Georgina Limon

Angiostrongylus vasorum in Great Britain: a nationwide postal questionnaire survey of veterinary practices

The lungworm, Angiostrongylus vasorum, was first reported in indigenous dogs in southwestern England in 1980 and has since been recorded in Wales, southeastern England and, more recently, in the West Midlands, northern England and Scotland. The nationwide distribution of the parasite was evaluated using a postal questionnaire sent to 3950 small animal practices during 2009. Information was sought on the location of each practice, awareness of the parasite locally, number of cases diagnosed over the past year and whether diagnosis was based on clinical signs alone or supported by additional tests. 1419 practices returned a usable response, the majority being located in a city/town. Nearly one-third of responding practices were aware of the parasite locally, 20.7 per cent had seen at least one confirmed case and 0.3 per cent >20 confirmed cases over the past year. The most widely used tests were faecal examination and any type of imaging. Existing clusters of infection were detected in southeastern England and south Wales; infection was also found to be widespread in central England, though patchy in northern England and Scotland. Using distribution of clinical cases as an indicator of parasite distribution, this study confirmed that A. vasorum has spread beyond traditional UK endemic foci.

Using mixed methods to investigate factors influencing reporting of livestock diseases: A case study among smallholders in Bolivia

Livestock disease surveillance is particularly challenging in resource-scarce settings, where disease events are often unreported. Surveillance performance is determined as much by the quantifiable biological attributes of the disease, as it is by motivations and barriers perceived by livestock keepers for disease reporting. Mixed methods designs, which integrate the collection, analysis and interpretation of qualitative and quantitative data in a single study, are increasingly used across different disciplines. These designs allow for a deeper exploration of the topic under investigation, than can be achieved by either approach alone. In this study a mixed methods design was used in order to gain a greater understanding of the factors that influence reporting of livestock diseases in Bolivia. There is a need to strengthen passive surveillance in this country, among other reasons as part of an eradication programme for Foot and Mouth Disease (FMD). Findings revealed livestock keepers in the study area were extremely unlikely to report the occurrence of livestock health events to the Official Veterinary Services (OVS). Communication outside the local community occurs more often through alternative routes and this is positively correlated with disease awareness. The main barriers to disease reporting identified were a lack of institutional credibility and the conflicting priorities of the OVS and livestock keepers. As for other animal and human diseases across the developing world, passive surveillance of livestock diseases in Bolivia should be enhanced; this is urgent in view of the current FMD eradication programme. Increasing timeliness and smallholders’ participation requires a detailed understanding of their likely actions and perceived barriers towards disease reporting. These insights are most likely to be developed through a holistic mixed methods approach of quantitative and qualitative analyses.

A note on the slaughter of llamas in Bolivia by the puntilla method.

Slaughter by puntilla followed by neck sticking was examined in 20 recumbent llamas. Repeat stabbing was needed to penetrate the foramen ovale in 45% of the llamas, and two animals attempted to stand after the first stab. Puntilla was found to be ineffective, as all animals showed rhythmic breathing movements at the flank following puntilla and before sticking, and 95% had a positive palpebral reflex at the same time. The findings indicated that it is difficult in practice to penetrate the spinal cord with a single puntilla stab.

An evaluation of the humaneness of puntilla in cattle

Slaughter by puntilla followed by neck sticking was examined in 309 cattle, to assess the humaneness of this method. After the neck stab, brain and spinal function as well as presence of selected cognitive responses were measured. In addition breed, sex, live weight, body condition score, number of stabs given and level of experience of the slaughterman were recorded. Repeat stabbing was needed to penetrate the foramen ovale in 24% of the animals, and was significantly less frequent in slaughtermen who were experienced, and more frequent in heavy weight animals (>380 kg). Prevalence of brain and spinal function was 91%. When animals attempted to stand after the neck stab they were more likely to have rhythmic breathing, positive palpebral response and responsiveness to threat, noise and short air stimulus. These findings indicate that nerve pathways are often functional after neck stab and therefore it is highly likely that the animals are still conscious.

Sarcocystis spp. in llamas (Lama glama) in Southern Bolivia: A cross sectional study of the prevalence, risk factors and loss in income caused by carcass downgrades

Llamas (Lama glama) are intermediate hosts of the protozoan parasite Sarcocystis spp. This parasite is described as causing economic losses in the production of llama meat in South America. The aim of this study was to estimate prevalence, identify risk factors and explore spatial patterns of Sarcocystis in llamas in an area of the Bolivian High Plateau including estimating financial losses due to carcass downgrades as a result of the presence of Sarcocystis cysts. Information was collected from a local abattoir between 2006 and 2011 on 1196 llamas. Sarcocystis status was determined at meat inspection where any carcasses with one or more visible cysts were deemed Sarcocystis positive. A high prevalence was found, estimated to vary between 23.4% (95% CI 16.6-30.1) in 2007 and 50.3% (95% CI 44.4-56.3) in 2011. Period prevalence between 2006 and 2011 was estimated at 34.1% (95% CI 31.4-36.8). Age, sex and type (analogous to breed) were identified as risk factors for Sarcocystis using a mixed-effects logistic regression model adjusting for clustering by community and owner. Llamas over 4.5 years of age had an increased odds of being Sarcocystis positive (OR 19.31, 95% CI 9.10-40.98) as well as females (OR 1.75, 95% CI 1.13-2.68) and long haired type llamas (OR 1.90, 95% CI 1.26-2.87). An interaction between age and sex was detected indicating that the increased odds of disease from the youngest age group to the 2.5-4.5 years group was much more pronounced in females than in males. Spatial patterns of Sarcocystis were explored at district level by means of Standardised Morbidity Ratios and some spatial heterogeneity was revealed. Estimates of financial loss due to the disease were calculated using the difference in price paid for Sarcocystis positive and negative meat. Loss due to Sarcocystis varied per year but could be up to 20% of the annual income generated through the abattoir by sale of meat. Overall this study shows a high prevalence of Sarcocystis in the study area with some heterogeneity between districts. It also identifies some previously unknown risk factors for Sarcocystis and gives financial estimates of the cost of the disease as a result of carcass downgrades. We hoped these findings will add to the understanding of Sarcocystis in llamas in Southern Bolivia and will be useful when considering if controls are necessary, worthwhile and practical.

Relationship between periparturient management, prevalence of MAP and preventable economic losses in UK dairy herds

Johnes disease (JD) is an infectious, progressive, gastrointestinal disease affecting ruminants. Calves are mostly infected in their first six months of life, or in utero. We investigated the impact of specific periparturient management practices on within-herd JD prevalence and economic losses foregone in UK dairy herds by means of data synthesis (systematic appraisal of published evidence and expert elicitation) and use of a pre-existing simulation model. Our results show the scarcity of accurate estimates of the impact of specific periparturient management practices on within-herd JD prevalence, which could, in part, be explained by challenges associated with the chronic nature of JD. Management practices aiming to limit the faecal-oral transmission route of Mycobacterium avium subspecies paratuberculosis (MAP) were found to be most effective at reducing within-herd prevalence of JD. Practices aiming to limit MAP transmission via colostrum and milk were found to be less effective. Losses foregone for a hypothetical herd of 200 milking cows were considerable; based on the assumptions, it is reasonable to expect between £7000 and £11,000 of losses foregone when management practices are implemented as a package of measures. The findings of this study are envisaged to enable farmers and veterinarians to make more informed decisions on changes to periparturient management to control JD.

Pathophysiology of free-bullet slaughter of horses and ponies

Forty-six equines were observed during routine commercial slaughter in an abattoir. The animals were shot once with a .22 calibre long rifle with hollow point rounds. Indicators of sensibility/insensibility were evaluated immediately after the shot (prior to exsanguination) and the resulting pathophysiology of free-bullet injury was assessed. All animals were rendered immediately insensible, with only one pony showing signs of a shallow depth of concussion, with an intermittently positive palpebral reflex but no other signs of brainstem function. All animals (100%) had some degree of damage to the structures of the brainstem or lobes of the cerebrums, while 41 (89%) had damage to the thalamus/hypothalamus. The bullet in one pony missed the brain but still caused mild damage to the thalamus, midbrain, pons and cerebellum, this animal had no signs of sensibility. The findings confirm that free-bullet shooting is an effective dispatch method for horses and ponies.

A review of the humaneness of puntilla as a slaughter method

Puntilla is a traditional slaughter method in which a knife is plunged into the back of the neck to sever the spinal cord. The aim is to produce immediate collapse of the animal. Puntilla is not condoned as a stunning method by the World Animal Health Organisation (OIE) because there is concern that the animal could be conscious during and after the neck stab. Nonetheless, it is still used in some developing countries. The effectiveness and humaneness of puntilla followed by neck sticking was examined at two slaughterhouses in Bolivia. Twenty llamas (Lama glama) and 309 cattle were observed during routine puntilla without stunning. The number of neck stabs was recorded, and then brain and spinal functions (rhythmic breathing, palpebral reflex and eyeball rotation) were assessed. In addition, the presence of specific cognitive responses (such as responses to a threat stimulus and noise, as well as to flavours and odours), were also assessed in cattle. Breed, sex, live weight, body condition score and the slaughterman’s experience were recorded. Repeat stabbing was needed to penetrate the foramen ovale in 45% of the llamas and two of them attempted to stand following collapse after the initial stab. All llamas showed rhythmic breathing movements at the flank following puntilla and before sticking, and 95% had a positive palpebral reflex at the same time. Twenty-four percent of the cattle needed repeat stabbing. Repeat stabbing was significantly less frequent with experienced slaughtermen, and more frequent in heavyweight animals (> 380 kg). Brain and spinal responses were present in 91% of the cattle following the stabs. When cattle attempted to stand after a neck stab they were more likely to have rhythmic breathing, positive palpebral response and responsiveness to threat, noise and brief air stimulus applied to the face. These findings indicate that it is difficult in practice to penetrate the spinal cord with a single puntilla stab. Some nerve pathways are often functional after the neck stab and therefore it is highly likely that the animals remain conscious in at least some modalities for the next part of the slaughter procedure. The challenge in developing countries, however, is to find a strategy that encourages use of a method which limits suffering whilst being accessible for routine slaughter practice.

Eimeria species occurrence varies between geographic regions and poultry production systems and may influence parasite genetic diversity

Highlights • Multivariate analysis revealed comparable poultry clusters in north and south India.• Eimeria species occurrence varied between system clusters.• E. tenella occurrence across systems may underpin region-specific genetic diversity.• E. necatrix was found to be more common in north than south India.

Toxoplasma gondii detection in cattle: A slaughterhouse survey

Toxoplasmosis is a zoonotic disease caused by the protozoan parasite Toxoplasma gondii. Ingestion of raw or undercooked meat containing viable cysts has been suggested to be a major source of T. gondii infection in humans. Suboptimal performance of serological assays in cattle has traditionally precluded accurate quantification of the extent to which cattle populations are infected and their meat harbour tissue cysts. In the absence of accurate estimates of the level of infection in the animal population, assessments of likely human exposure through the consumption of cattle meat remain highly speculative. Following the development of novel and sensitive molecular methods that can be applied to the relatively large numbers of samples required in observational studies, the first quantitative estimates of the frequency of T. gondii in meat samples from naturally infected cattle have become available recently. Such estimates are critical for the development of quantitative risk assessment models that could be used to inform food safety policies. The aim of this study was to generate the first estimates of the prevalence of T. gondii infection in a sample of cattle exposed to natural levels of infection and slaughtered for human consumption in the UK under commercial conditions. Such estimates provide great value to the global assessment of T. gondii burden given the scarcity of data available on the frequency of natural infection in cattle populations worldwide. Between October 2015 and January 2016 diaphragm samples were collected from 305 animals, slaughtered in ten commercial slaughterhouses across the UK. Movement histories showed that the animals sampled (41.6% females and 58.4% males) had passed through a total of 614 farms and 40 livestock markets across the country. Five animals (1.6%) were deemed positive for T. gondii following magnetic capture real-time PCR, confirmed by amplicon sequencing. The true prevalence of infection was estimated to be 1.79%. All positive animals were male, none of whom had been on the same farm and/or livestock market before slaughter and there was no apparent geographic pattern. The results from this study suggest a low level of infection in cattle raised and slaughtered in the UK and can be used to populate the first stages of formal risk assessments to quantify the likely extent of human exposure to T. gondii through the consumption of beef with relevance to the UK, EU and rest of the world.