An outbreak of primary photosensitisation in lambs secondary to consumption of <i>Biserrula pelecinus</i> (biserrula)

Kessell, Allan; Ladmore, Georgia; Quinn, Jane C.

doi:10.1111/avj.12318

Cited by 12 publications

(14 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this study, we present an outbreak with exceedingly high morbidity in sheep grazing the Mediterranean pasture legume Biserrula pelecinus L. during its vegetative stage, in which animals exhibited an unexpected acute primary photosensitisation during mid-winter. Dissimilar to the current report, all but one [ 4 ] of the previous reports of PS outbreaks were reported in spring, a season classically associated with presentation of photosensitivity in livestock. Winter is not traditionally a time when photosensitisation outbreaks present to the livestock veterinarian.…”

Section: Introductionsupporting

confidence: 53%

Section: Discussionmentioning

confidence: 96%

“…Previous reports of photosensitisation in lambs grazing biserrula identified dermal lesions of the face and ears [ 4 , 15 , 18 ] suggesting established or resolving lesions. Kessell et al (2015) [ 4 ] also presented a PS outbreak due to biserrula Casbah in winter, affecting 25% of animals. However, the high morbidity, the speed of onset (4 days on pasture) and severity of presentation of PS described in our study have not been reported for this pasture species previously [ 2 , 4 , 18 – 20 ].…”

Section: Discussionmentioning

confidence: 96%

“…Anecdotal reports of cases of photosensitisation in livestock associated with biserrula ingestion had been noticed since this legume was commercialised in 1997 as a highly productive pasture with multiple agronomic advantages [ 17 ]. However, it was only in the recent past that a direct connection between exposure to biserrula pasture and onset of primary photosensitisation was confirmed by detailed diagnostics [ 4 ].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Acute-onset high-morbidity primary photosensitisation in sheep associated with consumption of the Casbah and Mauro cultivars of the pasture legume Biserrula

et al. 2018

View full text Add to dashboard Cite

BackgroundPrimary photosensitisation (PS) subsequent to ingestion of the pasture legume Biserrula pelecinus L. (biserrula) has recently been confirmed in grazing livestock. Given the potential utility of this pasture species in challenging climates, a grazing trial was undertaken to examine if both varieties ‘Casbah’ and ‘Mauro’ were able to cause photosensitisation in livestock, and if this could be mitigated by grazing in winter, or in combination with other common pasture species.ResultsA controlled grazing trial was undertaken in winter in Australia with plots containing a dominant pasture of Biserrula pelecinus L. cv. ‘Casbah’ or ‘Mauro’, or mixed biserrula/perennial ryegrass populations. A photosensitisation grading system was established. 167 prime meat ewe lambs were introduced to the plots and monitored twice daily. Mild clinical signs were observed at 72 h on pasture. All animals were removed from biserrula dominant stands at this point. Four animals grazing ‘Casbah’ dominant pasture rapidly proceeded to severe photosensitisation in the following 12 h. Animals remaining on mixed biserrula/ryegrass stands did not exhibit severe PS but showed an 89% incidence of mild to moderate photosensitisation over the following 14 days. Animals on mixed lucerne showed significantly lower PS score than animals grazing biserrula varieties of any composition. The trial was halted at 14 days as only plots with low biserrula proportion still contained unaffected animals.Necropsy revealed severe multifocal erythematous ulcerations and alopecia of the ear pinnae, severe bilateral periorbital and conjunctival oedema and variably severe subcutaneous facial oedema. No evidence of hepatopathy was present. A diagnosis of acute unseasonal primary photosensitisation caused by biserrula ingestion with no other underlying pathology was confirmed.ConclusionsWe report an unseasonal outbreak of acute photosensitisation in sheep grazing Biserrula pelecinus L cvs.’Casbah’ and ‘Mauro’ with exceedingly high morbidity. A grading system is also proposed as a tool for objective and consistent clinical appraisal of future PS outbreaks. This finding expands our definition of seasonal and temporal risk periods for biserrula photosensitisation, and is the first to identify that both commercial cultivars of biserrula can cause primary photosensitisation in sheep.

show abstract

Section: Introductionsupporting

confidence: 53%

Section: Discussionmentioning

confidence: 96%

Section: Discussionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Acute-onset high-morbidity primary photosensitisation in sheep associated with consumption of the Casbah and Mauro cultivars of the pasture legume Biserrula

et al. 2018

View full text Add to dashboard Cite

show abstract

“…A case report from New South describes an outbreak of primary photosensitisation associated with the ingestion of Biserrula pelecinus in a flock of lambs. 8 Complete blood count and serum biochemistry values were within normal reference ranges and there were no apparent difference between affected and unaffected animals. Five animals showing clinical signs were necropsied and histopathological examination showed lesions suggestive of photosensitisation of the exposed unpigmented skin of the face and ears.…”

mentioning

confidence: 77%