Concerning Prevalent Disease in Pigs As It Occurs During The Summer Months

New Zealand Journal of Agriculture, Volume 65, Issue 5, 16 November 1942, Page 265

Concerning Prevalent Disease in Pigs As It Occurs During The Summer Months

The Livestock Division " Issues a Warning

ALTHOUGH the summer months are usually ideal for most classes of stock, particularly calves, lambs, dairy and fattening stock, it is rather remarkable that a considerable amount of disease is seen in pigs during this period. There must be a reason for this, and if one considers the conditions under which pigs are reared and fattened, with the conditions pertaining to other classes of stock, the explanation may probably be due to the following cause.

Whereas the former class are free at pasture and have access to a variety of food, the latter class are mainly confined to small sections and styes, the food supply being limited mainly to skim milk and whey and a limited amount of other food. During the warm summer months it is difficult to maintain the bulky milk by-products in the most wholesome condition for feeding to pigs owing to fermentation and bacterial changes. It is also more difficult to keep storage tanks, barrels, or other milk containers, feeding vessels and troughs in a clean condition owing to the prevalence of flies and the warmer temperatures. Greater care is therefore necessary to see that conditions in regard to the food supply and the general hygiene of the styes and sections is maintained at the best possible level during these months. General Considerations The endeavour to maintain health in pigs by suggestions regarding feeding and management under the varying conditions met with from farm to farm is a most important aspect of disease control? The surest way to control disease in pigs is to pay attention to the following: overcrowding, over-feeding, regularity in feeding, avoiding constipation or scouring, variety in the diet (roughage or green feed if need be), sanitation and drainage, hygiene, oiling to prevent lice and mange, prevention of checks in young growing pigs, prevention of extremes of temperature during the summer (hot days followed by cold nights), shade and draught-proof housing, the general maintenance of growth and bloom in pigs. This aspect of the

fight agains't disease in pigs cannot be too strongly stressed under our farm conditions, as there is a tendency to mass production or intensive methods of pig raising with a very limited variety in the nature of the general food supply for all classes of pigs, irrespective of the varying requirements of the pigs at different stages of growth and development. Another aspect of the fight against disease in pigs is careful observation and the immediate treatment of pigs that are off-colour. Isolation of the sick pig in the early stages in order to prevent other incontact healthy pigs in the same sty contracting the infection is the first thing to be done. Isolation is not an empty term; it requires to be applied and applied promptly, and with judgment in many cases. The separation of the healthy from the sick, the isola-

tion of newly-purchased animals until satisfied that disease is not being introduced, suitable nursing and special treatment of sick animals and the slaughter off of all chronically sick pigs are all valuable measures which can be put into operation without any specialised knowledge of the various diseases to which pigs are subject. On numerous farms these chronically sick pigs are seen. They are a direct menace and are frequently reservoirs of disease germs, having in many cases been affected with disease, partially recovering and remaining chronic carriers and spreaders of disease. They should be slaughtered. All pigs killed off on account of disease should be promptly disposed of by deep burial or burning. The intact disposal of a carcase without spilling blood, unless a special post-mor-tem examination is carefully carried

out, will prevent disease spread. If a post-mortem examination is held then all blood offal and carcass requires to be cleaned up, buried or burnt. Most farmers have healthy pigs because they pay attention to these aspects of disease prevention. Some have out-

breaks of disease in spite, of their care; this will happen but there may be some weakness in their management of which they are unaware. Others take little care and get into difficulties; the remarks already made are intended especially for them.

Necrotic Sores • re S ar d to specific diseases such as necrotic ulcers in pigs this disease has been dealt with so often in the “Journal of Agriculture” that every pig raiser in New Zealand must be thor-

oughly conversant with it. Photographs of the disease have been shown so that no possible mistake could be made regarding its identification. The treatment by scrubbing and dusting of the sores with powdered tartar emetic is a specific cure which kills off the spirochaetal organism and permits normal healing of the sores. “Blue Belly” “Blue Belly” (Suipestifer disease) and allied diseases.— Concerning the rather baffling internal diseases of pigs which result in mortality from time to time, on good and bad premises and show a variety of symptoms depending upon the part of the animal’s system most ■ seriously affected, and which, in the present state of our knowledge of pig diseases are not easily cured and in many cases very difficult to prevent, the following information is given on the subject: — While mass production of pigs is carried on under intensive or semi-inten-sive systems and while large numbers of animals are kept in close contact and confined under artificial conditions to suit man’s needs, the germs of disease are liable to become concentrated and . periodic outbreaks of this disease are more or less unavoidable. Outbreaks of this disease have been reported. in big pig plants where the standards of housing, hygiene, feeding and management are as near perfect as possible. This does not imply that .the position ,is hopeless. It is comparable with the human influenza situation. The pig disease germ is just as widespread as the influenza germ. It strikes just as unexpectedly and, like influenza it is controlled by taking the same suitable precautions regarding isolation and the prevention of spread. Like influenza this disease is well known. . - A good deal of investigation into pig

diseases generally was carried out by

Mr. D. Marshall, M.R.C.V.S., when stationed in the Waikato district when it was shown that most of the mortality was caused through this specific germ called bacillus suipestifer.' For general purposes it may be said that this germ could probably be found on all pig premises. The exact conditions enabling the flare-up of the germ and subsequent mortality in pigs are so complicated that they cannot be defined. The particular symptoms set up by the germ when it invades the pig’s system are easily recognised and depend to a very great extent upon the organs affected. - . Forms the Disease May Take 1. Lung Infection: If the, lungs are affected one would expect high temperature, redness of the skin of the belly and thighs, which is mainly a characteristic of the fever having no other relationship to the disease, and lastly and most important the peculiar

breathing difficulties associated with

lung disease. The affected lungs and air passages pass through the various stages of congestion until pneumonia supervenes. In the congestion stage bleeding may take place sometimes relieving the affected animal. This bleeding results from congestion of the nasal, bronchial and lung membranes, just as the redness of the belly is due to high temperature. Bleeding always gives a temporary relief to congested areas. However, bleeding is not considered a cure for the disease and the fact that some recoveries take place following bleeding must be regarded more as a coincidence. Much depends upon the virulence of the germ and the resistance of the animal. Naturally in a fevered animal there is no desire to eat, but thirst may be present. As the organism is teeming in the blood and in the lungs, a septic pneumonia soon supervenes . and the affected animals die quickly, ' or, if they recover, remain chronic lung cases, and per-

severance with them is seldom worth while. , , , ' , , , The Department has used drugs of the sulphanilamide group for the treatment of these lung cases and the resuits are quite promising. The drug however, is not generally available for

animal treatment and at present is reserved for the medical profession in case of an emergency. Consequently he necessary to wait for more suitable times before full advantage C an be taken of the prospective treatment and cure of individual affected pigs.

The measures already mentioned, isolation, nursing and treatment of less seriously affected, slaughter and burial of seriously affected and maintaining a careful watch to prevent spread of infection are the lines along which results are likely to be obtained. In all lung troubles breathing difficulties make it inadvisable to drench animals with medicine. However, such medicinal agents as salts or oil, if required, may be taken by the sick pig when mixed in a little milk or gruel.

2. Stomach Infection: With the same germ attacking the digestive system there is again evidence of fever, loss •of appetite, pinkness of skin, belly and underparts . of the body, probably constipation at first, followed by acute diarrhoea. When diarrhoea sets in there is a falling in of the flanks, pigs have an empty appearance, scour continuously and generally are very Jairsty, preferring to drink from stagnant pools and sewage rather than clean milk or water. Such symptoms as are here described will be reflected on a post-mortem examination by an acutely inflamed, reddened stomach, together with inflamed areas through the small bowels. Frequently large necrotic ulcers are seen on the lining of the bowels, particularly the blind gut, or this gut may show an acutely inflamed reddened lining throughout without ulceration. The droppings from such an animal are teeming with die germs, hence slaughter or isolation must be resorted to at once to prevent further spread of the disease.

The first time the pig is seen to refuse its food it should be removed to the hospital or sick sty. A good dose of castor oil or other suitable laxative should be given. Provide new whole milk as the drink, and prohibit any access to sewage. Warm dry housing free from draughts is necessary. Early cases will respond to this treatment. Delay is fatal, so that whatever hope for success is entertained, the case must be regarded as urgent. There is no specific medicinal agent which can be recommended. Whether the drug referred to above will prove of any value in the intestinal form of the disease is rather doubtful at present, but experiments will be continued with a view to discovery of anything useful. 3. Blood Poisoning form: The acute septicaemia or blood poisoning form of the same disease affecting lungs, stomach and intestines, in fact all organs where the germ is demonstrated in the blood proves rapidly fatal in spite of any treatment. In such cases prompt slaughter of the affected animals and deep burial or burning of the carcasses to prevent spread of the disease is about the only treatment left to the owner. Naturally in dealing with an outbreak on a farm, any sties vacated by affected pigs should be thoroughly cleaned out, sprayed with disinfectant, opened up to the sun and air and left vacant for a few weeks.

It may be poor consolation to owners having had experience of the disease to say that the same germ takes toll of many pigs in other countries such as the U.S.A, and Great Britain. This, however, appears necessary as some have the opinion that nothing is known about the disease and nothing can be done to lessen its incidence or prevent its spread. In some quarters there . appears to be a tendency to throw up in despair rather than apply what knowledge there is known about the disease. ’ This Division is in touch with work carried out in other countries with this and other diseases of pigs and whenever or wherever anything of value is available, the pig raiser will be fully advised. Infectious Pneumonia Another disease of pigs, which takes heavy toll upon occasions is that known as Pasteurellosis. This is a disease due to another variety of germ known as the Pasteurella suis. The disease is more particularly confined to younger pigs kept under poor conditions or oh a low plane of nutrition. The body resistance is thus lowered and the germ, which may be said to be almost a normal inhabitant of the respiratory system, takes on the role of an invader, setting up a form of blood poisoning or septicaemia, resulting in a train of symptoms mainly affecting the lungs and heart. There is coughing, nasal discharge, excessive or dif-

ficult breathing and panting, double flank action, pleurisy and pneumonia, resulting in the death of many young and store pigs. This disease may be easily introduced to clean premises through the purchase of pigs from saleyards; hence the wise precaution of isolating fresh purchases until they have settled down and the question of possible disease is beyond doubt. Even if an. outbreak of this disease occurs, it is not generally regarded in so serious a light as suipestifer disease on account of the fact that it mainly attacks the younger pigs and those undernourished. Porker pigs, baconer animals and sows and boars have usually sufficient resistance to prevent their being attacked by this type of germ. The actual germ responsible can only be demonstrated under the microscope; hence the advisability of forwarding suitable specimens to the Animal Research Station, Wallaceville. Here again, there is no specific medicinal treatment of any value. Good nursing, hygiene, feeding, the use of cod-liver oil to build up resistance, the segregation and isolation of the ' affected to prevent spread, the : isolation of all newly-purchased weaner or store pigs and such other preventive measures as may be applied under the varying farm conditions are the rational lines to follow.