Fowl Typhoid

WALTER J. HALL.

FOWL TYPHOID, a septicemic disease, may be acute or chronic, depending largely on the pathogenicity of the causative organism, Salmonella gallinarum. It is primarily a disease of pullets and mature chickens, but it may attack young chickens and turkeys, ducks, guinea fowl, pheasants, and some other birds.

It occurs throughout the United States and throughout the year but is most common in summer.

Symptoms are not distinct enough to be diagnostic. There is fever, loss of appetite, increased thirst, and usually a yellowish-orange diarrhea. Paleness of the head and shriveling of the comb are usual.

The changes seen inside birds dead of fowl typhoid are variable. Few abnormalities may be noted in the more acute cases that die at the beginning of an outbreak. Later, especially in young chickens, a marked swelling and redness of the liver, spleen, and kidneys are commonly observed. The more chronic cases may develop grayish spots on the heart muscle, with swelling and a bronze or dark-green coloring of the liver. The ovary may show flaccid, angular, or hemorrhagic ova, as in pullorum disease.

Rupture of the diseased ova frequently cause peritonitis (infection of the abdominal cavity), and salpingitis (infection of the oviduct). This infection disturbs the functioning of the oviduct, so that there is a loss of motility, resulting in the dropping of some yolks into the abdominal cavity, and the stagnation and hardening of those that enter the oviduct, with consequent cessation of laying.

Fowl typhoid should be differentiated from pullorum disease, fowl cholera, and blue comb. A positive diagnosis can be had only by isolating the causative organism.

Fowl typhoid may be spread from pen to pen, from house to house, and from farm to farm by people, animals, and equipment that are contaminated by manure, dirt, feed, or water, in which the germs can survive.

An acutely infected bird is the most dangerous spreader of the disease, because it gives off millions of germs constantly from its mouth and nostrils and through its droppings, thus quickly contaminating feed, water, and litter. Prompt segregation of the sick birds from the healthy birds is recommended.

In almost any outbreak of disease, some individuals survive, and many of the survivors become carriers.

The germ localizes in the ova. Some of the eggs will be infected and upon hatching may start an outbreak of fowl typhoid. Carrier pullets may lay infected eggs on the range or in the henhouse. An outbreak may start when those eggs get broken and are eaten by other pullets.

Since the bird dead of fowl typhoid is such a dangerous source of disease, it should be buried or burned promptly so that animals and insects cannot come in contact with it.

Animals may spread the disease by carrying contaminated material on or in their bodies. Among them are rats, other predatory or scavenger wild animals, buzzards, and possibly other free-flying birds. Flies and some other insects may also be involved.

Control procedures depend somewhat on the age of the birds and the purpose for which they are kept. The best control procedure is prevention, including the practice of sanitation, and the removal of carriers by agglutination testing.

Vaccination does not give effective immunity against fowl typhoid.

When an outbreak occurs in large breeding flocks, the pens or the part of the flock that is affected should be shut off from the remainder of the flock, and every practical sanitary pre. caution should be taken to prevent spread of the disease to healthy birds.

The following procedures will be helpful: Attend the sick birds last; disinfect footwear, hands, and utensils after caring for the sick birds; prevent contamination of feed and water by providing grilled covers; change the water often; give feed in small amounts to prevent waste and ground feeding.

Within 2 weeks after the outbreak has subsided, all birds should be tested by the agglutination test (using pullorum antigen), and all reactors should be removed.

The test should be repeated at 30-day intervals until no more reactors are found.

The easiest way to eradicate the disease in small flocks is to dispose of the entire flock, disinfect the premises, and restock with healthy birds.

No drugs are entirely satisfactory as curative agents. The sulfonamide drugs are used both as feed mixes and in drinking water to control mortality. These drugs reduce mortality while they are being administered, but mortality increases again upon withdrawal of the drug. The sulfonamides are toxic when fed continuously or in too large doses. This effect may be avoided by intermittent feeding.

Antibiotics, including Aureomycin, streptomycin, and penicillin, also have been used to some extent but results have been disappointing.

More recently furazolidone has been used to control the Salmonella diseases, including fowl typhoid, pullorum disease, and paratyphoid. This drug is nontoxic. Experimental and field reports on its effectiveness in controlling losses from the Salmonella diseases have been encouraging.

WALTER J. HALL, a graduate of the New York State College of Veterinary Medicine, taught in the veterinary science department of Montana State College before he joined the Department of Agriculture in 1924.