Effect of acetic acid consumption on clinical laboratory values in the dog

To investigate the influence of food enriched with acetic acid on the clinical, biochemical, electrolyte, blood gas, haematological and urinary variables in the dog, a cross-over study was carried out with periods of approximately 2 weeks involving six healthy, adult dogs. Another objective was to determine the maximum concentration of acetic acid that the dogs found to be palatable. The dogs were maintained on a commercial meat-based food with added acetic acid and/or glucose. The administered acetic acid was increased in stages. All dogs accepted the diet containing acetic acid at a level of 5% of metabolizable energy. Except for a decrease in plasma total protein, none of the variables were significantly affected by acetic acid consumption. Acetic acid feeding did not affect plasma acetate concentration and urinary acetate excretion, indicating that dogs efficiently metabolize ingested acetic acid.     

Clinico-pathological aspects of canine cutaneous and mucocutaneous plasmacytomas

In this study the clinico-pathological aspects of cutaneous and mucocutaneous plasmacytomas were investigated in 63 dogs (one dog with two tumours). The tumours were most commonly observed in the skin of the trunk and legs. Yorkshire Terrier (n = 8) was the most commonly affected breed and males were affected more commonly than females (36 versus 23, respectively). Plasmacytomas were histologically classified into mature, hyaline, cleaved, asynchronous, monomorphous blastic and polymorphous blastic cell types. Monomorphous blastic cell type was the most frequent type (n = 21), followed by cleaved (n = 19) and asynchronous (n = 11) cell types. Secondary amyloid depositions were observed in eight cases. Immunohistochemical staining showed monoclonal lambda light chain positivity in all cases. In the immunohistochemical staining for cyclin D1, which is a prognostic marker in human plasma cell tumours, moderate numbers of positive tumour cells were observed in only one case of (muco)cutaneous plasmacytoma. All other cases were negative or contained few positive tumour cells. On the other hand, high numbers of tumorous plasma cells reacted positively with cyclin D1 in three out of six cases of canine multiple myelomas. Prognosis of the (muco)cutaneous plasmacytomas was good, except in one dog which developed a lymphoma afterwards. No significant correlations were observed between the cell type and the location of the tumour, presence of amyloid or prognosis.     

Small intestinal morphology and disaccharidase activities in early-weaned piglets fed a diet containing spray-dried porcine plasma

The purpose of this study was to test whether dietary spray-dried porcine plasma (SDPP) in early-weaned piglets prevents small intestinal villus atrophy by trophic or protective activity. Fifty-four weaned, 18-day-old piglets were used to determine the effect of dietary SDPP on small intestinal villus length, crypt depth, enterocyt mitotic activity and brush border enzyme activities during the first week after weaning. The piglets were offered a diet containing either 8% SDPP or 8% casein. At 2 and 7 days after weaning, piglets were anaesthetized to provide samples of the small intestinal wall and killed immediately afterwards. There were no differences in daily gain and daily feed intake between the two dietary treatments. At day 2 after weaning, all piglets showed a marked reduction in villus height when compared with baseline values. In all piglets, small intestinal enterocyte mitotic activity had decreased by day 2 and was increased again on day 7. There were no significant effects of dietary SDPP on small intestinal villus length, crypt depth and enterocyt mitotic activity. This indicates that SDPP has no trophic effect on the small intestinal mucosa and that it does not protect against the damaging effect on the small intestinal villi that is associated with the process of weaning. There was no effect of SDPP on lactase-, sucrase- or maltase-specific activities that are a measure of the digestive function of the small intestine. It can be concluded that SDPP versus casein has no effect on small intestinal morphology and disaccharidase activities in early weaned piglets kept under low infection pressure.     

Susceptibility of trypanotolerant West African Dwarf goats and F1 crosses with the susceptible Sahelian breed to experimental Trypanosoma congolense infection and interactions with helminth infections and different levels of diet

Forty pure West African Dwarf (WAD) goats and 35 of its F1 crosses with the Sahelian breed were used in a multifactorial experimental design to evaluate the effects of an experimental Trypanosoma congolense infection and interactions with natural helminth infections and different levels of diet on health and productivity of these two breeds. Trypanosome infection caused a severe drop in packed cell volume (PCV), but this was not significantly affected by breed. Neither deworming nor diet had any effect on the course of anaemia after trypanosome infection. The mean score of parasitaemia tended to be higher in crossbreeds than in WAD goats although this was not significant (P>0.05). Similarly, the antibody response to trypanosome infection was not significantly different between breeds. Parasitaemia level was significantly influenced by the level of diet with the group under high supplementation having a higher mean parasitaemia score than the group under low supplementation. Weight loss due to trypanosome infection tended to be greater in crossbreeds than in WAD goats (P>0.05).During this study, there was no difference in mean helminth egg output between crossbred and WAD goats. However, between weeks 4 and 10 after trypanosome infection (corresponding to a period of heavy rainfall and highly infective pastures), the mean egg output was higher in the crossbreeds.The immunosuppressive effect of trypanosome infections was revealed by a lower antibody response to Haemonchus contortus in infected animals compared to the uninfected controls. Trypanosome infection tended to increase strongyle egg output. This study did no reveal any superior trypanotolerance of WAD goats compared to crossbreeds.     

Antibody-induced internalization of viral glycoproteins in pseudorabies virus-infected monocytes and role of the cytoskeleton: a confocal study

Addition of pseudorabies virus (PrV)-specific polyclonal immunoglobulins to PrV-infected monocytes induces internalization of plasma membrane anchored viral glycoproteins. This process may interfere with antibody-dependent cell lysis and resembles the well-studied physiological endocytosis process. A confocal study was designed to investigate whether the major cellular components, involved in physiological endocytosis (clathrin, actin, dynein and microtubules), play a role in this virological internalization process. In order to visualize the interaction of endosomes, which contain the internalized viral glycoproteins, with clathrin, actin, dynein and microtubules, a double labeling of viral glycoproteins and different cellular proteins was performed. Porcine monocytes were inoculated with the PrV-strain 89V87 at a multiplicity of infection of 50 for 13h. After the addition of FITC-labeled porcine polyclonal PrV-specific antibodies, cells were fixed with para-formaldehyde at different time points and afterwards permeabilized. The different cellular components were visualized with monoclonal antibodies and a Texas Red-conjugate, with the exception of actin, which was stained with phalloidin-Texas Red. The cells were analyzed by confocal microscopy. A clear co-localization was observed between the viral glycoproteins and clathrin and dynein during the internalization process. The microtubules were in close contact with the internalized vesicles. For actin no co-localization could be observed. It can be stated that clathrin, dynein and microtubules, important components during physiological endocytosis, are also of importance during the antibody-induced internalization of viral glycoproteins.     

Simultaneous intramammary and intranasal inoculation of lactating cows with bovine herpesvirus 4 induce subclinical mastitis

In this study, we examined whether an experimental bovine herpesvirus 4 (BHV4) infection can induce bovine mastitis, or can enhance bovine mastitis induced by Streptococcus uberis (S. uberis). Four lactating cows were inoculated intramammarily and intranasally with BHV4, and four lactating control cows were mock-inoculated. After 14 days, two of four cows from each group were inoculated intramammarily with S. uberis. No clinical signs were recorded in cows inoculated only with BHV4, and their milk samples showed no abnormal morphology, despite the fact that BHV4 replicated in inoculated quarters. Somatic cell count increased significantly in milk from three of six BHV4-inoculated quarters, compared to the non-inoculated quarters of the same cows (within-cow) and the quarters of mock-inoculated cows (control group) on days 8, 9 and 11 post-inoculation (pi). BHV4 was isolated from nasal swabs between days 2 and 9 pi. Clinical mastitis was observed in all four cows intramammarily inoculated with S. uberis. A preceding BHV4 infection did not exacerbate the clinical mastitis induced by S. uberis. S. uberis infections appeared to trigger BHV4 replication. From one quarter of each of two cows inoculated with BHV4 and S. uberis, BHV4 was isolated, and not from quarters inoculated with BHV4 only. In conclusion, BHV4 did not induce bovine clinical mastitis after simultaneous intranasal and intramammary inoculation. However, the BHV4 infection did induce subclinical mastitis in 50% of the cows and the quarters.     

Use of infrared thermography to detect injections and palmar digital neurectomy in horses

Thermography is a non-contact, non-invasive technique that detects surface heat emitted as infrared radiation. Because skin temperature reflects the status of underlying tissue metabolism and blood circulation, abnormal thermal patterns can signify areas of superficial inflammation. The objective of this study was to determine if thermography could detect the injection of analgesic and neurolytic agents and surgical palmar digital neurectomy. Procedures evaluated include injection of the lumbar region, suspensory ligaments, tibial nerve, palmar digital nerves, and palmar digital neurectomy. Thermographic images were obtained before and after the procedures until a significant difference was no longer detected. Local injection of the lumbar region and the suspensory ligament produced detectable thermal patterns for two days, and tibial nerve infiltration with a neurolytic agent was significant for two days. Analgesia of the palmar nerves was significant for 24h with bupivicaine, compared to five days for ammonium chloride. Palmar digital neurectomy produced more variable thermal patterns. While sensitive enough to detect changes in heat patterns from control regions, thermography is not specific enough to discriminate between procedures and injury inducing an inflammatory response.     

Morphological and biochemical aspects of apoptosis,oncosis and necrosis

Recent investigations have demonstrated the need for a precise differentiation of various forms of cell death such as apoptosis, oncosis, necrosis and programmed cell death. Apoptosis is marked by cellular shrinking, condensation and margination of the chromatin and ruffling of the plasma membrane with eventually breaking up of the cell in apoptotic bodies. Cell death marked by cellular swelling should be called oncosis, whereas the term necrosis refers to the morphological alterations appearing after cell death. Apoptosis and oncosis are therefore pre-mortal processes, while necrosis is a post-mortal condition. The term programmed cell death refers to the 'fixed' pathway followed by dying cells, whether or not with the characteristic morphology of apoptosis. Three mechanisms are actually known to be involved in the apoptotic process: a receptor-ligand mediated mechanism, a mitochondrial pathway and a mechanism in which the endoplasmic reticulum plays a central role. All three mechanisms activate caspases which are responsible for the characteristic morphological changes observed during apoptosis. A review of the different methods used for detecting apoptotic cells demonstrates that most of these techniques are not entirely specific.