Heart failure in two West Highland white terriers caused by congenital angiomatous cardiac anomaly.

The paper describes the clinical and pathological characteristics of an unusual cystic congenital cardiac anomaly that caused clinical signs of congestive heart failure, respiratory distress and cardiac arrhythmias in two West Highland white terrier puppies. In both dogs a definitive diagnosis was made postmortem.

Associative encoding of pictures activates the medial temporal lobes.

It remains unresolved whether the medial temporal lobe activations found in recent neuroimaging studies are mediated by novelty detection alone, by specific kinds of encoding or consolidation operations, or both. This study attempted to see whether associative encoding or consolidation is sufficient to cause such activation by matching for novelty across conditions. Using single-photon emission computer tomography (SPECT) (with TC99mHMPAO), we compared the activation patterns produced by the associative encoding and the perceptual matching of novel complex scenes in 10 normal subjects using both statistical parametric mapping (SPM) and a regions-of-interest (ROI) approach. During the encoding condition, significant activations were detected in the left hippocampal/parahippocampal region, the left cingulate cortex, and the right prefrontal cortex, using both statistical techniques. Additionally, activation was found in the right cingulate cortex, and a trend towards activation was found in the right hippocampal/parahippocampal region using the ROI approach. In contrast, no medial temporal activations were found during the matching condition, which produced bilateral occipito-parietal and right posterior inferior parietal (supramarginal gyrus) activations. These results no only confirm that the associative encoding and/or consolidation of complex scenes is partially mediated by medial temporal lobe structures, but also demonstrate, for the first time, that associative encoding/consolidation is sufficient to produce such an activation. The implications of the high degree of consistency revealed by the results of the SPM and ROI comparison are discussed.

Globule leukocytes and bovine parasitic bronchitis.

Globule leucocytes (GL) occur in the respiratory tract of cattle from foetuses to adult animals. Large numbers of this cell have been found in the lungs of cows both in normal lung and in the lungs of cows from various outbreaks of respiratory diseases, but the significance was not known. In the rat and in cattle, the occurrence of GL in the gastrointestinal and urinary tracts has been associated with parasitic infections. The relationship between the respiratory tract GL and Dictyocaulus viviparus infections in cattle was studied in three groups of parasite free calves experimentally infected with D. viviparus. Group 1 animals received single challenge infections. Group 2 had three subgroups (2a, 2b, 2c) which were either vaccinated and challenged (2a), given a single challenge (2b) or used as vaccinated controls (2c). Group 3 with four subgroups (3a, 3b, 3c, 3d) were either used as environmental controls (3a), vaccinated and repeatedly challenged (3b), given normal larvae of D. viviparus and repeatedly challenged (3c) or as a trickled group 3d. Although GL were found in infected calves, it was not possible to demonstrate a clear cut correlation between their presence or density and the method of exposure.

An outbreak of strangles in young ponies.

A natural outbreak of strangles occurred in a group of 19 young experimental ponies. The disease was diagnosed in 11 of them within two days of their arrival at Glasgow University veterinary school and five others developed clinical signs within a further four days, a morbidity rate of 84 per cent. All of the affected ponies had typical signs of strangles including dullness, anorexia, pyrexia, regional lymphadenitis, occasionally with rupture of the lymph node, conjunctivitis and a mucopurulent nasal discharge. Nine of the affected ponies were destroyed during the clinical phase of the disease for post mortem studies. The clinical disease in the remaining animals lasted approximately 21 days although one pony had to be destroyed 10 days after the onset of clinical signs because of the development of septic arthritis. All 16 affected animals exhibited peripheral blood neutrophilia and high plasma fibrinogen levels. beta haemolytic streptococci were isolated by nasopharyngeal swabbing from 18 of the 19 ponies. Streptococcus equi was confirmed only in three animals within the first four days of the outbreak. The majority of the other isolates identified to species were S zooepidemicus. beta haemolytic streptococci were still present in six ponies 40 days after they had clinically recovered and were isolated regularly from three ponies which did not develop clinical strangles but remained in contract with affected animals throughout the study.

A spongiform encephalopathy in a cat.

A cat which developed a change of temperament, with muscle tremors, ataxia and pupillary dilatation was suspected and later confirmed histopathologically to have a spongiform encephalopathy. The case is of special interest in view of the widespread concern about spongiform encephalopathies as a result of the recent epidemic of bovine spongiform encephalopathy.

Confirmation by Doppler echocardiography of valvular regurgitation in a horse with a ruptured chorda tendinea of the mitral valve.

Regurgitation of blood through the left atrioventricular valve owing to the rupture of one of the chordae tendineae of the valve was diagnosed in a horse with sudden-onset respiratory distress and a holosystolic cardiac murmur. Severe regurgitation was confirmed with Doppler echocardiography and prolapse of part of the valve leaflet was identified with B-mode ultrasonography. The rupture of one of the chordae tendineae of a right accessory cusp of the left atrioventricular valve was confirmed post mortem. Bronchiolitis, multifocal haemorrhages and haemorrhagic fibrous plaques were found in the pleura of the dorsocaudal segments of the lungs.

A scanning electron microscopic study of the equine upper respiratory tract.

The surface features of the upper respiratory tract of 20 clinically normal horses of various ages and types were studied with scanning electron microscopy. In the rostral part of the nasal cavity, there was a wide zone of non-ciliated epithelium whereas, caudally, the surface was well ciliated. This latter type of epithelium extended into the nasopharynx and guttural pouches although scattered areas of non-ciliated microvillous cells were also found.

An ultrastructural study of the equine lower respiratory tract.

The surface features of the lower respiratory tract of 20 clinically normal horses of different ages and types were studied with scanning electron microscopy. Parallel light microscopical and transmission electron microscopical studies were also carried out. The ciliary carpet was virtually complete from the trachea to the lobar bronchi. In small bronchi, ciliation was less complete allowing numerous non-ciliated mucous cells to become obvious. The terminal bronchioles, populated mainly by non-ciliated bronchiolar epithelial cells, had an abrupt junction with alveolar ducts. Interalveolar pores were common particularly in older horses.

Morphological, histochemical and ultrastructural features of the globule leukocyte of the bovine respiratory tract.

The histochemical and ultrastructural features of the globular leukocyte of the bovine respiratory tract is described and found to be similar to those localized in the abomasum and bile ducts of cattle. Histochemical analysis of these cells demonstrated low amounts of carboxylated mucin mixed with neutral mucin and large amounts of basic protein. Two types of globules were seen in the leucocytes; one with a homegeneous electron dense material and another with vesiculated, crastalloid containing bodies.

The globule leucocyte: morphology, origin, function and fate, a review.

A review of the literature concerning the origin, function and fate of the globular leukocyte is presented. The possible relationship of this cell to other cells such as erythrocytes, mast cells and lymphocytes in general is discussed with an aim toward delineating the probable functions of the cell. Although the globular leukocyte has been described in many species and in a variety of organs, its origin, fate and function remain to be clearly elucidated.

Control of parasitic bronchitis and gastroenteritis in grazing cattle by strategic prophylaxis with ivermectin.

In May 1985 four groups of 10 calves, aged between four and five months, were turned out on to separate, permanent pastures of equal area which had been seeded during the previous few days with larvae of Dictyocaulus viviparus. One group acted as a control, the second was vaccinated with lungworm vaccine before turnout and treated with thiabendazole three, eight and 13 weeks after turnout, while the third and fourth groups were given ivermectin three times (three, eight and 13 weeks after turnout) and twice (three and eight weeks after turnout), respectively. A severe outbreak of parasitic bronchitis resulted in the death of three control calves within five weeks of turnout and parasitic bronchitis and gastroenteritis affected the second group of calves after approximately four months at pasture. The calves given ivermectin excreted no lungworm larvae and remained free of clinical parasitism throughout the trial.

Scanning electron microscopic study of the lower respiratory tract in calves and adult cattle.

The surface characteristics of the lower respiratory tract of two groups of cattle were studied with the scanning electron microscope. Group A comprised six one-week-old calves and group B four adult cows. None of the animals had overt respiratory disease or gross morphological evidence of pulmonary lesions. The trachea, bronchi, bronchioles and alveoli of the cranial and the caudal lobes of the right lung were examined. In both groups the luminal surface of the trachea and large bronchi were completely covered by cilia, apparently forming an efficient mucociliary escalator. In the adult animals there were some patchy areas in the trachea and large bronchi devoid of ciliated cells; these were considered abnormal. In the bronchi, non-ciliated cells, mainly mucus-secreting, were not easily identified unless they were discharging secretion. In small bronchi, non-ciliated cells were more evident and easily seen. The bronchioles had many non-ciliated cells and very few ciliated cells capable of forming a complete carpet for a mucociliary escalator. Types 1 and 2 alveolar epithelial cells and alveolar macrophages were identified in both groups. Pores of Kohn were found in the alveolar walls in all animals.

Experimental production of diffuse pulmonary fibrosis and alveolitis in cattle: the effects of repeated dosage with 3, methyl indole.

Eleven Friesian steers were given 3, methyl indole (3MI) orally at dose rates ranging from 0.1 to 0.3 g/kg. Three of these (group B) received a single oral dose of 0.2 g/kg and subsequently developed respiratory distress. Their plasma 3MI concentrations six hours after dosing were between 2.25 and 7.23 micrograms/ml. The steer with the highest six-hour plasma value died at this stage and the dominant pathological feature was severe pulmonary oedema. The other two steers survived until they were slaughtered 96 hours after dosing; the major pathological findings in them were interstitial emphysema, hyaline membranes and alveolar epithelial hyperplasia. The other eight steers (group C) each received weekly oral doses of 0.1 g 3MI/kg for 10 weeks. One animal died after developing severe respiratory distress following its third dose. Thereafter, the others developed two separate patterns of response. Three steers (subgroup C1) became progressively more tolerant to oral 3MI, even in the face of dose rates increased to 0.2 and 0.3 g/kg during the 11th to 14th weeks of the study and also in the presence of relatively high plasma 3MI concentrations after dosing. One animal was slaughtered after its 10th dose and two after their 14th dose of 3MI; post mortem examinations revealed that their lungs were macro- and microscopically normal. The other steers (subgroup C2) all continued to react after each weekly oral dose of 3MI and their post-dosing plasma 3MI concentrations consistently remained relatively low. Latterly, each of the three steers which survived to the 14th week also exhibited persistent tachypnoea and marked hyperpnoea between dosings. On post mortem examination, in addition to the signs generally associated with acute 3MI toxicity (see above), each of the subgroup C2 steers were found to have diffuse pulmonary fibrosis and an alveolitis. While certain cattle appear to become tolerant to the effects of repeated doses of 3MI, the results of this study clearly demonstrated that, in others, such treatment eventually gives rise to diffuse pulmonary fibrosis and alveolitis.

Chronic obstructive pulmonary disease anatomical cardiac studies.

An abattoir survey on horses diagnosed as suffering from chronic obstructive pulmonary disease (COPD) on clinical grounds showed that the right ventricular wall thickness was not significantly different from that of normal horses. However, the weight ratio between the left and right ventricles was found to be significantly (P less than 0.001) different in COPD affected, compared with control, horses in a study of 17 physiologically and pathologically confirmed COPD cases, using ventricular weight measurements. No clinical evidence of right heart failure nor post mortem evidence of right heart dilatation was observed in any COPD affected animals. It is suggested that the low incidence and degree of cor pulmonale in equine COPD may be related to the reversibility of the pulmonary hypertension associated with this disease.

Acute fatal pneumonia in calves due to respiratory syncytial virus.

An acute pneumonia developed in 28 calves which had been housed together from one to two weeks of age. The clinical signs included pyrexia, tachypnoea, respiratory distress and coughing. Some of the calves died. The pneumonia was characterised by an alveolitis with multinucleated syncytia, alveolar epithelial hyperplasia and bronchiolitis. Interstitial emphysema was also present. Fifteen of 19 calves examined serologically had rising neutralising antibody titres to respiratory syncytial virus; in nine calves the rise was fourfold or greater. Respiratory syncytial virus was not isolated from the calves. There was no evidence of parainfluenza type 3 virus involvement. The adult cows being sucked by the calves remained clinically normal throughout the incident. Six calves examined six weeks after the outbreak started had a chronic cuffing pneumonia characterised by lymphocytic bronchiolitis; some of the calves also had bronchiolitis obliterans. Mycoplasma dispar was found in two of them.