The role of clinical examination in the accurate diagnosis of bovine neurologic disease

Accurate, specific diagnosis of bovine neurologic disease is both possible and necessary in practice settings. The requirements for accurate diagnosis are a knowledge of the pathogenesis and epizootiology of the bovine neurologic diseases as described in this issue and a systematic approach to clinical examinations including accurate history taking, careful physical examination, neurologic examination, and inspection of the environment. Support for an accurate diagnosis can be obtained by use of the clinical pathology laboratory and, in herd problems, necropsy. The value of a precise diagnosis in bovine neurologic disease lies in the avoidance of costly, inappropriate therapy, the restriction of transmission of zoonotic disease, avoidance of ineffective treatment, more efficient salvage of affected individuals, and cost-efficient implementation of appropriate preventive measures as well as a sense of professional satisfaction in overcoming a challenging and difficult diagnostic problem.     

Cytology of cutaneous lesions

Cytology is a quick, easy, and inexpensive way to gain useful information concerning the process(es) or etiology of cutaneous lesions. Cutaneous lesions can be separated quickly into inflammatory or noninflammatory conditions and organisms and neoplastic cells can be identified, allowing for a definitive diagnosis. Although not all lesions can be diagnosed cytologically, recognition of the process(es) (for example, purulent inflammation, eosinophilic inflammation, cysts) allows for better therapeutic management and a more accurate prognosis.     

An improved passive hemagglutination test for the serological diagnosis of bovine fascioliasis using the specific antigen f2.

Optimum conditions for coupling the specific antigen f2 of Fasciola hepatica to sheep red cells and for the preparation of control cells coated with an unrelated protein are described. With a careful selection of donor sheep for erythrocytes, the problem of anti-species antibodies in bovine sera has been overcome and results may be obtained within 1 h as only one step is required in the assay system. Incorporation of a concentration of 25 mM CaCl2 in the diluent achieved increased stability of the agglutinates and enabled a more precise estimation of the end-point to be made. Analyses performed on bovine sera obtained at slaughter provided results in good agreement with the presence of flukes or fascioliasis lesions in livers at routine slaughter inspection. The developed assay is simpler, faster, more sensitive (P less than 0.01) and has a cut-off between populations of negative sera more easy to define than a recently marketed enzyme-linked immunosorbent assay.     

On the titration of vaccines against pleuropneumonia. A new approach to an old problem, preliminary studies

A new technique is proposed for the titration of live vaccines against contagious bovine pleuropneumonia (CBPP). Presently, the one most widely used, combines a set of tenfold dilutions with the seeding of five tubes with samples taken from each of these latter. This technique is not very accurate or it requires a great number of tubes to increase its accuracy. The new technique starts with the same tenfold dilutions but after a relevant dilution, samples of 100 microliters are put into the eight wells of the first column of a microtitration plate and then with "glucose" medium. After a 6 to 9 days incubation time, the growth can be recorded by an indicator change of color. This technique is much faster and seems to be more precise. Furthermore the eight parallel titrations enable the results to be expressed by means and comparison of results can be statistically meaningful.     

Injection of the insertion of the deep digital flexor tendon in horses using radiographic guidance

Insertional tendinopathies of the DDFT have been reported both as the sole lesion and as part of a multifocal lesion (Dyson et al. 2003). Computed tomography (CT) and magnetic resonance imaging allow specific diagnosis of deep digital flexor tendon lesions within the hoof capsule; however, direct intralesional treatment of such lesions is difficult because of the hoof's rigid structure. A technique designed to mimic intralesional injection of insertional tendinopathies of the DDFT in the standing horse using radiographic guidance was assessed. Radiographic and contrast CT imaging and sectioning of the limbs confirmed accurate injection in all cases although inadvertant administration of injectate into adjacent structures was also evident.     

Serum vitamin B12 and methylmalonic acid determinations in the diagnosis of cobalt deficiency in pregnant ewes

Serum vitamin B12 and methylmalonic acid (MMA) concentrations were used to monitor the development of cobalt (Co) deficiency and repletion from the deficient state in housed pregnant hill sheep. Serum MMA concentrations were less variable and provided a more accurate diagnosis of Co deficiency than serum vitamin B12. This was particularly the case for subclinical disease. However, unlike serum MMA, concentrations of the vitamin in serum could be used prognostically. The most precise diagnosis was provided by serum vitamin B12 and MMA data used in conjunction, but where one technique is to be used, serum MMA determinations are preferred.     

Pathology of traumatic brain injury

Although traumatic brain injury (TBI) is frequently encountered in veterinary practice in companion animals, livestock and horses, inflicted head injury is a common method of euthanasia in domestic livestock, and malicious head trauma can lead to forensic investigation, the pathology of TBI has generally received little attention in the veterinary literature. This review highlights the pathology and pathogenesis of cerebral lesions produced by blunt, non-missile and penetrating, missile head injuries as an aid to the more accurate diagnosis of neurotrauma cases. If more cases of TBI in animals that result in fatality or euthanasia are subjected to rigorous neuropathological examination, this will lead to a better understanding of the nature and development of brain lesions in these species, rather than extrapolating data from human studies.     

Ultrasound-guided renal and hepatic biopsy techniques

Diagnostic ultrasound is an easy, accurate method of locating both kidneys and liver in the horse. Good contact between the transducer and body wall is essential for clear, precise images. The greatest limitation to ultrasonic organ localization and biopsy guidance is the inability of ultrasound to transmit through gas-filled structures and bone. These structures act as barriers to sound-beam penetration and prevent visualization of soft-tissue structures deep to them. Organ parenchyma can be evaluated with ultrasonography. Focal and/or diffuse lesions can alter the normal parenchymal pattern and result in an increased or decreased echogenicity of the diseased area. Under ultrasound guidance, the biopsy instrument can be directed into these areas to insure that the sample is representative of the disease process within that organ. Biopsy-associated complications can be identified early and monitored until resolution. Equine renal and hepatic biopsies are not innocuous procedures, but ultrasonographic guidance has helped to reduce the risks involved with the biopsy techniques.     

Immunostimulants: clinical evaluation in non-cancer patients

Immunostimulants have large potentialities but their clinical evaluation and development are still in infancy. The appropriate time to start clinical studies is not always easy to determine: when some knowledge is available on the targets of the molecule and on assays demonstrating some immunological effects, but before a full elucidation of the precise mechanism of action. The clinical fields in which an immunomodulator can be analyzed are very large: immunodeficiencies, infectious diseases, auto-immune conditions, allergic diseases etc., provided that there is a target cell able to respond to the compound. Well-controlled, double-blind investigations are necessary, using objective clinical criteria and precise laboratory tests. Adverse effects, including bone marrow lesions or auto-immune manifestations, should be carefully looked for. The presently described strategy will probably be modified with progresses in this new discipline. A precise methodology for clinical evaluation will hopefully contribute to the development of more and more potent immunomodulators with a clearly defined activity in human diseases.     

DORSAL PLANE COMPUTED TOMOGRAPHIC IMAGING OF THE ETHMOID REGION TO EVALUATE CHRONIC NASAL DISEASE IN THE DOG

Computed tomographic anatomy of the normal canine ethmoid region using both transverse and dorsal imaging plane is described. In the transverse plane, the cribriform plate appears as an irregular heart-shaped to rectangular structure that is generally visualized on no more than one to two contiguous 4-mm slices. In the dorsal plane, the cribriform plate appears as a discrete "V"-shaped structure and can be visualized on four to five contiguous slices. Successful visualization of the cribriform was less dependent on patient positioning for the dorsal plane imaging studies. Computed tomographic findings in four dogs with chronic nasal disease and complete postmortem examination of the ethmoid region indicate that the dorsal imaging plane allows a more accurate assessment of cribriform plate involvement than the transverse imaging plane.     

Radiographic evaluation of BFX acetabular component position in dogs

Objective: To assess the reliability of radiographic measurement of angle of lateral opening (ALO) and angle of version of BFX acetabular cups. Study Design: In vitro radiographic study. Sample Population: BFX cups (24, 28, and 32 mm). Methods: Total hip replacement constructs (cups, 17 mm femoral head and a #7 CFX stem) were mounted on an inclinometer. Ventrodorsal radiographs were obtained with ALO varying between 21° and 70° and inclination set at 0°, 10°, 20°, and 30°. Radiographs were randomized using a random sequence generator. Three observers blinded to the radiograph order assessed ALO using 3 methods: (1) an ellipse method based on trigonometry; (2) using a measurement from the center of the femoral head to the truncated surface of the cup; (3) by visual estimation using a reference chart. Version was measured by assessing the ventral edge of the truncated surface. Results: ALO methods 2 and 3 were accurate and precise to within 10° and were significantly more accurate and precise than method 1 (P<.001). All methods were significantly less accurate with increasing inclination. Version measurement was accurate and precise to within 7° with 0–20° of inclination, but significantly less accurate with 30° of inclination. Conclusions: Methods 2 and 3, but not method 1, were sufficiently accurate and precise to be clinically useful. Version measurement was clinically useful when inclination was ≤20°.     

Disorders of the origin of the suspensory ligament in the horse: a diagnostic challenge

Lameness in horses due to pain originating from the proximal metacarpal/metatarsal region remains a diagnostic challenge. In cases of obvious lameness the pain can be localised to this region by diagnostic anaesthesia. Because a variety of disorders can cause lameness in this region different imaging modalities including radiography, ultrasonography and scintigraphy should be used to arrive at an accurate diagnosis. Even though a precise anatomic-pathologic diagnosis can still be an enigma, because not only bone and joints, but also soft tissue structures including the proximal suspensory ligament, its origin at the proximal metacarpus/ metatarsus, its fascia, the superficial fascia, as well as the intermetacarpal/metatarsal ligaments, the accessory ligament of the deep digital flexor tendon and both digital flexor tendons may be involved. Magnet resonance tomography (MRT) shows a high diagnostic sensitivity in imaging soft tissue structures and bone. In horses MRT is still at the beginning. The MRT appearance of the proximal metacarpal/metatarsal region has not yet been evaluated in detail and there are only few anatomic studies of the origin of the suspensory ligament in horses. The first experiences showed, that more gross and histologic examinations are necessary to fully interpret MRT-images and to differentiate pathologic alterations from clinically not relevant variations.     

The effect of removing animals for slaughter on the behaviour of the remaining male and female pigs in the pen

The study was performed to investigate changes in the behaviour of male and female pigs when one or more pigs were removed from the pen and sent to slaughter. Twelve pens were included, half of them housed six female pigs each, while the other half housed six male pigs each. Skin lesions and behaviour were recorded on two occasions, four days before and two days after one or more animals per pen were sent to slaughter. On the first occasion the male pigs fought on average about twice as often as the females (2.6 vs. 1.0 per animal per hour) and had twice as many skin lesions (6.7 vs. 3.2). On the second occasion, the frequency of fighting among both males (6.8) and females (1.8) had increased, however, more in males than in females. The number of skin lesions was not significantly higher on the second occasion. In the male group there was also a tendency towards increased mounting on the second occasion (from 2.3 to 3.3 per animal per hour). The study shows that the very common practice of slaughtering pigs from one pen over more than one occasion results in an increase in unwanted behaviour. The effect is more pronounced in groups of entire male pigs than in groups of females.     

Forage quality analyses and interpretation.

The minimum analyses needed to determine the quality or nutritive composition of forages are DM, CP, ADF, NDF, Ca, and P. The accuracy of these and other analyses are affected by the sampling and analysis methods. Improper sampling is probably one of the largest but most overlooked sources of variation in analysis. Analysis methods must be both accurate and precise. New techniques like NIRS can be just as accurate and have better precision than conventional chemistry methods if correctly calibrated. Finally, understanding variations associated with the analysis and discerning sources of the variation as to errors in analysis, sampling, or natural variation caused by environmental growing conditions, plant species, or harvest practices is the biggest challenge for nutritionists. Forages cannot be fully and efficiently utilized in the diets of dairy cattle until their composition is accurately determined and interpreted for animal performance.     

Refining the clinical question: the first step in evidence-based veterinary medicine.

The ability to translate a clinical problem seen in practice into a focused and well-formed answerable clinical question is one of the hardest steps in practicing evidence-based veterinary medicine (EBVM). Asking answerable clinical questions that relate to your patient is the first evidence-based skill a veterinarian needs to learn, and it forms the cornerstone of the practice of EBVM. Like other clinical skills, the more you practice and work on refining clinical questions, the more precise these questions are and the easier the EBVM process becomes. This article reviews the different aspects of an answerable clinical question, its structure, and how to formulate questions better to get needed answers to clinical problems.     

Localised sarcoptic mange in dogs: a retrospective study of 10 cases

The authors report 10 cases of localised sarcoptic mange in dogs. In each case, lesions were localised to one precise area of the skin. Pruritus was present in nine cases and absent in one. Affected areas were the feet (one case), the face and/or the pinnae (six cases), the abdominal skin (one case), the flank (one case) and the lumbar area (one case). The types of lesions were erythema, papules, lichenification, scales, crusts and alopecia. Parasites were found in all cases except one, in which anti-immunoglobulin G Sarcoptes serology was positive. The acaricidal treatments given were lindane, ivermectin or selamectin and were all successful.     

Arthroscopic Surgery for the Treatment of Osteochondrosis in the Equine Shoulder Joint

Osteochondritis dissecans (OCD) and subchondral cyst-like lesions in 13 shoulders of 11 horses were treated arthroscopically by curettage and lavage. Lameness decreased in all 11 horses. Nine horses were sound, five of them athletically sound, after 5 to 20 months. Complications included the development of subchondral cyst-like lesions and signs of degenerative joint disease. Arthroscopic surgery of the equine shoulder can be done through two portals, one for the arthroscope and one for an instrument. A few hand instruments such as a probe, Ferris-Smith rongeurs, and small, large, and right-angled curettes are needed to debride most lesions. Motorized equipment can expedite the process.     

Beef cattle feed intake and growth: empirical Bayes derivation of the Kalman filter applied to a nonlinear dynamic model

Feed intake and growth rate of a single group of growing-finishing feedlot beef cattle are difficult to predict. Subsequent performance can be projected more precisely from past performance of a group of cattle. Using an adaptation of the statistical procedure called the empirical Bayes (EB) derivation of the Kalman filter, estimates from any dynamic model (M) can be adjusted based on past performance. The model may be either linear or nonlinear. With this procedure, predictions of intake and body weight gain are periodically updated by multiplying the estimates from M by statistically weighted factors. These factors are derived from the ratio of performance in each period to the performance predicted by M. For comparison to the EB adjustment, weighting of factors by least-squares (LS) adjustment also was tested to predict subsequent feed intake and gain. The test data base consisted of periodic feed intake and gain observations (usually 28 d) for 200 pens of feedlot steers. Bias of prediction was lower for EB than for M or LS for feed intake and (usually) gain. Intake and gain prediction errors averaged for the whole feeding period were .42 kg/d for intake and .14 kg/d for gain by EB, being .84 and .18 kg/d more precise than M and .12 and .33 kg/d more precise than LS predictions. More than two observations were needed before LS produced accurate prediction but after about 80 d, LS and EB estimates converged. Accuracy of both estimates continued to improve as days on feed increased.(ABSTRACT TRUNCATED AT 250 WORDS)     

Nonlethal clinical techniques used in the diagnosis of diseases of fish

Numerous nonlethal clinical techniques can be used on live fish to yield valuable diagnostic information. These techniques include skin, fin, and gill biopsies; bacteriologic cultures of gill or skin lesions; tissue and fluid aspiration; and radiography Most techniques can be performed on live fish without the use of anesthesia, although light sedation of the fish often simplifies the procedure, making the procedure more easily accomplished and less stressful on the fish. Because water conditions have a considerable effect on the health and well-being of aquatic animals, an in-house evaluation of water quality (eg, temperature, pH, ammonia, nitrites, nitrates, and salinity) is also paramount to any clinical diagnostic evaluation. As with domestic animals, a complete and accurate history and thorough external examination are prerequisite to the selection of appropriate diagnostic techniques as well as the formulation of any management or therapeutic plan. Through the correlation of clinical history, water quality variables, and results of diagnostic testing, an informed plan of action can be devised to correct acute or chronic problems in aquatic animals.