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Tuesday, February 26, 2013

Vaccination

Yesterday I popped Farley with 2 vaccines.

I considered long and hard what I wanted to do with the vaccinations this year. Last year I wasn't pleased with the slight hoof sensitivity that occurred after vaccination that lasted about 3 months - where she was once sound at a canter/gallop on gravel, she now only wanted to trot.

AAEP publishes vaccination guidelines/recommendation and if you aren't familiar what is in your 4 or 5 way, or other vaccines, it might be helpful to take a moment to review.

WEE and EEE:

These are zoonotic diseases that are transmitted by the mosquito vector. They cause severe enchephalitis in horses and humans (humans have low levels of the virus in their blood if they are infected and do not transmit the disease to mosquitos). The eastern form can be found on the west coast and vice versa. The disease can be fatal and can pass to humans. These are considered "core" vaccines by the AAEP and is in most of your standard combo vaccines. Because of vaccination, WEE and EEE epidemics no longer regularly occur in the US (reference: CDC website). Here is the link to a summary of cases/distribution of cases over the last couple of years: http://www.aphis.usda.gov/vs/nahss/equine/ee/

Did I vaccinate for this yesterday? No. My risk is low where I live, and during some years of competition, I was vaccinating for these 2 diseases as often as every 4 months based on AAEP recommendations for a performance horse. Because this is a core set of vaccinations that are given often, chances are if a vaccination was causing some increased inflammation/sensitivity, this is my prime suspect.

Tetanus toxid

I think everyone knows about tetanus. Horses are particularly sensitive. Tetanus vaccine is available by itself or in conjunction with lots of different combo vaccines.

Did I vaccinate for this yesterday? You betcha. Especially with that old wire injury that may or may not allow crud up in there and was causing problems....yep, she got popped with a tetanus toxoid vaccine in the right thigh.

 

West Nile

I spoke on this in an earlier post. Mosquito vector, zoonotic (but not passed between humans and horses). According to Aphis (http://www.aphis.usda.gov/vs/nahss/equine/wnv/index.htm) there were cases very very near me last year, AND Farley boards on a river bank. AND mosquitos have already started showing up. 3 types of vaccine available. AAEP recommends 6-12 month vaccination.

Did I vaccinate for this yesterday? Yep. I consider "before the vector season" to be the end of February in this area (the fruit trees are already coming into bloom....) and that will give me good protection through September, the peak time for WNV infections.

 

Influenza? Rhino? Strangles?

She didn't get any of these yesterday. There's a couple of reasons. Strangles I don't give for a variety of reasons. Influenza, Rhino, EHV are all a concern, but I'll evaluate once I know my competition season. I'll vaccinate no less than 1 month within a competition date to give the inflammation time to die down if it is going to affect her feet, and she'll have protection during the time she needs it most - at competition where she's sharing water troughs and around lots of strange horses. These are more examples of vaccines that were in the combo that I gave up to every 4 months so another good candidate for already having increased titers.

Splitting up some of my vaccines based on vector season and others based on competitions is a way to spread the vaccinations out over time. I like doing this especially if I suspect there was a problem last time. WNV and tetanus are diseases I'm worried about NOW, these others I worry about more when I'm competing, this they will come around in a couple months.

A note on spreading vaccines out: I talked to a vet with a vaccine company and he suggested that if I spread vaccines out to do it over a MONTH, not a week or so - introducing another vaccine 1-2 weeks post vaccination means introducing that vaccine at the height of the vaccine response (and inflammation) from the previous vaccination. If you are going to spread them out, make sure to wait at least a month.

Also on the suggestion of the same vet, I gave everything in the thigh instead of the neck. The neck is easy, but residual soreness in the neck can be harder to pinpoint and attribute to transient hoof sensivity.

What about NSAIDs? I decided that at least for tetanus and WNV NOT to give banamine or bute. Reducing the inflammation can potentially decreased the vaccine response, and because I'm giving those 2 only and not the combo, I elected to give them without any additional medications and see what her response is.

There's one more vaccine that I didn't mention above that I do keep Farley current on: Rabies. I don't have my license so I can't give it. Rabies occurs in wild populations of animlas, and according to the state I live in, bats testing positive for rabies were found in both the county that Farley boards in and surrounding counties. The chance for interaction between Farely and a bat, oppossum, or skunk is fairly high and thus, I chose to keep that vaccine current. One thing to remember about rabies. There is NO test that can be done on a living animal in order to determine whether it has been infected with rabies. ONLY a post-mortem (after death) brain sample can be definitively tested for rabies. I was told in class that we aren't even allowed to test for rabies antibodies in a suspected animal - they need to be euthanized and the brain sample submitted.

I write this from a horse owner perspective, not as a vet or future vet. As a vet I would absolutely tell you to vaccinate with all the core vaccines (barring any issues such as past reaction etc. - this is a THEORTICAL CONVERSATION). Perhaps spacing them out at least a month for clients with my worries, and administering a concurrent NSAID with the vaccines for the older horse who has a strong vaccination history for certain diseases not necessarily edemic in the area the horse lives or travels in.

I absolutely believe in the efficacy of power of vaccines and believe they do more good than harm. However, I look back at the volume of vaccination I did based on recommendations and wonder whether for an older, well vaccinated horse if some of the core are really necessary, especially for the horse, which seems to be more prone to issues associated with inflammation. On the dog side, the most current recommendation is that the core (distemper, hepatitis, parvo etc.) be given every 3 years. Horses are a different species and thus we cannot extrapolate from dog core recommendations to horses, but I do wonder what the titers look like long term for an older horse with a strong vaccination history.

One last note about vaccines - Dr. Bigbie, the vet who spoke about west nile a couple of days ago at the lunch talk (see previous notes on west nile) told me that years ago he wrote an article about rhino/influenza/EHV called "A snotty horse is hard to love" and even though he's done a ton of WNV stuff etc over the years, that's the first thing that will pop up on a google search of his name. Sure enough, I found the article: http://www.horses-and-horse-information.com/articles/0496rhino.shtml.

7 comments:

  1. I vaccinated yesterday too. I too wish there were some long-term studies on titers. My horse had bad reactions in the past. I do give benamine because even with minimal vaccines my horse is reactive/wimpy! I have had multiple long talks with my vet as to what to do, and to balance horse health/overall well being/my concerns. It is not easy, I still worry, both about giving him too much=reaction and not giving enough=illness/death.

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  2. This is an interesting perspective about the one month apart. I stopped vaccinating for everything other than tetanus two years ago. WNV has been ifey for us. For a while we did just west nile and tetanus but again, the reactions and some of experiences friends were having with the vaccine made me very nervous, and I decided thatgiven the low numbers of outbreaks in our area, it was a safe risk to take to not vaccinate..ofcourse that all depends on the weather patterns. Overall with vaccinations we were just having too many reactions that I felt it just wasn't worth it anymore. I am also curious about vaccinating in the leg, never have used that site before. Is there an inherant risk of abcess there like the hind quarter? I have also wondered about the titers and length of protection.Why is it horses are recommended to be vaccinated every year for these same things? It seems like maybe big Pharma has a hand in this ? I will read some of the articles you have provided.It''s definitely one of those horse management decisions that I constantly reevaluate and worry about.

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  3. What I find interesting about your readers (based on their comments) is that they all actively think about vaccination management. Most horse owners in my circle just give whatever the vet recommends.

    In my case I give the core because I stable and never know who is going in or out. I don't give strangles since my understanding is that it is a low risk disease my 15-year old horse.

    I am at a new stable now and they take a more active management toward insuring the boarders vaccinate and worm so we will see what happens.

    One vector you missed for rabies that is very common in your area is raccoons. Lots and lots of the little buggers.

    Pa

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  4. Suprisingly raccoons are not a major vector. I was under the impression that they were, but after sitting through some classes where we were discussing major rabies vectors and then going through the local rabies reports in reseraching these posts, bats are the major vectors in this area, followed by a few feral cat reports. Oppossums didn't pop up on my search, but according to the professors they are a major vector in this area so it got included here.

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  5. Regarding vaccinating in hind leg and abscess risk. There is a risk of abscesses no matter where you vaccinate - choosing a vaccination site is all about considering how harmful or difficult to treat an abscess in that area would be. The thigh of the horse (semitendonsus) was presented in school as an excellent place to vaccinate not just from an abscess treatment perspective but from the welfare of the horse being comfortable eating and drinking if it did abscess. I am not aware that vaccinating in the semitendonsus presents any more of an abscess risk than the neck. The biggest thing is not to miss and insert your needle and vaccination in the groove between the rectus femoris and the semitendonsus where the sciatic nerve lies. Similarly in the neck it's important to vaccinate in the "triangle" to miss the nuchal ligament etc. there's excellent pictures on the Internet that have real horses with the vaccination sites taped off so you can clearly see. Alternatively ask your vet. I think most equine vets are realistic that their clients are vaccinating and would be more than happy to point out the various locations and landmarks and give recommendations.

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  6. Sitting through another rabies lecture and there is a lot of rabies in raccoon, but it's mostly on the east coast. On the west coast skunks and opossums are a more significant vector.

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  7. Several years ago there was a rabid skunk at the neighbors.

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