Prevalence and risk factors for agents causing diarrhea (Coronavirus,Rotavirus, Cryptosporidium spp., Eimeria spp., and nematodes helminthes) according to age in dairy calves from Brazil

The present study attempted to verify the prevalence of and risk factors for diarrhea-causing agents in dairy calves from Brazil. Additionally, ages with a higher risk of occurrence for each agent were verified by means of the receiver operating characteristic (ROC) curve. The collections were performed on 39 farms, belonging to 29 municipalities located in eight states of Brazil. It was possible to conclude that the prevalence of Coronavirus, Rotavirus, Cryptosporidium spp., Eimeria spp., and nematodes was 7.20% (95% CI 4.54–9.78), 6.37% (95% CI 3.85–8.89), 51.52% (95% CI 45.26–55.57), 3.46% (95% CI 2.24–4.67), and 3.46% (95% CI 2.24–4.67), respectively. Ages with higher probabilities of occurrence of these diseases in calves were <?10, >?8, >?6, >?37, and >?36 days, respectively. Diarrhea occurred more significantly (P?<?0.0001) in animals less than 21 days old and mainly on those receiving milk through automatic feeders (P?<?0.001). Cryptosporidium spp. were a risk factor for the occurrence of Rotavirus, and vice versa (P?=?0.0039) and presented a positive correlation with Coronavirus (P?=?0.0089). Calves that drink water from rivers, streams, and ponds had a higher chance of being infected by Eimeria spp. (P?<?0.0001), as well as developing infection by nematodes (P?<?0.0001). The results found in this study highlight the importance of studying the agents of diarrhea together, once they act as coinfection where the losses triggered for the owners will involve some of these agents simultaneously.

     

Use of macrobenthic infaunal communities in the monitoring and control of the impact of marine cage fish farming

Benthic macrofaunal community changes are used extensively to monitor the impact of polluting discharges to the marine environment. Regulatory and pollution control authorities have recognized the particular value of the well studied and reported responses of infaunal communities to organic pollution including wastes from aquaculture. Benthic systems are embraced in both the consent (licence) to discharge and monitoring procedures for marine cage fish farms in the Clyde River Purification Board's (CRPB) area. The relevant protocols of the CRPB are described and data are presented from impact studies throughout west central Scotland, focussing on the sedimentary environment (macrobenthos, organic carbon and redox: Eh). Macrobenthic infaunal responses, though not fully understood, were considered to provide the best measure to date of determining the impacts of organic wastes from cage fish farming and a possible way forward in developing benthic Environmental Quality Standards (EQSs) for aquaculture. Some patterns in physico-chemical data were identified, but frequently, the relationship both with benthic infaunal data and each other were inconsistent. Grossly impacted faunal communities varied little between sites and could readily be described by the simple community determinands of abundance (A), species richness (S) and Shannon Weiner diversity index (H). Moderate to lightly impacted zones were less easily defined but detailed faunal studies have allowed the selection of some widely distributed marker species. However, site-specific observations emphasized the site individuality and difficulties of setting EQSs across the industry. Using the principles of enhanced species populations and by identifying marker species, measurable impacts were found to extend further than previously reported. In naturally enriched systems, like the Firth of Clyde and some sea lochs, difficulty in separating slight effects from background was experienced. Continued monitoring and impact assessment, as well as building a better biological data base, may help develop appropriate benthic EQSs relating to aquaculture.     

Long-term stability in core habitat of an endangered population of bottlenose dolphins (Tursiops truncatus): Implications for spatial management

1. A small population of approximately 68 bottlenose dolphins, Tursiops truncatus, resident in Doubtful Sound, New Zealand, is subject to physiologically challenging conditions, and is exposed to anthropogenic pressure from tourism.
2. A voluntary Code of Management incorporating dolphin protection zones (DPZs), in which tour boat access is limited, was established in 2008.
3. Kernel density estimation (KDE) was used to quantify dolphin habitat use over a 13-year period in order to describe seasonal variation in habitat use and consistency of habitat use over a decadal period, and to provide quantitative estimates of the extent of overlap between DPZs and core areas (50% volume contour) of habitat use.
4. Habitat use varied seasonally, with the inner fjord area used more frequently in warmer months, and with a shift in use to the outer fjord in colder months. Patterns in habitat use were highly consistent over the 13-year duration of the study.
5. The spatial overlap between the area of core dolphin habitat and DPZs was low (<18%) overall, and some DPZs were rarely used during colder periods.
6. Consistency in habitat use through time vindicates spatial management, but low overlap between core habitat and current DPZs suggests that an expansion of the DPZ areas would confer greater protection.

     

In vivo and in vitro genetic recombination between conventional and gene-deleted vaccine strains of pseudorabies virus

Pseudorabies virus (PRV), an alpha-herpesvirus, causes substantial economic losses in the swine industry and is currently the focus of eradication and control programs. Some of these programs rely on the ability of veterinarians to differentiate animals exposed to virulent strains of PRV from animals exposed to avirulent vaccine strains of PRV on the basis of a serologic response to nonessential glycoproteins that are deleted in some vaccine strains of PRV. Genetic recombination resulting in the creation of virulent strains of PRV with the same negative immunologic markers as vaccine strains could disrupt these programs. Two strains of PRV were coinoculated either into tissue culture or into sheep to facilitate recombination. Progeny viruses were selected to detect a specific recombinant phenotype. We were able to detect genetic recombination between vaccine strains of PRV following in vitro or in vivo coinoculation of 2 strains of PRV. The selected recombinants had marker-deleted phenotypes in strains with restored virulence genes. Increased virulence was observed in sheep after coinoculation of 2 avirulent vaccine strains of PRV.     

Transverse Flap Tracheostomy: A Technique for Temporary Tracheostomy of Intermediate Duration

A technique is described which is particularly useful in obese or heavily muscled animals when a single lumen tracheostomy tube is used, or when mechanical ventilation through a cuffed tracheostomy tube is required. The technique assures easy access to a large tracheal stoma which facilitates cleaning and tube replacement.     

Pathology of experimentally-induced, acute toxoplasmosis in macropods

SUMMARY Thirteen Tammar wallabies (Macropus eugenii) were dosed orally with 500, 1000 or 10 000 oocysts of Toxoplasma gondii, as part of a vaccination trial. Eleven animals died of acute toxoplasmosis 9 to 15 days after challenge. The lesions were similar in all animals, consisting of foci of necrosis and inflammation in the intestines, lymphoid tissue, adrenal cortex, heart, skeletal muscle and brain, and severe generalised pulmonary congestion and oedema. Free and intracellular tachyzoites of Toxoplasma were associated with the lesions. The remaining 2 animals had shown no signs of disease when euthanased four months after challenge. Small, focal, non-suppurative inflammatory lesions were seen in brain, heart and skeletal muscle of these animals and chronic Toxoplasma infection was confirmed by mouse inoculation.     

Aspergillosis in gentoo penguins (Pygoscelis papua) at Edinburgh Zoo, 1964 to 1988

Aspergillosis was the commonest cause of death in gentoo penguins (Pygoscelis papua) at Edinburgh zoo from 1964 to 1988. Chicks were the most susceptible group and 14 per cent of hatched birds died of the disease (47 per cent of post mortem diagnoses) although in two years no cases were recorded and in two other years there were outbreaks which killed more than 50 per cent of the birds hatched. There was no correlation between the size of the colony and the prevalence of the disease but the climate during the rearing and weaning periods may have influenced the prevalence. The majority of cases of aspergillosis occurred between July and September and affected two- to three-month-old chicks shortly after they had been moved from their parents to a crêche area for hand-feeding. No links were found between the occurrence of the disease and the date of hatching or the nest site, or whether the chicks were single, first or second-hatched twins, or with their weights, but the progeny of one parental pair were found to be overrepresented and more males than females died of the disease. Adult cases occurred sporadically and males were significantly more susceptible than females (P less than 0.05). Neither vaccination with a killed suspension of Aspergillus fumigatus nor therapeutic treatment with ketoconazole were effective in reducing the incidence of aspergillosis, although the late diagnosis of the disease was probably the main cause for the failure of these treatments.