Woodland
Mar. 1, 2010, 08:28 AM
This was on the Showing Appaloosas Board last week. It is very interesting! Cross posted with permission:
I'd like to address a few things regarding EPM so that minimal incorrect information is passed along.
1. There was an EPM vaccine on the market with a conditional license. However, that license was not renewed due to problems creating the disease in the lab in order to prove efficacy under field trials. No further EPM vaccines have been whispered about to date.
2. There are 2 very effective medications to treat EPM - Marquis (Bayer) and Navigator (Idexx). They are both 30 day treatment runs with occasional usage of another 30 days treatment. While they are expensive, they have been quite effective in EVERY horse I have used them. I have treated several aged (more than 20 years old) horses with both medications with good success. To date, no horse has had a relapse in my practice. Response to therapy is generally quick - within one week of initiating therapy.
3. This protozoal parasite damages primarily the spinal cord, but can land in the brain. Many of the early symptoms are caused by inflammation and medications aimed at reducing inflammation are an important part of therapy.
4. The older therapy of SMZ-TMP (Bactrim) and Daraprim was aimed at reducing the folate levels since the protozoan cannot synthesize folate. Most horses do not need to be supplemented with folate during this treatment regimen. It was minimal to moderately successful in controlling the disease, but recurrence/relapse was high (more than 50% recurred).
5. The affected horses can be dangerous to be around because they cannot control their movement well. Just beware and give yourself room to get away (being smushed inadvertently stinks!)
6. It doesn't matter why a horse is down - they need to be on their feet as soon as possible. A down horse is a ticking time bomb for many other problems that can ultimately cause the horse to be put down (pneumonia is the biggest one, but ulcerative/erosive pressure sores are a huge problem in the longterm down horse).
7. Positive diagnosis is based upon a cerebral-spinal fluid sample. Blood samples are not particularly effective for diagnosis. Many horses have been exposed to the parasite and will titer positive. Some affected horses have not had time to create a titer, but will be clinically affected. A rising titer taken 2 weeks apart is pretty indicative of disease, however, waiting 2 weeks to initiate therapy can be disastrous. Many vets and owners decide to treat presumptively and will have response to therapy long before a 2nd blood sample is done thereby confirming the diagnosis.
8. Using herbs/alternative medicine should be used cautiously. At this time, the US does not regulate the naturopathic side of pharmaceutics. Therefore, you really don't know what all is in the product that you buy and administer to the horse. Do be aware that herbs are still drugs, just in non-refined forms.
9. Forgoing deworming medications for the rest of the life of a horse should only be done if that horse is ROUTINELY tested for parasite eggs. If a horse has very low numbers of parasite eggs in it's fecal sample, deworming may not be necessary. This goes for all horses. We rarely see parasite caused colics anymore due to the widespread usage of dewormers. However, it can sure happen in the non-protected horse.
The most important take home message is to talk with your vet and form a good working relationship before disasters strike. I hope this information will help open a new door of communication for the members on this list.
Sharon Marshall, DVM (a vet first and director 2nd)
ApHC BOD 4b
I'd like to address a few things regarding EPM so that minimal incorrect information is passed along.
1. There was an EPM vaccine on the market with a conditional license. However, that license was not renewed due to problems creating the disease in the lab in order to prove efficacy under field trials. No further EPM vaccines have been whispered about to date.
2. There are 2 very effective medications to treat EPM - Marquis (Bayer) and Navigator (Idexx). They are both 30 day treatment runs with occasional usage of another 30 days treatment. While they are expensive, they have been quite effective in EVERY horse I have used them. I have treated several aged (more than 20 years old) horses with both medications with good success. To date, no horse has had a relapse in my practice. Response to therapy is generally quick - within one week of initiating therapy.
3. This protozoal parasite damages primarily the spinal cord, but can land in the brain. Many of the early symptoms are caused by inflammation and medications aimed at reducing inflammation are an important part of therapy.
4. The older therapy of SMZ-TMP (Bactrim) and Daraprim was aimed at reducing the folate levels since the protozoan cannot synthesize folate. Most horses do not need to be supplemented with folate during this treatment regimen. It was minimal to moderately successful in controlling the disease, but recurrence/relapse was high (more than 50% recurred).
5. The affected horses can be dangerous to be around because they cannot control their movement well. Just beware and give yourself room to get away (being smushed inadvertently stinks!)
6. It doesn't matter why a horse is down - they need to be on their feet as soon as possible. A down horse is a ticking time bomb for many other problems that can ultimately cause the horse to be put down (pneumonia is the biggest one, but ulcerative/erosive pressure sores are a huge problem in the longterm down horse).
7. Positive diagnosis is based upon a cerebral-spinal fluid sample. Blood samples are not particularly effective for diagnosis. Many horses have been exposed to the parasite and will titer positive. Some affected horses have not had time to create a titer, but will be clinically affected. A rising titer taken 2 weeks apart is pretty indicative of disease, however, waiting 2 weeks to initiate therapy can be disastrous. Many vets and owners decide to treat presumptively and will have response to therapy long before a 2nd blood sample is done thereby confirming the diagnosis.
8. Using herbs/alternative medicine should be used cautiously. At this time, the US does not regulate the naturopathic side of pharmaceutics. Therefore, you really don't know what all is in the product that you buy and administer to the horse. Do be aware that herbs are still drugs, just in non-refined forms.
9. Forgoing deworming medications for the rest of the life of a horse should only be done if that horse is ROUTINELY tested for parasite eggs. If a horse has very low numbers of parasite eggs in it's fecal sample, deworming may not be necessary. This goes for all horses. We rarely see parasite caused colics anymore due to the widespread usage of dewormers. However, it can sure happen in the non-protected horse.
The most important take home message is to talk with your vet and form a good working relationship before disasters strike. I hope this information will help open a new door of communication for the members on this list.
Sharon Marshall, DVM (a vet first and director 2nd)
ApHC BOD 4b