Despite many studies regarding tick ecology, limited information on long-term changes in tick populations exist. This study assessed the long-term population dynamics of the less frequently collected questing ixodid ticks in the Kruger National Park (KNP). From 1988 to 2002, monthly dragging of the vegetation was performed in three habitats (grassland, woodland and gully) at two sites in the KNP (Nhlowa Road, Landscape Zone 17, and Skukuza, Landscape Zone 4). Amblyomma marmoreum and Rhipicephalus evertsi evertsi were collected as larvae most commonly. Most A. marmoreum larvae were collected at Skukuza and numbers peaked from March to July. More R. evertsi evertsi larvae were collected at Nhlowa Road and numbers peaked in summer and in winter, while at Skukuza there was a single peak in spring. Haemaphysalis elliptica, Rhipicephalus simus and Rhipicephalus turanicus were collected as adults most commonly. More Ha. elliptica and R. turanicus were collected at Nhlowa Road than at Skukuza, while R. simus numbers from the two sites were approximately equal. Ha. elliptica were collected most often between February and June, and R. simus and R. turanicus during February and March. All three species were collected more frequently in gullies than in grassland or woodland. Their numbers increased in 1994/1995 following an eruption of rodents, the preferred hosts of the immature stages. The different host-seeking strategies of ticks largely determine the development stage at which they are likely to be collected during vegetation dragging and reflect a complex interaction between ticks, their hosts and the environment.

Objective-To evaluate tendon injuries in horses over a 16-week period by use of ultrasonography and low-field magnetic resonance imaging (MRI). Sample-Tendons of 8 young adult horses. Procedures-The percentage of experimentally induced tendon injury was evaluated in cross section at the maximal area of injury by use of ultrasonography and MRI at 3, 4, 6, 8, and 16 weeks after collagenase injection. The MRI signal intensities and histologic characteristics of each tendon were determined at the same time points. Results-At 4 weeks after collagenase injection, the area of maximal injury assessed on cross section was similar between ultrasonography and MRI. In lesions of > 4 weeks' duration, ultrasonography underestimated the area of maximal cross-sectional injury by approximately 18%, compared with results for MRI. Signal intensity of lesions on T1-weighted images was the most hyperintense of all the sequences, lesions on short tau inversion recovery images were slightly less hyperintense, and T2-weighted images were the most hypointense. Signal intensity of tendon lesions was significantly higher than the signal intensity for the unaltered deep digital flexor tendon. Histologically, there was a decrease in proteoglycan content, an increase in collagen content, and minimal change in fiber alignment during the 16 weeks of the study. Conclusions and Clinical Relevance-Ultrasonography may underestimate the extent of tendon damage in tendons with long-term injury. Low-field MRI provided a more sensitive technique for evaluation of tendon injury and should be considered in horses with tendinitis of > 4 weeks' duration.

Objective—To compare values of urodynamic measurements of cats with idiopathic cystitis (IC) with previously published data for healthy female cats. Animals—11 female cats with IC. Procedures—2 sequential cystometrograms and 2 urethral pressure profiles were obtained for each cat. All tracings were evaluated for evidence of overactive urinary bladder (OAB). Maximum urethral pressure (MUP), maximum urethral closure pressure (MUCP), and functional profile length were recorded. Results—Only 3 cats had obvious micturition events. None of the 11 cats had evidence of OAB. Although not significant, threshold pressure was lower in cats with IC than in healthy cats (mean ± SD, 89.0 ± 12.0 cm H2O vs 75.7 ± 16.3 cm H2O, respectively); however, the total volume infused was significantly lower in cats with IC (4.8 ± 2.1 mL/kg vs 8.3 ± 3.2 mL/kg). The MUCP was significantly higher in cats with IC than in healthy cats (158.0 ± 47.7 cm H2O vs 88.9 ± 23.9 cm H2O, respectively). The MUP was also significantly higher in all portions of the urethra in cats with IC. Conclusions and Clinical Relevance—No evidence of OAB was identified in any cat evaluated; therefore, medications used to target this abnormality did not appear justified. The high MUCP in cats with IC suggested that α1-adrenoceptor antagonists or skeletal muscle relaxants may be useful in this disease, and if these data were applicable to male cats, then α1-adrenoceptor antagonism may help prevent recurrent obstructive IC. Further studies are indicated to determine the effects, if any, these drugs might have in cats with IC.

Objective—To evaluate the effects of pilot hole diameter and tapping on insertion torque and axial pullout strength of 4.0-mm cancellous bone screws in a synthetic canine cancellous bone substitute. Sample—75 synthetic cancellous bone blocks (15 blocks/group). Procedures—For groups 1 through 5, screw size-pilot hole diameter combinations were 3.5–2.5 mm (cortical screws), 4.0–2.5 mm, 4.0–2.5 mm, 4.0–2.0 mm, and 4.0–2.0 mm, respectively. Holes were tapped in groups 1, 2, and 4 only (tap diameter, 3.5, 4.0, and 4.0 mm, respectively). One 70-mm-long screw was inserted into each block; in a servohydraulic materials testing machine, the screw was extracted (rate, 5 mm/min) until failure. Mean group values of maximum insertion torque, axial pullout strength, yield strength, and stiffness were determined. Results—Mean maximum insertion torque differed significantly among the 5 groups; the group 5 value was greatest, followed by group 3, 4, 2, and 1 values. Group 3, 4, and 5 axial pullout strengths were similar and significantly greater than the group 2 value; all values were significantly greater than that for group 1. Group 5 and 4 yield strengths were similar and significantly greater than the group 3, 2, and 1 values. Stiffness in group 3 was similar to group 4 and 2 values but significantly greater than the group 5 value; all values were significantly greater than that for group 1. Conclusions and Clinical Relevance—These synthetic cancellous bone model findings suggested that tapping a 2.0-mm-diameter pilot hole when placing a 4.0-mm screw is the optimal insertion technique.

Objective-To develop and evaluate a sandwich ELISA incorporating rabbit antiserum specific for canine surfactant protein A (SP-A) for use in measuring concentrations of SP-A in serum of dogs Sample-Serum samples obtained from 6 healthy dogs and 3 dogs with pulmonary disease. Procedures-Rabbit antiserum was prepared against purified canine SP-A. The IgG fraction was isolated via protein G affinity chromatography and was then biotinylated. The sandwich ELISA was performed by use of anti-SP-A antibody (IgG) preabsorbed with sera from healthy dogs. Validity of the ELISA was confirmed by determination of the detection limit, precision, reproducibility, and accuracy. Serum SP-A concentrations were measured in 6 healthy dogs and 3 dogs with pulmonary disease. Results-Detection limit of the ELISA was 2.0 ng/mL. Within- and between-assay coefficients of variation ranged from 3.8% to 14.1% and from 15.5% to 35.6%, respectively. The observed-to-expected recovery ratio ranged from 77.1% to 89.9%. Serum SP-A concentrations measured by use of the ELISA were ≤ 2.3 ng/mL in the 6 healthy dogs, 25.6 ng/mL in a dog with severe cardiac pulmonary edema, 8.3 ng/mL in a dog with pneumonia, and 10.1 ng/mL in a dog with lung lobe torsion. Conclusions and Clinical Relevance-The sandwich ELISA was found to be useful for measuring purified canine SP-A concentrations and canine SP-A concentrations in serum samples. The ELISA was precise, reproducible, and accurate. The ELISA may be beneficial in assessing serum concentrations of canine SP-A as a potential biomarker of pulmonary diseases in dogs.

Objective—To evaluate the radiographic, computed tomographic (CT), and cadaveric anatomy of the head of boa constrictors. Animals—4 Boa constrictor imperator cadavers. Procedures—Cadavers weighed 3.4 to 5.6 kg and had a body length ranging from 189 to 221 cm. Radiographic and CT images were obtained with a high-detail screen-film combination, and conventional CT was performed with a slice thickness of 1.5 mm. Radiographic images were obtained in ventrodorsal, dorsoventral, and left and right laterolateral recumbency; CT images were obtained with the animals positioned in ventral recumbency directly laying on a plastic support. At the end of the radiographic and CT imaging session, 2 heads were sectioned following a stratigraphic approach; the other 2, carefully maintained in the same position on the plastic support, were moved into a freezer (-20°C) until completely frozen and then sectioned into 3-mm slices, respecting the imaging protocol. The frozen sections were cleaned and then photographed on each side. Anatomic structures were identified and labeled on gross anatomic images and on the corresponding CT or radiographic image with the aid of available literature. Results—Radiographic and CT images provided high detail for visualization of bony structures; soft tissues were not easily identified on radiographic and CT images. Conclusions and Clinical Relevance—Results provide an atlas of stratigraphic and cross-sectional gross anatomy and radiographic and CT anatomy of the heads of boa constrictors that might be useful in the interpretation of any imaging modality in this species.

Objective—To investigate the effect of opsonization of Rhodococcus equi with R equi-specific antibodies in plasma on bacterial viability and phagocyte activation in a cell culture model of infection. Sample—Neutrophils and monocyte-derived macrophages from 6 healthy 1-week-old foals and 1 adult horse. Procedures—Foal and adult horse phagocytes were incubated with either opsonized or nonopsonized bacteria. Opsonization was achieved by use of plasma containing high or low concentrations of R equi-specific antibodies. Phagocyte oxidative burst activity was measured by use of flow cytometry, and macrophage tumor necrosis factor (TNF)-α production was measured via an ELISA. Extracellular and intracellular bacterial viability was measured with a novel R equi-luciferase construct that used a luminometer. Results—Opsonized bacteria increased oxidative burst activity in adult horse phagocytes, and neutrophil activity was dependent on the concentration of specific antibody. Secretion of TNF-α was higher in macrophages infected with opsonized bacteria. Opsonization had no significant effect on bacterial viability in macrophages; however, extracellular bacterial viability was decreased in broth containing plasma with R equi-specific antibodies, compared with viability in broth alone. Conclusions and Clinical Relevance—The use of plasma enriched with specific antibodies for the opsonization of R equi increased the activation of phagocytes and decreased bacterial viability in the extracellular space. Although opsonized R equi increased TNF-α secretion and oxidative burst in macrophages, additional factors may be necessary for effective intracellular bacterial killing. These data have suggested a possible role of plasma antibody in protection of foals from R equi pneumonia.

This is one of few published population-based studies describing breed specific rates of canine primary bone tumors. Incidence rates related to dog breeds could help clarify the impact of etiological factors such as birth weight, growth rate, and adult body weight/height on development of these tumors. The study population consisted of dogs within 4 large/giant breeds; Irish wolfhound (IW), Leonberger (LB), Newfoundland (NF), and Labrador retriever (LR), born between January 1st 1989 and December 31st 1998. Questionnaires distributed to owners of randomly selected dogs - fulfilling the criteria of breed, year of birth, and registration in the Norwegian Kennel Club - constituted the basis for this retrospective, population-based survey. Of the 3748 questionnaires received by owners, 1915 were completed, giving a response rate of 51%. Forty-three dogs had been diagnosed with primary bone tumors, based upon clinical examination and x-rays. The breeds IW and LB, with 126 and 72 cases per 10 000 dog years at risk (DYAR), respectively, had significantly higher incidence rates of primary bone tumors than NF and LR (P < 0.0001). Incidence rates for the latter were 11 and 2 cases per 10 000 DYAR, respectively. Pursuing a search for risk factors other than body size/weight is supported by the significantly different risks of developing primary bone tumors between similarly statured dogs, like NF and LB, observed in this study. Defining these breed-specific incidence rates enables subsequent case control studies, ultimately aiming to identify specific etiological factors for developing primary bone tumors.

Objective—To compare composition and colony formation of bone marrow mononuclear cells (BMMCs) harvested from dogs by means of a new perfusion method and the conventional aspiration method. Animals—7 healthy adult Beagles. Procedures—BMMCs were collected from the humeri and femurs of Beagles via perfusion and aspiration methods. Flow cytometric analysis was performed to quantify the presence of contaminant cells from the peripheral blood and the percentage of CD34+ progenitor cells in the BMMCs. A CFU assay was conducted to determine the number of progenitor cells in the BMMCs. Results—The perfusion method was safely performed in all 7 dogs. Flow cytometric analysis revealed that the percentages of contaminant CD3+CD4+, CD3+CD8+, and CD21 + lymphocytes in BMMCs obtained via perfusion were significantly lower than percentages obtained via aspiration. The percentage of CD34+ cells obtained via perfusion was significantly higher than that obtained via aspiration. In addition, perfusion yielded a significantly higher CFU count than did aspiration. Conclusions and Clinical Relevance—The perfusion method used in this study can minimize the contamination of bone marrow samples with peripheral blood and was a more efficient means for collecting canine bone marrow progenitor cells than the conventional aspiration method. Therefore, the perfusion method can be more suitable than aspiration for harvesting bone marrow cells for transplantation in dogs.

The interaction of Bordetella bronchiseptica, toxigenic Pasteurella multocida serotype D, and the mycotoxin fumonisin B1 (FB1) was studied. On day 0 of the experiment, 28 artificially reared 3-day-old piglets were divided into 4 groups (n = 7 each): a control group (A), a group fed FB1 toxin (B), a group infected with the 2 pathogens (C), and a group infected with the 2 pathogens and fed FB1 toxin (D). The B. bronchiseptica infection [with 106 colony-forming units (CFU)/mL] was performed on day 4 and the P. multocida infection (with 108 CFU/mL) on day 16. From day 16 a Fusarium verticillioides fungal culture (dietary FB1 toxin content 10 mg/kg) was mixed into the feed of groups B and D. In groups C and D, clinical signs including mild serous nasal discharge, sneezing, panting, and hoarseness appeared from day 4, and then from day 16 some piglets had coughing and dyspnea as well. Computed tomography (CT) performed on day 16 demonstrated lung lesions attributable to colonization by B. bronchiseptica in the infected groups. By day 25 the number of piglets exhibiting lesions had increased, and the lesions appeared as well-circumscribed, focal changes characterized by a strong density increase in the affected areas of the lungs. The gross pathological findings confirmed the results obtained by CT. These results indicate that, when combined with dual infection by B. bronchiseptica and P. multocida, dietary exposure of pigs to FB1 toxin raises the risk of pneumonia and increases the extent and severity of the pathological changes.