ANAPLASMOSIS

Anaplasmosis is a vector-borne, infectious blood disease in cattle caused by the rickesttsial parasites

Anaplasma marginale

and

Anaplasma centrale

. It occurs primarily in warm tropical and subtropical areas. The disease is not contagious but is transmitted most commonly by ticks. It can also be transmitted via contaminated needles, dehorning equipment, castrating knives, tattoo instruments, biting flies and mosquitoes. The intracellular parasite destroys red blood cells. It causes anemia, fever, weight loss, breathlessness, uncoordinated movements, abortion and death. Diagnosis is based on clinical signs and the examination of blood under microscope for evidence of the parasite. Affected cattle either die or begin a recovery within 4 days after the first signs of the disease. The mortality rate increases with the age of the animal. Unless infected cattle are detected during the early stages of the disease they should not be treated. If an animal with advanced anaplasmosis is forced to move or becomes excited, it may die from lack of oxygen, also antibiotic treatments do little or nothing to affect the outcome of the disease when given during advanced stages of the disease. Treatment consists of the administration of tetracycline. A vaccine is available that helps to reduce the severity of the infection. If you have any cattle with this disease it is very important to control ticks and follow strict sanitation procedures during vaccinations and other procedures to stop the spread of the disease to healthy animals. Animals that recover from anaplasmosis are carriers and can spread the disease. Chlortetracycline also known as CTC can reduce the risk of anaplasmosis. Chlortetracycline (CTC) consumed at the rate of 0.5 mg / lb. body weight daily during fly and tick season will help to prevent anaplasmosis. A consistent intake of the correct amount of mineral is crucial to a anaplasmosis prevention program. CTC is available in medicated feed, free choice salt-mineral mixes or medicated blocks. Be sure the product is labeled for anaplasmosis control and follow the label instructions exactly.

ANTHRAX

Anthrax, a highly infectious and fatal disease of mammals and humans, is caused by a relatively large spore-forming rectangular shaped bacterium called

Bacillus anthracis

. Most outbreaks occur in areas where animals have previous died of anthrax, as the spores remain viable for decades. The predominant sign in cattle with anthrax is a progression from a normal appearance to dead in a matter of hours. Most animals are simply found dead. Once an outbreak begins in the herd animals may be observed with signs of weakness, fever, excitement followed by depression, difficulty breathing, uncoordinated movements and convulsions. Bloody discharges from the natural body openings as well as edema in different parts of the body are sometimes observed. After death, the animal's body rapidly decomposes.

Some animals may be saved if treated very early with penicillin or tetracyclines. Vaccination is very effective in preventing further disease from occurring in animals on a property experiencing an outbreak, however full immunity takes 10 to 14 days to develop. Antibiotics must not be used at the same time as vaccines are given, since they interfere with the development of immunity.

For animals and humans, anthrax is a reportable disease in the United States. Local and state health departments, federal animal health officials, and the CDC's National Center for Infectious Diseases should immediately be notified of any suspected cases. Remember, this is a potentially fatal human pathogen, so appropriate measures must be taken to protect all personnel. A physician should be contacted for the best preventative measures for all exposed or potentially exposed humans.

   

BLACKLEG

Blackleg is a highly fatal disease of young cattle caused by the spore forming, rod shaped, gas producing bacteria Clostridium chauvoei. The spores of the organism can live in the soil for many years. The bacteria enters the calf by ingestion and then gains entrance to the body through small punctures in the mucous membrane of the digestive tract. Cattle that are on a high plane of nutrition, rapidly gaining weight and between 6 months and 2 years of age are most susceptible to the disease. The disease is not transmitted directly from sick animals to healthy animals by mere contact.

The first sign observed is usually lameness, loss of appetite, rapid breathing and the animal is usually depressed and has a high fever. Characteristic swellings develop in the hip, shoulder, chest, back, neck or elsewhere. First the swelling is small, hot and painful. As the disease progresses, the swelling enlarges and becomes spongy and gaseous. If you press the swelling, gas can be felt under the skin. The animal usually dies in 12 to 48 hours. In most cases the animal is found dead without being previously observed sick. The speed with which blackleg kills usually makes individual treatment useless.

Blackleg is almost entirely preventable by vaccination. The most commonly used clostridial vaccination in cattle is the 7-way type which protects against Clostridium chauveoi (blackleg), Clostridium septicum and Clostridium sordelli (malignant edema), Clostridium novyi (black disease), and three types of Clostridium perfringens (enterotoxemia).

  

PASTURE BLOAT

Bloat is a form of severe indigestion marked by a collection of gas in the rumen that the animal is unable to expel. Normal digestive processes create gases consisting chiefly of carbon dioxide and methane in the rumen. Most of the gases are eliminated by belching. Gases that are trapped may form a foam or froth in the rumen which further prevents their elimination. Froth formation can be caused by many factors resulting from interactions between the animal, rumen microorganisms, and differences in plant biochemistry. The main causes of bloat are an inherited tendency for bloat, certain proteins in forage (particularly in legumes), the coarseness of the roughage and the type of rumen microbial population. Pasture bloat usually occurs in animals grazing wheat pasture, lush legumes (alfalfa, Ladino, red clover) or fed green chopped legumes. To prevent pasture bloat in cattle you should plant pastures so that no more than 50 percent of the forage mixture is alfalfa or clover, fill cattle on dry roughage or grass pastures before turning to legume pastures, provide grass hay or graze in a rotation using grass pastures. Visual signs of bloated cattle include distension of the left side of the animal, discomfort as indicated by stomping of feet or kicking of belly, labored breathing, frequent urination and defecation, and sudden collapse. 

   

BRUCELLOSIS

Brucellosis of cattle, also known as "contagious abortion" and "Bangs disease", is caused by infection with the bacterium Brucella abortus, which can also cause a disease of humans known as "undulant fever". Brucellosis infection of cattle causes abortion or premature calving of recently infected animals, most often between the fifth and eight month of pregancy. Although federal and state regulations have helped to control this disease, there is still a threat. Infected cows frequently suffer from retained afterbirth, are difficult to get rebred and sometimes become sterile.

Brucellosis is spread from the vaginal discharge of an infected cow or from an aborted fetus. The organism has an affinity for the reproductive tract and abortions, retained placenta, weak calves and infertility frequently occur. Breeding bulls which are infected, can transmit the disease to cows at the time of service by infected semen. Milk produced front an infected cow may also harbor the organism. The infected milk creates a public health hazard as this is the organism that causes undulant fever in humans. There is no treatment for Brucellosis. Prevention of Brucellosis is accomplished by official calfhood vaccination of heifer calves. Vaccination must be done by an accredited veterinarian at calf ages that vary from two to four months using standard dosage vaccine, or from 4 to 12 months using reduced dosage vaccine. Each calf must be identified as officially vaccinated in compliance with state and federal regulations. Quarantines are imposed on infected herds by state and federal authorities until the herd has been proven free of the disease. 

    

BSE or Mad Cow Disease

Bovine Spongioform Encephalopathy (also known as BSE or "mad cow disease") is a progressive degenerative disease that affects to central nervous system of cattle. It belongs to a group of similar but distinct neurological diseases including Creutzfeldt-Jacob disease (CJD) in humans. The cause of BSE is unknown and there is no known treatment for this fatal disease.

Typically, it takes from two to eight years from the time of infection for the clinical signs of BSE to appear. BSE-affected animals may display symptoms such as nervousness or aggressive behavior, abnormal posture, lack of coordination and difficulty in rising. When first noticed, clinical signs may resemble those of rabies. Rabies progresses rapidly over a few days while the symptoms of BSE progress over a period of two to six months. Following the onset of clinical signs, the animal's condition deteriorates until it either dies or is destroyed.

Great Britain's outbreak is believed to have been caused by the inadvertent feeding to cattle of meat and bone meal supplements that were contaminated with an infectious agent. This occurred in the late 1970s and early 1980s. Once cattle became infected, the BSE agent was recycled in the cattle food chain through the feeding of rendered material from slaughtered animals to other cattle. This increased the magnitude of the epidemic. Great Britain banned the feeding of ruminant derived protein (from sheep and cattle) to ruminants in 1988. the use of potentially contaminated bovine tissue was prohibited in the manufacture of all animal feed. this ban has had an effect, as the number of BSE cases has declined since the winter of 1992-93. Diagnosis of BSE is based on clinical signs of the live animal followed by the appearance of characteristic lesions in a post-mortem microscopic examination of the brain. There are no tests for the disease in live animals

  

BVD

BVD (Bovine Virus Diarrhea) infection can cause numerous problems, such as damage to the digestive and immune systems, pneumonia, abortions, calf deformities, and others. Clinical signs in newborn calves infected with BVD include fever, nasal discharge, diarrhea, and inability to move about normally. Unfavorable reactions frequently follow the use of modified live virus BVD vaccines. The risk of these vaccination reactions should be weighed against the probability of losses resulting from BVD infection before a decision is made about using MLV-BVD vaccines. Appropriate recommendations should be made by the attending veterinarian after he has assessed the local BVD situation. 

      

CALF SCOURS

ADGRPID:116458|SERVTYPE:1 Calf scours or calf diarrhea causes more financial loss to cow-calf producers than any other disease-related problem they encounter. But calf scours is not a disease but a symptom of a disease which can have many causes. In diarrheas, there is a discharge of more fluid than normal from the bowel, often more frequently than normal. The discharge can be white, yellow, grey or blood-stained, and is often foul-smelling. Although more common in hand reared calves, it can also occur in calves which are being suckled by their mothers. Since a calf is approximately 70 percent water at birth, loss of body fluids through diarrhea can produce rapid dehydration. Dehydration and the loss of certain electrolytes produce a change in body chemistry in the calf. Although infectious agents may be the cause of primary damage to the intestine, death from scours is usually due to loss of electrolytes, changes in body chemistry, dehydration, and change in acid-base balance rather than by invasion of an infectious agent. The infectious agent that causes scours can be a virus (BVD, Rotavirus, coronavirus), bacteria (E. coli, salmonella, Enterotoxemia) or protozoa (coccidiosis, cryptosporidium). Treatment for scours is very similar regardless of the cause. It should be directed toward correcting the dehydration, acidosis, and electrolyte loss. Antibiotic treatment can be given simultaneously with the treatment for dehydration. Dehydration can be overcome with simple fluids given by mouth early in the course of the disease. If dehydration is allowed to continue, intravenous fluid treatment becomes necessary. The age of the calf when scours begins is an important consideration in its survival. The younger the calf, the greater the chance of death. Recent research has indicated that many scour cases can be directly related to lack of colostrum intake by the newborn calf. A calf that is well mothered and consumes 1 to 2 quarts of colostrum in the first few hours after birth absorbs a higher level of antibodies and is far less susceptible to scours and other calfhood diseases. 

    

CANCER EYE

Bovine ocular neoplasia includes a variety of benign and malignant skin tumors of the eyeball and eyelids. Benign tumors are growths that do not spread to other parts of the body and do not tend to grow into surrounding tissues. They can cause local problems with eye function, but do not affect the rest of the body. Malignant tumors are growths of cells that spread to other parts of the body and tend to invade surrounding tissues. Clearly, it is in the cattlemen's best interest from an economic, humane, and public perception standpoint to treat or market cattle with cancer eye as soon as practical.

Cancer eye appears to affect cattle that have non-pigmented skin, especially around the eye. You can reduce the incidence of cancer eye in your herd by selecting breeding stock with dark pigmentation or color around the eyes and by culling affected animals and their offspring from the breeding herd. The peak age for cancer eye is between 7 and 8 years of age. It occurs infrequently in cattle less than 3 years of age. Check eyes whenever cattle are gathered for other routine procedures, especially breeds known to be commonly affected. Veterinary treatments include surgery, cryosurgery (freezing), hyperthermia (heating), or combinations of these. The success rate, if treated early, approaches 90 percent. Given the genetic susceptibility of this condition, you may elect to cull affected cattle rather than treating them.

Cattle with advanced lesions that have spread to other parts of the body or invaded the local tissues around the eye should be humanely destroyed and not transported to market. If presented, they will be condemned and the presence of cattle with cancer eye at the market could create negative public perceptions.



       

COCCIDIOSIS

ADGRPID:116641|SERVTYPE:1 Coccidiosis continues to be one of the major disease problems for cattle producers. It is caused by microscopic, one-celled parasites. Coccidiosis occurs more frequently in calves from one to six months of age, but older cattle, especially those from one to two years, are often affected. Young calves are usually infected when they are placed in pastures or lots contaminated by older cattle or other infected calves. Occasionally, mature cattle are infected when they are brought in from large pastures and crowded into small feedlots or barns. Typical signs of coccidiosis are diarrhea, rough coat, loss of appetite and weight, and general emaciation. The general weakness may cause the calf to defecate without rising, thus soiling its tail and hindquarters. In more severe cases the manure may contain blood, mucus, and stringy masses of tissue. This occurs because the destruction of the epithelial cells results in the sloughing of the epithelium lining the intestine. Severe straining at defecation may be observed in the more advanced stages. Death may occur during the acute period, or later from secondary complications, such as pneumonia. As in many diseases, it is easier to prevent coccidiosis than it is to treat it. Because several days are required for sporulation, the oocyst stage in manure is the weakest link. Separating a cow and calf from a contaminated lot interrupts the life cycle and helps control the disease. Since moisture favors the development of parasites and dryness kills them, practices that reduce the moisture on pasture will decrease parasitic contamination. Pastures should be well-drained, watering troughs raised above the ground, and grazing should be kept to a minimum on lush grass along the edges of ponds and streams. In these areas where cattle congregate, overgrazing should be avoided. Otherwise, animals will be forced to graze to the roots of plants where they may ingest large numbers of parasites. Segregate severely parasitized animals and treat them with a coccidiostat. Follow recommended feeding practices. The effects of parasites are less severe in well-nourished cattle.

  

FOOT-AND-MOUTH

Foot-and-Mouth Disease is a severe, highly communicable disease of cattle, pigs, sheep, goats and deer. It is caused by one of the smallest disease producing viruses known. There are several different strains of the virus that cause the disease. The strain now in England and Europe is harder on pigs and cattle but milder in sheep and goats. Humans do not catch the virus. The disease is characterized by blister-like lesions on the tongue, nose and lips, in the mouth, on the teats and between the toes which then burst, leaving painful ulcers. The blisters cause a heavy flow of sticky, foamy saliva that hangs from the mouth. Infected animals sway from one foot to the other due to the tenderness of the feet. Although older cattle usually do not die from the infection, they suffer a severe illness which leaves them in a weakened state. They have high fevers, stop eating, give less milk and become lame.

The virus is extremely contagious and spreads rapidly unless it is contained. This usually requires quarantining infected farms, followed by slaughtering and burning all susceptible animals. Anyone having contact with animals in infected countries should not go near susceptible animals for at least five days. Because the virus is spread so easily, countries with the disease are banned from exporting animals and their products, creating further economic hardship. Foot-and-Mouth Disease was last seen in the United States in 1929. The U.S. Government places an extremely high priority on keeping the disease out of the country.

    

FOOTROT

Fusobacterium necrophorum and Bacteroides melaninogenicus are the predominant bacteria isolated from footrot. Footrot occurs in cattle of all ages, but it is most common in adults. The disease is seen year-round, but there is increased incidence in the wet summer and fall months.

Bacteria gain entrance through lesions on the lower part of the foot; the bacteria do not penetrate normal skin. Anything that can damage the skin between the claws should be considered as predisposing to the disease. Wet manure and mud can soften the skin between the claws and permit infection. Dried or frozen mud, stones, and stubble can bruise the tissues sufficiently to lower their resistance to disease.

Lameness appears suddenly; usually only one foot is affected. An animal will put little weight on the affected leg, but will place weight on the limb while walking or running. A moderate fever (103º-104º F.) may accompany the early signs. The typical early lesion is a break in the skin between the claws. Pus may be present, but not in large amounts. Edges of the break are covered with necrotic material, and the lesion has a characteristic foul odor. The foot is swollen and the animal is in acute pain.

Spontaneous recovery may occur, but if the animal is not treated, the lameness may persist for several weeks. Penicillin, tetracyclines, sodium sulfadimidine, sulfabromomethazine, and other antibacterial agents are used for systemic therapy. Daily treatment begun immediately after onset of lameness usually will give excellent recovery in two to four days. Treated animals should be maintained on a dry surface until recovered. Recent research has shown that dietary zinc supplementation is effective in treating and preventing footrot in cattle. Feeding chlortetracycline (CTC) at the rate of 0.5 mg / lb. body weight daily may also help prevent foot rot. Many mineral mixes and commercial supplements are formulated to contain the correct amount of chlortetracycline (CTC).

    

GRASS TETANY

Grass tetany is a serious, often fatal metabolic disorder characterized by low levels of magnesium in the blood serum of cattle. It is also called grass staggers and wheat pasture poisoning. It primarily affects older cows nursing calves less than two months old, but it may also occur in young or dry cows and growing calves. It happens most frequently when cattle are grazing succulent, immature grass and often affects the best cows in the herd.

High nitrogen fertilization reduces magnesium availability, especially on soils high in potassium or aluminum. Grass tetany occurs most frequently in the spring, often following a cool period (temperatures between 45 and 60°F) when grass is growing rapidly, but also is seen in the fall with new growth of cool season grass or wheat pastures.

Typical signs of grass tetany begin with an uncoordinated gait and terminate with convulsions, coma, and death. Animals on pasture are often found dead without illness having been observed. Evidence of thrashing will usually be apparent around the cow if grass tetany is the cause of death.

The prevention of grass tetany depends largely on avoiding conditions that cause it. Graze less susceptible animals on high risk pastures. Steers, heifers, dry cows, and cows with calves over 4 months old are less likely to develop tetany. The use of dolomite or high Mg limestone on pastures and including legumes in pasture mixes will decrease the incidence of tetany in grazing cattle. In areas where tetany frequently occurs, feed cows supplemental magnesium. Supplementation increases blood magnesium levels and alleviates much of the grass tetany problem. Adequate amounts of magnesium must be consumed on a daily basis.



    

IBR

ADGRPID:|SERVTYPE:

Infectious bovine rhinotracheitis (commonly called IBR or red

nose) is an acute, contagious virus disease of cattle. Often implicated as an infection which initiates the shipping fever complex. This infection usually occurs in the air passages of the head and the wind pipe. However, in females this virus also causes inflammation of the vulva and vagina and abortion. Abortion occurs about 20 to 45 days after infection. Cattle of all ages that have not been vaccinated or have not recovered from the disease are susceptible to IBR. The use of modified live vaccines on non-immune pregnant cows or on animals in contact with pregnant cows could possibly cause abortion. An intranasal vaccine is available that can be used on pregnant cows, if necessary. It is advisable that heifers be vaccinated or revaccinated 30 to 60 days before breeding. Many IBR vaccines include the entire IBR/PI3/BRSV/BVD shipping fever complex. 

   

EXTERNAL PARASITES

Horn flies, face flies, stable flies, ticks, lice and mites are the major external parasites in beef cattle.

Horn Flies

are about half the size of house flies and are dark gray. They are blood-sucking flies that stay on the shoulders and backs of cattle almost continuously. During extremely hot weather or when it rains, they may move to the protected underside of the animal. When disturbed, horn flies will fly up in a swarm but they will return to the animals almost immediately. A horn fly leaves the back of a cow or calf only to lay eggs in fresh manure. They suck blood from the host 24 hours a day. Individual flies pierce the skin with their short, tube-like mouthparts 20 to 30 times per day to ingest a small amount of blood. Their feeding activity is painful and annoys the animals, as well as causing some blood loss.

There are many effective options to keep horn fly numbers below the 100 fly per animal treatment threshold. Cost, convenience, and herd management practices, such as grazing rotation, can be considered when designing a control program that fits best. Backrubbers allow cattle to treat themselves while loafing and scratching. Dust bags are most effective when used where cattle have to pass under them daily to get to water or mineral. Feed additives target horn fly maggots breeding in fresh animal manure. High pressure sprays can be used to treat cattle thoroughly and inexpensively on a per head basis. An insecticide bolus is a large pill-like formulation that is given to the animal with a standard balling gun. Insecticide-impregnated cattle ear tags release small amounts of an insecticide which are distributed over the animal during grooming or rubbing. Pour on insecticides are ready-to use formulations that are applied in measured doses to animals based upon body weight

    

Face Flies

closely resemble house flies. Face flies cluster on the faces of cattle and feed on secretions from the mucus membranes of the eyes, nose, and lips. Face flies do not suck blood. They do irritate the surface of the eyeball and carry and spread bacteria and viruses that contribute to pinkeye problems. They spend only a small portion of their life on cattle which makes them more difficult to control than horn flies.

Stable flies are sometimes called biting house flies. The look very much like house flies. They feed primarily on legs and lower abdomen of cattle. The mouth parts penetrate the skin and allow them to engorge on blood two to three times a day depending on the weather. Once full they move to a resting place, usually in the shade, to digest the blood meal. The blood loss and pain associated with the bite of stable flies results in substantial economic loss.

Ticks

cause blood loss, discomfort, and spread diseases like anaplasmosis. Tick control is extremely difficult in areas with high tick populations. High concentrations of ticks usually occur in brushy pastures and woodlands so habitat management is an important part of tick control. Control on cattle through persistent use of approved pesticides is achieved by spraying, dipping, ear tags, pour-ons, dust, and backrubs. A good residual insecticide is necessary to prevent infestation.

Lice

cause skin irritation and itching. Both biting and sucking lice infest cattle. Infested cattle can experience reduced appetite and appear unthrifty.

Lice reside entirely on the host cow. Lice are present on cattle year around but increase in numbers in winter. In spring most parasites are lost with the winter hair coat. Lice control is most important in the fall and early winter when the lice populations increase. Treat with approved products. Treatment needs to be repeated in three weeks to kill hatching lice since most insecticides do not successfully kill eggs. Sprays and pour-ons are common methods to treat cattle lice.

Mite

infestation is called mange in cattle. A serious form of mange is called scabies. Scabies is caused by sarcoptic and psoroptic mites and must be reported to the disease control authorities. A less severe mange is caused by chorioptes, demodex, or psorergates mites. Mites are spread through close contact. Cattle infested with mites suffer hair loss and a thickening of the skin. Severe infestations can weaken cattle and make them vulnerable to diseases. Scabies can result in severely debilitated animal. Control of mites is difficult because mites burrow into hide. Injectable products or pour-on products with systemic activity work to control mites best. As with lice, a second application is necessary in two to three weeks to kill newly hatched mites.



           

INTERNAL PARASITES

The economic losses from worm parasite infections of cattle can be significant. Calves under one year of age are more susceptible than older cattle who frequently have been exposed to the parasites and have developed a degree of immunity.

Adult worms in cattle produce eggs that are passed in the manure. The eggs hatch, producing larvae that develop and move up onto the pasture grasses where cattle consume them. Eggs can survive the winter and hatch out with warm weather. Infection is most likely to occur when temperatures are between 60° and 80°F. and there is adequate rainfall. Deworming prior to the grazing season will greatly reduce the contamination of pastures during the grazing season. Cows dewormed in the fall usually have a higher conception rate the next breeding season, winter better and wean heavier calves.

There are several several anthelmintics approved for use in beef cattle. It is probably a good idea to rotate the wormer you use. Consult your veterinarian concerning the type to use and the timing to be the most cost effective for your area. Several are listed below by active ingredient and (brand). Albendazole (Valbazen) is available in paste or suspension. It is effective against all intestinal worms including tapeworms, and lungworms as well as liver flukes. It has a 27-day withdrawal for slaughter. It should not be used in animals during the first 45 days of pregnancy. Fenbendazole (Panacur, Safeguard) is available as a stable suspension or granules. It is effective against roundworms in the gut, larval forms in the tissues, and lungworms. Withdrawal time to slaughter is 8 days.

Ivermectin (Ivomec) for cattle is an effective medication against the internal worm parasites including lungworms as well as cattle grubs and sucking lice. It is available in injectable or pour-on formulations. Withdrawal time to slaughter is 35 days. Levamisole (Levisol, Tramisol) is available in boluses, a paste for oral administration, as a pour-on or an injectable form. Levamisole is effective against roundworms and lungworms. Withdrawal time is orally 2 days and injected 7 days. Morantel tartrate (Rumatel) comes in boluses or crumbles for oral use. It is effective against roundworms, and has a 14-day withdrawal time to slaughter. Oxfendazole (Synonthic) is a new wormer that is effective against intestinal parasites including tapeworms. This wormer has a unique delivery system in that the wormer is injected directly into the rumen. Oxfendazole is also available in the drench form. It has a 7 day withdrawal time to slaughter. Thiabendazole (Omnizole, TBZ) for oral administration is available in paste, boluses, suspension, or crumbles. It is effective against roundworms. Withdrawal time to slaughter is 3 days.

    

JOHNE'S DISEASE

Johne's Disease (pronounced YO-knees), or paratuberculosis, is a chronic wasting disease that causes considerable production losses in adult cattle, sheep, goats, deer, llamas, elk, and bison, and other ruminants. The disease is caused by Mycobacterium paratuberculosis, a bacterium related to tuberculosis. Johne's disease typically starts as an infection in calves, though visible signs do not generally appear until cattle are 2 to 5 years of age (and sometimes much older). The infection is difficult to detect in its early stages. This bacterium causes an inflamed intestinal tract that results in severe weight loss and diarrhea and lower milk production. Infected cattle frequently eat well, and look bright, however, they appear to be unthrifty. Body temperature may or may not be elevated. There is no cure for Johne's disease once an animal becomes infected.

Eradication of Johne's disease is extremely difficult because of its insidious nature, long incubation period, difficulty in early detection, and major management changes necessary to prevent and eradicate it. Consultation and action by a veterinarian experienced in the management of Johne's disease is necessary for the development of a herd-control and eradication program. Johne's disease has been reported in almost all countries around the world.



   

LEPTO

At least five species of leptospira, a corkscrew-like bacteria, affect cattle in the United States. The species most commonly found are hardjo, icterohaemorrhagiae, canicola, L.

pomona, and grippotyphosa.

The most common species affecting cattle is L.

pomona. Multiple abortions in the breeding herd is often

the first sign of the disease. The clinical signs in adult cattle are yellow mucous membranes and bloody appearing urine, which are seen only occasionally. The milk of lactating cows may become thick, yellow and blood-tinged. Abortion two to five weeks after infection is common, but most occur about the seventh month of gestation. Diagnosis is confirmed by a blood test or culturing the organism. Vaccines are available for five of the leptospira species that affect cattle. Vaccination should be done annually 30 to 60 days before the breeding season. Leptospirosis vaccine is often combined with Vibriosis vaccine.



  

LISTERIOSIS

Listeriosis, a disease of the central nervous system, is caused by the bacterium Listeria moncytogenes. This bacterium can live almost anywhere--in soil, manure piles, and grass. Listeriosis is common in cattle, sheep and goats and can occur in pigs, dogs, and cats, some wild animals, and humans. Animals infected with Listeria can show signs restlessness, loss of appetite, fever and nervous system disorders. Although not seen in every case, the most notable symptom gives this disease its nickname, "Circling Disease." Cattle with listeriosis are often seen walking in circles. Other, more subtle symptoms include uncoordinated movements, leaning against objects, and progressive paralysis. Death can occur within 2 to 3 days after the onset of symptoms, but cattle can survive for up to 2 weeks with the disease.

Healthy animals are not usually affected by Listeria. Cattle with lowered resistance to disease are prime candidates for listeriosis. Recognition of symptoms is important for successful treatment. Most animals will recover if treated with a broad spectrum antibiotic started early. Diseased cattle should be separated from healthy cattle and placed on a prolonged therapy program. In herds of valuable cattle, it may be advantageous to treat the whole herd. Vaccines are not available in the U.S.

  

LUMPY JAW

Actinomycosis or lumpy jaw produces immovable hard swellings on the upper and lower jawbones of cattle, commonly at the central molar level. It is caused by an anaerobic micro-organism, Actinomyces bovis. The bacterium invades tissue through breaks in the lining of the mouth caused by eating rough forage. The tumor-like swellings develop slowly and may take several months to reach a noticeable size. Lumpy jaw may be well advanced before external signs are visible. The lumps consist of honeycombed masses of thin bone filled with yellow pus. If neglected the swellings may become very large. In advanced cases openings develop and discharge small amounts of sticky pus containing gritty yellow granules.

Difficult breathing due to involvement of the nasal bones may be the first sign. As the disease progresses, chewing becomes more difficult and painful, resulting in loss of condition. Occasionally, the soft tissues of the head and alimentary tract can be involved. Lesions in the alimentary tract give vague symptoms of indigestion, often with chronic bloat.

The most common treatments are iodine therapy or tetracyclines. Treatment is often ineffective. If the disease is detected early, it may be better to dispose of the animal while it is still in good condition. Only the head should be condemned by meat inspectors, unless the lesions have spread elsewhere in the body. 

        

PINKEYE

Pinkeye (infectious bovine keratoconjunctivitis) is a common infectious disease affecting the eyes of cattle. The name describes the redness and inflammation of the lining of the eyelid and eyeball. Although pinkeye is non-fatal, it has a marked economic impact on the cattle industry. It is known to occur at all seasons of the year and in all breeds of cattle. Pinkeye and foot rot are the two most prevalent conditions affecting all breeding beef females One or both eyes may be involved. Excessive weeping of the affected eye and closure due to pain are the two signs most commonly observed. As the disease progresses, the cornea becomes cloudy or white. An ulcer (eroded circular spot) frequently develops near the center of the cornea. Cattle with pinkeye keep the affected eye or eyes closed because of pain and to avoid bright sunlight. They lose weight because they are reluctant to forage for feed and water. The course of the infection may run for 4 to 8 weeks, or even longer. As the eye begins to heal, white scar tissue infiltrates the cornea. In most cases this scar will gradually disappear as healing progresses and vision will be restored. However, in severely affected eyes, a white scar often persists and interferes with vision. If the ulceration is severe enough to penetrate all layers of cells forming the cornea, the fluid in the eyeball will escape. This results in the iris and/or lens protruding partially or entirely through the ulceration. If this occurs, there will be permanent blindness in the affected eye. Pinkeye is caused by a combination of factors. A good control program should incorporate procedures to reduce initial eye irritation. An intensive fly control program is essential to limit the spread of pinkeye in a herd of cattle. The insecticide-impregnated plastic ear tags are effective in controlling the horn fly and face fly. These ear tags are also an aid in controlling the stable fly and house fly, and remain effective for up to 5 months. Also sprays, charged backrubbers, and dusts bags are products that can provide chemical control. Manure, weed, and brush management are necessary for total fly control. Cattle often have grass or weed seeds in their eyes, and these materials no doubt irritate the eye and contribute to the development of pinkeye. Clipping pastures to reduce the amount of tall grass and weeds can be an important management technique in controlling pinkeye. Ultraviolet light (sun light) - breed for eyelid pigmentation, introduce Brahman influence into the herd, provide shade or tree rows with ample room to prevent overcrowding. Cattle with pinkeye can be helped by prompt treatment. Most antibiotics in eye sprays are effective in reducing the infection. Many eye sprays also contain an anesthetic to relieve the intense pain due to infection. A dye to act as a filter for some of the light rays is also commonly included and probably gives some protection to the injured eye. The aerosol pinkeye sprays are most effective if applied several times a day.

   

RINGWORM

Ringworm is a transmissible infectious skin disease caused most often by Trichophyton verrucosum, a spore forming fungi. The spores can remain alive for years in a dry environment. It occurs in all species of mammals including cattle and man. Although unsightly, fungal infections cause little permanent damage or economic loss. Direct contact with infected animals is the most common method of spreading the infection.

Spores germinate and attack the shafts of the hair and the surface layers of the skin. Exudates ooze from the damaged skin and mix with debris from skin and hair forming a crusty scab. The grayish white scab is noticeably higher than the surrounding skin. Ringworm is most frequent on the head and neck, but it may be found over the entire body in severe cases. Infection spreads from the center outwards and resulting in a circular lesion. Scabs fall from older lesions leaving a ring with a hairless area in the center. Hence, the name ringworm.

Ringworm will usually cure itself without treatment. Common treatments include topical application of a 2% solution of iodine, thiabendazole paste or any fungicide used to treat athlete's foot in man.

  

TRICHOMONIASIS

Trichomoniasis is a venereal disease of cattle that causes infertility and occasional abortions in cows and heifers. It is caused by Trichomonas fetus, a small motile protozoan found only in the reproductive tract of the bull and cow. Disease organisms transferred to the cow's vagina from the bull during breeding migrate up to the uterus and cause the infection. Recently infected cows develop a mild white sticky discharge from the vulva which can last for up to two months. Large number of cows, often over 90% of the herd, will be affected in herds that have not been previously infected. Repeat breeding or infertility of individual cows can last up to five months. The reason for repeat breeding appears to be death of the embryo, often within 10 days. Eventually cows begin to cycle again and can carry a fetus to term.

No vaccines are available for its prevention, but using artificial insemination and virgin bulls aid in control. Bulls are the main carriers of Trichomoniasis and, once infected, remain infected for life but show no signs of disease. Diagnosis of the disease can be confirmed microscopically.



   

VIBRIOSIS

Vibriosis (Campylobacter fetus) in cattle is an infectious bacterial disease of the genital tract causing infertility and occasional abortions. It is a venereal disease spread by infected bulls when they mate susceptible cows and heifers. It is considered to be the most important cause of infertility in cattle. Good vaccines are available, but it still causes losses simply because they are not used in many herds. Infection introduced into a non-exposed or non-vaccinated herd will spread rapidly during breeding.

Repeat breeding activity is generally seen in animals that were assumed to be pregnant. Irregular estrus cycles are common. Absorption or expulsion of a small fetus probably explains the long estrus cycle seen with this disease. Varying degrees of vaginal inflammation and uterine infection are present but may be unrecognized. Abortion rates in infected herds generally run from 5% to 30%. Some females may carry the fetus longer and may abort a sizeable fetus 5 to 6 months into the gestation period. Retained placentas are common. Diagnosis is confirmed by culture of the causative organism from cervical mucus or from an aborted fetus. Vibriosis is somewhat self-limiting as most of the cattle recover within a year. Disease carriers are common, however, and new infection can spread to non-exposed animals. Vibriosis is best controlled by vaccination, which renders animals highly resistant to infection. Vaccination involves two injections, 4-6 weeks apart in the first year, and a single dose of vaccine each year thereafter. Vaccination should be completed 4 weeks before breeding. Vibriosis vaccine is often combined with Leptospirosis in one vaccine. The use of artificial insemination is also valuable in limiting disease spread. Most A.I. organizations test the semen to assure that it is free of vibriosis and trichomoniasis. 

    

WARTS

Warts in cattle are caused by the contagious virus papillomavirus. Four types of the virus are known to produce warts on cattle.

Calves are most susceptible with few cases of warts seen in cattle over 2 years of age. Warts appear 1 to 6 months after infection with the virus. Not all animals carrying the virus will have warts. It can be transmitted from the unapparent carrier to the susceptible calf. Warts are usually more of an appearance problem than a physical problem. Warts usually shrink and drop off after a few months. This spontaneous recovery is probably the basis for the alleged effectiveness of many home treatments including rubbing with various kinds of oil, toothpaste of various brands, etc.

If there is a severe outbreat in the herd an autogenous vaccine can be prepared from chemically treated warts taken from animals in a herd. This autogenous vaccine is more apt to have the strain or type of papillomavirus causing the wart problem in the herd than the commercial vaccines. Warts can also be removed surgically with a scissors or a side cutter.

  

WOODEN TONGUE

Wooden tongue is an infection caused the rod-shaped bacterium, Actinobacillus lignieresii, which lives only in the presence of oxygen . The bacteria, which live in the mouth, invade tissue through breaks in the lining of the mouth. Any rough feed can cause mouth abrasions which allow entry of infection. Wooden tongue occurs almost entirely in soft tissue with the tongue and lymph nodes of the head most often affected. The disease starts suddenly with the tongue becoming hard, swollen and painful. Affected animals drool saliva and may appear to be chewing gently. The tongue often protrudes between the lips and nodules and ulcers may be observed on the tongue. They are unable to eat or drink and rapidly lose condition. The disease is progressive and often fatal unless treated.

It is important to begin treatment early as early treatment is usually successful, but advanced cases may fail to respond. The most common treatments are iodine therapy or tetracyclines. Advanced cases may require surgical drainage and irrigation with iodine solution for several days. Treated animals should be observed regularly, as relapses can occur.



   

NEOSPOROSIS

Neosporosis is found worldwide and causes to financial losses through embryonic losses, abortion, culled cattle and reduced milk production. Neospora caninum is a microscopic protozoan parasite that causes the disease neosporosis. Neosporosis is a major cause of abortion in cattle. Abortion can occur anytime throughout gestation. The Neospora caninum parasite appears to be spread by congenital transfer of the rapidly multiplying developmental stage of the parasite, called tachyzoites, from the mother across the placenta, to the fetus. It is thought that Neospora caninum can be transferred this way during pregnancy due to 'reactivation' of the cyst form of the parasite, followed by entry into the bloodstream, and transported across the placenta to infect the fetus. Although abortion is often observed, most calves are born infected with the parasite and yet show no clinical signs of disease. In herds that have problems with Neospora caninum any heifers retained for breeding are likely to abort during their first pregnancy. These calves then repeat the cycle and transmit the parasite to their own offspring during gestation. Neospora caninum oocysts are very resistant to harsh environmental conditions, and can remain infections for many months in any environment. Oocysts are shed by animals that are termed "hosts". The dog is the most common host, but it is possible that other canids like coyotes and foxes can also be carriers. It is believed that cattle ingest oocysts that are in contaminate feed or pastures and then become infected.

Diagnosis of Neospora caninum includes both blood testing of the aborting dam and examination of the aborted fetus by a diagnostic lab. The fetal brain is the most consistent infected tissue used to diagnose Neospora caninum. A killed vaccine is available. Administration of the vaccine has been associated with a statistical reduction in abortions. Once the vaccine has been given to a cow, a blood test for Neospora caninum is no longer valid. 