LIVER DISEASES
The liver is affected by several diseases, and the poultryman, who finds a spotted liver on post-mortem examination, will be much aided in determining the cause, if he takes into consideration the symptoms noticed before the fowl died, as well as the changes in the other internal organs. The importance of the post-mortem examination is in distinguishing whether the death of the fowl is due to a contagious disease.
The causes of diseased livers may be conveniently divided into two classes:
1. Diseased livers due to indigestion, e. g., enlargement.
2. Diseased livers due to a specific disease, e. g., tuberculosis.
Diseases Due to Indigestion
In this class may be included degeneration, inflammation, congestion, enlargement, and atrophy of the liver. There are more or less distinct differences in these diseases, but the only possible methods of treatment known at present are very much the same.
Symptoms. There are no definite external symptoms. The poultryman’s suspicions should, however, be aroused if fowls apparently in good health die suddenly. A post-mortem examination will reveal a liver of abnormal size, or somewhat shrunken, and of unhealthy texture.
Cause. The cause is generally something wrong in the feeding. Fowls may be eating too large a proportion of heat-producing foods and not enough green food. If an enlarged liver is associated with an excessive layer of fat covering the internal organs, it points to too large quantities of carbohydrates.
Treatment. Correct errors in feeding. Give more green food and let the fowls scratch for some of their grain. If errors in feeding and general management are not obvious, make experimental changes.
Diseased Livers Due to Specific Diseases
Tuberculosis, coccidiosis, gout and other specific diseases are responsible for spotted or diseased livers. (Fig. 24.) The section on diagnosis by post-mortem examination gives further information on these subjects and shows how the principal diseases may be distinguished.
The term cancer is sometimes applied to cases in which there are tumors on the liver.
MAGGOTS
Occasionally found in flesh wounds of poultry
Symptoms. A flesh wound that instead of healing develops into a sore with a slight running. On examination, maggots will be found.
Cause. Several species of flies are always ready to lay their eggs in any available wound or sore; therefore wounds must be watched in the case of poultry, as with all other animals of the farmyard. The eggs laid by these flies hatch and develop into small footless grubs commonly known as maggots.
Treatment. Wash the wound with 1 to 2% creolin; remove as many of the maggots as possible with a pair of tweezers or a feather. If the maggots are deep-seated, stuff the wound with a cotton wad saturated with strong creolin or 10% carbolic acid. Examine next day and remove dead maggots. Treat again in a similar manner if the maggots are not all killed. Fish oil, or iodoform made into a paste with vaseline, will prevent the flies depositing their eggs, if smeared on the surface of the wound.
MITES (AIR-SAC)
Not a common parasite
Symptoms. There are no definite external symptoms. If the bird is very badly affected, there may be evidences of suffocation. This may end fatally. A post-mortem examination will show the mites in the air passages and bronchi as small yellowish and whitish particles, which on careful observation may be seen to move.
Fig. 15
The Air Sac Mite(From Salmon.)
Cause. A small mite (Sarcoptes lævis) which infests the air sacs and bronchi. These mites, when present in large numbers, obstruct the air passages and cause suffocation. A secretion from the mucous membrane affected, results from the presence of the mites and increases the obstruction of the air passages.
Treatment. The fumigation method tried for gapes has been recommended, but there is little reason to expect success.