Development of allometric leaf area models for intensively managed black walnut (Juglans nigra L.)

? Introduction

Intensive plantation management of high-value hardwoods, such as black walnut (Juglans nigra L.), is focused on maximizing both stem form and growth at the stand and tree level. While significant research has focused on genetic improvement in black walnut, little is known about the production ecology of this species in plantation settings.

? Objectives

The aim of this study is to assess the applicability of nondestructive projected leaf area (PLA) estimation based on the pipe model theory in three single-aged J. nigra plantations representing discrete age classes ranging from 3 to 27?years of age.

? Results

Branch-level PLA was modeled as a function of branch basal cross-sectional area (R ²?=?0.875). Six nondestructive tree-level PLA models were assessed, with four models yielding R ²?>?0.90. Tree-level models performed well across age classes, with model fits comparable to previous studies in coniferous species.

? Conclusion

This study demonstrates that allometric approaches to modeling leaf area distribution in hardwoods are feasible, but future efforts may need to use different sampling approaches and/or quantify variables that have not been significant in conifers. This study represents an important first step into more quantitative analysis of production ecology of deciduous species in the CHFR of the USA.     

Caudal vena cava obstruction and ascites in a cat treated by balloon dilation and endovascular stent placement

OBJECTIVE: To present details of an unusual case of caudal vena caval obstruction and its management in a cat. STUDY DESIGN: Clinical case report. STUDY POPULATION: A 15 month old male castrated domestic shorthaired cat. RESULTS: The diagnostic evaluation included the use of digital subtraction angiography and ultrasonography to locate the caudal vena caval obstruction. Treatment initially involved puncture and balloon dilation of the obstructed area of the cava. After reobstruction, the stenotic area was redilated and stented. The cat was euthanatized 4 weeks later because of vomiting, anorexia, and abnormal behavior, presumed to be associated with liver disease. CONCLUSION AND CLINICAL RELEVANCE: Interventional radiography provided a minimally invasive way to manage this unusual vascular anomaly.     

B-cell lymphoma in the peripheral nerves of a cat

A B-cell, Burkitt-type lymphoma, diffusely affecting the peripheral nerves and intramuscular nerve branches was diagnosed in a 4-year-old domestic shorthair cat with a chronic progressive history of flaccid tetraparesis and generalized muscle atrophy. There was no evidence of cranial nerve, central nervous system, radicular, bone marrow, splenic, or lymph node involvement. The cat tested negative for feline retroviruses and a wide variety of herpes viruses, including Epstein-Barr virus. The clinical manifestation of this case was similar to the chronic polyneuropathic variant of human diffuse neurolymphomatosis; a condition most commonly caused by an axonopathy resulting from infiltration of peripheral nerves with non-Hodgkin's lymphoma.     

The effects of indwelling transurethral catheterization and tube cystostomy on urethral anastomoses in dogs.

The influence of urinary diversion procedures on urethral healing was studied in 15 male dogs following transection and anastomosis of the intrapelvic portions of their urethras. Dogs were randomly assigned to one of three treatment groups and had urine diverted from the surgical site by indwelling transurethral catheter, cystostomy catheter, or a combination of transurethral catheter and cystostomy catheter. There were no statistically significant differences in urethral healing when considering the different diversion methods, based on clinical, radiographic, and urodynamic parameters evaluated.     

PROBABLE TRIGEMINAL NERVE SCHWANNOMA IN A DOG

A 7-year-old male Husky dog developed atrophy of the right masseter muscle and pruritis of the right side of the face. A myogenic origin was excluded using muscular biopsy. Electrophysiologically, there was involvement of the motor and sensory fibers of the trigeminal nerve, suggesting a lesion located between the brainstem and the trigeminal ganglion. On MRI examination, a nodular mass was detected in the right caudal fossa. This mass was characterized by intense enhancement after injection of contrast medium. Because of the progressive clinical signs, electrophysiology, and MRI results, a presumptive diagnosis of a trigeminal nerve schwannoma was made. The animal's condition improved slightly with corticosteroids. The dog underwent euthanasia 3 months after initial presentation. Necropsy was not performed.     

Left ventricular radial colour and longitudinal pulsed-wave tissue Doppler echocardiography in 39 healthy domestic pet rabbits

This paper reports radial colour and longitudinal mitral annulus pulsed-wave tissue Doppler findings in a large cohort of healthy, adult pet rabbits. Thirty-nine rabbits (22 Dwarf Lops, 14 French Lops and three Alaskans) underwent conscious echocardiography. The median age of the rabbits was 22 months and the median weight was 2.8 kg (Dwarf Lop 2.4 kg/French Lop 6.0 kg). Adequate radial colour and longitudinal pulsed-wave tissue Doppler traces were obtained in 100% and 85% of cases, respectively. Most systolic tissue Doppler parameters were significantly higher in French Lops than in Dwarf Lops. Separation of mitral inflow diastolic waves was present in 40% of cases using conventional spectral Doppler and in >60% of cases using pulsed-wave tissue Doppler which could be beneficial when evaluating diastolic function in rabbits. This study can be used as a reference for normal echocardiographic tissue Doppler values for adult rabbits undergoing conscious echocardiography in clinical practice.