Dr. Kellon? Vets response (was Help interpreting test results)

Patty Sobel <psobel_gen@...>

I asked my vet to start the IV for a month for Libby's Lyme, followed by the 3 months of oral meds.  This is the response I received:

If you would like to treat Libby for Lyme rather than retest in a few weeks, there are some risks with giving daily Oxytetracycline.  We would prefer that a vet administer it if possible.  Any injection given in the carotid instead of the jugular by accident can cause serious complications.  The jugulars are the easiest veins to get to and there is a risk of damage to the veins with anyone administering a daily IV injection.  Oxytet itself can cause reactions in horses too.  Many of the horses on daily Oxytet administration on have either had a reaction or get thrombosis or phlebitis and we have to switch to oral medications.  Minocycline is oral and is better absorbed than Doxycycline so that’s an option.  As far as price, you might want to look into a lay up facility to administer Oxytet with a catheter every day as a cheaper option.  It would be over $100 per day for us to administer the drug and more on the weekends.

So would it be effective to just give the oral meds without the IV?  If so, do we give it for 3 months or 4 months?  I can't afford $100/day, and I don't want to harm Libby because I make a mistake with the IV.  I did email the vet and ask about inserting a catheter.  

Libby's case history:

Patty and Libby
Laurel, MD
May 2008


I've had to treat my mule twice for Lyme. I found a very good vet who was willing to put in and IV port so I could give the tetracycline daily on my own. There was no problem with the port. Unfortunately my mule coliced every day from the tetracycline and we had to discontinue it after 5 days. So, I ended up going with 2 months of oral doxy. Unfortunately the Lyme flared up again a few months after the first treatment and we had to treat again. The 2nd time we did 3 months of doxy 10 mg 2x a day. I got the doxy from Wedgewood pharmacy. It cost me $265 for the entire 3 month supply of doxy to treat my mule.  FAR, FAR less expensive than from any of the local vets. 

Cindy Ross, in Maine 2012

Kerry Isherwood

IMO your Lyme titer was not really that high. I work in a rehab barn and we have a chronic "Lyme-r" whose titers climb to nearly 20,000 before symptoms manifest. This particular horse, as well as the vast majority of horses, respond very well to the average oral doxycycline dose given twice daily. Its only the refractory cases where symptoms return despite months of highest safe doses oral doxy that need IV treatment. As I Licensed Veterinary Technician who has administered *lots* of the tetracycline family of drugs intravenously, doing so is not without risks & quite a bit of labor (it is very irritating to the animal's veins and must be adequately diluted, etc).

Unless your horse is symptomatic for Lyme disease, and bloodwork titers and clinical symptoms have not responded to months of high-dose oral doxycycline, then asking your vet for IV treatment is not necessary and your vet's email response was not surprising.

Again, IMHO,
from the Lyme hotbed of the US,

Emergency/Critical Care Specialist
Brewster, NY

Lavinia Fiscaletti

Hi Patty,

Generally, when ongoing IV medication is needed a catheter is inserted and left in place so that the infusion is done directly into the catheter so there is not issue with giving an injection into the wrong blood vessel. There are catheters that can be left in for up to 5 days and ones for up to 10 days. Then you change it out. Yes, there is always the possibility that there will be a reaction to the oxy-tet, just like that possibility exists for every other medication we administer to our horses. It is quite possible to accomplish this without moving the horse into a lay-up facility, to the vet's practice or needing the vet to come out 2x per day if you have a thorough understanding of what is involved, how to correctly do the infusions, what signs to be on the lookout for. Obviously, you and your vet need to have a good working relationship as well. This is all part of the cost-benefit analysis.

Oxy-tetracycline has a better track record for targeting encysted Lyme spirochetes. The doxy/minocycline have limited effectiveness against this form and because you are dealing with a chronic situation the encysted portion of the equation is likely to be a confounding factor. Increasing the length of time on the oral abx would not necessarily be effective and comes with its own set of possible complications - gastric issues being one.

Certainly the ideal set-up would be to have the horse in a veterinary-supervised setting, monitored continuously during the treatment period. Unfortunately, real life circumstances often force us to think outside the "ideal box" so that we can provide necessary treatment for our animals that would otherwise be unaffordable or undo-able.

Lavinia, Dante, George Too and Peanut
Jan 05, RI
EC Support Team

Lavinia Fiscaletti

Hi Kerry,

Agree that the titre is "not really that high". But it IS positive and Lyme is a very insidious disease that drives other issues. Libby has PPID, uncontrolled IR and sore feet that have not responded to dietary measures and control of her ACTH with pergolide. Previous treatment with doxy hasn't resolved the issue so in this case using the IV oxy-tet protocol seems to be a reasonable avenue to pursue. Waiting for more "symptoms to manifest" is akin to knowing there is a time bomb in the room but waiting for the explosion instead of trying to diffuse it before it explodes. High dose, long term doxy treatment is also not without possible downsides.

Lavinia, Dante, George Too and Peanut
Jan 05, RI (another Lyme hotbed)
EC Support Team

Kerry Isherwood

My fault! I misunderstood -- I did not realize the Lyme had already been treated with oral doxy and was refractory (hence why I was wondering why everyone was jumping to the IV protocols). I was hoping to let the owner know there were less risky alternatives in case she had erroneously been told, or had misunderstood from her vet, that the IV treatment was the necessary avenue to pursue if this was indeed the first titer pulled.

My apologies for interjecting without all that of the facts...

Kerry in NY

Stephanie Stout


I just wanted to add to the catheter discussion since I have experience with it. My horse had a catheter placed(10-day ones, and he had several replaced as he needed to have it for several weeks so I could give him fluids/meds for his kidneys). It is possible to manage it yourself, but you have to be really comfortable with needles/etc and be super duper sanitary. Unfortunately, I have a feeling why but can't prove, my guy got a jugular infection from the catheter which resulted in thrombosis of his jugular on one side. It is healing very slowly, but will take years and probably will never go back to normal again. So, I just wanted to say that if you do decide on a catheter, please please be extremely sterile, careful, and be sure that no horse buddies can get access to it. (I have seen the horror stories of fellow horses ripping out jugular catheter's)

Good luck!
Oct 2014