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Equine Infectious Anemia (aka EIA, Swamp Fever)

posted by Horse Owner Today    |   September 20, 2011 10:40

The disease

Equine infectious anemia (EIA), also commonly referred to as swamp fever or Coggins disease, is a viral disease of horses and other equidae that affects the immune system. It is transmitted by blood, mainly via blood-sucking insects, and by needles contaminated with blood containing the virus, or through breeding. The EIA virus can only reproduce in living cells, and in this way spreads throughout the animal. All infected horses carry the virus for life. The fact that the virus lives within the cell is the reason treatment and vaccination are ineffective.

In general, there are three forms of EIA in which the virus can be detected by the presence of antibodies produced by the horse in response to the EIA infection. In EIA's acute form, the virus actively multiplies and attacks the immune system and other body organs. Some of these horses may die suddenly, others may appear constantly and severely ill and harbor heavy concentrations of the virus in their blood. Horses afflicted by the chronic form of the disease may also contain high concentrations of the virus, but they tend to alternate between periods of appearing healthy and the disease state seen in the acute form. Some of these animals will debilitate over time, and present poor body condition. Acute and chronically infected horses always pose a high risk of infection to EIA-free horses because they have a high concentration of virus in their blood. The third form of EIA involves unapparent carriers. These are seemingly healthy horses that also carry the virus, but in a low or undetectable concentration in the blood. Inapparent carriers may never become acute or infectious; however, stress and other diseases or treatments can activate the acute form resulting in a high concentration of virus in the bloodstream. This third form of the disease is often the source of debate about the meaning of the Coggins test and the fate of the unapparent carriers among horse owners who are not well-informed about the disease.

The clinical symptoms of EIA depend on the severity of infection and vary from horse to horse. They can include one or more of the following: fever, depression, decreased appetite, fatigue or reduced stamina, rapid breathing, sweating, weight loss, bloody or watery eye discharge, swelling of legs, lower chest and abdomen, general weakness, wobbly gait, pale or yellowish mucous membranes, signs of abdominal pain, and abortion in pregnant mares.

The origin and evolution of the EIA control program

EIA has been recognized in Canada since 1881, originally as swamp fever. Initial efforts to control this disease based on the elimination of clinically ill horses were largely unsuccessful because infected but unapparent carriers perpetuated the disease within the horse population and served as a continuous source of infection for disease-free horses. In 1970, Dr. Leroy Coggins developed a diagnostic test for EIA using an agar-gel immunodiffusion (AGID) reaction. The Coggins' test is consistently reliable in detecting the presence of antibodies regardless of whether the infection is acute, chronic or unapparent. The test's reliability and the identification of unapparent carriers paved the way for implementation of more successful EIA control programs.

In 1971, EIA was made a reportable disease in Canada, and the first EIA program was introduced in 1972. Agriculture Canada offered the Coggins test to Canadian horse owners and voluntary testing was performed by accredited veterinarians. The government was only involved in trace-out investigations and testing after a reactor was reported. EIA reactors were either permanently quarantined or destroyed. There was no compensation paid for any destroyed horses during the first seven years of the program, but in 1978 the federal government introduced the compensation payment of $200 to owners whose horses were euthanised. In 1989, Agriculture Canada began to accredit private laboratories to perform the Coggins test although all atypical or positive results were confirmed in a federal laboratory before any quarantine and investigation activities were implemented.

From 1972 to 1993, of the approximately 1.8 million horses tested, some 14,000 were confirmed positive for EIA. Although some owners chose permanent quarantine for their animals, the majority of horses were destroyed. During the same time period, the rate of infection among horses tested dropped from 2.9% to 0.39%, indicating that the program reduced the number of infected horses and was successful in controlling the spread of the disease in all but some remote and high risk areas.

In 1994, the government reprioritized its activities and reduced its involvement in the program by modifying the EIA control policy. EIA remained a reportable disease and testing procedures and requirements did not change; however, Agriculture Canada notified the owners and "contact animal" owners instead of investigating reactors and testing positive animals. Horses in contact with reactors were not quarantined and their testing was conducted at the owner's expense by Canadian Food Inspection Agency (CFIA)-accredited veterinarians. Owners required a federal licence to remove infected animals from a premises. At this time the government also discontinued ordering the destruction of infected horses and the payment of compensation. Between 1994 and 1998, approximately 337,000 horses were tested and close to 550 reactors were either voluntarily destroyed or permanently isolated. During that period, the rate of infection among tested horses increased from 0.39% in 1993 to 0.66% as recorded in 1999.

The current EIA control program

In April 1998, the newly created CFIA was approached by the equine industry to modify the EIA program. EIA does not pose a risk to food safety or human health; however, the CFIA agreed that unless EIA was controlled there could be devastating effects on the Canadian horse industry including those related to international trade. Consequently the CFIA agreed to participate in the control of EIA providing the new program was industry-driven and self-funded.

This current program consists of two components. Under the first component, horse owners voluntarily pay to have their horses tested when they are identified by the industry (i.e. movement into shows, point of sale, etc.). Testing is conducted by private veterinary practitioners and EIA private laboratories accredited by CFIA for that function. The second component of the program is the mandatory response, for which the CFIA is responsible. Each time an EIA positive horse is discovered, it must be reported to the CFIA and disease control measures are implemented. The premises on which a reactor is discovered is declared an infected place and all susceptible animals must test negative to be allowed to move off the property. Horses in contact with the reactor within 30 days of the sampling date are also tested. All EIA test-positive horses are retested and reactors with clinical signs are ordered destroyed. Owners of horses that are confirmed positive for EIA without clinical signs must choose whether to either keep the horse in a permanent quarantine or have it destroyed. In the later case, the CFIA orders the horse destroyed and pays compensation. The government's part of the program is delivered at no charge to owners.

When the program was introduced in 1998, the maximum amounts payable were set at $500 and $1000 for grade and pure-bred horses respectively. To further promote the program and encourage testing, compensation has increased to a maximum amount payable of $2000 per horse.

Accredited laboratories charge owners $2 for each animal tested to offset the cost of the CFIA's mandatory response. While this amount may, in some years, cover the cost of compensation, it does not cover CFIA's cost in terms of manpower and operating cost. This is provided as a service to the industry.

The CFIA's position on EIA control program

The CFIA has not imposed the EIA program on horse owners, but has responded to a request from the industry to administer a program that the majority of horse owners support. Participation in the program is voluntary and all elements of the program have been developed in conjunction with the industry. The program is based on internationally recognized disease control standards, current knowledge of the disease, and diagnostic methods. As there is no effective treatment for EIA and no vaccine to prevent it, the disease can be successfully controlled by testing and the elimination of reactors including unapparent ones. The Coggins test is an integral part of the CFIA control program.

EIA does not pose a food safety risk and is not a public health concern, therefore the CFIA's involvement is based on the furtherance of animal health in Canada.

for more information:  www.inspection.gc.ca

What are the clinical signs of West Nile virus infection for horses?

posted by Horse Owner Today    |   August 19, 2011 07:48

Animals (particularly horses) infected with the virus show neurological disturbances. Clinical signs may include:

  • ataxia (lack of coordination);
  • depression or lethargy;
  • fever;
  • head pressing or tilt;
  • impaired vision;
  • inability to swallow;
  • loss of appetite;
  • muscle weakness or twitching;
  • partial paralysis;
  • coma; and
  • death.

The clinical signs of WNV in mammals can be confused with rabies.

Most infected domestic birds do not show signs of infection, and only domestic geese appear to be particularly susceptible to disease and/or death when infected.

WNV-infected geese will show signs of depression, loss of appetite, inability to stand, weight loss and death. The virus can be difficult to distinguish from Newcastle Disease and Avian Influenza in domestic birds.




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General | disease

Response to Central Nervous System Signs in Horses in West Nile Virus Endemic Areas

posted by Horse Owner Today    |   August 19, 2011 07:36


With numerous cases of the West Nile Virus (WNV) reported in horses in several Canadian provinces in the last couple of years, the question has arisen as to how to deal with situations where horses with central nervous system (CNS) neurological signs are reported from the field or at registered slaughter establishments. Clinical signs of WNV in horses could be indistinguishable from those seen in rabies. Thus, any horses showing neurological signs suggestive of and clinically indistinguishable from rabies have to be reported to the Canadian Food Inspection Agency (CFIA) for investigation.

The following provides a brief description of the epidemiology and pathogenesis of WNV in horses and, based on this, the course of action the CFIA will take to fulfill its mandate of protecting human and animal health.

Epidemiology and Pathogenesis of West Nile Virus in Horses

Natural WNV infections in horses have been reported in Europe, Africa, the Middle East and recently in North and South America. It appears that WNV affects horses of all ages, breeds and sexes. Its occurrence in North America is seasonal, and coincides with the presence of the mosquito vector. Most cases of WNV in horses are reported from mid-August to late October. It is estimated that between 10 to 40% of horses in endemic areas can be infected with WNV, but only 8% of these will manifest clinical signs of the disease. The WNV incubation period is usually from 5 to 15 days with a low level of transient viremia < 102.5 plaque-forming unit per milliliter (PFU/ml) of serum (range 101.0 to 103.0) developing one to two days post infection. Four to eight days following the infection, the WNV is no longer detectable in the blood of infected horses. Neurological signs may become apparent from 5 to 22 days post infection and most horses are usually not viremic at that stage. The clinical signs of WNV in order of their frequency include: ataxia, weakness of limbs, recumbency, muscle fasciculation, fever, paralyzed or drooping lip, twitching face or muzzle, teeth grinding, blindness, and traumatic lesions of the forelimbs and head due to compulsive movement. WNV in horses does not result in any gross pathological lesions and the virus can only be isolated from the brain and spinal cord of clinically ill horses. Approximately 60 to 70% of horses with clinical signs may fully recover.

Considering the sporadic occurrence of WNV-associated diseases in horses, the development of low-magnitude and short-duration viremia, as well as limited amount of antigen detected in CNS tissue, horses are considered an incidental and dead-end host of WNV. Consequently, horses do not play a significant role in the epidemiology of WNV and do not pose a risk to humans. Slaughter of clinically healthy horses under normal circumstances does not constitute any WNV health hazard to inspection staff or plant employees.



Human West Niles Cases in Canada & USA as of August 17, 2011

posted by Horse Owner Today    |   August 19, 2011 07:24

Total USA cases 53 as of August 17, 2011

Total Canada cases 1 as of August 17, 2011


State Cases
Arizona 4
California 10
Colorado 1
Florida 8
Georgia 1
Louisiana 2
Mississippi 14
Nebraska 1
New Jersey 1
North Dakota 2
South Dakota 1
Texas 6
Virgina 1
Wyoming 1


West Nile Dead Bird Surveillance 2011

posted by Horse Owner Today    |   August 19, 2011 07:20

2011 Summary by Province (Dead Bird Surveillance Map 2011) www.ccwhc.ca

Region Received Tested Positive Negative Pending
British Columbia 5 5 0 5 0
Alberta 0 0 0 0 0
Saskatchewan 1 1 0 1 0
Manitoba 1 1 0 1 0
Ontario 64 64 2 39 23
Quebec 1 1 0 1 0
New Brunswick 1 1 0 1 0
Nova Scotia 0 0 0 0 0
Prince Edward Island 0 0 0 0 0
Newfoundland and Labrador 0 0 0 0 0
Yukon Territory 0 0 0 0 0
Northwest Territories 0 0 0 0 0
Nunavut 0 0 0 0 0
TOTAL 73 73 2 48 23


FAQ's on Mosquitoes

posted by Horse Owner Today    |   August 5, 2011 08:26

Many websites provide information on mosquitoes, their habitats, behaviors, and impact on humans. We hope you can find answers to your questions on this page or website or through our links page.


How many kinds of mosquitoes are there? About 3000 species of mosquitoes have been described on a world-wide basis. Approximately 150 are known to occur in North America. The term "Mosquito State" is appropriate for New Jersey because 63 species of mosquitoes have been found within its boundaries, to date. Scientists group species by genus on the basis of the physical characteristics they share. The 3000 mosquito species found in the world are divided among 28 different genera. The genus Aedes contains some of the worst pests. Many members of the genus Anopheles have the ability to transmit human malaria. Ten different genera occur in New Jersey including: Aedes, Anopheles, Culex, Culiseta, Coquillettidia, Psorophora, Orthopodomyia, Uranotaenia, Toxorhynchites and Wyeomyia. It is sometimes more convenient to group mosquitoes by the breeding habitat they use. The major habitat groups found in New Jersey include: "Snowpool Mosquitoes", "Floodwater Mosquitoes", "Swamp Breeding Mosquitoes" and "Container Breeding Mosquitoes".

Why do mosquitoes bite? Mosquitoes belong to a group of insects that requires blood to develop fertile eggs. Males do not lay eggs, thus, male mosquitoes do not bite. The females are the egg producers and "host-seek" for a blood meal. Female mosquitoes lay multiple batches of eggs and require a blood meal for every batch they lay. Few people realize that mosquitoes rely on sugar as their main source of energy. Both male and female mosquitoes feed on plant nectar, fruit juices and liquids that ooze from plants. The sugar is burned as fuel for flight and is replenished on a daily basis. Blood is reserved for egg production and is imbibed less frequently. (See the video)

Why do mosquitoes leave welts when they bite? When a female mosquito pierces the skin with her mouthparts, she injects a small amount of saliva into the wound before drawing blood. The saliva makes penetration easier and prevents the blood from clotting in the narrow channel of her food canal. The welts that appear after the mosquito leaves is not a reaction to the wound but an allergic reaction to the saliva injected to prevent clotting. In most cases, the itching sensation and swellings subside within several hours. Some people are highly sensitive and symptoms persist for several days. Scratching the bites can result in infection if bacteria from the fingernails are introduced to the wounds.

Why are some people more attractive to mosquitoes than others? Scientists are still investigating the complexities involved with mosquito host acceptance and rejection. Some people are highly attractive to mosquitoes and others are rarely bothered. Mosquitoes have specific requirements to satisfy and process many different factors before they feed. Many of the mosquito's physiological demands are poorly understood and many of the processes they use to evaluate potential blood meal hosts remain a mystery. Female mosquitoes use the CO2 we exhale as their primary cue to our location. A host seeking mosquito is guided to our skin by following the slip stream of CO2 that exudes from our breath. Once they have landed, they rely on a number of short range attractants to determine if we are an acceptable blood meal host. Folic acid is one chemical that appears to be particularly important. Fragrances from hair sprays, perfumes, deodorants and soap can cover these chemical cues. They can also function to either enhance or repel the host seeking drive. Dark colors capture heat and make most people more attractive to mosquitoes. Light colors refract heat and are generally less attractive. Detergents, fabric softeners, perfumes and body odor can counteract the effects of color. In most cases, only the mosquito knows why one person is more attractive than another.

How long do mosquitoes live? Mosquitoes are relatively fragile insects with an adult life span that lasts about 2 weeks. The vast majority meet a violent end by serving as food for birds, dragonflies and spiders or are killed by the effects of wind, rain or drought. The mosquito species that only have a single generation each year are longer lived and may persist in small numbers for as long as 2-3 months if environmental conditions are favorable. Mosquitoes that hibernate in the adult stage live for 6-8 months but spend most of that time in a state of torpor. Some of the mosquito species found in arctic regions enter hibernation twice and take more than a year to complete their life cycle.

Where do mosquitoes go in the winter? Mosquitoes, like most insects, are cold blooded creatures. As a result, they are incapable of regulating body heat and their temperature is essentially the same as their surroundings. Mosquitoes function best at 80o F, become lethargic at 60o F and cannot function below 50o F. In tropical areas, mosquitoes are active year round. In temperate climates, adult mosquitoes become inactive with the onset of cool weather and enter hibernation to live through the winter. Some kinds of mosquitoes have winter hardy eggs and hibernate as embryos in eggs laid by the last generation of females in late summer. The eggs are usually submerged under ice and hatch in spring when water temperatures rise. Other kinds of mosquitoes overwinter as adult females that mate in the fall, enter hibernation in animal burrows, hollow logs or basements and pass the winter in a state of torpor. In spring, the females emerge from hibernation, blood feed and lay the eggs that produce the next generation of adults. A limited number of mosquitoes overwinter in the larval stage, often buried in the mud of freshwater swamps. When temperatures rise in spring, these mosquitoes begin feeding, complete their immature growth and eventually emerge as adults to continue their kind.

Can mosquitoes carry diseases? Any insect that feeds on blood has the potential of transmitting disease organisms from human to human. Mosquitoes are highly developed blood-sucking insects and are the most formidable transmitters of disease in the animal kingdom. Mosquito-borne diseases are caused by human parasites that have a stage in their life cycle that enters the blood stream. The female mosquito picks up the blood stage of the parasite when she imbibes blood to develop her eggs. The parasites generally use the mosquito to complete a portion of their own life cycle and either multiply, change in form inside the mosquito or do both. After the mosquito lays her eggs, she seeks a second blood meal and transmits the fully developed parasites to the next unwitting host. Malaria is a parasitic protozoan that infects the blood cells of humans and is transmitted from one human to the next by Anopheles mosquitoes. Encephalitis is a virus of the central nervous system that is passed from infected birds to humans by mosquitoes that accept birds as blood meal hosts in addition to humans. Yellow fever is a virus infection of monkeys that can either be transmitted from monkey to human or from human to human in tropical areas of the world. Dog heartworm is a large filarial worm that lives in the heart of dogs but produces a blood stage small enough to develop in a mosquito. The dog heartworm parasite does not develop properly in humans and is not regarded as a human health problem. A closely related parasite, however, produces human elephantiasis in some tropical areas of the world, a debilitating mosquito-borne affliction that results in grossly swollen arms legs and genitals.

Can mosquitoes transmit AIDS? The HIV virus that produces AIDS in humans does not develop in mosquitoes. If HIV infected blood is taken up by a mosquito the virus is treated like food and digested along with the blood meal. If the mosquito takes a partial blood meal from an HIV positive person and resumes feeding on a non-infected individual, insufficient particles are transferred to initiate a new infection. If a fully engorged mosquito with HIV positive blood is squashed on the skin, there would be insufficient transfer of virus to produce infection. The virus diseases that use insects as agents of transfer produce tremendously high levels of parasites in the blood. The levels of HIV that circulate in human blood are so low that HIV antibody is used as the primary diagnosis for infection.



Get The Buzz on Bugs

posted by Horse Owner Today    |   August 5, 2011 08:16


Minimize exposure to mosquitoes by reducing the potential breeding areas.  A mosquito takes 4 (four) days to develop from an egg into a flying, biting adult mosquito. 

Some suggestions include:

Drain small, warm still puddles of water including poorly drained eavestroughs, birdbaths, used tires, pool covers, toys or any standing water.

Clean water troughs on a weekly basis.

Cover rain barrel openings with screening.

Avoid outdoor activities during peak times of mosquito feeding - dawn and dusk.

Consider offering screened housing.


  Topical insect repellents and smudging can be useful.


  Keeps grass short around yardsite.


Eastern Equine Encephalitis (EEE) & Horses

posted by Horse Owner Today    |   August 5, 2011 08:00

Questions Regarding Eastern Equine Encephalitis and Horses

by Wayne J. Crans, Associate Research Professor in Entomology

Rutgers Cooperative Extension Fact Sheet # FS737


Eastern equine encephalitis, commonly referred to as EEE, is a virus disease of wild birds that is transmitted to horses and humans by mosquitoes. The virus is found near wetland habitats along the eastern seaboard from New England to Florida. New Jersey represents a major focus for the infection with some form of documented viral activity nearly every year. Horse cases are most common in the southern half of New Jersey because the acid water swamps that produce the major mosquito vectors are especially prevalent on the southern coastal plain.

The virus responsible for EEE attacks the central nervous system of its host and horses are particularly susceptible to the infection. Onset is abrupt and horse cases are almost always fatal. Symptoms include unsteadiness, erratic behavior and a marked loss of coordination. There is no effective treatment and seizures resulting in death usually occur within 48-72 hours of an animal's first indications of illness.


EEE is not new to New Jersey, but the disease is poorly understood by the average horse owner. A vaccine is available, but a surprisingly high number of valuable animals go unvaccinated each year. This fact sheet has been designed to answer the most commonly asked questions regarding EEE and its potential impact on New Jersey's horse industry. For additional information on the subject, contact your County Agricultural Agent, your County Mosquito Control Agency, the New Jersey Agricultural Experiment Station and the New Jersey Department of Agriculture - Division of Animal Health.

Where Does EEE Come From?

EEE virus occurs naturally in a wide variety of wild song birds. Blood samples from New Jersey birds indicate that Blue Jay, Wood Thrush, Tufted Titmouse, Chickadee, Catbird and Cardinal show the highest incidence of infection in our state. EEE virus normally appears in local bird populations shortly after the nesting season is over in the spring. Mosquitoes transmit the infection from bird to bird during the early summer months and infections usually peak sometime in August. In some years, the virus remains in local bird populations and does not pose a health threat to horses or humans. When mosquito populations are high, however, transfer from birds to horses and/or humans is possible. In a typical outbreak year, horse cases begin to appear in unvaccinated animals in mid-summer. All equine cases are the result of mosquitoes which have fed on infected birds and then feed on unvaccinated horses.

Does EEE Represent a Serious Health Threat to Humans?

Human cases of EEE are very rare, averaging less than 1 overt case every 5 years. The disease, however, produces serious illness when it is contracted via mosquito bite and the probability of recovery is less than 50%. In overt cases, the virus produces an illness that begins with low fever, headache and stiff neck. As the disease progresses, the patient can fall into coma with death as a likely outcome. Recovery is possible but individuals that do recover usually do so with brain damage. Children appear to be more susceptible to overt cases than adults. Research indicates that most humans that are bitten by infected mosquitoes abort the infection in the early stages and recover with no evidence that they ever had the disease. The overt to inapparent ratio of encephalitis in New Jersey is estimated at I overt case for every 23 individuals that are bitten by infected mosquitoes. Salt marsh mosquitoes are the main transmitters of EEE to humans in New Jersey, thus human encephalitis is a coastal phenomenon that is associated with the large populations of mosquitoes encountered at the shore. To date, no human involvement has ever been associated with the horse cases that are relatively common on the coastal plain in the southern portion of the state.

Can Humans Contract EEE Directly from Horses?

The virus that causes EEE cannot be passed from horses to humans by contact, body fluids or any other physical mechanism. Moreover, horses do not circulate sufficient virus in the blood stream to reinfect mosquitoes. EEE is only acquired from mosquitoes that have previously fed on infected birds. A sick horse does not pose a health threat to its human owners. A sick horse is an indication that the local bird population is circulating virus and that local mosquitoes are making contact with the infection. Transmission is not possible from horse to horse, horse to human or even horse to mosquito. Virtually the only way that EEE can be acquired is via the bite of a mosquito that has fed upon an infected bird.

What is the Best Method of Protecting My Horse?

The virus that produces EEE in horses is widespread in wild bird populations and professional vaccination is the only method available to protect horses from the disease. Vaccinations should be administered by a licensed veterinarian to assure that viable vaccine is utilized and injections are properly administered. Mistakes in vaccination protocol by well-meaning horse owners can result in ineffective protection in an animal that was thought to be risk free. All too frequently, owner vaccinated horses develop overt cases indicating that the animal was improperly vaccinated or was vaccinated with vaccine that had lost its protective properties. Properly administered vaccinations are effective for only one year, thus, booster shots are required on an annual basis. Newly vaccinated animals require a two-shot series administered 2-4 weeks apart before protection can be guaranteed. Foals should be re-vaccinated during summer to ensure protection during the first year of life. It is recommended in the face of a fall epidemic, horses vaccinated in March should be boostered later in the season.

What is the Best Method of Protecting My Family If My Horse Contracts EEE?

Although human cases have never been associated with equine EEE, a sick horse is an indication that the virus is present in local mosquitoes. There is no human vaccine available for routine usage, thus mosquito avoidance is the best protection in an area where EEE is known to be present. Homeowners should contact their county mosquito control agency and make them aware of the situation. Mosquito control personnel are familiar with the EEE cycle and have the expertise to reduce the mosquitoes that function in the cycle. Have your family and employees avoid mosquito-infested areas and use insect repellents when exposure is unavoidable. Eliminating water-holding containers from your property (buckets, tires and other receptacles) will reduce mosquito breeding in the immediate vicinity. Horse troughs provide excellent mosquito breeding habitat and should be flushed out at least once a week to reduce mosquitoes near the paddock area. Work with your county mosquito control agency and point out any wetland habitats that may have produced the mosquito responsible for the infective bite.

What Should I Do If My Horse Develops Symptoms?

Suspect horse cases should be reported to your veterinarian as soon as possible. Your veterinarian will diagnose the infection and take blood or tissue samples for confirmation. Euthanasia may be necessary because the disease is fatal in unvaccinated animals. The veterinarian will probably request the brain since brain tissue is the only certain way to confirm the diagnosis. Some horse owners are reluctant to report suspect cases for fear of quarantine. There is no quarantine for EEE and non-reporting only postpones the mosquito control activities that could protect other horses on your farm and the immediate vicinity. The cycle of EEE is not yet completely understood. Quick reporting of a suspect case could provide valuable information for the future.

Thanks are due to the New Jersey Mosquito Control Association, Inc., who contributed funds to defray the cost of this fact sheet.

New Jersey Agricultural Experiment Station Publication No. H-40101-02-93 supported by State funds

Rutgers Cooperative Extension

N.J. Agricultural Experiment Station

Rutgers, The State University of New Jersey , New Brunswick

Distributed in cooperation with U.S. Department of Agriculture in furtherance of the Acts of Congress of May 8 and June 30, 1914. Cooperative Extension works in agriculture, family and consumer sciences, and 4-H. Zane R. Helsel, director of Extension. Rutgers Cooperative Extension provides information and educational services to all people without regard to sex, race. color, national origin. disability or handicap, or age. Rutgers Cooperative Extension is an Equal Opportunity Employer.



Cutting Greenfeed - Timing is Everything

posted by Horse Owner Today    |   July 31, 2011 18:34

Colby Elford - Regional Livestock Specialist

Moose Jaw Regional Office, Ministry of Agriculture

Andre Bonneau – Forage Management Specialist

Moose Jaw Regional Office, Ministry of Agriculture


Greenfeed is useful feed source for cattle producers across the province.  Most annual forage crops are very productive as forage and fit well into crop rotations.  Oats, barley, and triticale are the most commonly used greenfeed crops.  Millet, corn, winter triticale and fall rye have also increased in popularity.


When planning to cut these crops for greenfeed, it’s important to remember they are not all the same.  Oats, rye and triticale should be cut in the milk stage while barley is best cut at the dough stage for a good balance of quality and yield.  Into the dough stage, triticale, rye and oats will likely be less palatable. 


As the plant develops from the boot stage to the hard dough stage, protein levels and energy content decreases while the fibre content of the straw increases.  This will have a negative effect on digestibility.  Not all crops decline in quality at the same rate.  Barley holds its quality much longer than oats, rye, or triticale.  Watch the staging of your greenfeed crop to be sure that you are harvesting the full potential of your crop. 


Another option is to turn the greenfeed crop into Yellowfeed.  Yellowfeed is the practice of applying glyphosate to the crop and allow the crop to desiccate and cure while left standing.  The plant will continue to grow for a short period after being sprayed until the glyphosate takes effect.  Consider this lag time when timing the glyphosate treatment.  The crop should be sprayed early enough prior to the desired harvest stage of the crop.  The time it takes will depend on growing conditions: application under good growing conditions need at least 3 days while the glyphosate needs more time under poor conditions.  One litre per acre of the original formulations should be enough to make yellowfeed.


The crop can then be cut and baled as normal but keep in mind the crop may lodge after seven days as the straw hasn’t had time to fully develop.  Since the crop is allowed to dry while standing, weathering loss can be minimized and producers can harvest their forage crop at the correct stage. 

For more information on greenfeed and yellowfeed, contact the Agriculture Knowledge Centre at 1 866 457-2377.



Moisture in Hay

posted by Horse Owner Today    |   July 15, 2011 09:11

by:  Andre Bonneau, BSA, P. Ag., Forage Management Specialist,

Saskatchewan Ministry of Agriculture.

All hay is put up with some moisture: it’s unavoidable and necessary to prevent leaf shatter and leaf loss.  However, there can be more moisture in the hay than necessary.  Too much moisture obviously makes the bale heavier and can eventually heat and spoil the hay. 

The safe amount of moisture in hay depends on the density of the bale and the ability of the bale to dissipate heat.  When forage is first baled up, the bale begins to heat almost immediately.  This is normal.  The problem begins when the heat builds up without dissipating and the forage breaks down.  Think of it in terms of surface area and volume relative to the weight of the bale: a small loose bale can dissipate heat better than a large heavy bale. 

For example, a small square bale weighing less than 75 lbs can be normally stored at 20% moisture with good ventilation.  Meanwhile, a heavy and dense large square bale should have less than 15% moisture.  

Note that bales should not be stacked until they’ve finished heating.  Stacking the bales too soon reduces the ability of the hay to dissipate heat and excessive heating can occur.

What’s happening?

Heat is generated by decomposition and microbial activity.  At a microscopic level, hay begins to decompose as soon as its cut.  In the swath, microbial activity will slow down as moisture levels decrease.  Once the hay is baled, the small amount of microbial activity is still generating heat but the heat isn’t dissipated as easily as it was in the swath.  Heating will continue as oxygen and moisture is used up and microbial activity is minimized.

Inoculants and hay preservatives

In general, hay preservatives make moisture unavailable to the microbes that may spoil the feed.  Hay preservatives do not increase the quality of the forage.  Adding any preservative to poor forage will only preserve poor forage. 

There are two common types of hay preservatives: organic acids and inoculants.


ORGANIC ACIDS, like propionic acid and citric acid, is the most common and effective hay preservative available.  The acid drops the pH of the moisture in the forage and makes it unavailable to microbes.  The amount of acid needed depends on the concentration of the acid and the amount of moisture in the forage.  Commercially available propionic acid will have instructions on the label.  Organic acids will help preserve hay at up to 30% moisture. 

INOCULANTS introduce lactic acid-producing bacteria (LAB) into the hay.   LAB is the same bacteria used in silage production.  These bacteria will form colonies in the hay to produce lactic acid and reduce the pH in the bale.  Lower pH reduces microbial activity and preserves the hay.   Inoculants are generally in a powdered form and are registered to preserve forage up to 23% moisture.

OTHER options are anhydrous ammonia and salt. 

Anhydrous ammonia ties up moisture and makes it unavailable to microbes.  However, the amount of anhydrous ammonia necessary makes it cost-prohibitive.  The difficulty and danger of using anhydrous ammonia also makes it an unpopular choice.

Salt used as a preservative works by making the moisture unavailable for microbial use.  The amount of salt needed to preserve hay is often impractical and expensive.  Some research suggests that the amount of salt needed can also make the forage unpalatable for livestock. 

Pay attention to moisture levels.

Some moisture in forage is unavoidable and acceptable.  It is impractical to put up feed absolutely dry.  Get a good hay moisture tester, learn how to calibrate and use it.  Monitor your hay as you bale and periodically in the hay yard. 

For more information, go to the Saskatchewan Ministry of Agriculture website at www.agriculture.sk.ca and search “Hay Preservatives – FAQs” or contact the Moose Jaw Regional Office at 1 866 457-2377.