Spotty Liver Disease: A review of an ongoing challenge in commercial free-range egg production

Courtice, Jodi M.; Mahdi, Layla K.; Groves, Peter J.; Kotiw, Michael

doi:10.1016/j.vetmic.2018.08.004

Cited by 28 publications

(29 citation statements)

References 32 publications

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“…Clinical observations have shown that birds are most likely to suffer the first occurrence of SLD when they enter peak lay (4). It has been hypothesized that the physiological changes that occur because of a rapid increase in egg production, such as negative nutrient balance, may affect liver metabolism and act as a predisposing factor for disease progression (6,30). We hypothesis that factors affecting gastrointestinal tract microbiota during peak lay period, such as changes in feeding patterns, may play an important role in SLD development.…”

Section: Discussionmentioning

confidence: 99%

Campylobacter hepaticus, the Cause of Spotty Liver Disease in Chickens: Transmission and Routes of Infection

Phung

Vezina

Anwar³

et al. 2020

Front. Vet. Sci.

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The epidemiology of Spotty Liver Disease (SLD) was investigated by assaying 1,840 samples collected from layer chickens and the environment in poultry farms across Australia for the presence of Campylobacter hepaticus, the agent responsible SLD in chickens. A C. hepaticus specific PCR and bacterial culture were used. Results showed that birds could be infected with C. hepaticus up to 8 weeks before clinical SLD was manifested. In addition, birds could be infected long before laying starts, as young as 12 weeks old, but the peak period for SLD outbreaks was when the birds were 26-27 weeks old. Campylobacter hepaticus DNA was detected in motile organisms such as wild birds and rats and so these organisms may be vectors for C. hepaticus dissemination. Moreover, water, soil, mites, flies, and dust samples from SLD infected farms were also found to be PCR-positive for C. hepaticus DNA. However, it still remains to be determined whether these environmental sources carry any viable C. hepaticus. The indications from this study are that environmental sources are a likely transmission source of C. hepaticus. Therefore, biosecurity practices need to be strictly followed to prevent the spread of SLD amongst and between flocks. Also, a rapid, molecular detection method such as PCR should be used as to monitor for C. hepaticus presence in flocks before clinical disease is apparent, and therefore inform the use of biosecurity and therapeutic measures to help prevent SLD outbreaks.

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Section: Discussionmentioning

confidence: 99%

Campylobacter hepaticus, the Cause of Spotty Liver Disease in Chickens: Transmission and Routes of Infection

Phung

Vezina

Anwar³

et al. 2020

Front. Vet. Sci.

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“…Chlortetracycline has been used as a treatment option during outbreaks, and currently there are no commercial vaccines available for SLD. 39 In addition to farm animals, companion animals (such as dogs and cats) may carry various Campylobacter species (primarily C. upsaliensis and C. jejuni) in their gastrointestinal tract asymptomatically, but Campylobacter occasionally causes enteritis in these species, especially in younger animals. 40 C. jejuni is also recognized as a rare cause of abortion in dogs.…”

Section: Clinical Diseases and Treatment Options In Humansmentioning

confidence: 99%

New and alternative strategies for the prevention, control, and treatment of antibiotic-resistant Campylobacter

Dai¹,

Şahin

Grover

et al. 2020

Translational Research

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Campylobacter is an enteric pathogen and a leading bacterial cause of diarrhea worldwide. It is widely distributed in food animal species and is transmitted to humans primarily through the foodborne route. While generally causing self-limited diarrhea in humans, Campylobacter may induce severe or systemic infections in immunocompromised or young/elderly patients, which often requires antibiotic therapy with the first-line antibiotics including fluoroquinolones and macrolides. Over the past decades, Campylobacter has acquired resistance to these clinically significant antibiotics, compromising the effectiveness of antibiotic treatments. To address this concern, many studies have been conducted to advance novel and alternative measures to control antibiotic-resistant Campylobacter in animal reservoirs and in the human host. Although some of these undertakings have yielded promising results, efficacious and reliable alternative approaches are yet to be developed. In this review article, we will describe Campylobacter-associated disease spectrums and current treatment options, discuss the state of antibiotic resistance and alternative therapies, and provide an evaluation of various approaches that are being developed to control Campylobacter infections in animal reservoirs and the human host.

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“…However, risk of disease is increased by loose housing overall, and not limited to free-range systems only. For example, spotty liver disease is known to be prevalent within Australia, with higher occurrence in those hens with access to litter or ground soil such as in barn and free-range systems (Courtice et al 2018). Internal parasites such as the helminth Ascardia galli are also more common in free-range hens within Australia (Dao et al 2019) than in hens housed in cage systems.…”

Section: Welfare Implications Of Rangingmentioning

confidence: 99%

Free-range egg production: its implications for hen welfare

2020

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Free-range laying hen housing systems are prevalent in Australia and perceived by consumers to provide greater opportunities for the expression of natural behaviour resulting in higher hen welfare. However, all housing systems have both benefits and risks and scientific evidence is needed on the welfare outcomes of free-range systems. In this review, the scientific literature is summarised from the past 10 years, from research conducted within Australia or internationally with brown laying-hen strains kept in free-range systems. It compiles information on range use by laying hens, hen behaviour while on the range, factors that affect range use, and impacts of ranging on hen health and other aspects of welfare. Novel insights have come from the use of radio-frequency identification systems that allow tracking of individual hens and have shown that the majority of hens access the range with multiple visits across the day, but a small proportion of hens within most flocks choose to remain indoors. Hens also vary in which areas of the range they use, and provision of natural or man-made shelters can increase both range access and range distribution. Hens spend most of their time foraging while outdoors, but the types and frequencies of behaviours vary depending on the resources available and other factors. Range access can be linked to health benefits such as improved plumage condition and reduced footpad dermatitis but there are also health risks associated with free-range systems such as greater susceptibility to disease (e.g. spotty liver disease), heat stress, predation, and potentially parasites in comparison to loose or cage housing systems. Design of the range area, indoor shed, management practices and rearing environments can all influence how hens utilise free-range housing systems. Further research is crucially needed on the impact of ranging on hen welfare in variable Australian climatic conditions, encompassing intense heat and sunlight as well as cooler or wet environments.

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Spotty Liver Disease: A review of an ongoing challenge in commercial free-range egg production

Cited by 28 publications

References 32 publications

Campylobacter hepaticus, the Cause of Spotty Liver Disease in Chickens: Transmission and Routes of Infection

Campylobacter hepaticus, the Cause of Spotty Liver Disease in Chickens: Transmission and Routes of Infection

New and alternative strategies for the prevention, control, and treatment of antibiotic-resistant Campylobacter

Free-range egg production: its implications for hen welfare

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