The literature on the diseases and parasites of the toad, Bufo marinus, is reviewed. Large numbers of potentially pathogenic bacteria, fungi, protozoa and helminths have been isolated from B. marinus, but the number of infectious agents reported as causes of disease is small. Pathological lesions have been caused by several bacteria (Aeromonas hydrophila, Mycobacterium spp., and a Gram negative bacillus, possibly Fusobacterium necrophorum), two fungi (Fonsacea pedrosoi and a Candida sp.), two protozoans (an unidentified amoeba and an experimental infection with Trypanosoma cruzi) and two helminths (Spirametra mansoni and Rhabdias spherocephala). Experimental infection with Toddia sp., an organism originally described as a protozoan, but probably a virus, resulted in death. Two neoplasms have been reported: an adenocarcinoma of the parotoid gland and a myelogenous leukaemia.
Extremes of temperature kill toads in experimental situations and appear to limit the geographical distribution of toads in Australia. Dehydration is a significant cause of mortality in juvenile toads in Panama, and, combined with starvation, may be the major cause of death in adult toads.
Apart from experimental studies on herbicide toxicity, temperature tolerance and osmotic tolerance, tadpoles have not been examined for disease.
There have been several reports of declines in populations of B. marinus, possibly associated with disease, but the postulated agent or agents have not produced obvious pathological changes.
The only indication of an agent which may be suitable as a means of biological control of B. marinus is a Toddia sp. from Brazil.