CT measures of lumbosacral paraspinal muscle size are not correlated with CT measures of lumbosacral stability in military working Labrador Retrievers

Management of degenerative lumbosacral stenosis in military working dogs more frequently utilizes core conditioning exercise programs. Future research on the effectiveness of these programs may benefit from an improved understanding of relationships between paraspinal muscle size and lumbosacral stability. The aim of this retrospective, secondary analysis, cross‐sectional study was to test the following hypotheses related to CT measures: (a) transverse paraspinal muscle area ratios differ between hip flexion and extension, (b) lumbosacral angle and lumbosacral range of motion differ by lumbosacral angle measurement technique, and (c) transverse paraspinal muscle area ratios are correlated with CT measures of lumbosacral stability (parasagittal and parasagittal oblique foraminal area changes) regardless of hip position and with lumbosacral range of motion within each hip position. Lumbosacral CT scans in hip flexion and extension were retrieved from a previous prospective study of military working Labrador Retrievers. A single observer performed triplicate measurements of transverse paraspinal muscle area ratios, parasagittal foraminal area, and parasagittal oblique foraminal area for each hip position and another observer independently performed triplicate measurements of lumbosacral angle and lumbosacral range of motion at L7‐S1 using two published techniques. Thirty‐nine dogs were analyzed and significant differences were identified between hip flexion and extension for all mean transverse paraspinal muscle area ratio values (P ≤ .05). Mean lumbosacral angles also significantly differed between the published techniques in both hip flexion and extension. When comparing mean lumbosacral range of motion values, one of the published techniques produced significantly smaller values. No significant correlation was found between transverse paraspinal muscle area ratios and parasagittal foraminal area changes, parasagittal oblique foraminal area changes, or lumbosacral range of motion. These results should be considered when designing studies using these CT measures in military working dogs.     

Phenotyping of lumbosacral stenosis in Labrador retrievers using computed tomography

Deep phenotyping tools for characterizing preclinical morphological conditions are important for supporting genetic research studies. Objectives of this retrospective, cross‐sectional, methods comparison study were to describe and compare qualitative and quantitative deep phenotypic characteristics of lumbosacral stenosis in Labrador retrievers using computed tomography (CT). Lumbosacral CT scans and medical records were retrieved from data archives at three veterinary hospitals. Using previously published qualitative CT diagnostic criteria, a board‐certified veterinary radiologist assigned dogs as either lumbosacral stenosis positive or lumbosacral stenosis negative at six vertebral locations. A second observer independently measured vertebral canal area, vertebral fat area, and vertebral body area; and calculated ratios of vertebral canal area/vertebral body area and vertebral fat area/vertebral body area (fat area ratio) at all six locations. Twenty‐five dogs were sampled (lumbosacral stenosis negative, 11 dogs; lumbosacral stenosis positive, 14 dogs). Of the six locations, cranial L6 was the most affected by lumbosacral stenosis (33%). Five of six dogs (83%) with clinical signs of lumbosacral pain were lumbosacral stenosis positive at two or more levels. All four quantitative variables were significantly smaller at the cranial aspects of the L6 and L7 vertebral foramina than at the caudal aspects (P < 0.0001). Fat area ratio was a significant predictor of lumbosacral stenosis positive status at all six locations with cranial L6 having the greatest predictive value (R² = 0.43) and range of predictive probability (25–90%). Findings from the current study supported the use of CT as a deep phenotyping tool for future research studies of lumbosacral stenosis in Labrador retrievers.     

Association between postoperative outcome and results of magnetic resonance imaging and computed tomography in working dogs with degenerative lumbosacral stenosis

OBJECTIVE: To determine whether results of magnetic resonance imaging (MRI) and computed tomography (CT) are associated with postoperative outcome in working dogs with degenerative lumbosacral stenosis. DESIGN: Prospective cohort study. ANIMALS: 12 dogs treated surgically for degenerative lumbosacral stenosis. PROCEDURE: The lumbosacral vertebral column was examined before surgery by use of MRI and CT and after surgery by use of CT. Outcome, based on performance in standardized training exercises, was assessed 6 months after decompressive surgery. Associations between imaging results and postoperative outcome were determined by use of a Fisher exact test and logistic regression. RESULTS: None of the dogs were able to perform their duties before surgery. By 6 months after surgery, 8 of 12 dogs had been returned to full active duty. Nerve tissue compression was effectively localized by use of CT and MRI. Significant associations between results of imaging studies and postoperative outcome were not identified. CONCLUSIONS AND CLINICAL RELEVANCE: Surgical intervention is justified in high-performance working dogs with degenerative lumbosacral stenosis. However, results of imaging studies may be less important than clinical or surgical factors for predicting outcome in affected dogs.     

The European system of veterinary specialization

Veterinary specialist diplomas were available in many European countries during the second half of the 20th century. However, such an early recognition of the importance of veterinary specialization actually delayed the concept of the European veterinary specialist in Europe, compared with the United States, where the first specialist colleges were established in the 1960s, because it was felt that the national system was functioning properly and there was therefore no need for a new structure in the European countries. The European Board of Veterinary Specialisation (EBVS) was established in 1996, and currently there are 23 specialist colleges with more than 2,600 veterinarians officially listed in the EBVS register as European specialists. The Advisory Committee on Veterinary Training (ACVT) approved the establishment of EBVS but never implemented a supervising body (with ACVT representation). Such a body, the European Coordinating Committee on Veterinary Training, was later implemented by the profession itself, although it still lacked a political component. Each college depends on the EBVS, which has the function to define standards and criteria for monitoring the quality of college diplomates. To become a European Diplomate, veterinarians must have gone through an intensive period of training supervised by a diplomate, after which candidates must pass an examination. Although the term European veterinary specialist still does not have any legal recognition, national specialist qualifications are being phased out in many countries because of the inherent higher quality of EBVS specialist qualifications.     

Use of animation-enhanced video clips for teaching abnormal breathing patterns

The ability to characterize disease of the respiratory tract accurately based on breathing pattern is helpful for the development of differential diagnoses and an efficient diagnostic plan and critical for the stabilization of patients in respiratory distress. Veterinary students do not have sufficient clinical experience to observe personally all types of respiratory diseases and their resultant abnormal breathing patterns. We developed a teaching tool, the animated breathing pattern videotape (ABV), to fill this gap. The ABV is a collection of video clips of small animal patients with normal and abnormal breathing patterns on a conventional videotape of approximately 20 minutes duration. Each video clip is shown for 20 to 40 seconds, followed by the same clip with superimposed animation of rib and diaphragm motion, followed by the initial clip again, without overlying animation. The ABV has since been used in teaching third-year veterinary students, interns, residents, practicing veterinarians, and veterinary technicians. Student evaluations and responses to questionnaires by interns, residents, practicing veterinarians, veterinary technicians, and peer reviewers have been uniformly positive.     

Lumbosacral stenosis in 29 military working dogs: epidemiologic findings and outcome after surgical intervention (1990-1999)

OBJECTIVE: To study the outcome of military working dogs (MWDs) diagnosed with degenerative lumbosacral stenosis (DLS) after surgical intervention and to determine what prognostic indicators affected outcome. STUDY DESIGN: Retrospective study. ANIMALS: Twenty-nine MWDs with DLS. METHODS: The medical records of dogs diagnosed and surgically treated for DLS at the Department of Defense Military Working Dog Veterinary Service Hospital were reviewed. Retrieved data were signalment, clinical signs, survey radiograph results, and surgical findings. RESULTS: Breed and sex were not found to have prognostic significance. Increasing age at surgery correlated with a poor surgical outcome. Twelve dogs (41%) returned to normal function, 11 (38%) improved, and 6 (20%) never returned to active duty. The average age at surgery was 74 months, 93 months, and 112 months for normal, improved, and dogs not returning to duty, respectively. Significant clinical findings associated with a poor prognosis were related to increasing neurologic severity. The only significant radiographic finding indicating a poor prognosis was foraminal narrowing. Surgical findings with negative prognostic significance were hypertrophic articular facets and interarcuate ligament. Recurrence rates were 16.7% and 54.5% for normal and improved dogs, respectively. CONCLUSIONS: MWDs with DLS have a good prognosis with surgical decompression if they are young dogs with mild clinical signs at the time of diagnosis. As age and severity of clinical signs increase, the prognosis for successful outcome decreases. Recurrence may be seen in some dogs. CLINICAL RELEVANCE: Information provided by this study should help military veterinarians determine the prognosis for working dogs with DLS after surgical treatment.     

COMPUTED TOMOGRAPHIC ANATOMY OF THE DISTAL EXTREMITY OF THE HORSE

X-ray computed tomography (CT) is an imaging tool that is becoming increasingly available for use in veterinary medicine. Advantages, including depiction of detailed cross-sectional anatomy, improved contrast resolution, and computer reformatting, make it a potentially valuable diagnostic technique. Veterinary application of CT has been primarily limited to use in small animals. Current reports describe the technique for use in the horse, but there are no published studies correlating serial CT images with equine cross-sectional anatomy. A study of the distal extremity of the horse was undertaken to facilitate interpretation of images produced using CT. Transverse CT images of the distal forelimb of equine cadavers were evaluated relative to gross anatomic dissection. Resolution of bone architecture in transverse plane images was satisfactory, but soft-tissue' resolution, although satisfactory for visualization of major structures, was relatively poor, probably due to lack of interposed fat and insufficient differences in physical density and atomic number. Thus it appears in the equine distal limb that CT may be most useful for evaluation of complex bone abnormalities.     

FEASIBILITY OF ULTRASOUND‐GUIDED EPIDURAL ACCESS AT THE LUMBO‐SACRAL SPACE IN DOGS

Epidural injections are commonly performed blindly in veterinary medicine. The aims of this study were to describe the lumbosacral ultrasonographic anatomy and to assess the feasibility of an ultrasound‐guided epidural injection technique in dogs. A cross sectional anatomic atlas of the lumbosacral region and ex vivo ultrasound images were obtained in two cadavers to describe the ultrasound anatomy and to identify the landmarks. Sixteen normal weight canine cadavers were used to establish two variations of the technique for direct ultrasound‐guided injection, using spinal needles or epidural catheters. The technique was finally performed in two normal weight cadavers, in two overweight cadavers and in five live dogs with radiographic abnormalities resulting of the lumbosacral spine. Contrast medium was injected and CT was used to assess the success of the injection. The anatomic landmarks to carry out the procedure were the seventh lumbar vertebra, the iliac wings, and the first sacral vertebra. The target for directing the needle was the trapezoid‐shaped echogenic zone between the contiguous articular facets of the lumbosacral vertebral canal visualized in a parasagittal plane. The spinal needle or epidural catheter was inserted in a 45° craniodorsal–caudoventral direction through the subcutaneous tissue and the interarcuate ligament until reaching the epidural space. CT examination confirmed the presence of contrast medium in the epidural space in 25/25 dogs, although a variable contamination of the subarachnoid space was also noted. Findings indicated that this ultrasound‐guided epidural injection technique is feasible for normal weight and overweight dogs, with and without radiographic abnormalities of the spine.     

Appraisal of the Australian Veterinary Prescribing Guidelines for antimicrobial prophylaxis for surgery in dogs and cats

The Australian Veterinary Prescribing Guidelines for antimicrobial prophylaxis for surgery on dogs and cats are evidence‐based guidelines for veterinary practitioners. Validation of these guidelines is necessary to ensure quality and implementability. Two validated tools, used for medical guideline appraisal, were chosen to assess the guidelines. The terminology from the GuideLine Implementability Appraisal (GLIA) and the Appraisal of Guidelines for Research and Evaluation version 2 (AGREE II) were adapted for use by veterinarians. A two‐phase evaluation approach was conducted. In the first phase of the evaluation, the GLIA tool was used by two specialist veterinary surgeons in clinical practice. The results of this phase were then used to modify the guidelines. In the second phase, the AGREE II tool was used by 6 general practitioners and 6 specialists to appraise the guidelines. In phase 1, the specialist surgeons either agreed or strongly agreed that the guidelines were executable, decidable, valid and novel, and that the guidelines would fit within the process of care. The surgeons were neutral on flexibility and measurability. Additional clarity around one common surgical procedure was added to the guidelines, after which the surgeons agreed that the guidelines were sufficiently flexible. In phase 2, 12 veterinarians completed the assessment using the AGREE II tool. In all sections the scaled domain score was greater than 70%. The overall quality of the guidelines was given a global scaled score of 76%. This assessment has demonstrated that the guidelines for antimicrobial prophylaxis for companion animal surgery are valid and appear implementable.     

A follow-up study of neurologic and radiographic findings in working German Shepherd Dogs with and without degenerative lumbosacral stenosis

OBJECTIVE: To identify radiographic abnormalities associated with degenerative lumbosacral stenosis (DLSS) in German Shepherd Dogs (GSDs) and determine whether specific radiographic abnormalities could be used to identify dogs at risk of developing DLSS. DESIGN: Cohort study. ANIMALS: 33 GSDs working as police dogs. PROCEDURES: Results of physical, neurologic, and orthopedic examinations were used to identify dogs with DLSS. Survey radiography of the lumbosacral junction was performed, and radiographs were compared with radiographs obtained 3 years earlier. RESULTS: DLSS was diagnosed in 15 of the 33 (45%) dogs. Thirteen of the 15 dogs with DLSS and 14 of the 18 dogs without DLSS had radiographic abnormalities of the lumbosacral junction. Twenty-two (67%) dogs were able to perform unrestricted duties, including 3 dogs with suspected DLSS. Six (18%) dogs had been excluded from active duty during the period of surveillance because of DLSS. Significant progression in specific clinical and radiographic signs was detected, but multiple logistic regression analysis did not identify any radiographic signs that could be used to predict the development of DLSS. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that survey radiography cannot be used to predict development of DLSS in working GSDs.     

Review and retrospective analysis of degenerative lumbosacral stenosis in 156 dogs treated by dorsal laminectomy.

The medical records of 156 dogs with degenerative lumbosacral stenosis (DLS) that underwent decompressive surgery were reviewed for signalment, history, clinical signs, imaging and surgical findings. The German Shepherd Dog (GSD) was most commonly affected (40/156, 25.6%). Pelvic limb lameness, caudal lumbar pain and pain evoked by lumbosacral pressure were the most frequent clinical findings. Radiography showed lumbosacral step formation in 78.8% (93/118) of the dogs which was associated with elongation of the sacral lamina in 18.6% (22/118). Compression of the cauda equina was diagnosed by imaging (epidurography, CT, or MRI) in 94.2% (147/156) of the dogs. Loss of the bright nucleus pulposus signal of the L7-S1 disc was found on T2-weighted MR images in 73.5% (25/34) of the dogs. The facet joint angle at L7-S1 was significantly smaller, and the tropism greater in GSD than in the other dog breeds. The smaller facet joint angle and higher incidence of tropism seen in the GSD may predispose this breed to DLS. Epidurography, CT, and MRI allow adequate visualization of cauda equina compression. During surgery, disc protrusion was found in 70.5% (110/156) of the dogs. Overall improvement after surgery was recorded in the medical records in 79.0% (83/105) of the dogs. Of the 38 owners that responded to questionnaires up to five years after surgery, 29 (76%) perceived an improvement.     

Automatic image registration of three-dimensional images of the head of cats and dogs by use of maximization of mutual information

OBJECTIVE: To validate mutual information criterion as a ready-to-use technique for automated alignment (ie, registration) of 3-dimensional (3-D) multimodal image data of the head of cats and dogs. SAMPLE POPULATION: Corresponding 3-D magnetic resonance imaging (MRI) and computed tomography (CT) brain scans of a 6-month-old Doberman Pinscher with a brain cyst; CT images of the head of a European shorthair cat with a meningioma before and immediately, 3, and 6 months after surgical resection; and CT and corresponding stacked anatomic cryosection images of the entire head of a 2-year-old sexually intact female Beagle. PROCEDURE: All images were matched retrospectively by use of an in-house computer program developed on the basis of a mutual information image registration algorithm. Accuracy of the resulting registrations was evaluated by visual inspection. RESULTS: All registrations were judged to be highly accurate. Additional manual corrections were not necessary. CONCLUSIONS AND CLINICAL RELEVANCE: Mutual information registration criterion can by applied to 3-D multimodal head images of cats and dogs for full automatic rigid-body image registration. The combination of such aligned images would considerably facilitate efforts of veterinary clinicians as indicated by its widespread use in brain surgery and radiation therapy of humans.     

Veterinary Products Committee working group report on feline and canine vaccination

* The working group was set up by the Veterinary Products Committee in response to current concern in both the public domain and in the scientific community about possible health risks related to the routine vaccination of cats and dogs. The working group concluded that vaccination plays a very valuable role in the prevention and control of the major infectious diseases in cats and dogs. Although adverse reactions to vaccination, including lack of efficacy, occasionally occur, the working group concluded that the overall risk/benefit analysis strongly supports their continued use. * Although for some diseases there is evidence of a longer duration of immunity following vaccination than the one year which is typically recommended on the product literature, there is currently insufficient information to propose revaccination intervals other than those proposed by the manufacturer and approved by the regulatory process. * Notwithstanding this, in view of the occasional occurrence of adverse reactions, the working group recommends that the product literature indicates that the regime for booster vaccinations is based on a minimum duration of immunity rather than a maximum. The working group further recommends that the product literature should state that a risk/benefit assessment should be made for each individual animal by the veterinary surgeon in consultation with the owner with respect to the necessity for each vaccine and the frequency of its use. * The evidence suggests that cats appear to be susceptible to the occasional development of sarcomas at sites of injection and there is some further evidence to suggest that, although other products may be involved, this may be more associated with the use of vaccines containing aluminium-based adjuvants. The working group therefore recommends that a generic warning to this effect should appear on the product literature for all feline vaccines administered by injection. The working group also highlighted the need for professional and educational bodies in the UK to bring to the attention of veterinary practitioners appropriate methods for prevention, diagnosis and treatment of this serious condition. * The working group considered in depth the monitoring of adverse reactions, including the advantages and disadvantages of surveillance schemes. A range of options for carrying out further epidemiological (analytical) studies was also considered. However, the working group emphasised that surveillance schemes, and the UK Veterinary Medicines Directorate (VMD) Suspected Adverse Reaction (SAR) Surveillance Scheme in particular, provided a very valuable resource. The large database within the VMD scheme (collected since 1985) was analysed as part of this report. Figures were derived in terms of incidence (reporting rate) of certain clinical signs per 10,000 doses, and risk factors as identified by statistical analysis. However, due to a number of constraints, the analysis was not fully comprehensive and the interaction of possible risk factors was not determined. * Product-related control charts were developed in order to detect changes in incidence rates of adverse reactions (per 10,000 doses sold) both within and between different vaccines. Such charts provide a powerful way to detect changing trends in incidence and, when used in conjunction with product characteristics, they may identify possible causes. In general, the data showed that the incidence of adverse reactions to cat and dog vaccines per 10,000 doses of product sold was relatively low. Although under-reporting is a feature of such surveillance schemes, it does appear that, overall, vaccination of cats and dogs should be considered safe and effective. * Finally, the working group was conscious, while preparing this report, of the extensive media coverage that has been given to the issue of the safety of human vaccines, in particular the mumps, measles and rubella (MMR) vaccine. The working group emphasises that the conclusions and recommendations included in this report relate only to the vaccines used in cats and dogs. The issues identified are specific to the diseases and species examined and no attempt should be made to draw analogous conclusions in relation to vaccines administered to humans.     

Clinical pulmonary function testing in dogs and cats.

Pulmonary function testing is a relatively new area in clinical veterinary medicine, with few individuals currently obtaining TBFVL and pulmonary mechanics on a clinical cases of respiratory disease in dogs and cats. ABG analysis is a technique available to all veterinarians through commercial laboratories or local hospitals. Information obtained from these tests will allow for a better understanding of the pathophysiology of naturally occurring diseases as well as assisting in the determination of the efficacy of various therapeutic agents (such as bronchodilators), which to date has been lacking in veterinary medicine.     

Veterinary specialization in Europe

The development of veterinary specialization in Europe is described, from its inception in 1989, through the establishment of the European Board for Veterinary Specialisation (EBVS) in 1996, to the establishment of the supervising European Coordinating Committee for Veterinary Training (ECCVT) in 2005. Currently there are about 1,500 European veterinary specialists in 21 different disciplines, which can be organ, species or discipline oriented. Each specialization is supervised by a college. Each college has representatives on the EBVS, which defines the rules, oversees procedures within the colleges, and deals with appeal procedures. The ECCVT, which consists of representatives from the European Association of Establishments for Veterinary Education (EAEVE), the Federation of Veterinarians in Europe (FVE), and the EBVS, is the supervising body that can approve procedures for the recognition of European veterinary specialists and acts as a liaison between the veterinary profession and relevant European and international bodies with respect to matters relating to post-graduate education.     

X-ray-computed tomography, nephrotomography, and ultrasonography of the adrenal glands of healthy dogs

X-ray-computed tomography (CT), nephrotomography, and ultrasonography were performed in 10 clinically healthy dogs (weighing 14 to 33 kg) to visualize the adrenal glands. In all 10 dogs, CT enabled visualization of both adrenal glands. Cross-sectional diameter was measured accurately. The size and shape of CT sections of the adrenal glands varied widely because of individual differences in the actual size and shape of the adrenal glands and because of their position in the plane of the CT scans. In 5 dogs, nephrotomography enabled visualization of 1 or both adrenal glands as oblong craniocaudal-directed densities in the craniodorsal portion of the abdomen. In 7 dogs, transverse ultrasonography enabled visualization of 1 or both adrenal glands as round or oval hypoechoic structures in the surrounding hyperechoic fat.     

Prevalence of and risk factors for leptospirosis among dogs in the United States and Canada: 677 cases (1970-1998)

OBJECTIVE: To determine whether there was a temporal trend in prevalence of leptospirosis among dogs in the United States and Canada and to determine whether age, sex, and breed were risk factors for the disease. DESIGN: Retrospective study. ANIMALS: 1,819,792 dogs examined at 22 veterinary teaching hospitals between 1970 and 1998. PROCEDURES: The Veterinary Medical Data Base was searched for records of dogs in which a diagnosis of leptospirosis was made, and hospital prevalence was calculated. Logistic regression was used to examine the association between leptospirosis and age, sex, and breed. RESULTS: 677 dogs with leptospirosis were identified. Thus, hospital prevalence was 37 cases/100,000 dogs examined. A significant increase in leptospirosis prevalence between 1983 and 1998 was identified. Male dogs were at significantly greater risk of leptospirosis than were female dogs; dogs between 4 and 6.9 years old and between 7 and 10 years old were at significantly greater risk than dogs < 1 year old; and herding dogs, hounds, working dogs, and mixed-breed dogs were at significantly greater risk than companion dogs. CONCLUSIONS AND CLINICAL RELEVANCE: The prevalence of leptospirosis among dogs examined at veterinary teaching hospitals in the United States and Canada has increased significantly since 1983. Male dogs of working and herding breeds were at greater risk.     

Interobserver reliability of computed tomographic contouring of canine tonsils in radiation therapy treatment planning

In radiation therapy (RT) treatment planning for canine head and neck cancer, the tonsils may be included as part of the treated volume. Delineation of tonsils on computed tomography (CT) scans is difficult. Error or uncertainty in the volume and location of contoured structures may result in treatment failure. The purpose of this prospective, observer agreement study was to assess the interobserver agreement of tonsillar contouring by two groups of trained observers. Thirty dogs undergoing pre‐ and post‐contrast CT studies of the head were included. After the pre‐ and postcontrast CT scans, the tonsils were identified via direct visualization, barium paste was applied bilaterally to the visible tonsils, and a third CT scan was acquired. Data from each of the three CT scans were registered in an RT treatment planning system. Two groups of observers (one veterinary radiologist and one veterinary radiation oncologist in each group) contoured bilateral tonsils by consensus, obtaining three sets of contours. Tonsil volume and location data were obtained from both groups. The contour volumes and locations were compared between groups using mixed (fixed and random effect) linear models. There was no significant difference between each group's contours in terms of three‐dimensional coordinates. However there was a significant difference between each group's contours in terms of the tonsillar volume (P < 0.0001). Pre‐ and postcontrast CT can be used to identify the location of canine tonsils with reasonable agreement between trained observers. Discrepancy in tonsillar volume between groups of trained observers may affect RT treatment outcome.