The effects of femoral stem and neck length on cement strains in a canine total hip replacement model

OBJECTIVE: To determine the effects of femoral prosthesis stem length and head size on cement strains in a canine hip replacement system. STUDY DESIGN: An in vitro experimental model. SAMPLE POPULATION: (1) Three standard and 3 1-cm shortened femoral implants with +3 femoral heads. (2) Two standard implants with +0, +3, and +6 femoral heads. METHODS: Femoral stems were embedded in polymethylmethacrylate cement. A uniaxial proximodistal-oriented strain gauge was applied to the cement on the medial and lateral aspects of the construct 1.5 cm, 6.0 cm and 7.0 cm distal to the collar. Each construct with a +3 femoral head was mounted in a materials testing system. An axial compressive load (0-200 N) was applied to the femoral head and cement strains were recorded. Additionally, 2 standard length constructs were also tested with +0 and +6 femoral heads. The effects of stem length and neck length on cement strains were assessed with analysis of variance. RESULTS: Strains increased at all locations with increasing loads for all constructs. Shorter implants had higher strains by 152% and 171%, lateral (P =.003) and medial (P =.0025) to the stem tip. No significant strain differences were noted, at any strain gauge location, between different neck lengths (P values ranged from.20 to.67). CONCLUSIONS: Although a shorter implant stem has a potential to improve implant fit, it led to significantly higher cement strains that may increase the risk for aseptic loosening. Changes in femoral neck length did not significantly affect cement strains under the conditions tested. CLINICAL RELEVANCE: Shortening of the femoral stem currently cannot be recommended in canine total hip replacement. The existing use of variable neck lengths likely does not increase the risk of failure of the femoral stem.     

Echinococcus multilocularis (Cestoda,Taeniidae) in Red foxes (Vulpes vulpes) in northern Belgium

The first record of the tapeworm Echinococcus multilocularis (Cestoda, Taeniidae) in Red foxes (Vulpes vulpes) in northern Belgium is described. Between 1996 and 1999, 237 dead foxes were examined for the presence of this tapeworm using the intestinal scraping technique. Four foxes (1.7%) were found to be infected with E. multilocularis and showed medium to very high parasitic burdens. Three infected foxes originated from the south of the study area and the fourth animal came from the north of the study area near the border with The Netherlands. These findings are discussed in relation to the high endemicity of E. multilocularis in southern Belgium and to the increased distribution of the Red fox (V. vulpes) in northern Belgium during the last two decades.     

Responses of horses in behavioural tests correlate with temperament assessed by riders

REASONS FOR PERFORMING STUDY: Behavioural tests as well as observers' ratings have been used to study horses' temperament. However, the relationship between the ratings and the responses in behavioural tests has not yet been studied in detail. OBJECTIVES: The aim of the present study was to examine this relationship between ratings and responses. METHODS: Eighteen mature Swedish Warmblood horses were subjected to 2 behavioural tests, one relating to novelty (novel object test) and one to handling (handling test). Subsequently, 16 of these horses were ridden by 16 equally experienced students, having no former experience with the horses. Immediately after each ride, the students scored the horse for 10 temperamental traits using a line rating method. RESULTS: It was shown that for each temperamental trait all 16 riders agreed on the ranking of the horses (0.212相似文献   

The accessory lung lobe in thoracic disease: a case series and anatomical review

Diseases of the accessory lung lobe (AccLL) are often overlooked in dogs and cats, perhaps because of its recessed location. Diseases of this lobe also can mimic diseases of the diaphragm or structures comprising the caudal mediastinum. Normal anatomy of the AccLL and the diagnostic tools used today will be reviewed to help differentiate disease of adjacent organs. Four cases will also be described to illustrate disease presentation and radiographic findings affecting this lobe.     

Ultrasonographic and histologic evaluation of medial and middle patellar ligaments in exercised horses following injection with ethanolamine oleate and 2% iodine in almond oil

OBJECTIVE: To describe the ultrasonographic and quantitative histologic effect of injecting 2% iodine in almond oil (IAO) and ethanolamine oleate (EO) in the medial and middle patellar ligaments of horses and to determine whether a difference in response exists between IAO and EO treatment. ANIMALS: 10 healthy horses. PROCEDURE: In 5 horses, the medial and middle patellar ligaments of 1 limb were injected with EO, whereas IAO was injected in the medial and middle patellar ligaments of another 5 horses. Ultrasonographic evaluation was performed on the experimental and control limb before injection of IAO and EO and prior to euthanasia to determine cross-sectional area and evaluate fiber pattern. The patellar ligaments were harvested 2 weeks after injection and examined histologically to evaluate the inflammatory response, fibroplasia, and chondroid metaplasia. RESULTS: Injection of the patellar ligaments with IAO resulted in a greater increase in cross-sectional area on ultrasonography than EO. Both agents caused a decrease in echogenicity of the ligament. Histologically, significantly greater infiltration of inflammatory cells and fibroplasia developed after injection with IAO, compared with EO. Both agents resulted in significantly greater fibroplasia relative to control specimens. CONCLUSIONS AND CLINICAL RELEVANCE: Injection of the medial and middle patellar ligaments with IAO induces more severe inflammation and fibroplasia than EO. Maturation of the inflammatory and fibrous response may contribute to resolution or attenuation of upward fixation of the patella by subsequent stiffening of the ligaments.     

Udder cleft dermatitis and sarcoptic mange in a dairy herd

OBJECTIVE: To determine prevalence of udder cleft dermatitis in a dairy herd that was experiencing an outbreak of sarcoptic mange. DESIGN: Clinical survey. ANIMALS: 1,597 Holstein cows and late-gestation heifers. PROCEDURE: Animals were examined for udder cleft dermatitis and for skin lesions consistent with sarcoptic or chorioptic mange. Skin scrapings were collected from 56 cows and examined for ectoparasites. The herd was revisited 1 year later, and prevalences of udder cleft dermatitis and lesions consistent with mange were determined in 506 cows. RESULTS: Of the 1,597 cattle examined, 280 (18%) had udder cleft dermatitis, and 1,397 (87.5%) had lesions consistent with mange. In 43 of 56 (77%) cows, skin scrapings revealed Sarcoptes mites. Udder cleft dermatitis was significantly more common in older than in younger cows. In first-lactation cows, udder cleft dermatitis was less common during the first 4 months of lactation than in the later stages of lactation, but udder cleft dermatitis was identified in cows in all stages of lactation and in cows that were not lactating. The herd was treated with eprinomectin to control mites, and prevalence of lesions consistent with mange 1 year later was only 2.8%. However, prevalence of udder cleft dermatitis was still 12%. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that cows in any stage of lactation and cows that are not lactating can have udder cleft dermatitis but that lesions are more common in older cows. Control of sarcoptic mange was accompanied by a moderate reduction in the prevalence of udder cleft dermatitis but did not eliminate the condition.     

Seasonal interaction of serum vitamin D concentration and bone density in alpacas

OBJECTIVE: To evaluate temporal changes in bone mineral density associated with seasonal variation in serum vitamin D, calcium, and phosphorus concentrations in alpacas. ANIMALS: 5 healthy mature neutered male alpacas. PROCEDURE: Metacarpal bone mineral density was measured at 4 times during a year. Each time alpacas were weighed, blood was collected for determination of serum calcium, phosphorus, and vitamin D concentrations, and samples of feed were analyzed for nutrient content. Vitamin D status was determined by use of an assay that measured serum 25-hydroxycalciferol concentration. Effects of changes in serum vitamin D, calcium, and phosphorus concentration and body weight with season on bone mineral density were determined. RESULTS: Bone mineral density, body weight, and serum vitamin D and phosphorus concentrations varied with season. Bone mineral density, serum vitamin D concentration, and body weight also varied among individual alpacas. Serum vitamin D concentration was lower in January than the previous October and increased from May to the following September. The decrease in bone mineral density lagged behind the decrease in serum vitamin D concentration and was lower in May, compared with the previous October. Body weight was lower in May than the previous October or following September. Solar radiation was highest in July and lowest in December. CONCLUSIONS AND CLINICAL RELEVANCE: Seasonal changes in bone mineral density are associated with changes in serum vitamin D concentrations in alpacas. Changes in bone mineral density associated with a decline in serum vitamin D concentration may predispose some alpacas to developing fractures minimal trauma.     

In vitro biomechanical study of rotational stabilizers of the canine elbow joint

OBJECTIVE: To develop a model for measuring rotary stability of the canine elbow joint and to evaluate the relative contribution of the anconeal process (AN), lateral collateral ligament (LCL), and medial collateral ligament (MCL). SAMPLE POPULATION: 18 forelimbs from 12 canine cadavers. PROCEDURE: Forelimbs were allocated to 3 experimental groups (6 forelimbs/group). Each intact forelimb was placed in extension at an angle of 135 degrees and cycled 50 times from -16 degrees (pronation) to +28 degrees (supination) in a continuous manner at 2.0 Hz. Cycling was repeated following sectioning of the structure of interest (group 1, AN; group 2, LCL; and group 3, MCL). Torque at -12 degrees (pronation) and +18 degrees (supination) was measured for each intact and experimentally sectioned limb. A Student t test was performed to compare torque values obtained from intact verses experimentally sectioned limbs and for comparison with established criteria for differentiation of primary (> or = 33%), secondary (10 to 33%), and tertiary rotational stabilizers (< 10%). RESULTS: In pronation, the AN was the only primary stabilizer (65%). For supination, the LCL was a primary stabilizer (48%), AN was a secondary stabilizer (24%), and MCL was a tertiary stabilizer (7%). CONCLUSIONS AND CLINICAL RELEVANCE: With the elbow joint in extension at an angle of 135 degrees, the AN is a primary rotational stabilizer in pronation, and the LCL is a primary stabilizer in supination. Disruption of the AN or LCL may affect rotary range of motion or compromise stability of the elbow joint in dogs.