Please note: There has been several reported cases of equine strangles throughout the state. Please be advised to take all precautions when horses are moving for shows, racing, sales, etc. We expect to begin seeing cases of WNV and possibly EEE. The mosquitoes have had extraordinary conditions with all the rains we have experienced. Also, remember to advise livestock owners traveling to states experiencing outbreaks of VS that livestock entering NJ from Colorado, Texas and NM must test negative within ten days prior to movement into New Jersey, have permits to enter NJ, and will be quarantined for 14 days in the state. Details follow…


Strangles

Strangles is a highly contagious disease caused by the bacterium Streptococcus equi. Found throughout the world, strangles is considered to be an obligate parasite of equine and now known to survive mostly in moist or wet environments. Transmission of the bacteria from horse to horse usually involves direct face-to-face contact or exposure of horses to contaminated feed, water, hands, veterinary instruments, grooming tools and twitches. The disease can also be acquired from exposure to a contaminated environment as long as the organism remains viable. However, a dry environment quickly kills the bacteria.

Strangles is characterized by sudden onset of fever, loss of appetite, painful swallowing, drooling, swelling between the jaw and base of the ear, nasal discharge, cough and abscess formation. Horses usually develop fevers two to nine days before they become infectious to other horses, making isolation of horses with fevers a potential key to limiting the spread of the disease on a farm. Although the clinical diagnosis of strangles is fairly straightforward, there are advantages to culturing for the bacteria. Such culturing permits a definitive diagnosis of the disease, and an antibiotic sensitivity test will be performed in the lab to aid in selecting the appropriate antibiotic if determined that it is needed. Antibiotic therapy is usually not included in the treatment of strangles because of the inherent risk of developing the generalized form of the disease, known as bastard strangles. Bastard strangles is a more serious, often fatal, disease, compared to the typical case of strangles, which is more of a nuisance than a long-term health threat to the horse.

Antibiotics are sometimes used if:

· The size or location of the abscess becomes life threatening
· Vital signs become compromised
· Owner insists on antibiotic therapy

The Division of Animal Health Laboratory will culture for strangles at no charge. Sample submission is extremely important in culturing S. equi. Satisfactory specimens include throat culture, trans-tracheal wash, pus from an abscess, nasal discharge or nasal flushes. Swabs are of value in transporting the material to the lab.

However, Streptococcus is easily dried out during shipment, making it advisable to place swabs in a non-nutritional transport media (Amies, Amies with charcoal, or Stuarts’s) and ship them rapidly. Laboratory identification will take between 48 and 72 hours, while confirmatory tests require an additional 24 hours.

Treatment of uncomplicated strangles typically involves monitoring the vital signs, temperature, heart rate and respiratory rate, and treating symptomatically.

Strangles: control plan

· Isolate newly-introduced animals for two weeks and observe for signs of strangles or other diseases
· Immediately quarantine affected or suspect cases
· Obtain rectal temperatures of in-contact horses twice daily for two to three weeks and separate horses with temperature elevations of 1.5º F or greater
· Culture recovered horses on three occasions at four-to-seven-day intervals following abscess drainage to determine cessation of shedding. Culture specimens should be obtained from nasal swabs or washes.
· Prophylactic administration of an antibiotic such as penicillin G should be utilized only in severely affected horses and as recommended by the attending veterinarian
· Practice good fly control
· Vaccinate before an outbreak occurs
· Practice good biosecurity techniques

Disinfection of Equine Facilities

Proper disinfection of facilities is paramount in disease prevention. An appropriate disinfectant should destroy the organisms on the surfaces where they are located. The chemicals effectively used in human hospitals to disinfect linoleum, stainless steel, plastic and glass are vastly different from those used in barns and on horse equipment. Farms have a variety of porous and nonporous surfaces so the disinfectant must be effective in the presence of organic matter in which the majority of pathogens are found. Streptococcus equi, S. zooepidemicus, influenza and herpes virus are present in nasal discharges; Salmonella, E. coli, Actinobacillus and rotavirus are found in feces. Steam is an effective disinfectant, killing both viruses and bacteria particularly when utilized with a detergent to remove organic debris. Literally hundreds of disinfectants are on the market for veterinary and medical use. Because of their effectiveness in the presence of organic matter, phenolics are recommended for use in horse facilities. Bleach and quaternary ammonium compounds are inactivated by organic matter. Iodophores and chlorhexidine are most appropriately used for hand washing. Formaldehyde, although highly germicidal, is too dangerous for routine use. It is necessary to carefully read the product label to identify the active ingredients. Phenolics can be recognized by the "-phenol" or "-phenate" at the end of the chemical name. Quaternary ammonium compounds are identified by "-ammonium chloride" in the active ingredients. Iodophores contain iodine or povidone iodine. Many different phenolic compounds are commercially available. Tek-Trol® (Bio-Tek Industries Inc., Atlanta) and 1 Stroke Environ® (Calgon-Vestal Laboratories, St. Louis) are approved for use in equine quarantine facilities. Both contain over 20% of available active ingredients. When the labor-intensive process of cleaning and disinfecting stalls is undertaken, the most effective germicidal compounds should be used. The most important, and the most overlooked, step in disinfecting a stall is thorough washing of surfaces with and anionic detergent using a steam cleaner to remove as much soil and organic matter as possible. Cationic and nonionic detergents interfere with the actions of phenols. Even the best disinfectants do not work effectively when poured directly on organic debris. Surfaces must be cleaned, rinsed and allowed to dry. The disinfectant should be sprayed on, allowed to dry, and repeated. Contact time with the surface is important to ensure effective germicidal activity. Rinsing off disinfectants is not advisable except when used on feed and water containers. Besides disinfection of facilities and equipment, isolation of sick animals and use of protective clothing is an absolute necessity. Separate grooming and stall cleaning equipment should be used for sick animals. However, if this is not possible, these items require cleaning and soaking in disinfectant solution for a minimum of 10 minutes. Clothing and towels used on horses should be soaked for 10 minutes in disinfectant solution prior to laundering. Footbaths at the entry to barns and stalls need to be replenished with fresh disinfectant at least twice daily, more with heavy use. Here's a good rule of thumb; if it isn't edible and doesn't move, disinfect it! Regular hand washing is essential after working with sick animals. Povidone iodine or chlorhexidine hand washing products are best, but alternatively germicidal soap can be used. In instances where water is not available, waterless hand foams, containing >62% ethyl alcohol, are germicidal and can be purchased through human medical supply stores. These products are rubbed onto the skin and evaporate within one minute with no sticky residue. More information on disinfectants available can be obtained on the following websites: http://ohioline.osu.edu, http://aphis.usda.gov/vs/, http://agmkt.state.ny.us, and http://www.biosecuritycenter.org.