Colour Dilution Alopecia (CDA) in Ten yorkshire Terriers

Abstract— Clinical laboratory investigations as well as light, electron microscopic and X-ray microanalytical studies on skin biopsy specimens and hair from 10 yorkshire terriers suffering from Colour Dilution Alopecia (CDA) were carried out. Biochemical data detected a marked melanin reduction in hair from affected areas. Histologically, melanin clumps were mainly evident in the epidermal basal layer cells as well as inside the bulb and hair shaft. Ultrastructurally, basal keratinocytes were overloaded by fully melanized melanosomes disrupting cytoplasmic structures. Intracytoplasmic and free melanosomes were also evident in all cutaneous layers. Scanning electron microscopy showed holes and bulges scattered in the hair shaft. X-Ray microanalysis demonstrated silicate particles in the more superficial cuticular holes and calcium in the deeper fractured layers. Based on these observations a new hypothesis on the pathogenetic mechanism(s) of alopecia is proposed. Résumé— Diverses investigations, microscopie optique, microscopie électronique, études microanalytiques aux rayons X ont été réalisées sur des biopsies cutanées et des poils provenant de dix yorkshire Terriers présentant une Alopécie des Robes Diluées. Les examens biochemiques montrent une diminution nette de la mélanine dans les poils provenant des régions malades. Des aggrégate de mélanine sont observés dans les cellules de l'assise basale épidermique ainsi qu'à l'intérieur des bulbes pileux et des tiges pilaires. Sur le plan ultrastructural, les kératinocytes basaux montrent une surcharge en mélanosomes détruisant ainsi les structures cytoplasmiques. Des mélanosomes libres et intra-cytoplasmiques sont également observés dans toutes les couches épidermiques. La microscopie électronique à balayage montrent des trous et des bosses dispersés dans la gaine folliculaine. Des analyses en rayons X démontrent la présence de particules de silicate dans les trous les plus superficiels de la cuticule et du calcium dans les couches plus profondes. A partir de ces observations, une nouvelle hypothèse sur la pathogénie de dette alopécie est proposée. [Roperto F., Cerundolo, R., Restucci, B., Vincensi, M. R., De Caprariis, D., De Vico, G., Maiolino, P. Colour dilution alopecia (CDA) in ten yorkshire Terriers (Alopécie des robes diluées (ARD) chez dix yorkshire Terriers). Resumen— Se llevaron a cabo análisis clinicos asi como estudios microanaliticos con rayos X y microscopia electrónica sobre biopsias cutáneas tomadas a diez yorkshire Terriers que padecian de Alopecia de Color Diluido (CDA). Los estudios bioquimicos detectaron una fuerte reducción en melanina en el pelo de las zonas afectadas. A nivel histológico, los agregados de melanina se localizaban principalmente en la capa basal de la epidermis asi como en el bulbo piloso y en en pelo. A nivel ultraestructural, los queratinocitos basales estaban sobrecargados de melanosomas totalmente melanizados, alterando su estructura citoplasmática. También se identificaron melanosomas en forma libre o a nivel intracitoplasmático en todas las capas cutáneas. La microscopia electrónica de escáner mostró cavidades y prominencias diseminadas a lo largo del pelo. Mediante microanalisis por rayos X se detectaron partículas de silicato en las cavidades cuticulares más superficiales y calcio en las capas més profundas. Teniendo en cuenta estos hallazgos, se propone una nueva hipótesis sobre el/los mecanismo/s patogénico/s de la alopecia. [Roperto F., Cerundolo, R., Restucci, B., Vincensi, M. R., De Caprariis, D., De Vico, G., Maiolino, P. Colour dilution alopecia (CDA) in ten yorkshire Terriers (Alopecia de color diluido (CDA) en diez yorkshire Terriers).     

COMPUTED TOMOGRAPHY-GUIDED PERCUTANEOUS BIOPSY IN THE DOG AND CAT: DESCRIPTION OF TECHNIQUE AND PRELIMINARY EVALUATION IN 14 PATIENTS

A technique for computed tomography (CT)-guided percutaneous biopsy described for use in humans was adapted to the dog and cat and is evaluated in 14 patients. Nine retrobulbar, 1 cranial mediastinal and 4 pulmonary masses and 1 hilar lymph node were biopsied in 13 dogs and 1 cat. Tissue samples sufficient for diagnosis were obtained in 12 of the 15 lesions. Diagnoses were made following cytologic (3/12) or histopathologic (3/12) evaluation or both (6/12) and included retrobulbar lymphoma, carcinoma, spindle cell sarcoma and suppurative inflammation; pulmonary carcinoma, granuloma and eosinophilic/histiocytic inflammation; nasal carcinoma, thymoma and metastatic carcinoma of a hilar lymph node. In each patient, the needle tip was identified within the lesion on the CT image. The primary limitation was non-diagnostic samples in 3 of 15 lesions due to necrosis or insufficient tissue. Complications were minor. In addition to biopsy guidance, CT imaging provided information not obtainable with fluoroscopy or ultrasonography which assisted in tumor staging and therapy planning. Although a larger number of patients and biopsy locations would be required for a thorough assessment, the free-hand technique described in this preliminary report appeared to be a safe and useful option of biopsy guidance in the dog and cat.     

A NEW AND VERSATILE LARGE ANIMAL DIAGNOSTIC RADIOLOGY UNIT

The plans and technical specifications of a unit specifically designed for large animal radiography are described. The unit has two examination rooms, one for routine radiography in the standing position and the other for special procedures and investigations utilizing a custom-designed table with a carbon fiber top. The table is computer operated and the x-ray tubes above and below it are capable of penetrating the thickest parts of horses as well as performing such procedures as linear tomography, angiography, and magnification radiography. The facility is equipped with an image intensifier, television monitor, 100 mm spot film camera, Potter-Bucky grid, and Puck film changer as well as a number of additional features for coping with anesthetized large animals. The unit has been in operation for three years and has greatly improved the quality of radiographic examinations as well as opening up some important lines of investigative research     

RADIOGRAPHIC APPEARANCE OF EQUINE LUMBOSACRAL AND PELVIC ABNORMALITIES BY LINEAR TOMOGRAPHY

Radiologic findings are described in 20 horses with clinical signs of a caudal lumbar or hindlimb problem; the horses were subjected to linear tomography of the lumbosacral and pelvic regions. The cases could be divided into four groups: sacroiliac arthrosis (6 horses), lumbosacral abnormalities (3 horses), pelvic or lumbar fracture (6 horses), and no radiographic abnormalities (5 horses). Five of the six horses with sacroiliac arthrosis had spur formation, with localized arthrosis at the caudal aspect of the sacral wing and its articulation with the auricular surface of the ilium. In one horse these lesions were confirmed at postmortem examination. The sixth horse, a Standardbred trotter, had more even and widespread arthrosis of the sacroiliac joint. The three lumbosacral abnormalities were present in two horses with fusion of the L₅-L₆ articulation and one horse with a wider than normal sacrolumbar articulation. Linear tomography also proved to be of diagnostic and prognostic value in the evaluation of lumbar and pelvic fractures. Finally, tomography could be used to eliminate the presence of sacroiliac or lumbosacral damage in some horses that presented with clinical signs suggestive of disease of the lumbosacral or sacroiliac region.     

ANATOMY OF THE CANINE ORBITAL REGION

Computed tomography (CT) was used to study the normal anatomy of the orbital region in one Beagle. Direct transverse and reformatted dorsal, sagittal, and oblique plane images were used to distinguish various soft tissue structures. Intraorbital fat provided a natural contrast against which extraocular muscles and nerves could be discerned. The noninvasive nature and the multiplanar imaging capabilities of CT provided a means by which the orbital contents could be precisely localized and differentiated from one another.     

COMPARISON OF RADIOGRAPHY AND COMPUTED TOMOGRAPHY FOR THE DIAGNOSIS OF CANINE NASAL ASPERGILLOSIS

To compare the radiographic and computed tomographic (CT) findings and to evaluate the sensitivity of radiography and CT for diagnosis of nasal aspergillosis in dogs, the radiographic and CT studies of 48 dogs with chronic nasal disease were reviewed separately. The radiographic and CT findings were recorded, and a diagnosis was made. The results obtained in the dogs with nasal aspergillosis (n = 25) were used. Based on definite aspergillosis as diagnosis, CT had a sensitivity of 88% and radiography of 72%. Considering definite and probable aspergillosis as equivalent, CT had a sensitivity of 92% and radiography of 84%. The sensitivity was higher in dogs with lesions affecting the entire nasal cavity and frontal sinus on at least one side (n = 20) with a sensitivity of 100% for CT and 90-95% for radiography than in dogs with lesions restricted to the nasal cavities (n = 5) where CT had a sensitivity of 60-80% and radiography of 0-40%. CT was superior to radiography for evaluation of the nasal cavities (mucosal thickening along the nasal bones, surrounding bone hyperostosis/lysis), frontal sinuses (mucosal thickening along the frontal bone, fluid/soft tissue, frontal bone hyperostosis/lysis), and differentiation between a cavitated-like or a mass-like process. This study suggests that CT is more sensitive than radiography for diagnosis of nasal aspergillosis in the dog because of a better demonstration of some changes suggestive of nasal aspergillosis. A diagnosis of a nasal aspergillosis restricted to the nasal cavities or associated with an FB is challenging, even with the use of CT.     

湿地松种子衬比射线检验方法的研究

对温地松种子进行对比射线方法检验,结果表明,其最佳x射线摄影衬比过程为:将种子在25℃下浸种24h,擦干种子表面水分后,置入40%KI溶液中处理5h,在流水中冲洗5～6min,置于70℃下干燥24h。使用SOⅡ胶片和HY—35型射线机时,拍摄条件为:电压20kV,电流4mA,曝光时间100s,焦片距25cm。由此认为,未被浸渗而胚和胚乳发育良好的种子具生活力,可用来估算种子的发芽能力。用上述衬比方法测定35份湿地松种子,其发芽能力与实际发芽率相当一致。     

The 3D anatomy of the cervical articular process joints in the horse and their topographical relationship to the spinal cord

Reasons for study: Detailed anatomy of the equine cervical articular process joints (APJs) has received little attention in the literature and yet disorders of this joint have been linked to spinal cord compression resulting in severe clinical signs such as ataxia and weakness. This study aimed to describe the 3D anatomy of the APJ in relation to the spinal cord in the horse. Hypothesis: Artificial distension of the APJ causes the joint pouches to extend into the vertebral canal, with the potential for APJ effusion to cause spinal cord compressive disease. Methods: Six cadaveric necks (C1–C7) of clinically normal horses were used in this study. Computed tomography scans of the cervical APJ were acquired after injection of a negative contrast agent to maximal distension. The resulting images were semi‐automatically segmented using greyscale thresholding and reconstructed in 3D by polygonal surface meshing. The 3D reconstructions were used to assess the topographic anatomy of the APJ in relation to the spinal cord and to measure joint volume at each cervical vertebra in relation to vertebrae size. Results: Joint volume varied significantly between joint location (P<0.0001) and was positively correlated to the vertebral site (from cranial to caudal) (r = 0.781, P<0.0001). After distension, the medial outpouch of the APJ extended towards the vertebral canal from a dorsolateral location but in none of the 6 horses was there apparent compression of the dura mater surrounding the spinal cord. There was no significant difference in the extent of medial outpouch at any vertebral level (P = 0.104). Flexion of the neck resulted in minor changes to the shape of the APJ but did not result in the medial outpouch encroaching any closer to the spinal cord. Conclusions: From this study, it appears that in the absence of any other soft tissue or bony changes an effusion of the APJ is unlikely to cause spinal cord compression. However, given that the APJ and spinal cord are in close approximation, in the presence of other anatomical changes, an effusion may have the potential to cause compression. Potential relevance: This study confirms that the APJ extend into the dorsolateral aspect of the vertebral canal in a ventromedial direction, suggesting that oblique myelographic views are recommended for the diagnosis of spinal cord compression when pathology of the APJ is suspected.     

Survey of giardiosis in household and shelter dogs from metropolitan areas of Curitiba, Paraná state, Southern Brazil

Giardia duodenalis is a protozoan parasite that causes a broad range of clinical symptoms varying from none--in asymptomatic carriers--to mild recurring diarrhea consisting of soft, light-colored stools to acute severe diarrhea. In different parts of the world this parasite has raised increased interest due to its possible zoonotic transmission. Among domestic animals, dogs can play an important role in environmental contamination. As there is little information on the frequency of giardiosis in dogs from the Metropolitan Area of Curitiba-State of Paraná, Southern Brazil, the aim of the present work was to evaluate the prevalence of G. duodenalis in two dog populations (household and shelter). To attain the proposed aim, we collected fecal samples from 200 dogs and utilized three diagnostic techniques: Faust's technique (Faust et al. 1939), Benbrook's technique (1963) and polymerase chain reaction (PCR). Faust's technique presented the best results, as it was able to detect a larger number of Giardia cases. Taking Faust's technique as the standard, Benbrook's technique presented 66% sensitivity and PCR demonstrated 69% sensitivity. The shelter dog population showed a 24% occurrence of G. duodenalis while the household population showed a 9% occurrence. Other epidemiological aspects like age, sex, environmental conditions and methodological aspects are discussed in the present article.     

Spectral domain optical coherence tomography (SD-OCT) assessment of the healthy female canine retina and optic nerve

Objective To provide normative data for canine whole retinal thickness (WRT), nerve fiber layer thickness (NFL), photoreceptor layer thickness (PR), and outer nuclear layer thickness (ONL) using spectral domain optical coherence tomography. Animal studied: Twelve healthy adult intact female beagles. Procedure Horizontal volume scans through the area dorso‐temporal from the optic nerve (superior retina), and the area ventro‐temporal from the optic nerve (inferior retina) were used to evaluate the thickness of retinal NFL, PR, ONL, and WRT. Peripapillary circular scans were used to evaluate NFL thickness. Statistical analyses were performed to compare the thickness of the individual layers between the superior and inferior retina (paired t‐test). One‐way analysis of variance (ANOVA) was used to compare the thickness of peripapillary NFL between the superior, inferior, temporal and nasal quadrants of the circle scan. Results The WRT, PR, and NFL thickness were greater in the superior than in the inferior retina (198.7 ± 9.6 μm vs. 164.4 ± 6.4 μm, P < 0.0001; 95.5 ± 6.5 μm vs. 78.8 ± 7.4 μm, P < 0.0001; and 26.4 ± 1.6 μm vs. 25.0 ± 1.9 μm, P = 0.0236, respectively). No statistical difference was found between the ONL thickness of the superior and inferior retina (50.1 ± 6.4 μm vs. 44.3 ± 3.6, P = 0.0578). Peripapillary NFL thickness showed a similar tendency as the linear scans, with the superior quadrant having the greatest thickness (91.26 ± 7.0 μm) and the inferior quadrant being the thinnest (76.42 ± 9.2 μm) (P < 0.001). Conclusions Results of our in vivo studies showed significant differences between thickness values for the superior (tapetal) and inferior (nontapetal) retinal regions.