American Bullfrog

Health Issues Which May Affect This Animal

What Causes This Disease?

Chytridiomycosis is caused by a fungus, Batrachochytrium dendrobatidis, which seems to be specific to amphibians.

Where Is The Disease Found?

Chytridiomycosis is found throughout most of North America. It has been documented in a variety of amphibian species in Idaho.

Signs of Disease

Chytridiomycosis usually presents as a high mortality event in affected bodies of water. The fungus usually affects the skin and causes water balance problems. Adult amphibians infected with chytrid fungi have exhibited symptoms such as extended back legs, lethargy, and loss of the righting reflex. In larvae, jaw sheaths and tooth rows of tadpoles lack pigment or appear deformed, which may impede feeding activity. Chytrid can affect growth of juvenile amphibians and cause stunting or limb or mouthpart deformities.

Read More About Chytrid Fungus (Chytridiomycosis)

What Causes This Disease?

Ranavirus is a virus within the Iridoviridae family of viruses.

Where Is The Disease Found?

Ranavirus is found in most parts of North America. It has not been detected in Idaho.

Signs of Disease

Ranavirus is usually found due discovery of a high mortality event in amphibians. Mortality events due to ranaviruses occur most commonly in larval amphibians such as mole salamanders (Ambystoma spp.), true frogs (Lithobates spp. and Rana spp.) and chorus frogs (Pseudacris spp.). Overall mortality rates in juvenile frogs and salamanders in a wetland can exceed 90%. Affected individuals usually present with subtle to severe hemorrhages in the ventral (belly) skin, especially at the base of the hind limbs and around the vent opening. Other clinical signs include lethargy, swimming erratically, weakly, or on their sides, and mild to severe fluid accumulation under the skin in the lymphatic sacs of the abdomen and proximal hind limbs. Internally, there may be fluid accumulation in the body cavity and hemorrhages on the surfaces the heart, stomach and liver. Occasionally, white, pinpoint areas of dead tissue are evident in the liver or spleen. Ulcers of the skin and palate tend to be randomly scattered.

Read More About Ranavirus

American Bullfrog

Lithobates catesbeianus

IDAPA Classification: Game Fish
View Species Profile