assessment was also deemed to be inaccurate for colic prediction. Using the objective scoring system, there were no significant differences between or within the observers' results. A score of seven out of 12 was found to have an 83% likelihood of being associated with a positive diagnosis of sand colic. The designed objective scoring method creates a more uniform and accurate method to assess the sand accumulation.

Use of positive reinforcement conditioning to monitor pregnancy in an unanesthetized snow leopard (Uncia uncia) via transabdominal ultrasound.

Closely monitoring snow leopard (Uncia uncia) fetal developments via transabdominal ultrasound, with minimal stress to the animal, was the goal of this project. The staff at Potter Park Zoo has used the principles of habituation, desensitization, and positive reinforcement to train a female snow leopard (U. uncia). Ultrasound examinations were preformed on an unanesthetized feline at 63 and 84 days. The animal remained calm and compliant throughout both procedures. Fetuses were observed and measured on both occasions. The absence of anesthesia eliminated components of psychologic and physiologic stress associated with sedation. This was the first recorded instance of transabdominal ultrasound being carried out on an unanesthetized snow leopard. It documents the feasibility of detecting pregnancy and monitoring fetal development via ultrasound. Zoo Biol 27:78-85, 2008. (c) 2007 Wiley-Liss, Inc.

Treatment of malignant lymphoma in an African lion (Panthera leo).

A 14 yr-old male, vasectomized African lion (Panthera leo) exhibited mild weight loss despite adequate appetite. Splenomegaly was diagnosed on physical examination. On the basis of hematology and clinical pathology, malignant lymphoma with chronic lymphocytic leukemia was diagnosed. Abdominal exploratory surgery and splenectomy were performed. Histologic examination and immunohistochemistry confirmed a small cell peripheral T-cell lymphoma. Initial treatments consisted of doxorubicin and prednisone, with later addition of lomustine. The lion remained in clinical remission at 2 mo, 6 mo, and 12 mo postchemotherapy physical examinations. The lion survived 504 days from initial diagnosis. At necropsy, the only lesions consistent with lymphoma were localized epitheliotrophic infiltrates of small neoplastic T lymphocytes within the nasopharyngeal epithelium and the underlying submucosa observed on microscopic examination.

Evaluation of the effects of nephrotomy on renal function in clinically normal cats.

OBJECTIVE: To evaluate the effects of nephrotomy on renal function in clinically normal cats. ANIMALS: 20 specific-pathogen-free, 9- to 11-month-old female mixed-breed cats. PROCEDURE: Serum chemistry analyses, CBC determinations, urinalyses, microbiologic urine cultures, renal ultrasonography, abdominal radiography, and single-kidney and total glomerular filtration rate (GFR) determinations by use of renal scintigraphy and measurements of plasma disappearance of technetium 99m-diethylenetriaminepentaacetic acid were performed before surgery and at 3, 12, 26, 52, and 78 weeks after surgery in 10 cats that underwent unilateral nephrotomy and in 10 control cats that underwent a sham surgical procedure. RESULTS: Two cats (1 from each group) did not complete the study, and their data were eliminated from analyses. Unilateral nephrotomy resulted in a 10% to 20% reduction in mean single-kidney GFR, compared with that of nephrotomy contralateral control kidneys. However, mean total GFR in nephrotomy-group cats was not significantly different from that of sham-group cats. Over the 78 weeks of study, mean total GFR declined 34% and 40% in nephrotomy- and sham-group cats, respectively. Adverse events associated with nephrotomy included persistent microscopic hematuria, renal pelvis hyperechogenicity with distant shadowing on ultrasonographic evaluation, dilatation of renal pelves, and hydronephrosis. CONCLUSIONS AND CLINICAL RELEVANCE: Nephrotomy in normal functioning feline kidneys results in a modest relative reduction in renal function, compared with contralateral kidney controls, but has minimal effect on total GFR when compared with sham-operated control cats. However, any detrimental effects of nephrotomy may be magnified in cats with diseased kidneys, which may have little or no capacity for repair or compensation.

Measurement of normal middle ear cavity volume in mesaticephalic dogs.

Water-filling and serial computed tomographic (CT) imaging techniques were used to measure normal middle ear cavity volume (MECV) in 18 dogs (10 live dogs, eight cadavers; 36 ears in total). The specific aims of this study were to (1) compare MECV measurements by water-filling and CT techniques and (2) define a model of MECV vs. body weight (BW) from CT values. There was a significant difference between the two techniques (P = 0.02). The volume obtained by water filling was consistently greater than that obtained by computed tomography. MECV (expressed in ml) increased with BW (expressed in kg) according to the following formula: MECV = -0.612 + 0.757 (In BW) (P<0.01, R2 = 0.74).

Effect of induced unilateral synovitis of distal intertarsal and tarsometatarsal joints on sagittal plane kinematics and kinetics of trotting horses.

OBJECTIVE: To study the effect of unilateral synovitis in the distal intertarsal and tarsometatarsal joints on locomotion, including the compensating effects within and between limbs. ANIMALS: 4 clinically normal horses. PROCEDURE: Gait analyses including kinematics, force plate, and inverse dynamic analysis were performed at the trot before lameness, after which synovitis was induced by injecting endotoxin into the right distal intertarsal and tarsometatarsal joints. Gait analyses were repeated 24 to 30 hours later during lameness. Differences between the stride variables during the 2 conditions (lame and sound) were identified. RESULTS: Tarsal joint range of motion, peak vertical force, and vertical impulse were decreased during lameness. Mechanical deficits included a decrease in negative work performed by the tarsal extensors during the early stance phase and a decrease in positive work by the tarsal extensors during push off. No compensatory changes in work were performed by other joints within the lame hind limb during the stance phase. Vertical impulse in the diagonal forelimb decreased, but there were no significant changes in forces or impulses in the ipsilateral forelimb or contralateral hind limb. CONCLUSION AND CLINICAL RELEVANCE: Results indicate that horses are able to manage mild, unilateral hind limb lameness by reducing the airborne phase of the stride rather than by increased loading of the compensating limbs.

Vertical position of the patella in the stifle joint of clinically normal large-breed dogs.

OBJECTIVE: To define the vertical position of the patella in clinically normal large-breed dogs. SAMPLE POPULATION: Cadavers of 13 clinically normal large-breed dog. PROCEDURE: Both hind limbs were harvested with intact stifle joints and mounted on a positioning device that allowed full range of motion of the stifle joint. Lateral radiographic views were obtained with the stifle joints positioned at each of 5 angles (148 degrees, 130 degrees, 113 degrees, 96 degrees, and 75 degrees). Vertical position of the patella through a range of motion was depicted on a graph of mean stifle angle versus corresponding mean proximal patellar position (PPP) and distal patellar position (DPP) relative to the femoral trochlea for each dog. Ratio of length of the patellar ligament to length of the patella (L:P) was determined for each dog. Overall mean, SD, and 95% confidence intervals for L:P were calculated for all dogs. RESULTS: Evaluation of vertical position of the patella through a range of motion revealed a nearly linear relationship between joint angle and PPP and joint angle and DPPF Evaluation of L:P results did not reveal significant differences between limbs (left or right) or among joint angles. Overall mean +/- SD L:P for all dogs was 1.68 +/- 0.18 (95% confidence interval, 1.33 to 2.03). CONCLUSIONS AND CLINICAL RELEVANCE: The L:P proved to be a repeatable measurement of vertical patellar position, which is independent of stifle angles from 75 degrees to 148 degrees. This measurement could be used as a quantitative method for diagnosing patella alta and patella baja in large-breed dogs.