Pathological and Molecular Investigations on Foot and Mouth Virus Outbreaks Among Cattle Herds in Dakahlia Governorate, Egypt

Abstract

The present study represents an extensive field survey of the pathological affections caused by local Food and Mouth Disease (FMD) virus throughout Dakahlia governorate, North Egypt. The study included 670 cattle belonging to local and Frisian breeds. The age of the examined animals ranged from ten days to four years and they were of both sexes. The morbidity rates among the investigated cattle herds of either Frisian or native origin were 100% and 5% respectively. We observed early mortality in infected calves aging ten days old and older calves. This was concurrently associated with lesions of severe myocarditis which appeared to be responsible for the death. On the other hand, adult cattle showed vesicular lesions, erosions and ulcers on the mucous membrane of the mouth and skin on the feet and udder. In addition, fever, anorexia, and pstyalism were observed. Histopathological examination of both young calves and adult cattle revealed multitude of inflammatory and necrotic lesions in the myocardium, liver, lung, intestine and udder. Molecular examination and gene sequencing revealed the presence of RNA belonging to FMD virus 'type A' in the affected tissues. The nucleotide sequence of the isolated virus strain was submitted to the gene bank (accession number: BankIt1911105FMD/A/EGY/Dakahlia/ KX083565). In conclusion, the study emphasized the importance of FMD as a viral disease induced relatively high mortality and morbidity especially in young calves and gives an account on the associated pathological lesions.

Pathological Studies on Foot and Mouth disease at Kaluobia Governorate

“…In the present study, the most prominent signs in young calves (1-2 months old) represented by sudden death. These results completely agreed with Ali, et al (2016) and Jubb, et al (2016). However, Aktas, et al (2015) recorded fever, tachypnea, tachycardia and arrhythmia in calves less than 2 months of age before death; while with increasing the age of calves the characteristic signs of foot and mouth disease represented by vesicular lesion in feet and mouth were observed.…”

“…Clinically, the affected cattle and buffalos in this work were suffering from fever, inappetence, anorexia, lameness, marked ptyalism, ropy salivation, and protrusion of tongue, these results completely agreed with El-Ashmawy, et al (2013), El-Bayoumy, et al (2014) and Ali, et al (2016).…”

“…Cross section of affected muscle showed grayish white foci or spots in the myocardial muscle giving the characteristic tiger heart appearance. These results completely agreed with Ali, et al (2016). Meanwhile, the postmortem examination of older calves (12-24 months old) in this study revealed presence of dark red ecchymotic hemorrhagic areas on the surface of the auricle and the ventricles; this result totally agreed with Ali, et al (2016) and also, in cross section of affected heart in this study showed multiple grayish white necrotic foci in the myocardial muscle.…”

“…These results completely agreed with Ali, et al (2016). Meanwhile, the postmortem examination of older calves (12-24 months old) in this study revealed presence of dark red ecchymotic hemorrhagic areas on the surface of the auricle and the ventricles; this result totally agreed with Ali, et al (2016) and also, in cross section of affected heart in this study showed multiple grayish white necrotic foci in the myocardial muscle. Similar results were obtained by El-Ashmawy, et al (2013) who found grayish white small foci of necrosis at the heart base of adult animals and these areas appeared as cooked and pale friable areas.…”

“…The results of RT-PCR revealed FMD virus serotype O in the examined sample which has been responsible for many recent outbreaks in Egypt as reported by Ibrahim, et al (2014) and also by Aidaros, et al (2016) who found that the most prevalent serotype was (O) in Gharbia and Kaluabiagovernorates during 2014-2015. However, the involvement of other virus strains such as A and SAT2 were previously isolated in Egypt by El-Ashmawy, et al (2013), El-Bayoumy, et al (2014) and Ali, et al (2016).…”