Major infectious diseases that affect the digestive system of the pig

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* Summary

* Introduction

* Development

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ABSTRACT

For this study collected information from a five-year period 2001-2006 in different pig farms in Cuba Granma territory in order to present the current status of some of the major digestive diseases of infectious origin, which are sometimes almost enzootic and need to know and establish preventive and recuperative measures for its eradication and reducing economic losses in the pig farming sector.

Keywords: Infectious diseases, digestive tract pig pig production.

INTRODUCTION

Infectious diseases that affect the digestive system of the pig have been traditionally, and still are, one of the main concerns of veterinarians since with respiratory diseases are responsible for much of the economic losses to the pig farms.

Spain is currently the second largest producer in the EU pig and pig farming has experienced a steady increase for years. The increase has been accompanied census of constant also increased farm size recently associated changes in production systems that have been directed mainly to seek better systems for infectious disease control.

Many of the changes in production systems are proving that they are not the panacea that some advocated absolute few years ago. It is often forgotten that carry bacteria on Earth more than 3500 million years and have a tremendous capacity to adapt, therefore changes in production systems can help control some bacteria, but there will always be suitable ecological niches for other bacteria that can exert their pathogenic action even better when some competitors are eliminated.

Pig production is intensive production which works on animals increasingly selected from some points of view. Pigs have a current capacity of weight gain and feed conversion into meat steadily increasing but largely genetic selection has forgotten or neglected include disease resistance among its objectives. The current pig is an animal with a very lean and digestive pushed to the limit of its capacity and is therefore much more likely to suffer from digestive disorders.

Moreover, production systems have been based largely on the possibility of using antibiotics or other chemotherapeutic agents to fill gaps in the housing, in handling, hygiene and many other fundamental aspects of animal health. The use of antibiotics is increasingly difficult and we think that this trend, sometimes irrational, is unstoppable at the moment. Every day there is less “growth promoters”. Antibiotics are used as such get a better feed utilization by the pig, but have no direct metabolic effect. Have an efficiency based on its antimicrobial activity exclusively controlling certain populations of intestinal bacteria metabolism whose metabolism is detrimental to the pig.

We must also add that the feed formulation is still very far from being an exact science. Some nutritionists conceive the pig as a machine, engine that runs on a fuel whose composition has little importance as long as the final formula is appropriate to mark what needs tables, a fatal error. The pig is a living being whose digestive system has a capacity to adapt to limited dietary components that can not be forced without running the risk of upsetting the digestive physiology and cause of diarrhea in animals.

This makes the pig digestive diseases are taking a growing importance is heightened because these diseases are almost always done in enzootic farms and because in many cases have not sufficiently effective control measures.

The aim of this paper is to present the current status of some of the major digestive diseases of infectious etiology, which are sometimes almost enzootic in pig territory Granma in Cuba.

DEVELOPMENT

The main digestive diseases that occur in our animal farms are:

1. Colibacillosis

2. Colienterotoxemia

3. Hemorrhagic Necrotic Enteritis4. Proliferative enteropathy

5. Salmonellosis

6. Dysentery

7. Intestinal spirochetosis

8. Transmissible Gastroenteritis

9. Rotavirus Diarrhea

Of them discuss the following:

Colibacillosis

These types of infections are due to agents and enteropathogenic enterotoxigenic strains of E. Coli and often appear suddenly during the first week after weaning.

While it affects the growth of animals, no consequences as serious as edema disease. Its causes are caused by two types of colon bacilli:

– E. Coli enterotoxigenic

– E. Enteropathogenic Coli.

Strains of E. Enterotoxigenic coli produce enterotoxins that alter the balance hydroelectric and cause secretory diarrhea. Very often (in over 50% of cases), such strains are also isolated in animals afflicted with diarrhea in fattening.

In contrast, strains of E. Enteropathogenic coli cause injuries and destruction adhesion directly on the osmotic cell and cause malabsorption diarrhea. Although these serious enteritis are less than those produced by strains of E. Coli enterotoxigenic affected animals take longer to recover.

Salmonellosis

It is a group of diseases caused by bacteria of the group previously Paratific salmonella, which usually evolves with septicemic processes or sub-acute gastroenteritis or chronic affects all domestic species including man. Pigs and poultry are the most affected.

Sources of infection

Sick animals are clinically healthy and capable of being carriers and disposers of bacteria to the medium. The main and most important element is infecting and contaminating feces.

We can not mention the role of man as a germ carrier.

Transmission routes

These germs can exist in the intestinal flora of diverse species of healthy animals, but the frequency of these carriers of bacteria varies greatly depending on the species and the area.

The spread between sick and healthy is important in this disease, as well as carriers of bacteria. Other possibilities are the direct or indirect action of wastewater that is contaminated with feces of infected animals or man. May be contaminated fishmeal and meat.

Facilitate the spread, decreasing the body’s natural resistance due to nutritional disorders, transportation tiring, intense parasitosis, wet and cold accommodation, etc. These predisposing causes are of special importance for the development of the disease.

It is considered that animals are cured as permanent carriers therefore pose a constant danger.

Symptoms

The morbid phenomena appear and 24-48 h in horses, several days in calves, etc.., Generally estimated within 18-24 h, for all species, but may extend slightly over time appointed.

Acute enteritis is characterized by more or less severe, resulting in diarrhea and dehydration. Sometimes they cause septicemia from the intestine into the blood can multiply in it. Enteritis enteritis often becomes chronic with the destruction of lymphoid follicles. There may be transient intestinal ulcers and bleeding.

Adult cows can carry and if they are pregnant, according to the intensity of the infection can cause abortion or birth of weak offspring who subsequently die.

In pigs the disease presents as a very common infectious disease in young pigs. Its main etiologic agent is Salmonella cholerae suis and its incubation period is usually not less than 3 or 4 days. At this time there may be fever and often also vomiting and diarrhea, and after 2 or 4 days, intense discomfort, animals can die, having occurred in the non-pigmented skin reddish coloration affecting the ears, belly face and thighs.

Diagnosis

The symptomatological not give a vague idea of what morbid symptoms. Necropsy allows diagnosis at least likely to be observed in acute cases, along with possible bleeding, swelling of the spleen and sometimes especially necrotic foci in the liver. Ongoing slow intestinal ulcers also.

The bacteriological investigation will tell us the accurate diagnosis for which must be sent to the laboratory portions of spleen, liver with gall bladder, lungs with purulent foci, kidney, small intestine portions. Live animals, blood and feces.

Measures contraepizoticas

The procedure to be followed is:

* Elimination of predisposing causes

* Elimination of sick animals

* Disinfection of facilities

* Can be used with curative chloramphenicol

* Can also be used antidiarrheal powders, in cattle, swine and goats

* It can also be used oral sulfamethazine

Preventive and recuperative

Preventive measures are:

1. Avoid the stress of all types that can reduce the resistance of animals

2. Clean daily craft, shade houses, yards and pens, eliminating all manure.

Hemorrhagic enteritis or swine dysentery

Begins to appear at weaning (although it can also affect the bristles) and manifests definitely fattening. It is caused by a spirochete anaerobic, the Serpulina hyodisenteriae, but does not act alone. Some tests presumes that there hemolysing spirochetes and other intestinal bacteria, such as Campylobacter jejuni and coli, Bacteroides vulgatus, Fusobacterium necrophorum, Clostridium perfringens and difficile, favoring the colonization of the Serpulina hyodisenteriae.

In any case, the pathogenic bacteria responsible hyodisenteriae Serpulina unclear. This bacterium produces a cytotoxic betahemolisina causing a phenomenon of disseminated intravascular coagulation, so must also consider the power of endotoxic lipopolysaccharide structure. When the disease is played, its pathological manifestations confined to the digestive tract, specifically in the area of the cecum and colon.

Epizootiology

Agent. – The fact of plurality immunological S. hyodysenteriae and limited cross-protection between the nine known serological types can justify paradoxical reappearance of the disease-carrier pigs by introduction of new serotypes-in farms where the DP is well controlled; vaccine failures also explain specificity. Variations in virulence influences the severity of clinical outbreaks of DP low virulence strains induce immunity against homologous virulent, and constitute the foundation of live attenuated vaccines. This organism is relatively resistant to environmental conditions, sensitive to heat, drying and oxygenation, does not survive more than six days in liquid effluents (53) and 18 days in faeces on the soil moist at 4 C. For large-scale epidemiological studies can use different types of S. Epidemiological hyodysenteriae, from those characterized by high variability, such as electrophoretic types (74), of which Australia was detected in 50 types in 231 strains, concurring several within a farm, to others whose polymorphism is much more restricted, as are types genomic (11 genotypes) (14).

Hosts (21, 27). – The pig is the natural host of S. hyodysenteriae and sensitive species only, which does not prevent the agent has been isolated occasionally birds (Rhea americana) (31) dogs (23) and mice on farms affected by the DP. These secondary hosts except mice (180 days of excretion), serpulinias excreted in faeces for a few days or just a few hours. The flies act as mechanical vectors (4 hours) of low intensity. It is unlikely that the source host side are the introduction of infection to a farm exempt, but help disseminate between ships, especially mice (31). All these measures justified pest control, insect and confinement of dogs and birds in the control and eradication plans.

S. hyodysenteriae infects hog intestine and excreted only through faeces. Young pigs and bait, between 15 and 70 kg in weight are more likely to have DP. But adults also can sicken and piglets. There is a correlation between the activity of mitochondrial dysfunction-inducing strains of S. hyodysenteriae and sensitivity of age-related pigs (77). It is not uncommon for pigs apparently healthy carriers resulting serpulinas seronegative. The recovered from the disease can excrete the seeds even for three months, although acquired immune resistance, it is possible that under circumstances of intense immunosuppression and exposure to very high doses infective disease relapse. If overcoming the disease has been mediated by a treatment institution of protective value reduced immunity, the disease reappearing after deletion of chemotherapy or effect of stress. Mothers are at par and protective lactegnicas fecal contaminants, leaving unprotected piglets after weaning.

Environmental aspects (21, 27). – The hygienic conditions of exploitation, health plan and generally poor management influences the epidemiology of PD. Usually sufficient separation of 1 km to avoid contagion between farms. Lack of facilities for quarantine and indifference to the health of the pigs acquired origin favor the introduction of infection. However transport vehicles and enclose a risk visitors on Serbulinas as introducers. The late weaning epigenic facilitates transmission (56). Systems of continuous occupation of ships favor persistence of infection. Food rich in readily fermentable soluble carbohydrates, and rich in starch increases the responsiveness, sensitivity and intensity excretory of pigs (58, 66). Clinical outbreaks usually preceded by sudden changes in feed, removal of the medication in the feed and generally stressful situations.

Clinical Symptoms

The symptoms of hyperthermia and infection are abdominal pain. When developing in subacute or acute causes diarrhea in animals plentiful with lots of blood and mucous. According to the efficacy of the medication being used, the process can cause substantial morbidity and 90% mortality 30%. As a consequence of the disease, delays occur in the growth of piglets.

Diagnosis

Diagnosis is usually made from an examination of the lesions found at autopsy. The difficulties involved in attaining a Serpulina cultivation makes the confirmation of the disease is very delicate. Among other reasons, because the insulation does not confirm infection, as before is necessary to differentiate between two bacteria: the Serpulina hyodisenteriae and Serpulina innocens, since the latter, similar to the first, is not pathogenic.

Swine Transmissible Gastroenteritis (TGE)

Concept

It is a disease of viral etiology that is characterized by producing profuse diarrhea and vomiting and dehydration and causes a great morbiletalidad in nursing piglets.

History

The disease was first described in 1946 in the U.S., then spread to Europe and other continents. In Cuba, first reported in the west of the country on April 16, 2003, by the National IMV observing a existence of 43 outbreaks in six provinces.

Economic Importance

The economic impact is huge with high infant mortality in piglets up to 100% and also affects adults although mortality is low.

Etiology

The virus belongs to the coronavirus, quenched with 3% formaldehyde and organic solvents is sensitive to caustic and ultraviolet light.

Epizootiology

The only virus is pathogenic for pigs of any age and race, but as age increases, decreases susceptibility. The animals in the incubation phase or already recovered are the primary source of the virus that can disseminate several weeks.

Other sources of infection include colostrum from infected pigs, as well as food and water contaminated with secretions and excretions virulent.

Clinical Symptoms

The incubation period ranges from 18 to 24 hours in animals and infants 2-4 days in older animals.

The disease begins a sudden implementation is presented first persistent vomiting and diarrhea then generally keeps appetite, dehydration is marked by the loss of large amounts of electrolytes and water, there is a very intense headquarters and morbidity reaches 100% and mortality in pigs is very high adult and not exceeding 5%.

Injuries

It is characterized by dilation of the small intestine and a degenerative process in parenchymal organs.

In her stomach and gastritis petechiae may appear that can range from severe catarrhal to fibrinous. In the small intestine is present catarrhal enteritis with villous atrophy, with congestion in some organs (liver, spleen and brain).

Diagnosis

By observation of the clinical symptoms.

The three-log increase in paired sera titles by neutralization test, and immunofluorescence.

The isolation was performed on primary cell cultures of kidney.

Differential Diagnosis

With him hog cholera auque here’s a high fever, erythema of the skin and nervous symptoms.

Contraepizoticas preventive measures

Vaccination 100% of the mass and mainly in breeding. In Cuba the most important thing is to prevent violations of the rules at border points to protect the country

Contraepizoticas recuperative measures

In the presence of a disease dictates the strictest quarantinable, take all remedial measures established and reported to all instances to be an exotic disease.

If the primary focus is located and the number of animals is small it comes to eradicating mass slaughter of affected and can also be applied gradually sacrifice or create adequate population immunity naturally or artificially.

Banned antibiotics and enteric diseases

The resolutions adopted by the European Commission to prohibit the use of certain antibiotics in animal nutrition have unleashed a sustained dispute between the competent bodies of the European Union and companies, institutions and producers, mainly pigs and poultry affected by the measures.

On 1 July l999 ban took effect four antibiotics used in animal feed as growth promoters. The measure adopted by the European Commission affects Bacitracin Zinc; spiramycin, virginiamycin and tylosin. This prohibition requires that none of these additives can be found in factories, stores, farms or be incorporated into feed as promoters. The four banned antibiotics were used in disease prevention and performance improvement in the intensive livestock, mainly pigs and chickens.

Last December, the EC stated that the use of these antibiotics as growth promoters could contribute to increasing resistance of bacteria to these products and other similar human therapeutic use. These suspicions, but did not respond to any firm conclusions from studies conducted to test, were endorsed by the SCAN (Scientif Committee of Animal Nutrition). The subsequent delivery of the draft to the Committee ban animal feed in the European Union, found that two thirds of the member countries pronounce themselves in favor of it to make way for the resolution.

From a technical standpoint, the ban also has its lights and shadows. In the pig sector argues that now only available four antibiotics as growth promoters: monensin, salinomycin sodium, avilamycin Flavofoslipol and, just the least used in the sector, as its activity is lower mainly to digestive disorders, quite common in the transition of piglets.

In the pig sector, professionals doing some clinical considerations expressed as the suppression of Tylosin as promoter affect enteric spirochete Serpulina pilosicoli especially to increase the frequency and clinical proliferative ileitis. Thus, the ban on virginiamycin affect enteric spirochetes, and proliferative enteropathy probably allowing the growth of clostridia.

CONCLUSIONS

Digestive diseases in swine species pose the greatest health risk of spread of disease in swine farms and are the largest cause negative economic impact with high morbidity and mortality in the younger categories.

RECOMMENDATIONS

Keep active in all pig farms contraepizoticas plan preventive and recuperative measures against infectious diseases transmissible from pigs.

REFERENCES

* Current status of digestive diseases in pigs. ftp/articles/articulo829.pdf.

* Risk pig farms.

* Diseases of the boar.

* Current status of digestive diseases in pigs.

* Anti swine salmonellosis.

* Enteropathies pig.

* Hemorrhagic dysentery.

* Enf.entericas pig.

* Fernandez, LH, Reinaldo, GL, Alonso, SR, Rodriguez, DJ Pig Health Manual Volume II. Editorial “Flix Varela” Page 9-11. Havana. Cuba.1999.