Anaplasmosis Outbreak in Lambs: First Report Causing Carcass Condemnation

Abstract

In spring and summer 2020, six outbreaks of condemnation of jaundiced lamb carcasses were diagnosed in different farms in Aragón region, Spain. Anaplasma ovis was identified in all affected farms. Four hundred and ninety-two lambs from two affected farms were more closely examined. Clinical examination, haematologies, biochemistries, histopathology and microbiological and molecular analyses were performed. After slaughter, 34.84% of the lambs showed jaundiced carcasses and 79.64% presented splenomegaly at the abattoir. All tested lambs with icteric carcasses showed positive A. ovis PCR, although 72.72% of the unaffected lambs also tested positive. However, the bacterial load was significantly higher in the animals that showed jaundiced carcasses (Cq: 25.00 vs 26.16; p = 0.004). Moreover, all the tested lambs that showed severe anaemia were PCR positive. On the contrary, the PCR negative lambs did not show anaemia. Lambs that presented icteric carcasses displayed severe regenerative anaemia with significantly lower erythrocyte count (7.18 vs. 11.97), haematocrit (26.89 vs. 34.82) and haemoglobin (8.50 vs. 11.10) than unaffected lambs. Reticulocyte count (18.80 vs. 5.65) was also significantly increased in affected animals. This article describes a new disorder caused by Anaplasma ovis that is producing significant economic losses associated with the carcass condemnation of apparently healthy lamb.

Ticks and Tick-Borne Pathogens Associated with Dromedary Camels (Camelus dromedarius) in Northern Kenya

“…High infection rates of 88.3% found for A. ovis in clinically healthy sheep blood during this study suggest that sheep in northern Kenya may serve as reservoirs for this pathogen. Although A. ovis infection is generally a subclinical infection in small ruminants, more severe infections resulting in significant economic losses have been reported in Spain [ 95 ].…”

Ticks and tick-borne pathogens associated with dromedary camels (Camelus dromedarius) in northern Kenya

“…High infection rates of 88.3% found for A. ovis in clinically 213 healthy sheep blood during this study suggest that sheep in northern Kenya may serve as 214 reservoirs for these pathogens. Although A. ovis infection is a subclinical infection in small 215 ruminants, more severe infections leading to significant economic losses have been re-216 ported in Spain (94). 217 We found high infection rates for R. africae in Am.…”

Haemoparasites—Challenging and Wasting Infections in Small Ruminants: A Review

“…However, infection with A. ovis may predispose animals to other infections and parasite infestation resulting in clinical disease or even death and may therefore have an impact on health, milk and meat production in small ruminants [ 61 ]. Recently, outbreaks of anaplasmosis in lambs due to A. ovis , have been reported, including severe anaemia and icteric carcasses [ 62 , 63 ]. The pathogenesis of this strain has to be further unravelled.…”

“…Recently, outbreaks of anaplasmosis in lambs due to A. ovis, have been reported, including severe anaemia and icteric carcasses [62,63]. The pathogenesis of this strain has to be further unravelled.…”