Oral pentobarbital intoxication in a bitch

Pentobarbital intoxication in a 5-year-old female Samoyed was confirmed by the finding of a high concentration of the drug in serum. The dog apparently had consumed one of her pups, which had been euthanatized the day before with a 26% sodium pentobarbital solution. She was admitted in a condition consistent with light general anesthesia. The dog recovered after gastric lavage supportive therapy, and the administration of an alkalinizing solution to hasten drug excretion. This case demonstrates the hazards associated with indiscriminate disposal of carcasses containing large amounts of euthanasia solution.     

Experimental matrix plug production in male cat urine following a natural case of urolithiasis due to matrix plug

Urethral obstruction occurred in a 2-year-old entire long-haired red cat. A suspicion that this was a case caused by matrix plug formation could not be confirmed as reverse flushing using a topical corticosteroid and a trypsin digest appeared to have broken up the obstruction. Nine days later the cat passed a large mucoid mass which, when placed into a simulated urethra produced an obstruction. Histological examination of this plug confirmed that there were no crystalline components and on appearance it was similar to that of natually occurring matrix plugs.     

FIELD TRIALS WITH LYOPHILISED HERPESVIRUS OF TURKEYS VACCINE AGAINST MAREK''S DISEASE IN LAYER AND BROILER REARING FLOCKS

The safety and immunogenicity of commercial lyophilised herpesvirus of turkeys (HVT) vaccine against Marek's disease (MD) was evaluated in 19 field trials involving 76,848 vaccinated and 87,590 control chickens. In the first series of 11 trials involving one commercial vaccine at a dose of 536 plaque forming units (PFU) there was a significant reduction in the incidence of MD (P less than 0.001) and in total mortality (P less than 0.001) from 0 to 18 weeks due to vaccination and the overall protection was 85.2%. In the second series of eight trials involving another commercial vaccine at a dose range of 1360 to 1900 PFU there was a significant reduction in the incidence of MD (P less than 0.001) from 0 to 18 weeks of age due to vaccination. The overall protection was 77.8%. In both series there was a significant difference in MD mortality between meat breeders and crossbred pullets (P less than 0.005) in response to vaccination. There was also a significant difference in total mortality from 0-6 weeks of age between the two series suggesting either differences in response to the two vaccines or differences in the vaccination technique. In a number of trials the incidence of MD was low in the controls, however, where MD incidence was above 2% in the controls protection usually exceeded 80%. It was concluded the vaccines were safe and efficacious and the degree of protection was comparable to that obtained by HVT vaccines described in other countries.     

Public health and research perspectives on the microbial contamination of foods

Scientific advances in methodology and epidemiology have resulted in a renewed awareness of foodborne disease, and increased contact among nations of the world has stimulated rapid global distribution of foods as well as foodborne pathogens. New food vehicles are being identified for old, familiar pathogens, and new pathogens are being discovered. Current research in food microbiology has spurred development of rapid and specific methods to identify these pathogens and to assess their virulence. Organisms of recent interest, such as Bacillus, Yersinia, Campylobacter, Listeria, Sporothrix, Giardia, Cryptosporidium, and Anisakis, are the foci of new investigations, as are the more familiar foodborne pathogens, Salmonella, Shigella, Clostridium, Staphylococcus, Entamoeba and Ascaris. Some foodborne organisms, such as parasitic protozoa, serve as hosts for unique bacterial and viral symbionts but also might become infected with mammalian viruses. The remote possibility of the transmission of human immunodeficiency viruses in foodborne protozoa is discussed.     

Development of immunity to incoming radiolabelled larvae in lambs continuously infected with Trichostrongylus vitrinus

Infective third stage larvae (L3) of Trichostrongylus vitrinus were radiolabelled with 75 selenium by a method which did not affect their viability. Three groups of six-month-old lambs were infected daily with 1000 L3 for four, eight and 12 weeks, respectively. After each period, one of those groups (n = 5) and a group (n = 4) of worm-free controls were challenged with three consecutive daily doses of 1000 radiolabelled L3, killed 10 days after the first dose, and their worm burdens examined. After four weeks of continuous infection partial immunity to the establishment of challenge L3 was apparent, and by eight and 12 weeks, with the exception of one sheep, there was almost total resistance to incoming worms. Immunity was also expressed as an inhibition of the development of established worms.     

Intestinal stasis and rupture in rabbits

During one year 23 of 110 New Zealand white, adult male laboratory rabbits died. The pathological findings included intestinal stasis, intestinal blockage, acute intestinal rupture and intestinal rupture with peritonitis. These changes were considered to represent stages in an intestinal stasis and rupture syndrome. Another group of 20 comparable rabbits remained unaffected.     

Postnatal development of the brain stem auditory-evoked potential in dogs

Recordings of averaged brain stem auditory-evoked potentials were obtained from 13 Beagle pups of both genders to document the postnatal development of the response from age 1 to 76 days. Responses were recorded between needle electrodes placed on the vertex and the ipsilateral ear, with ground at the interorbital line. Recordings were performed without sedation. Low-amplitude responses to high-intensity stimuli could be recorded from animals prior to opening of the ear canals. Peak latencies did not change after day 20 for peak I, day 30 for peaks II and III, and day 40 for peak V. As a result, the interpeak latencies between peaks I and III did not change after day 30, but continued to decrease until day 40 for peaks III-V and I-V. Peak amplitudes reached plateau values by day 20 (peak I) or day 30 (peaks II, III, and V). All of the measured latency and amplitude values had significant (P less than 0.001) linear regression lines of latency vs age and amplitude vs age. The brain stem auditory-evoked potential thresholds were mature by day 20.