Weather as a factor in animal disease

Nature

Weather conditions may contribute to the incidence of animal diseases via their effect on fodder and therefore on nutrition and the general resistance of animals to disease. They may also contribute directly to produce a favourable environment for the growth of spores and parasites which cause disease, or to the spread of viruses and bacterial spores. In addition weather factors affect the proliferation of the intermediate hosts, such as flies and mosquitoes. Seasonal considerations can account for animal infertility.

Background

The influence of weather on animal disease emerged as a global concern in the late 19th century, when epizootics were linked to climatic anomalies such as droughts and floods. Advances in veterinary epidemiology throughout the 20th century deepened understanding of how temperature, humidity, and precipitation patterns facilitate outbreaks of vector-borne and respiratory diseases. Recent international surveillance has highlighted the increasing unpredictability of weather as a critical factor in transboundary animal disease emergence.

Incidence

Extreme heat or extreme cold adversely affect animal resistance to disease and may lead to undernourishment through lack of fodder. Extreme cold is the more harmful. Weather factors affecting the growth of spores and parasites and the incidence of viral or bacterial infection include wet weather, wind, rainfall followed by hot weather, hot dry weather, and drought. Mosquitoes and flies tend to proliferate during the rainy season where intermittent rainfall is followed by summer temperatures. Diseases affected by the weather include anthrax, African horse sickness, foot-and-mouth disease, fowlpest, and coccidiosis.

Counter-claim

Weather as a factor in animal disease is vastly overstated and not an important problem at all. Modern veterinary care, controlled environments, and advanced farming techniques have rendered weather’s impact negligible. Focusing on weather distracts from real issues like poor management and lack of vaccination. Blaming the weather is an outdated excuse that ignores the true causes of animal disease, and it should not be considered a significant concern in today’s world.