An abscess is a localized bacterial infection that often contains white, green, or yellow creamy material.

Diseases Wildlife Get
Viruses, bacteria, fungi, and parasites are a normal and unavoidable part of the natural environment, so some disease is normal within a wildlife population. Usually diseases affect only a portion of animals and are not detrimental to a population, yet some diseases can spread widely and become a serious concern. MDC biologists watch for outbreaks of diseases that can harm wildlife populations as well as those that can be transmitted to humans, pets, and livestock.
Browse this section to learn about diseases that affect wildlife in Missouri and which ones can be harmful to humans and domestic animals.
- Avoid handling sick or dead wildlife.
- If you must handle a dead animal, always wear gloves and wash your hands after.


Brainworm is caused by the parasitic roundworm Parelaphostrongylus tenuis.

CWD is a slow-progressing disease affecting members of the deer family (cervids).

These growths are variable in color, texture, number, and size (from a dime to a baseball), and often found around eyes and neck.

Hair loss can be caused by a variety of bacteria, parasites, and fungi.

Hemal nodes are pea-sized spherical structures embedded within the fatty tissues of the body.

Biting midge flies in the genus Culicoides spread the viruses that cause this disease.

Varying sizes of purple-gray, flat, oval parasites (flukes) may be seen in the liver.

Adult female botflies eject developing larvae into the nostrils of deer.

Yellow or reddish, clear fluid under skin or within muscle.

Illness ranges from no symptoms to severe disease. Leptospirosis can be fatal if not treated.

Canine and feline distemper are caused by two different viruses that affect wild and domestic carnivores.

Hemal nodes are pea-sized spherical structures embedded within the fatty tissues of the body.

Cysts, often resembling fluid-filled bladders, can appear on the surface of several organs in the abdomen as well as in the muscle tissue.

Infected mammals show varying degrees of hair loss, usually on the legs and tail.

Rabies is a viral disease of mammals. Rabies testing requires brain tissue.

RHDV2 is a highly contagious and potentially fatal disease for rabbits. It is a foreign animal disease and is of high concern in the United States.

The roundworm is called Baylisascaris procyonis. It is found primarily in raccoons.

Roundworms are some of the most common worms found in wildlife worldwide.

Tularemia is caused by a bacterium called Francisella tularensis.

Trichinosis is caused by a roundworm called Trichinella found in the muscles of infected animals.

Infected bats may exhibit white fungal growth on the muzzle and/or wings, and they often display abnormal behaviors in their hibernation sites during winter.

Aspergillosis is a fungal infection caused by several Aspergillus species.

Avian pox is caused by a virus and has been shown to infect numerous species of birds worldwide.

HPAI is a highly contagious virus in wild and domestic birds.

Symptoms of lead poisoning may include weakness, drooping wings, inability to fly, and green, watery diarrhea.

This disease of wild turkey is so newly discovered that much remains unknown.

Affected birds have cream-colored cysts resembling rice grains in the breast, heart, and leg muscles.

Pigeons and doves are commonly infected, but they may not show clinical signs.

WNV primarily infects and multiplies in birds, which serve as reservoirs (a persisting group of carriers) for the virus.

The affected skin may have pale patches and/or a characteristic sore or lesion shaped like a saddle across the dorsal fin.
Fluke larvae burrow into the flesh of the fish and form a cyst.

Melanosis is not an infection but an increase in the melanin in the skin.

Red, off-white, and white worms found under the skin, in the intestines, and in the body cavity.

The diseased flesh appears tough, granular, coarse, and yellow to brown, often resembling freezer-burned meat.

Tapeworm larvae (plerocercoids) often appear as white cysts or coiled worms in the flesh or internal organs

The most common causes are three bacteria in the genus Aeromonas.

Fish have wartlike growths on the skin, fins, and occasionally gills.

Water molds (which are not true molds or fungi) appear as white, gray, or tan cottony growths on the skin of the fish when submerged in water.