Equine Equipment

Equine Equipment
[phpbay]Equine Equipment, 20, “63512″[/phpbay]
[phpzon]Equine Equipment, 10, “All”[/phpzon]

Equine-influenza a Likely Outbreak

.Introduction-Causative-agent

Equine influenza (EI) is caused by a type A Orthomyxovirus. The viruses are 80 to 120 nanometers (nm) in diameter, and consist of a core of eight separate segments of single-strand ribonucleic acid (RNA) surrounded by a spiked arrangement of glycoproteins. These viruses are classified based on the relative numbers of hemagglutinin (H) and neuraminidase (N) glycoproteins in the lipid outer layer. Strains (or subtypes) of influenza viruses are formally described according to their type (A, B, or C), host species, location of first isolation (city or country), strain number (if any), year of first isolation, and antigenic subtype (H and N designation); shorthand methods of identification are limited to the H/N description. The two major strains known to cause disease in equids are H7N7 (A/eq/Prague/56[H7N7], type A influenza, equine, first isolated in Czechoslovakia in 1956) and H3N8 (A/eq/Miami/2/63[H3N8], type A influenza, equine, first isolated in Miami, strain 2, isolated in 1963). The two subtypes are immunologically distinct. Sub lineages of the two major strains (e.g., A/eq/Newmarket/2/93[H3N8], A/eq/Kentucky/92[N3H8]) have emerged due to antigenic shift (reassortment of the genome resulting in genetic alteration) and antigenic drift (point mutations in the genetic code causing minor alterations in the H and N glycoproteins).

Natural-distribution

Equine influenza affects horses, donkeys, mules, and other equidae. The virus is widespread with only Iceland, New Zealand, and Australia considered to be free of the virus. The H7N7 subtype is believed to be extinct or present at very low levels. The H3N8 subtype appears to be a mutation of an avian influenza virus.An outbreak involving a modified H3N8 subtype (designated A/eq/Jilin/89[H3N8]) occurred in China in 1989. High morbidity (80%) and mortality (20%) were observed. Other important outbreaks of the H3N8 subtype have occurred worldwide, including in Trinidad (1979), Argentina (1985), South Africa (1986), and Jamaica (1989). Most confirmed outbreaks occurred at racetracks; as a result, horseracing activities were suspended for prolonged periods of time, resulting in marked economic losses. In Nepal this disease was reported in Nepalganj in year 1988/1989.Same year disease outbreak had occurred in many part of India too. Recently Australia recorded the outbreak of this disease in many part of country. As mule and horses are being used as draught animal in many remote part of country. As these days we all are talking about avian influenza how much we are aware about it.

Transmission

Equine influenza is spread via aerosolized respiratory secretions and fomites, including contaminated inanimate objects and people moving between infected and uninfected horses. The most common source of infection and outbreak is the introduction of a new animal into the herd. The incubation period is usually one to three days. Incubation periods approaching seven days have been observed, but are less common. Infected horses shed virus in their respiratory secretions during the incubation period, and continue to excrete the virus for four to five days after clinical signs are observed. It is also possible for an infected animal to shed the virus for 7-10 days after the animal has appeared to recover. Viral shedding is thought to reach its peak during the first 24 to 48 hours the animal is febrile. Infected droplets may be able to spread as far as 50 yards. Virtually 100% of horses that are exposed become infected. Nearly 20% of infected horses do not exhibit clinical signs of disease, but still shed virus and can spread the infection Morbidity-and-mortality

Morbidity associated with EI in naïve populations is estimated at 60 to 90%; to date, mortality of horses with confirmed infection has ranged from 1% to 20%. Higher fatality rates are observed in foals, malnourished or immunocompromised equids, and donkeys.

.Clinical-signs

Equine influenza virus causes clinical disease of the upper respiratory tract. The virus spreads rapidly, and naïve or immunocompromised horses are at higher risk of developing disease. Clinical signs include fever, coughing, serous to mucopurulent nasal discharge, depression, muscle soreness, anorexia, and enlarged regional lymph nodes. Colic (abdominal pain) and edema of the legs and scrotum have also been observed with influenza infection.In the absence of secondary complications, healthy, adult horses usually recover from EI within one to two weeks; however, coughing may persist for a longer period. Young foals lacking adequate maternal antibodies are at risk of developing a rapidly fatal viral pneumonia. Recovery from EI is complicated and prolonged by the development of secondary bacterial infections. Deaths have been reported as caused by secondary bacterial pneumonia and pleuritis. Purpura hemorrhagica, a potentially fatal, immune-mediated disease, has also developed secondary to EI infection. Fatal interstitial myocarditis (inflammation of the heart muscle) can occur during or after infection.

Diagnosis

A tentative diagnosis of EI is often made based on clinical signs. Diagnosis can be confirmed by detection of the virus in samples from nasal swabs. Traditionally, a diagnosis of EI was confirmed by inoculating embryonated hen eggs with material from nasopharyngeal swabs and subsequently isolating the virus. Alternatively, paired acute and convalescent serum samples can be submitted for EI hemagglutinin inhibition; a fourfold-or greater increase in antibody titer is diagnostic for EI. Other diagnostic methods include reverse transcriptase polymerase chain reaction (PCR) and nested reverse transcriptase polymerase chain reaction. Reverse transcription PCR is more rapid and sensitive than serologic testing, and more rapid and specific than virus isolation.Preferred samples for diagnostic testing are fresh nasopharyngeal swabs that are shipped overnight at room temperature. If serologic testing is desired, a minimum of 2 ml of whole blood should be collected in an EDTA (lavender top) or ACD (yellow top) tube and shipped overnight at room temperature.

Treatment

As for all viral disease, treatment is largely supportive. Good husbandry and nutrition may assist horses in mounting an effective immune response. Rest reduces viral shedding. Because tracheal clearance rates (an indication of the ability of the respiratory tract to eliminate particles, mucus, and infective organisms) are reduced for up to one month after infection, rest is also recommended after resolution of clinical signs. Antipyretics are recommended for horses with fevers exceeding 105°F (40.5 C) and/or severe depression and anorexia. Pneumonia in more severely affected horses responds best to a combination of broad-spectrum bactericidal antibiotics and maintenance of hydration via intravenous administration of fluids.

Prevention-and-control

Inactivated intramuscular and intranasal vaccines are commercially available for prevention of influenza in equids. The American Association of Equine Practitioners (AAEP) has produced Guidelines for Infectious Disease Outbreaks; these guidelines state that the administration of booster influenza vaccines to apparently healthy animals in the face of an outbreak may be of value. For animals that were unvaccinated prior to the outbreak, the use of a modified live intranasal vaccine may be preferred because it can induce protective immunity within 5 days. The EI virus is an enveloped virus that appears to be easily killed by disinfectants in common use in veterinary facilities, such as quaternary ammonium compounds and 10% bleach solutions. The most common source of infection is the introduction of a new animal into the herd; therefore, isolation of newly acquired animals is recommended. Isolation protocols should be rigorously applied for horses showing signs of respiratory disease, and should be maintained for 21 days after the last horse has appeared to recover from the infection. Clothing, equipment, surfaces, and hands should be cleaned and disinfected after exposure to horses known or suspected to be infected.

About the Author

Dr.Kedar Karki M.V.St. Preventive Veterinary Medicine

Southern california what Equine Vet??!?!?

I know of four equine vets in my area, that are either, way over priced, do not have the right equipment or are full of shit with diagnosis.

can anyone recommend me a vet in the high desert area that or Santa clarita valley that will travel to the Antelope Valley, that is resonably priced with an ultrasound machine?

Thanks.

I’m not sure if Dr. Connelly will travel out to where you are (He’s in Agua Dulce), but look him up and see if he will. He’s worked on several of my horses who are/were in AD and he’s been good and reasonable.

I had the SAME problem with Bakersfield DVM, I couldn’t believe that they’d charge a $250.00 call charge to go to Walker Basin (Caliente) when one of their vets actually lives in Twin Oaks!

You also might try Larry Ellsworth out in Tehachapi, I’ve known him for about 3 decades now and he’s always been fair, even when he was in LA.

Classic Equine Equipment – 30sec Spot

Silly Summer Parade seeks volunteers
Being silly isn’t as easy as it looks. It takes a lot of people to pull off something completely wacky, and the Old Strathcona Foundation is searching for a few goofballs to help make its 23rd annual Silly Summer Parade a success. Volunteers are needed to work a number of positions during the [...]