This is an archived Horseadvice.com Discussion. The parent article and menus are available on the navigation menu below:
HorseAdvice.com » Horse Care » Horse Vaccines, Vaccination, Coggins Test » Vaccines an Overview » West Nile Virus »
  Discussion on Should I be using the West Nile Vacc?
Author Message

Posted on Thursday, Sep 6, 2001 - 9:54 am:

I hope this hasn't already been discussed, but my trainer is getting our barn the West Nile vaccine. Do you think that is safe, considering how little research has been done on it (I saw in the article that only 700 horses had been tested)?
Thanks!!

Posted on Thursday, Sep 6, 2001 - 7:44 pm:

Boy, I would like to know the answer to that also. I've been on the fence about it until I heard regular announcements on WABC radio for the past week. They were directed to horse owners and telling them to contact their vet this week because they would be in and the supply would be limited. They were done like public service announcements, not advertizements. That's scary because WABC radio is mainly directed at the NY metropolitan area urban and suburbanites and not really the country horsey set.

I could better understand it coming from the Animal Channel or ESPN on TV. Anyway, our vet called us to say she was offering it to her regular patients first. So.....we're getting it. Dr. O........any words of reassurance for nervous nellies?

Posted on Friday, Sep 7, 2001 - 6:32 am:

I think this is probably a reasonably safe vaccine. Being similar to the other viral encephalitis's they sort of knew what would work quickly. But remember there can be reactions to even the safesest vaccine. The question you should ask yourself is my horse at risk? The map-link in the site is current through Sept 4 2001. Birds are considered the best sentinel for iding locations that are at risk. Check it out.
DrO

Posted on Friday, Sep 7, 2001 - 6:50 am:

We gave 6 of our 7 horses their first west nile virus vaccine injection on Tues. So far so good, no fever or soreness. As we are in La. with a reported horse fatality in Vermilion Parish and plenty of water around, we felt we had no choice but to give it and hope for the best.

A side note on this; we were in Tennessee at a TWH breeding farm about a month ago, and the owners were unconcerned about the disease. I was amazed!

Posted on Saturday, Sep 8, 2001 - 8:01 am:

I am not amazed. Currently WNV has not appeared in TN.
The current status as of Sept 4th Summary of Equine Cases of Clinical WNV Infection (n=66) 1 January through 5 September, 2001:

Connecticut (1 county, 1 equine)
Hartford County (1 premises, 1 horse)

Florida (16 counties, 54 equine)
Baker County (1 premises, 1 horse)
Clay County (2 premises, 2 horses)
Duval County (3 premises, 3 horses)
Gadsden County (1 premises, 1 horse)
Hamilton County (1 premises, 1 horse)
Holmes County (1 premises, 1 horse)
Jefferson County (19 premises, 20 horses)
Leon County (4 premises, 4 horses)
Madison County (4 premises, 4 horses)
Marion County (1 premises, 1 horse)
Nassau County (1 premises, 1 horse)
St. Johns County (2 premises, 2 horses)
Suwannee County (2 premises, 2 horses)
Taylor County (8 premises, 8 horses)
Wakulla County (2 premises, 2 horses)
Walton County (1 premises, 1 horse)

Georgia (3 counties, 5 equine)
Brooks County (2 premises, 2 horses)
Clinch County (1 premises, 1 horse)
Lowndes County (2 premises, 2 horses)

Kentucky (1 county, 1 equine)
Bourbon County (1 premises, 1 horse)

Louisiana (1 parish, 1 equine)
Vermilion Parish (1 premises, 1 horse)

New York (1 county, 2 equine)
Suffolk County (2 premises, 2 horses)

Pennsylvania (2 counties, 2 equine)
Bucks County (1 premises, 1 horse)
Montgomery County (1 premises, 1 horse)

When you look at this pattern really only Fla and Southern Ga. have a serious incidence. I would be preparing if I lived along the Gulf Coast east of Texas or if I lived in a county that had reported the disease within a county or two buffer and also has any yearly incidence of the other encephalitis viruses. There is more information in the article on this latest summary.
DrO

Posted on Sunday, Sep 9, 2001 - 3:24 pm:

Illinois has just reported WNV in Cook County - not equine victims; 'just' two dead crows.

Yikes. I thought we'd have at least until next spring before WNV hit here.

Posted on Sunday, Sep 9, 2001 - 10:14 pm:

Add Indiana to the list also. In the past week 2 dead crows found in the Indianapolis area tested positive for West Nile. I live approx. 60 miles northeast of Indianapolis and am somewhat concerned. I will be calling the vet tomorrow to see what his opinion is.

Posted on Sunday, Sep 9, 2001 - 11:49 pm:

Lisa, I saw that too :( I'm in Warsaw, in Kosciusko County. None reported here yet, but it's bound to come soon.

Suzy

Posted on Monday, Sep 10, 2001 - 3:28 pm:

Lisa and Suzy,
I have been keeping up on this too. My vet is coming wednesday to give my horses their fall shots. I called her to ask if they should have the WNV vaccine. Her reply was she was not going to give it to her own horses because it's new and hasn't been tested on enough horses yet. She said the shot is a live virus and could give a horse WNV.(chances are low)With such a low reported finding in Northern Indiana and with the colder weather coming on, it would help kill off the mosquito population. I'm going to take my vet's advise and wait.(I live 15 miles west of South Bend at Hudson Lake.)

Posted on Monday, Sep 10, 2001 - 7:01 pm:

Cheryl,
Your vet is incorrect, this is a killed virus vaccine.
DrO

Posted on Monday, Sep 10, 2001 - 10:29 pm:

Dr. O - I applaud your quick response with factual data! That's one of the main reasons - right up there with the ability to ramble on to my heart's content with my horse stories - I love this site. I'm in Alabama (and haven't looked into the other's biographies) and we are calm but cautious. Personally, I'm beginning to think this WNV scare is somewhat analogous to the shark attacks. Fact is, there are no more shark attacks this year than last year. Yet, in being cautious in our analysis, we do pay attention to the number of shark attacks being reported. Likewise, we horse people down here in Alabama are paying attention to the WNV "synDrOme", but thus far, haven't seen a need to be aggressive in the way of vaccines or any other precaution. Actually, at this point, there are hardly any mosquitos at all! Again Dr.O - thanks for the information and please keep us updated.

Posted on Tuesday, Sep 11, 2001 - 12:58 am:

My vet SUSPECTS she has a case here in NJ. But Wendy, as I am now understanding it, the fact that they're seeing it more and more in birds ( I think the Philadelphia Zoo lost two birds to it ), is the troublesome part. Soon the migratory birds will begin their flights south. If they take the disease with them, and mosquitoes in other areas bite them, what effect will this have on the spread of the disease? It's unknown factors like this that are so troublesome and make this a matter for horse people to track carefully and stay current on.
My vet has sent in the blood on the horse she suspects. I'll have to try to get the story when she returns for our group's second shot.

Posted on Tuesday, Sep 11, 2001 - 1:23 am:

I'm not eager to give DJ such a new vaccine, that's for sure. I'm hoping that it will get cold here before it becomes a problem - if it ever actually does. Meanwhile, I'll just watch and wait.

Suzy

Posted on Tuesday, Sep 11, 2001 - 6:39 am:

It is always a balance of risk vs benefit. As of right now, the risk is very low, even in the worst counties where there are reported horse cases but the risk in not 0 anywhere in the East and it steadily spreads West. This is balanced with the cost of a young vaccine of uncertain efficacy and risk. Everyone must decide for themselves where they draw the line and realize that it is drawn with incomplete information at this time and that the facts may change.
DrO

Posted on Thursday, Sep 27, 2001 - 7:40 am:

I am in Central Florida and have given the first dose of the vaccine to all of my horses. We have no reports of the disease in my county. I would not want to be one to find out I should have vaccinated and didn't. Even though the vaccine is very new, I feel an ounce of prevention is worth a pound of cure. My horses have had no reaction to the vaccine and will get their second injection next month. Marti

Posted on Thursday, Sep 27, 2001 - 9:19 am:

I am located in Georgia, and my trainer had his whole barn (36 horses) vaccinated with 1st and 2nd doses with no side effects. I have done my 3 horses at home including a pregnant broodmare with no problems. I agree with the recent comment that I would not want to be the one who should have vaccinated.

Posted on Thursday, Sep 27, 2001 - 9:39 am:

The CDC provides links to individual state and city West Nile Virus information, including reported confirmed cases, at https://www.cdc.gov/ncidod/dvbid/westnile/city_states.htm. This might help you decide whether or not there's a risk.

Since I'm not worried about the safety of the vaccine, I'm going to go ahead and have my two horses vaccinated even though no one is really sure that it works (there's only a reasonable expectation that it works).

Mary in Ohio

Posted on Thursday, Sep 27, 2001 - 10:43 am:

Does anyone know the incubation period for WNV? I cannot seem to locate it anywhere. I ask because my horse (and barn) has been vaccinated with round one of the WNV vaccine. However, I have word from my vet that she is currently treating a possible WNV case that HAS been vaccinated & a friend in Tallahassee that works for a large animal vet said they are treating 4 WNV cases each having one or all rounds of the vaccine. Fortunately, my barn is doing all it can to control the mosquito population in and around our horses and we're doing just fine. The chance of acquiring is rare but possible. your input is greatly appreciated. Thanks
Claudia in North Central Florida

Posted on Thursday, Sep 27, 2001 - 4:55 pm:

We've had two confirmed equine cases of WNV here in VA in the county next to us. I wasted no time. My boy got his first round last week!

Posted on Thursday, Sep 27, 2001 - 6:02 pm:

My Vet has it on hand, but suggests we wait. NC hasn't had any reported cases that we know of yet...is that right Dr. O? I didn't see any on your list. I can only think that it's just a matter of time before there are reported cases here in NC. I am interested in updates on the horses that have been vaccinated. Have you vaccinated your horses yet - Dr. O? I know you are in NC too. Also my Vet said something about cases being reported in humans first. When that happens he will give our horses the vaccine. He said the vaccine is very expensive. I would appreciate hearing any comments from all of you on this.

Thanks,
Cathie =^..^=

Posted on Thursday, Sep 27, 2001 - 10:33 pm:

Debra - as a fellow Virginian, what VA county are you in &/or where were the confirmed WNV cases?
Thanks! Bonnie

Posted on Friday, Sep 28, 2001 - 8:14 am:

Hello Everyone,
Boy I think we need to slow down a bit here, I sense a bit of panic. Lets see, going from easiest to hardest:

1) No cases in NC yet. The map listed above and others are linked to from the article in The Advisor on WNV. I have heard of one new case in VA in Culpepper county the past week.

4) Though human cases this year do not seem as prevalent has horse cases this year usually many bird cases appear before horses become ill and this was also true before they were looking specifically for the disease in birds.

2) In order to calculate incubation you have to infect some horses on purpose in the same manner they were infected in the wild. This has not been done with this strain that I know of. We are estimating from epidemiology (does not appear after the mosquitoes), serological conversion times (does not completely convert by the time clinical signs show) and some of the other viral encephalitides (EEE and WEE) that the incubation is probably 1 to 3 weeks but this is not certain.

3) Concerning the diagnosis of vaccinated animals, I am a bit skeptical. One of the problems with the vaccine in its current state is that you cannot differentiate infection from vaccination serologically (reference: communication from Fort Dodge to veterinarians). So how do they know it is WNV?

The only way would be very expensive and difficult testing. It is important to get this done however so that we know. This confusion is one very good reason to avoid unneccassary vaccination. We do feel this vaccine has a low rate of adverse reactions but we are uncertain as to how effective it is.

I want to take on this "better safe than sorry" attitude. When we begin to vaccinate for diseases that the risk for infection is very low these become by concerns:
1) Causes a missed diagnosis: Your horse now tests positive so that probably is what it is the logic will go. Maybe there was something more treatable.
2) Creates a sense of endemic disease where there is none.
3) Causes a waste of resources or depletes resources where they could be better used. This includes money and time and vaccine. This also includes resources used up treating vaccinates for other diseases that you now cannot rule out by serologically ruling in WNV.
4) Creates an artifical sense of security preventing more effective preventive measures from being taken like avoiding endemic areas or more careful mosquitoe exposure management.
5) What if you are the person who has that rare but severe reaction to the vaccine but are actually at a very low risk of exposure.

It seems to be we are at the point where a single possible case creates a stampede and no one looks at the thousands and thousands of horses in the same area that are not getting sick. Everyone must decide for themselves where the cost vs benefit equation figures in for themselves but you are less likely to do more harm than good if you rely on logic and not emotions to decide.

For more on the factors involved with making a descision on whether to vaccinate or not see, Care: General Care: Vaccinations.
DrO

Posted on Friday, Sep 28, 2001 - 8:35 am:

Although I wasn't in a "panic" prior to reading this, Dr. O, I happen to live in Culpeper County & this is the first I've heard of a WNV case here. (We've been too busy cleaning up from Monday's tornadoes to keep abreast of local current events!) Please - do you have any more specific info before I call my vet in a state of calm hysteria?
Thanks - Bonnie

Posted on Friday, Sep 28, 2001 - 11:35 am:

My logic told me that my horses are at minimal risk for contracting West Nile Virus in southern Ohio. There has been one reported dead bird in a one contiguous county, and I am careful about eliminating standing water on my property, and I have neighbors who are good about this too. However, when the state vet makes a public service announcement about contacting your vet to schedule vaccinating your horses, and your own vet, who is normally conservative about vaccination, contacts you to set up the vaccination (and you've been told its in short supply), it's difficult to resist "the better safe than sorry" approach.
I have found it much easier, for some reason, to resist having my boys vaccinated for EPM.

Posted on Friday, Sep 28, 2001 - 11:54 am:

No Bonita, I heard this report on the radio and do not have more information, if should be confirmed from a second source. Mary, as I wrote above on Sept 8th, if you have had a case in your county or a contiguos county you fall within MY definition of a reasonable reason to give the vaccine.
DrO

Posted on Friday, Sep 28, 2001 - 1:01 pm:

Opps I see I missed one question. Cathie, no I have not vaccinated my horses for WNV. I have not even stocked it yet because there was a reported possible shortage and it looked like FL was going to need most of it.
DrO

Posted on Friday, Sep 28, 2001 - 2:31 pm:

Thanks Dr. O - I was beginning to think you dodged the question. Thanks for going back and picking up on that. It was important to me. That's three Vets out of three that I know that have NOT vaccinated their own personal horses (IN NC!). Please let me/us know when you change your mind.

Thanks,
Cathie =^..^=

Posted on Friday, Sep 28, 2001 - 10:57 pm:

yep, you can add Lake county and monroe (key west) and Broward counties to that list for Florida.

Some one mentioned they were in Central Florida. Both Marion and Lake Counties (orlando/ocala areas) are Central FLorida, so its heeeerrre.

What to do?

Jojo

Posted on Tuesday, Oct 2, 2001 - 8:32 pm:

Just a note from South Florida
My vet has a horse in the clinic that MAY have WNV, or may have EPM. The problem is that it will take 2 weeks to find out definitively if it has WNV. The horse came in with a high fever, which is now gone, but he is very neurologic. I'll keep you posted.

Posted on Tuesday, Oct 2, 2001 - 8:56 pm:

We had the first few dead birds here in Central Ohio now.

Posted on Wednesday, Oct 3, 2001 - 7:57 am:

Let's all do our part and make heroic efforts to dump all standing water around our areas. Put mosquito dunks into the ditches that harbor mosquitoes, and spray or fog where you can. I feel like the mosquitoes are bad this year. However...come to think of it, I feel like that every year. Ugh! I hate those things. My girls are in the Buccas fly sheets (I know...here I go again about the fly sheets...sorry!) which seem to truly help keep the mosquito bites off of them. I know for sure because the one I have in the low neck version has bites when she comes in on her neck. The two other mares wearing the high neck version do not. If we all get together on this we might help keep some of these mosquito borne diseases at bay. I have recruited friends and neighbors to dump and spray too. Every little bit helps.

Dr. O, will the fact that cold weather is on it's way help to slow the spread of this down? Or will we hear more about this in Florida and the warmer states from the bird migration?

Thanks,
Cathie =^..^=

Posted on Thursday, Oct 4, 2001 - 6:59 am:

Yes the early cold will definately help and yes I believe we will hear of more cases origintaing from FL before this year is out.
DrO
New Member:
Shorty

Posted on Tuesday, Sep 17, 2002 - 11:15 pm:

I LIVE IN NORTHEAST, FL AND REGRET EVER GIVING THE WNV SHOT. I BELIEVE IT HAS DONE MORE HARM THAN GOOD IN MY SITUATION. I HAVE DONE A LOT OF RESEARCH ON WNV AND AM CONVINCED IF YOU HAVE A HEALTHY HORSE THINK TWICE AND DO YOUR HOMEWORK AND THEN DECIDE. CHECK OUT HOW MANY HORSES HAD WNV IN YOUR AREA BEFORE AND AFTER THE VACINE WAS DISTRIBUTED IN YOUR AREA. ONE VERY WELL KNOW VET DOWN SOUTH FROM ME HAD 70 CASES COME TO THEM AND THEY CONTACTED THE MANUFACTURE AND EVEN TOLD THEM THERE IS SOMETHING WRONG. HERE IN MY OWN CITY ONE VET SAID THEY HAD 14 CASES AFTER THE FIRST SHOT WAS GIVEN AND ANOTHER VET SAID THEY HAD SEVERAL CASES, COINCIDENTAL OR WHERE THEY ALL IN THE INCUBATION PERIOD? ONE OF MY HORSES SHOWS A SYMPTON OF THE WNV AND AFTER GOING TO THE U OF FLORIDA VET HOSPITAL AND HAVING EXTENSIVE TREATMENT WHICH THEY COULD NEVER FIGURE OUT WHAT WAS CAUSING MY PROBLEM. I STARTED REALLY DOING SOME HEAVY RESEARCH AND WAS SHOCKED AT WHAT ALL WE HAVEN'T BEEN TOLD ABOUT THE VACINE AND THE VIRUS, THE PROS AND CONS. YOU DO THE HOMEWORK AND THEN THINK LONG AND HARD ABOUT THE SHOT. I PERSONALLY KNOW 4 PEOPLE WHO GAVE THE SHOT THEN THEIR HORSE "GOT" WNV..... I JUST WANT YOU TO DO WHAT IS BEST FOR YOUR HORSES. GOOD LUCK IN WHATEVER YOU DECIDE.
Moderator:
DrO

Posted on Wednesday, Sep 18, 2002 - 6:12 am:

Hello Elaine,
They would not have to be incubating the virus to get the infection after the first shot. A good immune response does not occur until after the second shot, so a horse could have received the first injection or even be exposed shoretly after the second shot and still be.

You are correct in that we still have big gaps in our knowlege about this vaccine but it seems very unlikely that one of the problems is that the vaccine causes WNV infection. I personally have given almost a thousand doses without a reaction that I am aware of. What is the difference between our area and yours: we are not having natural cases in horses yet, your area has been very hard hit with naturally ocuring cases.
DrO
Home Page | Top of Page | Join Us!
Horseadvice.com is a BBB Accredited Business. Click for the BBB Business Review of this Horse Training in Stokesdale NC