Ultrassonografia em modo A e B na avaliação pré-operatória da lente e do segmento posterior de olhos de cães com catarata / A and B mode ultrasonography in preoperative evaluation of lens and posterior segment of dogs eyes with cataract

Ultrasonography of the lens and posterior segment is an indispensable step in the preoperative evaluation of dogs with cataracts, since ophthalmoscopy is not feasible when there is opacification of the lens. This study evaluated the echographic conditions of cataractous lens and fundus of the eye in dogs affected by cataracts. The study was conducted in 30 dogs (56 eyes), 10 males and 20 females, with different types of cataracts at different stages of development. Echography in A and B modes, simultaneously, was carried out for the examination of the lens and posterior segment. The examinations revealed anterior cortical, posterior cortical and nuclear cataract in 12 eyes (21.4 percent), anterior cortical, posterior cortical, nuclear and posterior capsular in 23 eyes (41 percent), anterior cortical, posterior cortical and posterior capsular cataract in one eye (1.7 percent), anterior cortical and nuclear cataract in one eye (1.7 percent), anterior cortical, nuclear and posterior capsular cataract in five eyes (8.9 percent), and anterior cortical cataract in seven eyes (12.5 percent). Abnormal ultrasonographic alterations were observed in the posterior segment in 26 eyes evaluated (46.4 percent). Vitreal degeneration was detected in 12 eyes (21.4 percent), images of vitreal exudate or hemorrhage in seven eyes (12.5 percent), persistence of hyaloid artery in four eyes (7.1 percent) and lens subluxation in three eyes (5.3 percent). The results obtained reiterate the importance of ultrasonography in canine patients presented for cataract surgery given that alterations of the posterior segment are difficult to identify in a clinical examination when the lens is opacified.

A ultrassonografia do segmento posterior do bulbo do olho é etapa indispensável na avaliação de cães com catarata que serão submetidos à facectomia, uma vez que a oftalmoscopia não é factível quando há opacificação da lente, notadamente nas cataratas maduras. Este estudo avaliou as condições ecográficas da lente cataratogênica e do fundo de olho de cães cursando com catarata. Foram avaliados 30 cães (56 olhos), sendo 10 machos e 20 fêmeas, cursando com catarata em diferentes estágios de desenvolvimento. Realizou-se a ecografia em modo A e B simultaneamente. Os exames revelaram catarata cortical anterior, posterior e nuclear em 12 olhos (21,4 por cento), catarata cortical anterior, posterior, nuclear e capsular posterior em 23 olhos (41 por cento), catarata cortical anterior, posterior e capsular posterior em um olho (1,7 por cento), catarata cortical anterior e nuclear em um olho (1,7 por cento), catarata cortical anterior, nuclear e capsular posterior em cinco olhos (8,9 por cento) e catarata cortical anterior em sete olhos (12,5 por cento). Alterações no segmento posterior foram observadas, à ultrassonografia, em 26 olhos avaliados (46,4 por cento). Degeneração vítrea foi detectada em 12 olhos (21,4 por cento), imagens compatíveis com exsudato ou hemorragia em sete olhos (12,5 por cento), persistência da artéria hialóide em quatro olhos (7,1 por cento) e subluxação da lente em três olhos (5,3 por cento). Os resultados obtidos reiteram a importância da ultrassonografia em cães candidatos à cirurgia de catarata, uma vez que o exame do segmento posterior do bulbo do olho é de difícil execução, devido à opacificação da lente.

Conjunctival effects of canine distemper virus-induced keratoconjunctivitis sicca.

OBJECTIVE: This study compared the histopathology of canine distemper virus (CDV)-induced keratoconjunctivitis sicca (KCS) to non-infectious KCS in conjunctival tissues. ANIMALS STUDIED: Forty mongrel dogs were assigned to three distinct groups: (i) non-infectious KCS (G1, n = 10), (ii) CDV-induced KCS (G2, n = 20), and (iii) healthy animals without any ocular alterations (G3, n = 10). PROCEDURE: IgG titers and physical and ophthalmic examinations (e.g. Schirmer tear test [STT], tonometry, biomicroscopy, indirect biomicroscopy, and fluorescein test) were performed on all dogs. Conjunctival biopsies were collected and examined microscopically. RESULTS: Non-infectious and CDV-induced KCS demonstrated similar histopathological changes. Both types of KCS correlated with low STT, conjunctival hyperemia, mucopurulent ocular discharge, predominant lymphoplasmacytic infiltration, and acantholysis and keratinization of the ocular surface. G1 had lower conjunctival goblet cell counts than G3. Inclusion bodies were sporadically found in conjunctival samples of dogs from G2. The severity of ocular lesions in G1 and G2 did not correlate with the histopathological findings. CONCLUSIONS: Dogs with non-infectious and CDV-induced KCS had very similar conjunctival histopathology. Our findings suggest that the pathophysiology of CDV-induced KCS is likely to be the same as non-infectious KCS, that is, a result of lacrimal deficiency and inflammation of the ocular surface.

Effects of isoflurane on echocardiographic parameters in healthy dogs.

OBJECTIVE: To study the echocardiographic effects of isoflurane at an end-tidal concentration approximating 1.0 times the minimum alveolar concentration (MAC) in healthy unpremedicated dogs. STUDY DESIGN: Prospective experimental trial. ANIMALS: Sixteen mature mongrel dogs of either sex weighing 11.06 +/- 2.72 kg. METHODS: After performing a baseline echocardiogram in the awake animal, anesthesia was induced with increasing inspired concentrations of isoflurane via a face mask until tracheal intubation was possible. Following intubation, the end-tidal concentration was decreased to 1.4% for the rest of the anesthetic period. Serial echocardiograms were recorded at 25, 40, and 55 minutes after the end-tidal concentration was reached. RESULTS: No changes were observed in heart rate. However, significant decreases were seen in left ventricular end-diastolic diameter (Mean maximal change: 13.8%), interventricular septal thickness during systole (15.2%), interventricular septal thickening fraction (72.2%), left ventricular free wall thickening fraction (63.5%), ejection fraction (39.9%), and fractional shortening (46.7%). In addition, peak flow velocities across mitral, pulmonic, and aortic valves were significantly lower than baseline values. Decreases were also observed in end-diastolic left ventricular volume index (approximately 32.1% from the awake value), stroke index (58.2%), and cardiac index (55.3%) when compared with awake measurements. CONCLUSIONS: and clinical relevance Our results indicate that 1 x MAC isoflurane caused significant myocardial depression in healthy dogs. These changes in myocardial function need to be considered carefully when isoflurane is to be used in dogs with poor cardiovascular reserve.

Effects of isoflurane on Tei-index of myocardial performance in healthy dogs.

Recently, the Tei-index, a noninvasive index that combines systolic and diastolic time intervals, has been proposed to assess global cardiac performance. However, the effects of isoflurane on the Tei-index have not been characterized. This study aimed at studying the effects of 1.0 minimal alveolar concentration isoflurane anesthesia on the pre-ejection period (PEP), left ventricular ejection time (LVET), PEP/LVET ratio, isovolumic relaxation time (IVRT), stroke index (SI), cardiac index (CI), heart rate (HR), and the Tei-index in healthy unpremedicated dogs. We observed significant increases in PEP, PEP/LVET ratio, IVRT, and TEI, whose maximal increases obtained throughout the study were 47%, 48%, 78%, and 56%, respectively. The LVET and HR did not change significantly, whereas the SI and CI decreased during anesthesia (29% and 26%, respectively). In conclusion, isoflurane produced direct effects on the Tei-index. The changes in systolic and diastolic parameters were supportive of this finding and were consistent with an overall impairment of left ventricular function during anesthesia.