Crenosoma vulpis or lungworm is common in the United States. Symptoms include coughing and respiratory distress. Lungworm can lead to death. Diagnosis can be determined in post-mortum or necropsy exam.┬áLarvae are excreted in the feces and become infective after one […]

Nosema Cuniculi

This is reported as being a sporadic problem, in Norway, in blue foxes. It is transmitted by healthy appearing femlaes to unborn young. Most in a litter will die. Symptoms include loss of balance, weakness, and convulsions. Laboratory test reveal […]


Coccidia is a protozoan parasite that will cause loose or bloody stools and unthriftiness. It can be diagnosed easily with a fecal exam. It will usually affect juvenile animals as adults can develop immunity against the parasite. Treatment with Corid […]

Mange Mites

These are mite infections of the skin. While common in wild foxes, it appears to be less common under ranch conditions. Female mites burrow just under the skin to lay eggs. This causes severe irritation and itching. The skin is […]

Mineral oil is added to the young fox's ears to prevent of ear mites.

Ear Mites

These are very common in foxes. Black debris and irritated ears (internal) are suggestive. Irritation is due to mites deep in the ear canal. They are very small but easily seen under a microscope in the laboratory. In severe cases, […]

Hookworms (Ancylostoma)

These are a more serious problem in young animals. The worms are active blood suckers in the gut causing anemia, dark stools and death if present in large numbers. Their life cycle is somewhat similar to roundworms. However, infective larvae […]


These are a common problem during warm weather. Adult female fleas bite foxes to obtain blood. They then lay eggs in cracks, etc. around pens and next boxes. These eggs hatch to small larvae which soon form into pupae. Any […]


There are two types of tapeworms of concern. Both can live as adults in the fox gut and pass eggs. Eggs are picked up by a second host. In one, Dipylidium caninum, this host is the flea larvae. Infected adult […]

Figure IX. Roundworm egg in feces magnified 300 times.


These are more common in young animals. They cause no major problem unless present in large numbers. Adult worms in the fox gut pass eggs in the feces (Figure IX). After several weeks of warm, damp weather, these eggs develop […]