Diagnostic Imaging of Diseases Affecting the Guttural Pouch.

The most common diseases of the guttural pouch are empyema, tympany, mycosis and temporohyoid osteoarthropathy. The challenge in diagnosis of guttural pouch diseases lies in the complex anatomy of the guttural pouch and adjacent associated structures. Diagnostic imaging is a good complement to endoscopy for the diagnosis of some guttural pouch diseases, especially to make a full assessment of the lesions involving the pouch and surrounding structures. This review article describes the value of each diagnostic imaging technique in the diagnosis of guttural pouch disease and the corresponding imaging findings. Radiography is generally used as the first line to complement endoscopic findings, and can give useful additional information although it is limited by superimposition. Ultrasonographic examination of the guttural pouch is of limited value due to the presence of gas in the guttural pouch but can eventually be used to detect fluid within the pouch or can help to evaluate the soft tissues located lateral and ventral to the guttural pouch. Cross-sectional imaging, especially CT, is increasingly available and appears to be the best technique to fully assess the surrounding soft tissues and to precisely identify lesions of the temporohyoid apparatus, temporal bone and skull base that are associated with guttural pouch disease.

Attenuation From Shoes and Pads in Equine Nuclear Scintigraphy, With Relevance to Solar Views.

Nuclear scintigraphy can be beneficial in the investigation of equine lameness and poor performance. Images obtained through the sole allow for better identification of a region of increased radionuclide uptake in the foot. The presence of shoes or pads may affect these images. To determine the degree of radioactive attenuation different types of shoes and pads of different thickness and materials were evaluated by placing the material directly on the gamma camera detector acquiring flood images from a point source. The study compared five different types of shoes from 3 different shoeing materials, steel, aluminum, and polyurethane. This study also assessed 8 different types of pads that were selected based on the subjective densities and variable rigidity of the materials. All types of shoes/pads evaluated caused some degree of attenuation (P < 0.05). Steel shoes of all types cause the most attenuation (54%), followed by aluminum shoes (22%), and the shoes or pads composed primarily of a plastic polymer cause the least amount of attenuation (15%). The results of the study found that pads or shoes cause significant (p < 0.05) attenuation of gamma radiation. Composition, thickness and density characterized mass absorption coefficient, of the material affect the amount of gamma radiation attenuation. Because of the attenuation of gamma radiation, we recommend shoes and pads be removed prior to nuclear scintigraphic examination of the front foot if a solar image is desired, as this attenuation may affect image quality.

Measurement of Incisor Overjet and Physiological Diastemata Parameters in Quarter Horse Foals.

Cephalometric studies are important to quantify abnormalities of jaw length and positioning. In this study, 4 to 7-month-old Quarter horse foals (n = 51) were examined to determine overjet (horizontal overlap) prevalence and measure the size of the physiological diastemata. Results were analyzed in relation to age, sex, and lineage. Another aim of this study was to develop a simple field technique for measuring incisor malocclusion and physiological diastemata dimensions that could be used to monitor the growth of the rostral components of maxilla, incisive bone, and mandible. The overall prevalence of overjet lesions in these foals was 51%. Females were overrepresented (61.5%). Overjet occurred more commonly in show foals (50% prevalence) than other working (7.7%) and race (42.3%) lineage foals. Significant differences were found between maxillary and mandibular physiological diastemata lengths in foals of all ages and, as expected, there was a positive statistical correlation between age and maxillary and mandibular physiological diastemata measurements. Incisor overjet was present in 44.4% of 4-month-old foals, 45.5% of 5-month-old foals, 58.3% of 6-month-old foals, and 60% of 7-month-old foals. There was a weak positive correlation between age and the presence of incisor overjet. It was concluded that incisor overiet was common among Quarter horse foals, especially those from show and race lineages. The field technique for physiological diastema measurements was considered effective.

Thyroid hormones response to marcha gait in Mangalarga Marchador horses / Resposta dos hormônios da tireoide após a execução da marcha em equinos da raça Mangalarga Marchador

The aim of this study was to evaluate thyroid hormones response to marcha gait by measuring serum concentrations of total (TT4) and free thyroxine (FT4), and total triiodothyronine (TT3) in Mangalarga Marchador horses. Blood samples were collected from 15 Mangalarga Marchador horses at four different moments: before (M0) and within five minutes (M1), 30 minutes (M2) and 2 hours (M3) after exercise (marcha gait for 40 minutes). Mean values of TT4 were 2.24 ± 0.36 µg/dL on M0, 2.41 ± 0.35 µg/dL on M1, 2.76 ± 1.36 µg/dL on M2 and 2.36 ± 0.40 µg/dL on M3 (p=0.2906). Mean values of FT4 were 0.78 ± 0.14 ng/dL on M0, 0.84 ± 0.11 ng/dL on M1, 0.89 ± 0.18 ng/dL on M2 and 0.85 ± 0.14 ng/dL on M3 (p=0.2305). For TT3, mean values were 0.92±0.28ng/mL on M0, 0.99±0.39ng/mL on M1, 1.20±1.07ng/mL on M2 and 0.87±0.24ng/mL on M3 (p=0.4697). Analysis of the results revealed that marcha gait did not influence serum mean values of thyroid hormones, although it was observed influence over heart rate and body temperature.

O presente estudo teve por objetivo avaliar a resposta dos hormônios da tiroide frente a um exercício físico (provas de marcha) através das mensurações séricas de tiroxina total (T4T) e livre (T4L), e triiodotironina total (T3T) em equinos da raça Mangalarga Marchador. Para tal, foram obtidas amostras de sangue de 15 equinos, da referida raça, em quatro momentos assim definidos: antes (M0) e com 5 minutos (M1), 30 minutos (M2) e 2 horas (M3) após a execução de exercício físico (40 minutos de marcha). Os valores médios para T4T foram de 2,24± 0,36µg/dL em M0, 2,41±0,35µg/dL em M1, 2,76±1,36µg/dL em M2 e 2,36±0,40µg/dL em M3 (p=0,2906); para T4L foram de 0,78±0,14ng/dL em M0, 0,84±0,11ng/dL em M1, 0,89±0,18 ng/dL em M2 e 0,85±0,14 ng/dL em M3 (p=0,2305); e para T3T foram de 0,92±0,28ng/mL em M0, 0,99±0,39ng/mL em M1, 1,20±1,07ng/mL em M2 e 0,87±0,24ng/ mL em M3 (p=0,4697). A análise dos resultados demonstrou que não houve influência da marcha sobre os valores séricos médios dos hormônios tireoidianos, apesar de haver influência sobre a frequência cardíaca e temperatura corporal.