Observations on presumptive lumpy skin disease in native cattle and Asian water buffaloes around the tiger reserves of the central Indian highlands

Abstract

Case history: Between August and October 2020, following the monsoon, signs of lumpy skin disease (LSD) were recorded and described in 154 oxen, 34 cows, 13 calves (Bos indicus) and two Asian water buffalo (Bubalus bubalis) cows belonging to smallholder farmers in 32 villages located around the Kanha and Bandhavgarh tiger reserves in the state of Madhya Pradesh, central India. Affected animals were subjected to a full clinical examination and detailed findings were recorded in a clinical register. A semi-structured questionnaire was attached to the existing clinical register format to gather information on the clinical disease history and animal husbandry practices relevant to the spread of LSD virus. Clinical findings: The affected animals were between 4 months and 14 years of age (mean 6.4 (SD 2.5) years). Persistent high temperature, depression, anorexia, and characteristic round nodules (lumps) on the skin were reported. The nodules were 2–5 cm in diameter and spread over the face, ears, neck, back, perineum, scrotum, legs, tail, udder, and nasal and oral mucosa. Secondary complications of myiasis (n = 39), mastitis (n = 16) and ulcerative lesions on legs were noticed. Death was reported for one animal (0.5%). The affected animals’ recovery times were variable (mean 18.4 (SD 2.7) days). There was a significant positive correlation between delay in initiating treatment and the duration of sickness. Reduction in milk yield of 30–55% was reported in Bos indicus cows. Diagnosis: Clinical findings and treatment responses consistent with lumpy skin disease and its sequelae. Clinical relevance: The presumptive LSD outbreak caused serious economic loss to the animal keepers. LSD is a new disease for India and in the absence of active immunisation, efficient vector control, animal movement control and stall-feeding practice, it will inevitably become endemic in the country. The severe impacts resulting from the introduction of a new disease to a previously unaffected country highlight the need for iterative improvements in global transboundary disease surveillance. The value of clinical examination and recording of findings is demonstrated in the context of smallholder farming systems with limited access to laboratory diagnosis, which are common around the world. The description of an LSD outbreak in naïve populations of cattle and buffalo illustrates the need for increased awareness of the associated clinical signs and maintenance of high levels of biosecurity in hitherto disease-free countries.