Magyar Állatorvosok Lapja

A 3-year-old Tennessee Walking Horse stallion is presented to the University of Tennessee Veterinary Medical Teaching Hospital, Tennessee, USA with a history of exercise intolerance and coughing during exercise. Endoscopic examination revealed intermittent dorsal displacement of the soft palate (DDSP) due to a flaccid, hypoplastic epiglottis. Based on radiology of the throat and larynx, the epiglottic the length of the body of thyrohyoid cartilage to tip of the epiglottis was 7.3 mm. Epiglottic augmentation surgery was elected to correct the problem. During the surgical procedure, after laryngotomy, teflon paste was injected submucosally into the ventral surface of the larynx in 5 rows. The cricothyroid ligament and subcutis were closed and the skin incision was left open to heal by second intention. The aetiology, pathogenesis, clinical aspects and different treatment options for DDSP in horses are also discussed in the paper.

The author placed 2-4 pairs of silver electrodes on pregnant uterus during laparotomy and a catheter into the aorta. The frequency and length of uterine contractions and change of pressure in uterus were measured by means of electrodes. From blood taken from the aorta steroid and PGFM concentration were measured. He found that uterus is not completely immobile during pregnancy, long-lasting contractions can be seen 13.6 times a day averagely. Long-lasting contractions of 12 minutes, averagely slightly affect intra-uterine pressure. Contractions pause for 6-9 hours following the regression of luteal corpse, 24-48 hours preceding calving. Due to single prostaglandin treatment for induction of calving, following a transient rest period reactivation of uterus started 10-18 hours after treatment. Examined by ultrasonography, dilatation of caudal cervix started 26-29 hours after injection and in case of anterior position a speed of 1.57 cm/h and in case of posterior position a speed of 2.25 cm/h was measured.

Because the expected gain from keeping is in case of a primiparous sow always higher than the expected gain from a replacement gilt, the culling of these sows has to be avoided. In practice, however, about 14% of the primiparous sows are culled, of which 50% for reproductive reasons. This culling is only a part of the reproductive problems encountered with primiparous sows. Primiparous sows also show: a prolonged weaning to oestrus interval (WOI), a higher use of oestrus inducing hormones, a smaller litter size and a lower farrowing rate from first insemination. The problems are interrelated. This means that concentrating on one factor, e.g. - the WOI, may lead to an overall impovement in reproductive performance. To achieve this, body weight loss during lactation has to be reduced. Adequate housing during first gestation and after weaning, with absence of chronic social stress is important. Reduction in litter size during the first lactation has, besides an effect on weight loss, an important effect on its own on WOI, due to the reduction of the suckling intensity. High environmental temperatures during lactation are responsible for a greater part of the seasonal effect than light is. Breed differences in WOI make the choice of breed of importance. Insemination strategies have to be adjusted for WOI to get the best results. Creating a longer interval between weaning and first breeding after weaning, by progestagens or by using the second heat for breeding, is an other possibility to improve litter size in primiparous sows. Further research into these possibilities and their consequences is needed. Reduction of the WOI will improve the production and reduce the culling of primiparous sows. Farm production will benefit from both.

In the study 224 lactating cows in their middle lactation, producing milk with a somatic cell count (SCC) less than 400 000/ml were involved. Quarter and individual composite milk samples were subjected, respecitvely to California Mastitis Test (CMT) and somatic cell counting (Fossomatic method). 41 udder quarters of 34 cows showed a positive CMT reaction greater then "+", which means 15,18% of the total cows. In the SCC groups <100 000/ml and 100 000-400 000/ml respectively 7,63% and 23,58% of the cows had at least one inflammed quarter. The authors propose that all of the lactating cows should be involved in the screening tests of the infected udder quarters.

Enterohaemorrhagic Escherichia coli O157:H7 (EHEC) was recognised as a human pathogen following outbreaks of haemorrhagic colitis (HC) in the USA, 1982. Since then EHEC became an emerging food-related pathogen causing a wide variety of diseases in human including mild to bloody diarrhoea, haemorrhagic colitis (HC) that can lead to the life threatening haemolytic uremic syndrome (HUS). EHEC infection is a severe public health problem in developed countries. In 1996, there was an outbreak involving more than 6000 people in Japan. In the United States, the number of EHEC infections could be as high as 20 000 per a year, of which about 250 are deadly. The source of infection is mostly eating undercooked ground beef. In Hungary, there have only been sporadic cases detected so far. With several virulence factors involved in its pathogenesis, EHEC is a classic pathogenic model organism. All isolates have one or two bacteriophage encoded toxins, called Shiga toxin (Stx), a serotype specific virulence plasmid of cc. 60 MDa (pO157) and a pathogenecity island (pai). pO157 promotes the EHEC adherence both in vivo and in vitro, but so far there is no cloned pO157-specific EHEC adhesin. pO157 encodes Katalase peroxidase (KatP), Serine protease (EspP), EHEC-haemolysin (enterohaemolysin) and a type II secretion pathway operon. EHEC-pai is a 43.3 kb length extraneous DNA that contains all the genes necessary for causing attaching effacing lesions. Diagnosis is mostly based on the detection of Stx through its cytotoxic effect on Vero cells, with the help of Stx-antibodies, by hybridisation using Stx specific DNA probes or by DNA amplification (PCR). The antibiotic therapy of EHEC infections is not without risk and further studies are needed to elucidate its benefits. There are encouraging results of using a Stx-receptor analogue to develop drugs or vaccines.

Groups of pigs free from Aujeszky-disease virus (ADV) antibodies were vaccinated once or twice with Aujeszky-vaccine Auphyl-plus that contains an attenuated strain MNC+/10a (15) with an oil/water emulsion adjuvant. Strain MNC+/10a is a genetically improved version of vaccine strain K/61 (6) whose impaired gC-function has been restored. il MNC+/10a forms larger plaques in cell culture and induces more antibody in pigs even after a single injection as compared to strain K/61 (15). Two injections of Auphyl-plus separated by 3 weeks induced 10-30 fold antibody titres than one injection of the vaccine. Three weeks after the first or second injection pigs were challenged intranasally with 10(4) PFU of virulent strain NIA-3 in two separate experiments. Most unvaccinated animals showed severe respiratory and nervous signs after 4-6 days and the average daily weight gains were reduced to about -2.5% in the control groups. Altogether ton of the twelve control animals succumbed to the challenge infection. A single dose of the vaccine was sufficient to prevent disease but did not prevent mild (<41 degrees C) fever and a transient (1-2 days) anorexia in some animals (Table 1). Two doses of vaccine prevented both (Table 1, Fig, 2). The average daily weight gains of the once and twice vaccinated groups were 1.47% and 0.90%, respectively as compared to the weight loss of -2.5% in the unvaccinated pigs. Virus shedding measured by total virus excreted was significantly reduced (150 times) in the twice-vaccinated group as compared to controls (Fig, 3 and 4). Duration of virus shedding was reduced to 7,2 and 5,4 day in the once and twice vaccinated groups, respectively as compared to surviving control pigs (Table 1). To simulate natural conditions of virus spread, pigs vaccinated twice were placed in the pens of twice vaccinated, intranasally, challenged animals, None of the contact-challenged vaccinated pigs shed virus during a two-weeks observation period. In spite of this lack of excretion of challenge virus four our of six animals seroconversed to gE three weeks later (Table 2). Further refinement of contact infection is needed to simulate virus spread between animals under field conditions.