A tumour of vascular origin in a horse     

J. C. Wise  D. E. Crosby  A. N. Walton  A. Neef  P. L. Shearer  D. J. Woodward  B. J. Hilbert 《Equine Veterinary Education》2021,33(10):e352-e356

Tumours of vascular origin are uncommon in horses. This report describes the surgical treatment of a large subcutaneous tumour in a Quarter Horse colt. The histopathological appearance of the mass was most consistent with a haemangioma. While these neoplasms of vascular origin are often difficult to characterise, it has been suggested that there is a continuum of types with some cases falling between the categories. Further classification of vascular tumours requires special stains and immunohistochemical techniques.  相似文献   

Proposed design modifications to reduce risk of operating rotary field mowers     

White KL  Wells LG  Shearer SA  Piercy LR 《Journal of agricultural safety and health》2000,6(4):249-259

The primary objective of this project was to reduce risk of injury associated with operating a rotary mower driven by a tractor power take-off (PTO) by developing and evaluating design improvements and determining their economic feasibility. Researchers have concluded that alteration of machinery design has a greater impact on the reduction of accidents than safety training. Implementation of an Operator Presence Sensing System (OPSS) and removal of the PTO are the two injury-reducing, engineering modifications evaluated by this research. Hydraulic power allows this to occur by providing dynamic braking, few moving parts (removal of the PTO), and controllable power. A hydraulic circuit was developed to power the mower and to enable an OPSS. Tractor hydraulics were simulated using a hydraulic training bench. Two mower configurations were tested: 6.55 cm3 rev(-1) (0.4 in.3 rev(-1)) displacement motor with a 0.748 kg blade and 47.5 cm3 rev(-1) (2.9 in.3 rev(-1)) displacement motor with a 9.4 kg blade. A PTO-driven rotary mower was not used to test the circuit due to spatial and safety limitations of the hydraulic training bench. Results from the first mower configuration verified the concepts behind the hydraulic circuit. The second configuration verified the OPSS and indicated the applicability of the circuit to a rotary mower.  相似文献   

Sea Trout of the North Esk     

D. J. Pratten  W. M. Shearer 《Aquaculture Research》1983,14(2):49-65

The sea trout population of the River North Esk was sampled by means of a stationary trap situated on Kinnaber Mill Lade which drains its water from the main river. Commencing in 1971 the number of trout taken in the trap was noted daily, and from 1976 all stages of trout caught in the trap were tagged. The peak of the sea trout smolt migration was usually in May or June, and over the period of study exhibited a tendency to occur later each season. Two-year-old smolts comprised the largest age class in the smolt samples with 3-year-old fish being the other substantial age class. Samples of smolts taken for sex determination were found to be predominantly female. In 1979 and 1980 the sea trout smolt production of the North Esk was estimated from a mark-recapture experiment to be 51,969 and 78,208 respectively. A proportion of finnock (post-smolts) returned to fresh water in the year of their smolt migration and were taken moving upstream into the trap from July onwards, with a peak of movement occurring in the autumn. The main run of adult sea trout into the trap was found to take place at any time between July and October. The adult sea trout sampled were predominantly maiden spawners of ages 2.1+ and 3.1+ years. Both finnock and adult sea trout samples exhibited a similar freshwater age composition to that of the smolts.  相似文献   

Effects of source and washing of erythrocytes on growth of bacterial pathogens from the bovine mammary gland     

J K Shearer  M B Brown  P A Reed 《American journal of veterinary research》1988,49(2):198-200

Effects of source and washing of RBC on quantitative growth and hemolytic zone sizes of common bacterial pathogens of the bovine mammary gland were evaluated. Blood samples used to prepare the blood agar media were obtained from 10 adult dairy cows, 10 dairy calves, and 10 sheep. Hemolytic zone sizes produced by Staphylococcus aureus were significantly (P less than 0.01) larger on blood agar prepared with washed RBC than on blood agar prepared with nonwashed RBC, regardless of RBC source. With the exception of Corynebacterium bovis, growth of all bacteria was equivalent or significantly higher on medium prepared with washed RBC, compared with that on medium prepared with nonwashed RBC, regardless of RBC source. Significantly higher numbers of C bovis (P less than 0.01) and Streptococcus agalactiae (P less than 0.01) were isolated on medium prepared with washed cow RBC. Significantly higher numbers of Str uberis (P less than 0.01) and S aureus (P less than 0.05) were isolated on medium prepared with washed sheep RBC and washed calf RBC, respectively. Growth of Escherichia coli was not affected by the RBC source. Seemingly, RBC used in the preparation of medium should be washed. The source of RBC, as well as inter-animal variation, also should be considered in the quality control of medium.  相似文献   

Functional and corrective claw trimming.     

J K Shearer  S R van Amstel 《Veterinary Clinics of North America: Food Animal Practice》2001,17(1):53-72

Foot care and claw trimming require proper systems for restraint, sharp knives and trimming equipment, and an understanding of the biomechanics of weight bearing and hoof overgrowth in cattle. The objective of functional claw trimming is to correct hoof overgrowth, thereby re-establishing appropriate weight bearing within and between the claws of each foot. Traditional trimming methods fail to achieve these objectives. Corrective trimming procedures are applied to horn lesions affecting the claw capsule. Primary objectives of corrective trimming are to adjust weight bearing to provide rest for diseased claws and to remove loose horn and hard ridges that may cause further injury to the corium. The application of a foot block to the healthy claw is a valuable aid in foot care when corrective trimming alone is insufficient to provide needed relief from weight bearing. Finally, the use of topical treatments under a bandage is controversial. It is recommended that caustic treatments be avoided and that the use of a bandage be limited to conditions requiring hemostasis or when operators are committed to their removal within a period of 2 to 5 days depending on the level of environmental contamination.  相似文献   

Inoculum density — host response relationships of spring wheat cultivars to infection by Septoria tritici     

B. L. Shearer 《European journal of plant pathology / European Foundation for Plant Pathology》1978,84(1):1-12

Eightinoculumdensities (ID), increasing in geometric progression from 0.1×10⁵ to 12.8×10⁵ conidia ml^–1 ofSeptoria tritici were sprayed onto the leaves of five cultivars ofTriticum aestivum, differing in resistance toS. tritici. Host response to infection byS. tritici, measured as either thelatencyperiod (LPD) orpercentage ofleafarea covered bylesions with pycnidia (PLAL), was significantly linearly correlated with log₁₀ID (r=0.84 to 0.96, with 6 degrees of freedom). As the ID increased from 0.2×10⁵ to 12.8×10⁵ conidia ml^–1, LPD decreased by 1 to 2 days for the susceptible and resistant cultivars and by 3 to 5 days for the moderately susceptible cultivars. Within the same ID range, PLAL increased from 73% to 90% for the susceptible cultivar and 2 to 12% for the resistant cultivar. The ID₅₀ value (the number of conidia required for 50% PLAL) calculated from the regression equations relating log₁₀ID to PLAL for each cultivar, ranged from 6.42×10³ conidia ml^–1 for the susceptible cultivar to 7.13×10¹³ conidia ml^–1 for the resistant cultivar. Estimates of the number of conidia ml^–1 required to initiate a lesion (obtained by substituting 1% PLAL into the regression equations relating log₁₀ ID to PLAL) ranged from 16 conidia ml^–1 for the susceptible cultivar to 1.0×10⁴ conidia ml^–1 for the resistant cultivar. Using the change of PLAL with ID, the restriction of lesion development for each cultivar could be partitioned into that due to host resistance and that due to interaction between lesions. Log₁₀LPD was significantly correlated negatively with PLAL. As a general rule when screening cultivars for resistance toS. tritici, it is advisable to inoculate them with several inoculum densities and to determine the latency period.Samenvatting Sporensuspensies vanSeptoria tritici die in dichtheid (ID) varieerden volgens een geometrische reeks van 0,1 tot 12,8×10⁵ sporen.ml^–1, werden gebruikt bij de inoculatie van kiemplanten van vijf cultivars vanTriticum aestivum die verschilden in resistentie tegenS. tritici.De reactie van de waardplanten werd gemeten aan de latentie periode (LPD) en aan het percentage bladoppervlak dat ingenomen werd door vlekken met pycniden (PLAL). Beide grootheden toonden een significante lineaire correlatie met log₁₀ID (r=0,84 tot 0,96 bij 6 vrijheidsgraden). Bij een toename van ID van 0,2×10⁵ tot 12,8×10⁵ sporen.ml^–1 nam de lengte van de latentie periode af met 1 tot 2 dagen bij de vatbare en de resistente cultivars, en met 3 tot 5 dagen bij de matig vatbare cultivars (Fig. 2).In hetzelfde traject van inoculumdichtheid nam de PLAL toe van 73 tot 90% bij vatbare cultivars, en van 2 tot 12% bij de resistente cultivars (Fig. 3). De ID₅₀-waarde, het aantal sporen dat nodig is om 50% aantasting te verkrijgen, werd berekend uit de regressievergelijkingen die voor iedere cultivar het verband aangeven tussen log₁₀ ID en het aantastingspercentage (PLAL). Deze waarde varieerde van 6,42×10³ sporen per ml voor vatbare tot 7,13×10³ sporen per ml voor de resistente cultivars (Tabel 1). Schattingen voor het aantal sporen dat nodig is om een vlek te doen ontstaan werden verkregen door de 1% aantastingswaarde te substitueren in de eerder genoemde regressievergelijkingen. Deze waarden varieerden van 16 sporen.ml^–1 voor de vatbare cultivar tot 10000 sporen.ml^–1 voor de resistente cultivar (Tabel 1). Via de toename van de aantastingsgraad (PLAL) per eenheid stijging in de inoculumdichtheid kon de remming op de vlekontwikkeling opgesplitst worden in een gedeelte dat toegeschreven werd aan de resistentie van de plant en een gedeelte dat te wijten was aan de interactie tussen de vlekken (Fig. 4 en 5; Tabel 2).Log₁₀ LPD was negatief gecorreleerd met PLAL (Fig. 6). Bij het toetsen van cultivars op resistentie tegenS. tritici zouden sporensuspensies van verschillende dichtheden gebruikt moeten worden en zou de latentie periode, evenals de aantastingsgraad bepaald moeten worden.  相似文献   

Bovine dental fluorosis: histologic and physical characteristics   总被引：2，自引：0，他引：2  

T R Shearer  D L Kolstad  J W Suttie 《American journal of veterinary research》1978,39(4):587-602

Incisor teeth from 5- to 6-year-old Holstein-Friesian cattle maintained on a ration averaging 40 ppm F annually from 4 months of age were analyzed by a variety of histologic techniques. These techniques included photomicroscopy, microradiography, protein staining, and microhardness testing. The features of fluorotic enamel that were noted were: hypomineralized outer enamel, coronal cementum hyperplasia, disrupted subsurface pigment band, hypoplastic pits, puckered incremental lines, periodic radiolucent regions, positive protein staining, and decreased microhardness of the outer enamel. These results were similar to the lesions of dental fluorosis observed in other species, and explain the external appearance of fluorotic bovine teeth observed under field conditions.  相似文献   

Resistance to moxidectin and abamectin in naturally acquired Ostertagia circumcincta infections in sheep     

PL Hughes  PB McKenn  A Murphy 《New Zealand veterinary journal》2013,61(4):202-204

AIM: To investigate the occurrence of resistance to macrocylic lactone (ML) anthelmintics by Ostertagia circumcincta in lambs on a sheep and cattle property in the North Island of New Zea- land.

METHODS: Thirty lambs were randomly allocated to one of five equal-sized groups, consisting of an untreated control and four treatment groups. The treatments, which were administered at the manufacturer's recommended dose rates, included oral moxidectin, oral abamectin (both at 0.2 mg/kg), an albendazole-levamisole combination, and an albendazole-levamisole-ivermectin combination. Post mortem worm counts were undertaken 7 days after treatment to determine the efficacy of each anthelmintic.

RESULTS: The albendazole-levamisole and albendazole-levam-isole-ivermectin combinations both reduced O. circumcincta burdens to zero whereas for moxidectin and abamectin efficacies of only 72% and 29%, respectively, were recorded.

CONCLUSIONS: These results clearly demonstrated the occurrence of resistance to MLs by O. circumcincta. Although this is not the first occasion where resistance to this anthelmintic family has been detected in this parasite in sheep in New Zealand, it is the first instance that resistance to either moxidectin or abamectin has been reported.  相似文献   

Equine alopecia areata: a retrospective clinical descriptive study at the University of California,Davis (1980–2011)     

Danielle E. Hoolahan  Stephen D. White  Catherine A. Outerbridge  Patrick L. Shearer  Verena K. Affolter 《Veterinary dermatology》2013,24(2):282-e64

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Attitude of Brazilian veterinarians in the recognition and treatment of pain in horses and cattle     

Sílvia ERS Lorena  Stélio PL Luna  B Duncan X Lascelles  José E Corrente 《Veterinary anaesthesia and analgesia》2013,40(4):410-418

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