BackgroundClimate affects the thermal adaptation and distribution of hosts, and drives the spread of Chytridiomycosis—a keratin-associated infectious disease of amphibians caused by the sister pathogensBatrachochytrium dendrobatidi(Bd) andB. salamandrivorans(Bsal). We focus on their climate-pathogen relationships in Eurasia, the only region where their geographical distributions overlap. Eurasia harbours invaded and native areas of both pathogens and the natural habitats where they co-exist, making it an ideal region to examine their environmental niche correlations. Our understanding of how climate change will affect their distribution is broadened by the differences in climate correlates and niche characteristics betweenBdandBsalin Asia and Europe. This knowledge has potential conservation implications, informing future spread of the disease in different regions.ResultsWe quantified the environmental niche overlap betweenBdandBsalin Eurasia using niche analyses. Results revealed partial overlap in the niche with a unique 4% of non-overlapping values forBsal, suggesting segregation along certain climate axes.Bdtolerates higher temperature fluctuations, whileBsalrequires more stable, lower temperature and wetter conditions. Projections of their Realized Climatic Niches (RCNs) to future conditions show a larger expansion of suitable ranges (SRs) forBdcompared toBsalin both Asia and Europe, with their centroids shifting in different directions. Notably, both pathogens' highly suitable areas in Asia are expected to shrink significantly, especially under the extreme climate scenarios. In Europe, they are expected to expand significantly.ConclusionsClimate change will impact or increase disease risk to amphibian hosts, particularly in Europe. Given the shared niche space of the two pathogens across available climate gradients, as has already been witnessed in Eurasia with an increased range expansion and niche overlap due to climate change, we expect that regions whereBsalis currently absent but salamanders are present, and whereBdis already prevalent, may be conducive for the spread ofBsal.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12862-023-02132-y.