Hedie Bustamante

Stress and pain response after oligofructose induced-lameness in dairy heifers.

Lameness is one of the most painful conditions that affects dairy cattle. This study was conducted to evaluate clinical signs and plasma concentration of several pain and stress biomarkers after oligofructose-induced lameness in dairy heifers. Lameness was induced using an oligofructose overload model in 12 non-pregnant heifers. Clinical parameters and blood samples were obtained at 48 and 24 h and at 6, 12, 24, 36 and 48 h after induction of lameness. Clinical parameters included heart rate, respiratory rate, ruminal frequency and lameness score. Plasma biomarkers included cortisol, haptoglobin, norepinephrine, beta-endorphin and substance P. Differences were observed in all parameters between control and treated heifers. The plasma concentration of biomarkers increased significantly in treated animals starting 6 h after induction of lameness, reaching maximum levels at 24 h for cortisol, 48 h for haptoglobin, 6 h for norepinephrine, 12 h for substance P and at 24 h for beta-endorphin. Overall, our results confirm that lameness associated pain induced using the oligofructose model induced changes in clinical parameters and plasma biomarkers of pain and stress in dairy heifers.

Hallazgos de tomografía computarizada en coenurosis cerebral crónica con hidrocéfalo secundario en una oveja joven

SUMMARY The purpose of this study was to describe the computed tomographic (CT) features of a 14 month old ewe showing clinical signs of cerebral coenurosis. The CT analysis of the head was made using a fourth generation CT scanner. On transverse CT images the cyst was seen as an hipodense, ring enhanced mass located in the cerebral hemispheres and ventricular system. Ventriculomegaly and atrophy of the cortical tissue was also observed indicating the presence of secondary hydrocephalus. The Coenurus was surgically removed by skull trepanation through the frontal bone and after a few days the animal recovered its healthy status. CT proved to be useful in demonstrating the anatomic location of the cyst and was helpful in surgical planning.

Efectos cardiorrespiratorios de la administración de xilazina-morfina en perros anestesiados con pentobarbital sódico

SUMMARY Cardiorespiratory effects after the administration of morphine, xylazine and the combination of xylazine and morphine were evaluated. Six young and healthy dogs were used for this study. Each animal received four treatments after being anaesthetized with sodium pentobarbital (30 mg/kg), a) 5 ml of saline; b) 0.4 mg/kg of xylazine; c) 0.4 mg/kg of morphine and d) 0.4 mg/kg of morphine plus 0.4 mg/kg of xylazine. The following variables were analyzed for one hour: heart rate, respiratory rate, systolic, diastolic and mean arterial blood pressure. Also, samples for blood gas analysis during times –5, 1, 5, 10, 15 and 30 were taken. Results obtained show that heart rate diminished significantly (P 0.05) in arterial pH, PaO 2 , PaCO 2 and bicarbonate in dogs.

Immunofluorescence characterization of spinal cord dorsal horn microglia and astrocytes in horses

The role of glial cells in pain modulation has recently gathered attention. The objective of this study was to determine healthy spinal microglia and astrocyte morphology and disposition in equine spinal cord dorsal horns using Iba-1 and GFAP/Cx-43 immunofluorescence labeling, respectively. Five adult horses without visible wounds or gait alterations were selected. Spinal cord segments were obtained post-mortem for immunohistochemical and immunocolocalization assays. Immunodetection of spinal cord dorsal horn astrocytes was done using a polyclonal goat antibody raised against Glial Fibrillary Acidic Protein (GFAP) and a polyclonal rabbit antibody against Connexin 43 (Cx-43). For immunodetection of spinal cord dorsal horn microglia, a polyclonal rabbit antibody against a synthetic peptide corresponding to the C-terminus of ionized calcium-binding adaptor molecule 1 (Iba-1) was used. Epifluorescence and confocal images were obtained for the morphological and organizational analysis. Evaluation of shape, area, cell diameter, cell process length and thickness was performed on dorsal horn microglia and astrocyte. Morphologically, an amoeboid spherical shape with a mean cell area of 92.4 + 34 µm2 (in lamina I, II and III) was found in horse microglial cells, located primarily in laminae I, II and III. Astrocyte primary stem branches (and cellular bodies to a much lesser extent) are mainly detected using GFAP. Thus, double GFAP/Cx-43 immunolabeling was needed in order to accurately characterize the morphology, dimension and cell density of astrocytes in horses. Horse and rodent astrocytes seem to have similar dimensions and localization. Horse astrocyte cells have an average diameter of 56 + 14 µm, with a main process length of 28 + 8 µm, and thickness of 1.4 + 0.3 µm, mainly situated in laminae I, II and III. Additionally, a close association between end-point astrocyte processes and microglial cell bodies was found. These results are the first characterization of cell morphology and organizational aspects of horse spinal glia. Iba-1 and GFAP/Cx-43 can successfully immune-label microglia and astrocytes respectively in horse spinal cords, and thus reveal cell morphology and corresponding distribution within the dorsal horn laminae of healthy horses. The conventional hyper-ramified shape that is normally visible in resting microglial cells was not found in horses. Instead, horse microglial cells had an amoeboid spherical shape. Horse protoplasmic astroglia is significantly smaller and structurally less complex than human astrocytes, with fewer main GFAP processes. Instead, horse astrocytes tend to be similar to those found in rodent’s model, with small somas and large cell processes. Microglia and astrocytes were found in the more superficial regions of the dorsal horn, similarly to that previously observed in humans and rodents. Further studies are needed to demonstrate the molecular mechanisms involved in the neuron-glia interaction in horses.

Efecto sedativo de la asociación xilazina-morfina en caninos

SuMMARy The aim of this study was to evaluate the sedative and adverse effects produced by the endovenous combination of xylazine and morphine administered to dogs. Fourty dogs of different breed, size and age were used. Each animal received 0.4 mg/kg of xylazine and 0.4 mg/kg of morphine i.v. Sedation was evaluated using the punctuation score described by Young y col (1990). The scores were obtained before the administration and 5, 10 and 20 minutes after administration. Heart rate, respiratory rate and the presentation of side effects during the evaluation time were also recorded. The results obtained show also that the scores in the analyzed variables presented significant differences (P < 0.05), indicating a marked sedative effect produced by the association between xylazine and morphine. In the same way, there was a significant decrease (P < 0.05) in heart rate and respiratory rate. Side effects that appeared during the study were excitement and respiratory effort. It can be concluded that the endovenous administration of xylazine and morphine combination produced significant sedation in dogs and side effects as excitement and minor respiratory effort.

Plasma concentration of norepinephrine, beta-endorphin, and substance P in lame dairy cows

Abstract Introduction Lameness is a painful and debilitating condition that affects dairy cows worldwide. The aim of this study was to determine the plasma concentration of norepinephrine, β-endorphin, and substance P in dairy cows with lameness and different mobility scores (MS). Material and Methods A total of 100 Friesian and Jersey cows with lameness (parity range: 1–6; weight: 400–500 kg; milk yield: 22–28 L a day, and lactation stage less than 230 days) were selected. Animals were selected and grouped according to MS (MS 0–3; n = 25), and plasma concentration of norepinephrine, substance P, and β-endorphin was measured using ELISA. Results Cows with MS 3 had higher plasma concentrations of norepinephrine and substance P and lower plasma concentrations of β-endorphins when compared to MS 0 cows. Conclusion Variations in plasma concentration of norepinephrine, substance P, and β-endorphin could be associated with intense pain states in dairy cows with lameness, but are insufficient to differentiate these states from the mildest pain states. Further studies are necessary in order to evaluate the potential use of these biomarkers in the detection of chronic bovine painful conditions.

Periurethral Vascular Hamartoma in a 6-Month-Old Foal With Idiopathic Hematuria: New Differential Diagnosis

ABSTRACT Hamartomas are nonmalignant masses of normal tissue organized in a chaotic manner. Here, we describe a 6‐month‐old 120 kg Chilean Criollo foal that manifested chronic hematuria observed since birth. Severe anemia and lack of development were the main complaints of this referral. The foal was depressed and in poor body condition, and had lagged development and a coarse haircoat. Mucous membranes were pale, and numerous blood clots were observed toward the end of micturition. Severe normocytic normochromic anemia was confirmed by hematological analysis; there were no significant findings in serum biochemistry or coagulation tests. Transabdominal ultrasonography and urinary tract endoscopy yielded no clinically relevant results. Empirical treatment was initiated on a tentative diagnosis of idiopathic renal hematuria (dexamethasone 0.1 mg/kg [0.045 mg/lb], q 24 hours, IV, sodium ceftiofur 2.2 mg/kg [0.99 mg/lb], IM, q 24 hours, and blood transfusions), but the foals condition further deteriorated, warranting euthanasia. Necropsy revealed a vascular malformation on the extraluminal portion of the proximal urethra at the bladder junction, with a 3 mm urethral communication. Histopathologic examination confirmed this mass to be a hamartoma of vascular origin, which incidentally communicated with the urethral lumen and led to progressive blood loss. In this case, the location of this malformation impeded its discovery and ultimately an accurate diagnosis. Hamartomas are currently not listed as a differential diagnosis for bleeding‐related urinary tract disorders in the modern literature; therefore, we propose that they should be considered as a differential diagnosis in cases of unexplained or refractory idiopathic hematuria. HighlightsUnexplained chronic hematuria and anemia in a 6‐month‐old Chilean Criollo foal with ill thrift.A vascular malformation communicating with the urethral lumen caused progressive blood loss.This is the first description of a periurethral vascular hamartoma in horses.

Microglia and astrocyte activation in the spinal cord of lame horses

OBJECTIVE To determine the microglial and astrocyte response to painful lameness in horses. STUDY DESIGN Ionized calcium binding adaptor molecule 1 (Iba-1) and glial fibrillary acidic protein (GFAP) expression, cell density and morphology were determined through immunofluorescence within the dorsal horn of equine spinal cord. ANIMALS A total of five adult horses with acute or chronic unilateral lameness, previously scheduled for euthanasia. METHODS Musculoskeletal lameness was evaluated in five horses through visual evaluation according to clinical guidelines. Spinal cord samples were obtained immediately after euthanasia, and distal limb lesions were confirmed through dissection and radiography. Iba-1 immunostaining was used for detection and characterization of dorsal horn microglia. GFAP was used for immunostaining of dorsal horn astrocytes. Iba-1 and GFAP labeled cells were quantified in the dorsal horn, and intensity of fluorescence was compared between the ipsi- and contralateral dorsal horn to the affected limb, and between dorsal horn segments of all horses. RESULTS Iba-1 expression was higher in the ipsilateral dorsal horn of the affected limb in contrast to the contralateral side dorsal horn. GFAP markers did not demonstrate increased astrocytic activity on the dorsal horn ipsilateral side to the distal limb lesion of affected horses. Horses with acute lameness predominantly had a spherical shape microglial phenotype, while cells from chronic lameness cases had variable morphology. Astrocytes evidenced small somas and large processes in both acute and chronic lameness, with higher GFAP localization in the main branches. As in the case of rodents, the localization of microglia and astrocytes in horses was mainly situated within laminae I, II and III. CONCLUSIONS AND CLINICAL RELEVANCE Iba-1 and GFAP are functional and morphological markers of spinal microglial cells and astrocytes in horses with lameness.

Pericardial effusion and cardiac tamponade in a dog with hypothyroidism

RESUMEN La relacion entre hipotiroidismo y enfermedades cardiovasculares en perros frecuentemente esta asociada con la presencia de signos clinicos como bradicardia sinusal, alteraciones miocardicas y complejos QRS de bajo voltaje y onda T invertida en el electrocardiograma. Varios estudios en perros hipotiroideos no han mostrado la presencia de efusion pericardica, sin embargo, en humanos es bien conocida la presencia de efusion pericardica asociada a hipotiroidismo, pero el taponamiento cardiaco no es un signo frecuente. Un perro Golden Retriever fue presentado con historial clinico de letargia progresiva, intolerancia al ejercicio, intolerancia al frio y dificultad respiratoria durante 3 semanas. Al examen clinico el perro presento disnea, tonos cardiacos tenues e hipertension. El examen ecocardiografico demostro la presencia de fluido en el saco pericardico y taponamiento cardiaco. Se realizo una pericardiocentesis y el analisis citologico del fluido descarto la presencia de celulas neoplasicas. La informacion entregada por los propietarios, ademas de la deteccion de zonas alopecicas en cola y abdomen sumado a la evolucion clinica llevo a analizar las hormonas tiroideas, confirmando el hipotiroidismo. Una vez realizadas dos pericardiocentesis y posterior suplementacion con hormonas tiroideas clinicos no presentaron recurrencia. Aunque la etiologia de la efusion pericardica no fue confirmada es posible que el hipotiroidismo haya causado la efusion pericardica, o bien el perro padecio una efusion pericardica idiopatica y coincidentemente hipotiroidismo. Sin embargo, de acuerdo con los signos clinicos descritos y evolucion de este caso, se sugiere que aun cuando la efusion pericardica es un signo no descrito en el hipotiroidismo canino, se debe considerar la evaluacion de las hormonas tiroideas en perros con efusion pericardica idiopatica.

Evaluación a través de tomografía computarizada del efecto de una infusión endovenosa de ketamina en el desarrollo de atelectasia inducida por anestesia general en perros

The aim of this study was to assess through computed tomography the presence of pulmonary atelectasis in dogs under inhalatory anesthesia and evaluate the ef...