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 epizootic outbreaks were linked to climatic anomalies. Subsequent research, particularly during the 20th century, revealed patterns between weather events—such as droughts, floods, and temperature extremes—and the incidence of vector-borne and respiratory diseases in livestock and wildlife. This recognition has intensified with climate variability, prompting international monitoring and predictive modeling efforts.

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.

Claim

Weather is a critical and often underestimated driver of animal disease outbreaks. Ignoring its impact is reckless, as shifting temperatures, humidity, and extreme events directly influence pathogen survival and transmission. The devastating consequences for livestock, wildlife, and even human health are undeniable. Addressing animal disease without prioritizing weather as a key factor is shortsighted and dangerous. We must urgently recognize and act on this connection to protect global food security and ecosystem stability.

Counter-claim

The idea that weather significantly influences animal disease is vastly overstated. Modern veterinary science, improved animal husbandry, and advanced disease control measures have rendered weather a negligible factor. Focusing on weather distracts from real issues like poor management and inadequate vaccination. Blaming the weather is an excuse, not a solution. In today’s world, weather is simply not an important problem when it comes to controlling animal disease.