The Interstitial Pneumonias

The term interstitial pneumonia or alveolar epithelial hyperplasia has been used to designate the lung diseases in which there are inflammatory lesions of the septa or dividing wall of the air sacs or alveolar of the lung. The term and understanding of “atypical” pneumonia has been difficult, particularly in regard to terminology and etiology. All of these terms have been used interchangeably:      1.Acute Bovine Pulmonary Emphysema (ABPE) “Fog Fever”      2.Atypical Interstitial Pneumonia (AIP) Usually seen in the feedyard environment.      3.Pulmonary Adenomatosis “Farmer’s Lung”      4.Acute Respiratory Distress Syndrome (ARDS) Plant toxins, etc Acute Bovine Pulmonary Emphysema (ABPE),”Fog Fever”, is an acute respiratory distress syndrome that usually occurs in the fall in adult beef cattle moved from dry, sparse overgrazed pasture to lush, green pasture. Almost all outbreaks of ABPE occur within two weeks of pasture change. ABPE is caused by ruminal production of 3- methylindale (3MI) from ingested L-tryptophan (TRP) in the feedstuffs. Adult breed cows are most commonly affected because this is the type of animal most likely to be subjected to abrupt pasture change.The type of pasture appears to be unimportant, as long it is lush. In severe cases there is an acute onset of severe dyspnea (difficult breathing) with a loud expiratory grunt, frothing at the mouth and open mouth breathing with tachypnea (rapid breathing). It is important to note that coughing is not prominent. In animals that die, ecchymotic to petechial hemorrhages occur in the larynx, trachea and bronchi with frothy fluid is present in the airways, and there will be congestion and edema of the lung giving it a smooth, glistening, and glasslike appearance. An Acute Respiratory Distress Syndrome (ARDS) is any respiratory condition characterized clinically by a sudden onset of severe dyspnea (difficult breathing) and pulmonary lesions of congestion, edema, thickening of the alveolar epithelium and interstitial emphysema. One example of ARDS would be Moldy Sweet Potato toxicity, which is caused by ingestion of a furanoterpenoid toxin. There is an acute onset of tachypnea and hyperpnea (rapid excessive breathing), tachycardia, and dyspnea with loud expiratory grunting, frothing at the mouth, extension of the head and neck, flaring of the nostrils and frequent deep coughing. Signs usually occur within 1 day of exposure and death may occur 2-5 days. At necropsy the lungs are wet, firm, enlarged and fail to collapse with yellow gelantinous edema fluid and emphysema throughout. Pulmonary adenomatosis, “Farmer’s Lung”, is an allergic respiratory disease caused by inhalation of organic dusts. Farmer’s Lung is caused by exposure to the dust from moldy hay, grain, or other vegetable matter containing spores and products of themophilic actinomycetes such as Micropolyspora faeni and Thermoactinomyces vulgaris. Pulmonary adenomatosis is a disease of confined adult cattle, primarily dairy cattle. Typically a succession of acute cases occurs during the winter housing period. The acute form is indicative of recent exposure and is characterized by a sudden onset of dullness, decreased appetite, hypogalactia, coughing, expiratory tachypnea, and dyspnea. There is a moderate transit fever. The chronic form is insidious in onset and may not be detected until there is considerable fibrosis. Some may not be detected until turned out in the spring when increased exercise causes an acute crisis. There is a history of weight loss and coughing for several winters with remission in the grazing season. If the condition can be arrested before significant fibrosis occurs, the prognosis is good. Farmer’s Lung is a problem in areas with wet summers and severe winters, a situation that results in the combination of moldy hay and housing of cattle in the winter. Bailing and stacking of hay with a high moisture content results in overheating of the stacks. Thermophilic molds are released when the hay is distributed for feeding. At necropsy, in acute cases, the lungs are superficially grossly normal; however, with closer examination small gray spots in many lobules will be noticed. The primary interstitial pneumonia of feedlot cattle is Atypical Interstitial Pneumonia (AIP) which is also accompanied with edema and emphysema of the lung. Affected animals have an acute onset of severe breathing difficulty and majority die regardless of treatment. Lungs from animals that have died from AIP are enlarged, rubbery and have a mottled (checkerboard) interstitial emphysema appearance. In the Bovine Respiratory Disease Complex (BRDC) the pathology involvement of the lung is usually fibrinous and found in the lower ventral portion of the lung whereas in AIP the upper or dorsal part of the lung is involved. The exact cause is not known. Some studies suggest that it may be related to dietary factors, and dust since it is most often seen in the summer months and also may be associated with lung disease such as Bovine Respiratory Syncytial Virus (BRSV). The diseases discussed are all characterized by diffuse pulmonary involvement and by marked alveolar epithelial hyperplasia. The disease called AIP includes those cases that are pathologically similar to ABPE and ARDS but epidemiologically different. Future research can be expected to reveal additional etiologic agents. A survey is presently being conducted in cooperation with University of Georgia and Colorado State University and with feedlots and veterinary consultants regarding the management factors and other diseases that may lead to the development of AIP. The aim of this survey is to gather information regarding size, geographic location, and management factors from feedlots where AIP is a problem and also from feedlots where the disease is not a problem. The information will help point researchers in the right direction in future research to determine the cause of Atypical Interstitial Pneumonia. References: Breeze, Roger, Carlson, James R.; Current VeterinarymTherapy I – Food Animal Practice, pp 832-725 Hjerpe, C.A.; The Lungs and Mediastinum. Bovine Medicine and Surgery – Second Edition, pp 714-725 Smith, J.A., “The Interstial Pneumonia,” Large Animal Medicine, 1990 Bradford P.Smith, pp 596-608

BRD Complex Viral Conditions, ETC

BVD Infection of Feedyard Cattle    If you ever want to start an argument in a feedyard about vaccination programs, mention BVD (bovine virus diarrhea). The folklore, myths and half-truths concerning this virus are many. BVD does play a key role in feedlot respiratory disease, but we are unsure of its exact role and even more unsure of possible control methods.    BVD was first described in 1946 as a severe and often fatal disease of dairy cattle. Early researchers named this disorder “mucosal disease” and many people still call the severe digestive form of BVD by this name. We now know that BVD can affect other organs, including the respiratory and immune systems. Because of the complexity of this disease, we do not completely understand all the effects of BVD virus on cattle.    BVD in the feedyard can mimic many other diseases or show no obvious signs at all. Common clinical signs include depression, off-feed, discharge from the eyes and nose, coughing and rapid respiration. These signs may or may not progress to a severe watery diarrhea with ulcers in the mouth and entire digestive system. This set of signs could account for any of a number of diseases seen in feedlot cattle and explains why it is important to avoid a diagnosis of BVD from clinical signs alone.    In order to put this viral disease in perspective, let’s look at the effects of BVD on the respiratory system and the Bovine Respiratory Disease complex.    BVD has two prime effects on the respiratory system. First is a direct negative effect on the local disease fighting mechanisms of the lungs and upper respiratory tract. Second, BVD virus can cause a severe disruption in the body’s immune system.    The end result is that the BVD infected animal is more susceptible to any infection, but most importantly bacterial pneumonia such as Pasteurella haemolytica(Mannheimia haemolytica), Pasteurella multocida and Hemophilus somnus. Mycoplasma bovis may also play a role.    In order to have a problem with BVD in a feedyard, you must have two factors present: (1) a susceptible animal and (2) a virus capable of causing disease.    Of course, salebarn cattle and freshly weaned calves are more susceptible to any disease challenge. Also, some strains of virus are capable of causing disease to greater extent than other strains.    If you take a highly susceptible calf that has been freshly weaned and expose it to an extremely hot virus in the feedyard, the outcome usually is death. Conversely, if the cattle are protected against BVD or non-stressed, the same virus may have little to no effect on them. Control of BVD    There are three schools of thought concerning BVD vaccination:    1. First, all cattle must be vaccinated with a modified live virus (MLV). This procedure has one serious drawback. Any MLV vaccination on stressed calves is potentially harmful, but the effects of MLV BVD vaccines can be even more harmful than most by causing immunosuppression of an already compromised animal. There are good MLV BVD vaccines that confer adequate protection to feedlot cattle with minimal side effects, but the potential for this adverse reaction is present with many MLV BVD vaccines.    2. The second school of thought says vaccinate for BVD with a killed product. Killed products have been much improved over the last few years and offer good protection without causing adverse reactions. Opponents of these vaccines agree that protection is adequate, but rather slow in appearing.    3. The third school of thought is that BVD vaccination has no effect on respiratory disease in a feedlot.    In our practice, recommendations on BVD vaccination are based upon the type of cattle fed, past health history and confirmed presence of BVD problems through diagnostic techniques.    In summary, BVD has the potential to cause serious problems in feedlot cattle. The key to control lies in proper diagnosis and sound preventative measures. Respiratory Syncytial Virus Vaccine    Currently, two modified live vaccines and one killed respiratory syncytial virus vaccines are available for use in beef cattle. In order to understand the potential use of these products, let us examine this virus, its clinical manifestations and application of vaccination to a feedlot health program.    Bovine Respiratory Syncytial Virus (BRSV) is named because of its ability to form syncytia in infected cells. Syncytia are simply an aggregation of cells that clump together in a large mass with an indistinct internal structure.    This virus was first seen in Europe and Japan. Reports of outbreaks in the U.S. were first seen in Nebraska and Colorado. A human counterpart has been recognized that has many similarities to the virus seen in cattle.    When BRSV is exposed to susceptible cattle, an incubation period of 2 to 10 days can be expected.    Clinical signs during an outbreak are of rapid onset and include increased respiratory rate, depression and discharges from the eyes and nose. Salivation or slobbering is common and may be blood-tinged as can the discharge seen coming from the nose. Coughing is usually marked and seems to persist throughout the course of infection. Swelling may occur around the eyes but is usually pronounced in the throat region. Body temperatures are increased and range from 104° to 108° F. Abortions usually are not seen but some have been reported.    The disease outbreak can affect all ages of cattle, but is usually most pronounced in freshly weaned calves. Infections can range from mild to marked and affects a large number of cattle, but usually with a low death loss. As with any virus infection, bacterial pneumonia can be a secondary invader.    The clinical picture of BRSV can resemble other viral infections such as IBR, PI3 or BVD, except that the disease is usually mild and the marked swelling in the throat latch is rather unique.    Other viral infections such as those mentioned can cause much higher death losses; but early in the outbreak there has been confusion as to the actual agent involved. Many times BRSV has not been identified until other common viral agents have been eliminated as the causative agent.    As yet, in our feedyard experiences, the problems with BRSV have been minimal. That is, we have not recognized this condition in the pure form. This is not to say that BRSV has not been involved in certain respiratory problems. As with other viral agents, over- growth of Mannheimia haemolytica or Pasteurella multocida may actually mask the true initiator of the problem. BRSV can cause severe damage to the trachea and lung, which would then allow for bacterial pneumonia to occur.    In order to diagnose BRSV as a problem, you must attempt to isolate the virus from the lung, trachea or nasal secretions. The affected lung must also be examined under the microscope for the syncytial formation so characteristic of this disease. These two procedures may prove very unfruitful in the feedlot environment.    Blood samples and serology taken at the time of respiratory outbreak and repeated 2 to 4 weeks postoutbreak are the most beneficial method of positive diagnosis currently. Continued development of more accurate and effective diagnostic techniques is     under way.        In summary, Bovine Respiratory Syncytial Virus is usually a mild viral infection which can be relatively severe under some circumstances. This disease is usually a problem in freshly weaned calves, but can be a problem in any age of cattle. Other Respiratory Diseases    Many times when we talk about respiratory disease, infectious bronchopneumonia or Bovine Respiratory Disease Complex (BRDC) is the focal point.    In the feedyard, other forms of respiratory disorders exist. Diphtheria and “hardbreathers” or “honkers” can be problems, although not as common as BRDC. Diphtheria    Diphtheria is an infectious disorder of the upper airways. A focal point of damage usually occurs to the larynx or voice box and allows for opportunistic invasion of the damaged airway lining by bacteria. The bacteria that invades the airway is the same organism that causes foot rot in cattle.    Symptoms of the calf affected with diphtheria may include difficulty in breathing, excessive salivation, swelling around the throatlatch and increased body temperature. Often the most obvious clinical sign is the foul smelling breath that occurs. Because of the bacterial invasion of airway tissues and the particular pathogenic organisms involved, dead tissue is formed at the site of infection causing the fetid odor.    Diphtheria in a feedyard may often be an uncommon occurrence, but may occur secondary to feeding coarse feedstuffs, in the form of hay or finished feed. Other outbreaks of widespread diphtheria have not been attributed to any known factors.    Treatment for the condition is generally quite satisfactory, if treated symptomatically with a broad spectrum antibiotic. Treatment should also include therapeutic agents to decrease swelling and increase the overall airway opening. Swelling in the voice box or larynx area can lead to a greatly decreased airway capacity. Hardbreathers    Hardbreathers or honkers are frequently seen in the feedyard. A hardbreather is an animal that usually has 45 to 60 days or more on feed. It generally is seen in a pen of cattle having difficulty breathing. Depending on the severity, a “honk” may be heard as air is expelled.    Hardbreathers are not caused by a single condition, but by several possible conditions. These conditions may include (1) IBR, (2) acute spread of a low level pneumonia, (3) allergic tracheitis, (4) atypical interstitial pneumonia, or (5) respiratory syncytial virus.    It is difficult, if not impossible, to tell which of these conditions the animal has when it is pulled. Laboratory tests and response to treatment are necessary to separate these five causes of a hardbreather. And it is important to know the causes before proper treatment can be instituted. Acute IBR    Acute IBR infection is seen as a single condition in cattle with greater than 45 to 60 days on feed. Cattle often have severe respiratory difficulty and a high body temperature (in excess of 105°F). A blood tinged nasal discharge may also be present.    Animals with low grade pneumonia which previous therapy failed to completely resolve the condition, often are triggered by the IBR virus into an active, more severe respiratory condition.    As the animal becomes closer to finish and fatter, the digestive tract is pushed forward into the diaphragm causing pressure on the previously compromised lung thus causing less total function air space and many times death. Allergic Tracheitis    Allergic tracheitis and atypical interstitial pneumonia are actually an acute response to chronic exposure to allergy – causing moldy feed or other airborne allergenic particles. These animals appear very suddenly with no previous indication that there was a problem.    Such cases may occur when the animals are moved longer distances, as might occur to reimplant. Airway space was adequate when in the pen, but the exertion of movement caused the animal to become decompensated and thus suffer an acute lack of necessary oxygen. Respiratory Syncytial Virus    Respiratory Syncytial Virus (RSV) has been reported by some to be a cause of allergic tracheitis and atypical interstitial pneumonia. It is unclear at this time as to the significance of this condition in fat cattle pneumonia.    Therapeutic goals for these conditions are relatively simple: (1) avoid any procedure at the time of treatment that would increase the animal’s need for additional oxygen; (2) supply therapy to open narrowed airways; (3) reduce swelling and possible allergic reaction; and (4) treat with a short withdrawal antibiotic.    Animals treated may respond favorably at first only to relapse soon after treatment is completed. Therefore, you should keep the option of early slaughter open should treatment response be unsuccessful.    Even though the incidence of fat cattle respiratory conditions is much less than BRDC in newly arrived cattle, the economic losses incurred are much greater per animal affected. For example, an animal lost soon after arrival will realize an economic loss that is roughly two-thirds that of an animal that is near finish. Therefore, it is easy to see that keeping the animal healthy throughout the feeding period is important for efficient economic returns. More information may be received through Beef Production Medicine which can be purchased in the publication section of this web site.

Respiratory Disease of Feeder Cattle

Respiratory disease of cattle is known by various names – pasteurella pneumonia, shipping fever or Bovine Respiratory Disease complex.

No matter what it is called, this disease accounts for huge economic losses every year. So it is important for cattlemen to be familiar with recognition, treatment and prevention of this disease.

There are several types of respiratory disease, but the one of most concern is the infectious form. We all are familiar with the calf that has pneumonia. This sick calf will be depressed, drawn, gaunt and unwilling to move. It will cough, breathe rapidly, have a yellowish

discharge from the eyes and nose, and have a fever of 103° to 106° F.

The first thing we often do when we see these signs is reach for a bottle of antibiotic. Rather than reach for a bottle of antibiotic, let’s look at the factors that interact to cause pneumonia. Once we better understand these factors, we can work toward more effective prevention and treatment programs.

Pneumonia results from a complex series of steps that are only partly understood. Research has shown that three factors must be present for a calf to get sick with pneumonia: (1) stress, (2) viral infection and (3) bacterial infection. Stress can be caused by routine

procedures such as castrating and dehorning. Also, new situations – nutrition, weather, congregation and transportation – can induce stress.

When a calf is stressed, its body reacts by secreting hormones that positively and negatively affect bodily functions. On the negative side, stress causes the entire body to be more prone to infection. This occurs by allowing disease causing organisms easier routes of entry and by disarming some of the body’s important defense mechanisms against disease.

So the first step toward pneumonia occurs following a stressful event.

The second step takes place when the body’s defenses are down and viruses invade the nose and other parts of the respiratory system. Viruses that commonly take advantage of this situation usually include IBR and BVD. Other viruses such as BRSV and PI3 sometimes cause problems.

Virus infection in cattle could be compared to the common cold or flu in humans, which rarely cause death. Although viruses may cause death, the major role they play in pneumonia is to allow the third factor of this disease – bacteria – to gain a foothold and possibly lead to death.

Pasteurella haemolytica (Mannheimia haemolytica) and Pasteurella multocida and Hemophilus somnus account for the majority of bacterial infections of pneumonia.

These bacteria gain entry via infected nasal secretions (much like virus particles may), or they may be stimulated to grow from normally low populations in the throat. Either way, without proper recognition and antibiotic treatment, these organisms can cause death

rather quickly in affected animals.

Since antibiotics kill or inhibit growth of bacteria, these are the organisms that we are trying to eliminate when we use drugs such as an antibiotic.

Respiratory Viral Disease

Respiratory viral disease can be devastating to animal health. It continues to be poorly understood and treated with mediocre results.

Viruses are not actually alive but are particles of genetic material that must infect the animal’s own living cells before they can reproduce and cause damage. The use of antibiotics will not directly fight a viral infection; but in most instances, antibiotics are indicated to treat the coinciding bacterial disease.

Viruses are spread from one animal to another via (a) direct nose-to-nose contact,
(b) contact with nasal secretions or other bodily exudates from an infected animal, or

(c) through aerosol particle transfer between animals. Exposure to viruses is unavoidable

in a feedyard, so we must concentrate our efforts on prevention and control-mainly with timely vaccination- preferably before exposure to the disease causing virus.

The four most common respiratory viruses are IBR, PI3, BVD and BRSV.

IBR (infectious bovine rhinotracheitis) has also been called “rednose.” It causes a reddened, tender nasal surface that crusts over and peels, as well as sore and runny eyes. Internally, the animal’s trachea or windpipe becomes very inflamed and may fill up with

a thick exudate. IBR has also been implicated in genital infections in cows, as well as in central nervoussystem disorders.

PI3 (parainfluenza 3) has long been recognized as a respiratory pathogen in cattle, especially lightweight calves. Its most harmful characteristics is that it destroys the cilia (hairlike projections) in the trachea, which prevent foreign matter and bacteria from

entering the lungs.

BVD (bovine virus diarrhea) has long been recognized to cause problems in the digestive tract, but in recent years has been implicated as a respiratory agent. BVD is very immunosuppressive; it weakens the animal’s immune system and thereby lessens its

ability to fight disease. Some cattle have been proven to be chronic carriers of one type of BVD and develop severe digestive and respiratory disease when exposed to another strain. Unfortunately, there is no practical and quick way to identify these animals, and we have

no accurate estimate of the extent of this problem.

An Ounce of Prevention: Feedyard Receiving Programs

Computerization has helped us evaluate the costs of disease and the savings through prevention. As a result, our focuses in feedyard health programs have evolved away from antibiotic treatment and mass medication. The new focus is towards vaccination, stress management and immune competence. The objective is to block or minimize the processes that amplify disease susceptibility. Feedyard veterinarians face a unique challenge. No other food animal production is as variable and non-integrated as the beef industry. Repeated transportation, resulting in environmental and nutritional changes, is the norm rather than the exception. Thus, the types and degrees of stress must be identified and addressed. A strategic receiving program should be designed and executed with the same organization and detail as a processing or treatment program. The Three “Rs” Many of the needs of stressed cattle are summed by the three R’s of a receiving program: rest, rehydration, and rumen. Transported cattle become physically fatigued from standing especially if hauled long distances over 12 to 24 hours. Additionally, mental stress can be a factor due to loading, unloading and commingling with unfamiliar cattle. We recommend that a spacious, dry (or bedded) pen be provided during receiving. Specific parameters include 150 to 200 square feet of pen space per head and 12 to 16 inches of feedbunk space per head. If bedding is used, be sure it is removed when it becomes wet or soiled. If left in place, it becomes a seedbed for contamination and infection. Before stressed cattle are processed, a rest of at least 12 to 24 hours is suggested. Research test after test shows how stress compromises current immune function, as well as further development of immunity. A rest period simply allows the animal to regain some of the immunocompetence that transportation and marketing stressors have disfavored. So rested cattle respond better to the vaccines administered during processing. Practical observations have suggested that a 1/2% to 1% increase in morbidity is seen for each 24 hour delay in processing after arrival. Of course, short-haul, healthy country cattle experience minimal stress and immediate processing can be performed as a matter of convenience. Also, highly stressed sick cattle may need immediate handling if they merit mass or individual treatment. If this is the case, recognize that prevention has given way to treatment and results rarely are optimal. Keen observers learn through practice and experience how to differentiate between sick cattle and stressed cattle. The veterinarian may check white blood cells counts, plus serum glucose levels and fibrinogen, to aid in this differentiation. Rehydration of transported or water-deprived cattle is crucial. Weight loss or shrink during transport or other handling procedures consists of “fill” loss and tissue losses. Fill consists of digestive tract contents and bladder contents at initial weigh-up. Tissue losses are made up of evaporative, urinary and even fecal losses at some point when fill is gone. Tissue losses result in some degree of dehydration as well as disruption of extracellular and intracellular fluid components. Experience and recent research show that in shrinks greater than 7%, stress is significant. And in long-haul cattle it can be significant when shrink is less than 4%. Unreasonably low shrinks may indicate a high degree of previous loss before initial weigh-up. Rehydration is more critical initially than feed consumption. The old industry practice of holding cattle off water to make them consume feed is unsound. Free choice, clean, fresh water should be available at all times. We avoid water medication whenever possible, as it may alter palatability and water intake. (One exception has been a commercial vitamin E additive that actually seemed attractive to cattle.) Do not assume that cattle are drinking just because water is available. Electric current, unpalatable or toxic contents, ice and ignorance of location may deter or prevent water intake. Water troughs in receiving pens should be checked and cleaned daily. The final R (for rumen) is representative of a large array of nutritional needs. Highly available energy is critical to restore energy balance in the food-deprived animal. But beware of over-consumption, which can lead to metabolic and/or clinical acidosis. The energy-depleted animal may be in a catabolic state, breaking down muscle and other proteins for energy sources. Protein supplementation provides readily available amino acids to aid in slowing and reversing the catabolic process. Non-protein nitrogen should be avoided, however, due to both palatability and toxicity problems. Recently, much attention has been given to vitamins and trace minerals, especially in relation to immune development and protection of tissues. Particular focus has been on vitamins A, C and E, plus the micro-elements zinc, copper and selenium. Research results show this to be promising. Remember, however, it is critical that a physiological balance be maintained on these compounds and elements. Over-supplementation is at best inefficient, and it can be toxic. Roughage, the Natural Foodstuff Roughage provides early fill in the deprived rumen and acts as a substrate for microflora. Reestablishment begins with forage (hay), the natural foodstuff of the ruminant. Native long-stem high quality grass hay is preferable. It can attract cattle to a bunk, and it can deter them from walking fencelines. Starter ration recommendations vary greatly, though a general consensus suggests the following: Energy is provided in a medium level concentrate (about 55%). This is based on a 500 pound calf; and for every 100-pound decrease in body weight, a 10% increase in concentrate is recommended. High levels of protein (13% to 14%) should be provided from a natural protein source. Vitamins and trace minerals should be assessed for need based upon other ration components and cattle source and condition. Health and performance are very dependent on the job done in the receiving period. Before any thought is given to processing and treatment programs, a detailed and effective receiving program should be implemented.

Biosecurity-An Extension of Herd Health Management and Emergency Preparedness

Biosecurity-An Extension of Herd Health Management and Emergency Preparedness Terrorism is defined as an act of terrorizing or state of being terrorized by intimidation. Those weapons available to terrorists for intimidation include chemicals, biological, radiological, nuclear and explosive. Biological terrorism involves the use of microorganisms or toxins derived from living organisms to induce death or disease in human beings, animals or plants. A microorganism to be pathogenic and effective in biological terrorism against animal agriculture must be highly infectious and contagious, have the ability to survive in the environment, have predictable clinical disease pattern (including morbidity and mortality), be pathogenic to livestock and poultry, easy to acquire or produce, attributable to as if it was caused by a natural outbreak, not harmful to person causing the infection and easily spread. Foot and Mouth Disease (FMD) is one example that meets these criteria and also poses the greatest potential threat to the cattle industry. Biosecurity is defined as a comprehensive management program to avoid introduction of virulent (FMD) and zoonotic (a disease of animals that can be transmitted to humans-Anthrax) disease causing pathogens into a livestock herd, non-confinement and confinement, and to prevent the movement of these pathogens within the herd. Biosecurity, as an international, worldwide practice of protecting animals from infectious diseases, has become a major concern with the worldwide threat of Foot and Mouth disease (FMD) and Bovine Spongiform Encephalopathy (BSE). A high percentage of beef operations are managed with an open herd policy that allows entry or re-entry of animals or animal products. During calving season, foster calves may be grafted onto cows. Feedyards and stocker operations commingle cattle routinely. Seedstock operations use artificial insemination or embryo transplants throughout the breeding season. All these management practices, which have been discussed in the management section of this book, place beef operations, cow-calf, stocker, and feedlot operations at risk of disease. To plan an effective Biosecurity Herd Health Management Program (BHHMP), a risk analysis should be conducted.      1. Risk assessment          Identify the level of any infectious diseases already existing, identify and prioritize     those diseases targeted for control and identify the diseases not present and you wish to continue to exclude. i.e.-Bovine Respiratory Disease Complex and Foot & Mouth Disease      2. Risk management          Formulate a comprehensive prevention health program and implement.      3. Risk communication          Explain the plan to management, personnel, suppliers and customers to ensure buy-in and implementation.      4. Collate and analysis results frequently. The first step is to know the complete condition of your operation- herd health, nutrition and facilities. Be aware of potential diseases, how they are contacted and the risks. Biosecurity can be broken down into external and internal components.      External Biosecurity: The rules and procedures implemented to avoid contamination of the herd from outside sources.      Internal Biosecurity: The rules and procedures implemented to avoid any spread of disease within the herd. Many of the components of a Biosecurity Herd Health Management Program are just good common sense. Biosecurity Herd Health Management Programs (BHHMP) programs should include all management, prevention and treatment procedures. See Chart #1.      External and Internal    1. An awareness of diseases-both domestic and foreign. See Chart #2     2. Disease management-prevention, incubation, treatment and risks.     3. An accurate evaluation of health and nutrition of herd.     4. Strict herd health and vaccination programs     5. Health, vaccination and production records of purchased animals      Internal     1. Where possible quarantine program and separate facilities for new animals      2. Isolation, hospital pen for sick animals      3. Clean, sanitary cattle equipment, facilities and lots      External     1. Ability to control human traffic-control access to property, provide disposable protective clothing and provide disinfectant for incoming visitors.      2. Ability to control herd contacts/purchases.      3. Regular veterinary inspection and consultation. Biological security measures are becoming standard in many agricultural sectors. The USDA has implemented three levels for its personnel to follow to minimize the risk of disease introduction. For more detailed information go to www.aphis.usda.gov/oa/fmdbiose.html. Biosecurity Levels Routine levels of biosecurity measures are described below. When in doubt as to which level of biosecurity is needed, choose the higher level. These steps should be repeated for each premises that is visited. Level 1- Visits to farms or ranches that entail office or home visits only.         No contact with livestock or their housing (including pet horse or work dog).         Use the minimum measures such as:         Minimum Biosecurity Measures         1. Avoid livestock areas, pens, barns, etc., unless it is necessary to complete the goal of the visit.         2. Park your vehicle on paved or concrete areas, away from production sites on farm, to avoid contact with dirt, mud or manure. If not possible, be certain that tires are free of dirt and debris by hosing the tires and wheel wells before leaving the premises. If this does not clean the tires adequately, take the vehicle to a nearby pressure car wash.         3. Wash hands with soap and water or an antibacterial gel before entering and after leaving the premises to avoid transmitting disease agents from person to person. Level 2- Visits to farms or ranches where minimal contact with livestock or their housing (barns, pens, hutches, etc) is unavoidable to attain the goal of the visit,  i.e. property appraisals, tour of production facilities. Contact constitutes walking through animal housing or pastures where the animals are not within reach.         1. Apply minimum biosecurity measures plus:         2. Immediately put on clean rubber or new plastic boots upon exiting the vehicle.         3. After returning to your vehicle, clean and disinfect any equipment used with a brush and approved EPA disinfectant solution (see listed supplies- Chart 3).         4. Clean rubber boots with an approved EPA disinfectant diluted with water.             Scrub the bottoms of the boots with a brush to remove all dirt or debris.         5.  Dispose of disinfectant solution according to the label. Unused       disinfectant solution should not be discarded on ground.         6. If wearing plastic boots, place them in a plastic bag that should be left on the premises for the owner/producer for disposal or place in a designated dirty' area of your vehicle.        Level 3- Visits to farms/ranches where there will be close contact livestock. This includes contact such as walking through narrowly confined pens/ lots where animals are within reach or actually handling/inspecting the animals.         1. Apply measures used in Levels 1 & 2 plus:         2. Pre-plan the needed supplies and clothing for daily visits.         3. Use a pair of clean coveralls for each premises.         4. Designate a 'dirty' area in your vehicle for clothing and equipment that        has been used on the farm.         5.  Put on clean coveralls and rubber boots immediately upon exiting the        vehicle.         6. After returning to your vehicle, clean and disinfect all equipment used        (including eyewear) and place all disposable supplies in a plastic bag to         leave with the owner/producer for disposal. If not possible, place plastic        bag in the 'dirty' area of the vehicle and dispose of in a manner that        prevents exposure to other livestock.         7. Clean rubber boots with an approved EPA disinfectant diluted with water.         8. Scrub the bottoms of the boots with a brush to remove all dirt or debris.         9. Dispose of disinfectant solution according to the label. Unused disinfectant        solution should not be discarded on ground.         10. Remove coveralls so that they are inside out and place in a garbage bag.         11. Place the clean equipment and boots in the designated 'clean' area of the        vehicle.         12. If the vehicle was not parked on a paved surface, wash vehicle tires and        wheel wells to remove dirt and debris at a nearby pressure car wash.         13. At the end of the day, dispose of all plastic bags that contain dirty supplies in a manner that prevents exposure to other livestock. Launder all coveralls.         14. Personal hygiene should include shampooing hair and cleaning under fingernails. Gempler’s, Inc describes a biosecurity program as an insurance policy for the health and productivity of the herd. It will not be free. Producers must make decisions about their "risk tolerance level" based on the chances of a disease occurring and the expected economic losses from the disease. There must be planning, commitment and education of all personnel throughout the operation to attain the goals set for an effective Biosecurity Herd Health Management Program (BHHMP). The components of a biosecurity program are all good management practices that will optimize beef production, increase the profitability and ensure a safe food supply. The ultimate fate of our industry is on the line, and collective anti-terrorism actions must be a top objective for all in the industry. Resources for biosecurity information can be assessed at: http://www.biosecuritycenter.org/. Purdue University. This site offers a list of peer-reviewed biosecurity references, disinfectant information, and state regulations involving dead animal disposal, reportable diseases and nutrient management. www.gemplers.com/biosecurity.htm Gempler’s Inc http://www.humanitarian.net/biodefense Humanitarian Resource Instiute http://www.beef.org/ National Cattleman’s Beef Association http://www.drovers.com/ The Drovers http://www.usda.gov/ Department of Agriculture www.aphis.usda.gov/vs/ Veterinary Services www.avma.org/vmat/default.asp American Veterinary Medical Association http://www.firstgov.gov/ For government information