This is an archived Horseadvice.com Discussion. The parent article and menus are available on the navigation menu below:
HorseAdvice.com » Diseases of Horses » Skin Diseases, Wounds, and Swellings » Bumps / Nodules / Warts / Tumors » Overview of Bumps, Nodules, Warts & Tumors »
  Discussion on Habronema
Author Message
Member:
vickiann

Posted on Saturday, Jan 28, 2012 - 1:36 pm:

Dr. O, I have just been reviewing the article about Habronema in the Overview of Bumps, Nodules, Warts & Tumors, which states that this problem has all but been eliminated due to the use of Ivermectin.

Unfortunately this problem actually seems to be increasing in our area.

It seems that local veterinarians and the hospitals have been doing a fair number of surgeries.

The surgeon who worked on a friend's stallion (and who has worked on many cases) believes that the increase is due to a growing resistance to Ivermectin.

On my Florida farm we have had a lot more flies over the past 3 years, including having them all winter long so that I am having to use fly masks daily.

Fortunately for me, I have not had a persistent Habronema problem for a few years on any of my horses.

We seem to be getting some conflicting information about Habronema and are wondering whether it is simply available out there in the environment, as one Vet said, or if it is spreading because of horses actually being wormed less often as we are now encouraged to use fecals more and worm less.

My friend's stallion first came down with the problem a number of years ago and had bad lesions for a couple of years in a row and then was free of it for a few years after my friend did more frequent worming doses on him during the summer months.

Last summer he developed a new case that began at the base of his penis and spread outward from there, inside of his entire sheath. The first week of December, a surgeon removed as much tissue as she could and things were looking really good but the incision has since become reinfested so that the prognosis is looking more and more grim if this continues to progress. At this point it is possible that the area has become cancerous, according to the surgeon.

Do you have any new information or insight on this problem?

If one horse has it on a farm should all of the horses be wormed with Ivermectin or should one wait until a horse comes down with Habronema to begin worming frequently?

Are there things that a horse owner can do to prevent a particular horse from contracting this pesky and potentially serious problem?

It seems that some horses will just pop the larvae out without a problem developing while other individuals may have much worse problems. Does these mean that the horses who react badly have an autoimmune problem or a weak immune system?
Moderator:
DrO

Posted on Wednesday, Feb 1, 2012 - 3:32 pm:

I have had other members from Florida express your concern Vicki so I should revise the article to reflect different experiences in tropical environments. We do not see this in our southern region of the country but it will be interesting to see if they recur now that we are using less ivermectin and moxidectin. We should note that habronemiasis does not lead to cancer, it is most likely the other way around where cancer attracts flies and becomes infected.

I have not seen any significant new research on habronema but taking your questions one at a time:
1) I would not recommend prophylactically treating all horses for habronema with the possible exception of a horse with a wound in an area that does have a very high incidence. The problem with prophylaxis is that exposure can occur at anytime.
2) Prompt wound treatment that includes wound protection, fly repellents, and good fly control including the rapid removal of manure from the premises would continue to be the basis for control.
3) I don't know what might explain the individuals with much worse problems but it may have more to do with an overreaction of the immune system as opposed to lack of immunity.
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