<abstract xmlns="http://www.w3.org/1999/xhtml"><sec id="j_jvetres-2020-0035_s_005_w2aab3b7b6b1b6b1aab1c14b1Aa"><h3>Introduction</h3><p>Malignant catarrhal fever (MCF) is a rare, under-explored lethal viral infection of cattle with gammaherpesvirus aetiological agents. Most often, the disease occurs on farms where cattle and sheep are kept together. However, other trigger mechanisms and environmental factors contribute. This study investigates the causation of MCF.</p></sec><sec id="j_jvetres-2020-0035_s_006_w2aab3b7b6b1b6b1aab1c14b2Aa"><h3>Material and Methods</h3><p>An outbreak of MCF occurred in June - August 2017 in Kharchev village in Irkutsk Oblast, Russia. In this paper, we provide epidemiological (sanitary status of pastures, watering places, and premises) and weather data during the outbreak, and descriptions of the clinical signs and post-mortem changes in cattle. The virus was detected and isolated from pathological material samples and identified by molecular methods.</p></sec><sec id="j_jvetres-2020-0035_s_007_w2aab3b7b6b1b6b1aab1c14b3Aa"><h3>Results</h3><p>Extreme weather conditions, mixed-herd cattle and sheep farming, and unsatisfactory feed quality contributed to the outbreak. A virus related to herpesvirus OvHV2 was isolated and typed (MCF/Irkutsk/2017). Phylogenetic analysis showed its close genetic relationship to isolates from cattle and sheep in Germany, USA, and the Netherlands.</p></sec><sec id="j_jvetres-2020-0035_s_008_w2aab3b7b6b1b6b1aab1c14b4Aa"><h3>Conclusion</h3><p>Sporadic outbreaks of MCF caused by biotic and abiotic factors together are typical for the Russian Federation, and the Irkutsk outbreak epitomised this. Temperature anomalies caused pasture depletion, resulting in feed and water deficiency for grazing animals and dehydration and acidosis. Heat stress in animals ultimately led to the occurrence of MCF in the herd.</p></sec></abstract>

IntroductionMalignant catarrhal fever (MCF) is a rare, under-explored lethal viral infection of cattle with gammaherpesvirus aetiological agents. Most often, the disease occurs on farms where cattle and sheep are kept together. However, other trigger mechanisms and environmental factors contribute. This study investigates the causation of MCF.Material and MethodsAn outbreak of MCF occurred in June - August 2017 in Kharchev village in Irkutsk Oblast, Russia. In this paper, we provide epidemiological (sanitary status of pastures, watering places, and premises) and weather data during the outbreak, and descriptions of the clinical signs and post-mortem changes in cattle. The virus was detected and isolated from pathological material samples and identified by molecular methods.ResultsExtreme weather conditions, mixed-herd cattle and sheep farming, and unsatisfactory feed quality contributed to the outbreak. A virus related to herpesvirus OvHV2 was isolated and typed (MCF/Irkutsk/2017). Phylogenetic analysis showed its close genetic relationship to isolates from cattle and sheep in Germany, USA, and the Netherlands.ConclusionSporadic outbreaks of MCF caused by biotic and abiotic factors together are typical for the Russian Federation, and the Irkutsk outbreak epitomised this. Temperature anomalies caused pasture depletion, resulting in feed and water deficiency for grazing animals and dehydration and acidosis. Heat stress in animals ultimately led to the occurrence of MCF in the herd.

Malignant catarrhal fever in cattle in the Irkutsk Region

Journal of Veterinary Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"Malignant catarrhal fever in cattle in the Irkutsk Region"}

IntroductionMalignant catarrhal fever (MCF) is a rare, under-explored lethal viral infection of cattle with gammaherpesvirus aetiological agents. Most often,...

Reported cases	Date of the study of blood serum	Number of diseased cows	Air temperature (°C)	Laboratory findings
Reported cases	Date of the study of blood serum	Number of diseased cows	Air temperature (°C)	Total protein (g/L)	Total calcium (mmol/L)	Reserve alkalinity (mmol/L)
1	23.06.2017	1	35	95.0	4.00	18.2

				94.0	3.55	16.3
2	30.06.2017	2	32	96.6	3.86	18.0

3	1.07.2017	1	32	84.3	2.84	23.4

				97.4	4.23	18.4
4	6.07.2017	2	29	86.0	3.00	20.0

5	19.07.2017	1	30	82.8	2.93	22.6

				85.0	2.67	23.3
6	6.08.2017	2	33	80.7	2.78	27.0

				96.5	3.67	18.7
7	7.08.2017	2	29	84.0	2.50	25.0

				96.8	4.25	17.2
8	14.08.2017	2	34	95.3	3.00	26.5

M±m			32 ± 1.00	90.338 ± 1.868	3.329 ± 0.179	21.123 ± 1.061

Standard^{Data are mean ±SD (14)}				72.0–86.0	2.50–3.13	19.0–27.0

Malignant catarrhal fever in cattle in the Irkutsk Region

Published Online: May 12, 2020

Page range: 215 - 222

Received: Aug 20, 2019

Accepted: Apr 30, 2020

DOI: https://doi.org/10.2478/jvetres-2020-0035

Keywords
cattle, malignant catarrhal fever, outbreak, clinical signs, climate change, Russia

© 2020 O. Zakharova et al. published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Clinical baseline characteristics and laboratory findings of cows with MCF

Malignant catarrhal fever in cattle in the Irkutsk Region

Published Online: May 12, 2020

Page range: 215 - 222

Received: Aug 20, 2019

Accepted: Apr 30, 2020

DOI: https://doi.org/10.2478/jvetres-2020-0035

Keywordscattle, malignant catarrhal fever, outbreak, clinical signs, climate change, Russia

© 2020 O. Zakharova et al. published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Clinical baseline characteristics and laboratory findings of cows with MCF

Keywords
cattle, malignant catarrhal fever, outbreak, clinical signs, climate change, Russia