Should you be worried about Meningeal worm? Do you have: white tailed deer, snails and alpacas or llamas? If the answer is yes keep reading.
If you think your alpaca has meningeal worm stop reading and call your vet. Then come back and finish reading while you wait.

It’s only January and it’s been a rough year out in the barn. Thursday the 11th after work I went out to close up the barn but I was missing an alpaca. Fred was in the barn but George was no where to be found. Walking into the pasture it didn’t take long to see his fluffy white outline in the field.
He was laying down in the typical cush position but he didn’t get up when he saw me walking over. Even after I got right next to him and told him to get his butt out of the rain he didn’t move. His eyes seemed out of focus and even when I pushed on his butt he would. not. move.
I had to basically pick him up (he’s about 150 pounds) and half carry/half push him into the barn. I immediately knew what was going on and my heart dropped.

This wasn’t my first brush with m-worm. A few years ago Fred and George had a baby, his name was Henry and he was a fuzzy ball of happiness.
I wasn’t blogging very much when he was born and I don’t think he’s ever even been mentioned here. Before he was a year old Henry started showing the signs of meningeal worm infection.
He was so little and even with immediate help from the vet he wasn’t able to pull though. The second worst day of my life was when he died. It’s been two years and I still can’t look at pictures without crying.

Had I known how Henry would die I would have had him euthanized. If Fred or George had shown any signs of difficulty breathing I would have called the vet back out and had then euthanized too.
Luckily it never got to that point with them. There is a line between a merciful death and holding out for recovery. As the owners and caretakers of the animals it’s our jobs to draw those lines.
Back to 2018, I had the vet come out on Friday and she agreed that it was meningeal worm. I was given a pile of drugs and instructions for 5 days of treatment. Then you wait.
It’s be about two weeks and he’s completely back to normal. He was more or less better by Saturday. Of course Fred needed to get in on the action and she started showing symptoms on the 28th. Her treatment didn’t go nearly as neatly. I’ll be writing two posts about those experiences soon.
Meningeal Worm Introduction:
M-worm is a White Tailed Deer parasite that uses snails as it’s secondary host. Alpacas get infected when they eat those snails or even when they come into contact with the snail trails. I live in a very wet area with lots of deer.
It’s basically m-worm paradise here. The vet was telling me about a man a few towns over that lost 1/2 his herd to m-worm even though he was following the anti-parasitic protocol put out by Cornell.

I give Fred & George monthly shots but I stopped when the ground froze. Frozen ground, no snails, no worms, right? That would be a no. They’ll both be getting monthly shots of Ivermectin from now on. Old literature gives an Ivermectin worming schedule that skips the winter months, do not skip months.
The symptoms take around 45 days to appear, that’s why it’s surprisingly common to see break though infections in December-January even though the animals have been off pasture or at least away from snails for a while. Basically, you’re never safe, stay vigilant.
Meningeal Worm Prevention:

Based on where you live you may never have a problem with m-worm or you may be fighting a losing battle. If you are in an area where it’s a problem you absolutely need to keep up on a worming schedule.
If you aren’t sure talk to the local large animal vet, they’ll be able to help you out and figure out a preventative worming plan. You can buy Ivermectin at Tractor Supply by the vial and you’ll need needles and syringes to administer the shots.
You can also keep away the parasite vectors, white tailed deer and snails. I’m not in the position to afford deer fence around the property and I’m not willing to use chemicals to kill snails. I have read that ducks and guinea hens are great in the battle against snails. My duck population has dwindled and the last guinea hen got hit by the school bus.
My snail killer lineup needs to be rejuvenated and I’m still mulling over my options. I’m leaning toward the guinea fowl, they’re loud and annoying but I haven’t seen a tick since I brought them home and Lyme disease is no joke around here. My dog ended up with Lyme in April so they’re looking really good right now.
I’m also reminiscing about my Muscovy ducks and thinking it’s time for them to make a come back if I can find any locally this spring.
Meningeal Worm Symptoms:
M-worm affects the nervous system. The back legs are usually affected first. That’s why when George wouldn’t get up I started to get concerned. When I noticed his gait was stiff and he was standing against the wall I knew what I was dealing with. I don’t have any pictures, I wasn’t focused on anything but helping them get better.
Alpacas are very good at hiding illness. The best way to know something is wrong is to spend time with your animals. You can’t know when they start to act off if you don’t understand how they act when they’re healthy.
If an animal seems off keep an even closer eye on them. If they show signs of stiffness in the back legs when they walk or can’t get up call the vet asap. If you have drugs on hand start treatment.
Wednesday night George was slow getting to the barn, Fred was there to greet me at the gate but he was still outside. I wrote it off as enjoying the nice weather but looking back it was probably an early sign. Early treatment is of the utmost importance. When neurological damage is done, it’s done. That’s why it’s so important to catch this early and treat it aggressively.
Meningeal Worm Treatment

The treatment for Meningeal worm is a 5 day course of Ivermectin, Banamine (anti-inflammatory) and Dexamethasone (anti-inflammatory steroid) injections. Along with a double dose of Safe-Guard which is an oral wormer, also for 5 days.
The doses are based on weight, your vet will be able to help you out with that. You can buy both wormers over the counter at Tractor Supply. You will also need needles and syringes, I got those from my vet. Needles are hard to come by in New York state.
A side effect of the wormers is swelling so it’s important to also treat with anti-inflammatory medications. Both Banamine and Dexamethasone are prescription medications. You guessed it, talk to the vet. Buying a bottle is cheaper than getting individual doses.
I feel very fortunate that my second and third brush with meningeal worm has had positive outcomes. I spent a lot of time looking for information on meningeal worm and alpacas and I kept ending up on the same difficult to navigate forums where the information went completely over my head. I hope I have condensed my knowledge of m-worm in a readable way.
I’m in the process of writing up the individual stories for George and Fred because they were very, very different. Symptoms are based on where the worms are and that can make a huge difference in how the infection appears between animals.
You can read more about my alpacas here:




Ellen
Wednesday 29th of January 2025
We lost all but one of our alpacas due to those parasites. We tried everything that was suggested. But where we live the large animal vets had no idea what to use to help us try to save our herd. I decided to try the guineas. You still have to use the injectables. But the guineas help with the removal of the snails. Believe it or not, but our last and only girl is still around and it's been 5 years. That was a hard lesson on us and we will not restock our herd. I hope all goes well with you.
Rick Borden
Tuesday 20th of February 2024
My wife and I are right now dealing with it in our girl named Pie. It's been 10 days and she still can't use her back legs much. We rigged a sling with a come along for the first 5 days and now I help her stand but she can't stand up by herself. Her spirits are good and she us still feisty with the others ( which she always was) so that's good. This was a good article and I appreciate the info, thank you.
Alecia
Wednesday 21st of February 2024
I'm so sorry that you're going through this. My girl Fred still has hind leg weakness years after surviving her Meningeal worm infection, if she gets going too quickly she ends up spinning in a circle. I hope Pie gets better soon
Annie Bruetsch
Monday 12th of August 2019
Thanks great words of wisdom! So difficult to watch and treat
Spring Mills Alpacas
cindi Kent
Monday 13th of May 2019
We have an alpaca that had the apparent m-worm symptoms this last winter, however we did not have any knowledge of the m-worm ....we had a vet out to check him out...she was supposed to be a known alpaca-vet in our area....as we did not know the symptoms of this infestation, we were convinced that he had an accident of falling on the ice and injured his back...the vet gave injections of steroids and after a couple of weeks he got up on his own and we thought he was on his way to recovery...sadly yesterday while our shearer saw him and heard the story he informed us of the m-worm...my question is....after a few months of his symptoms, is he in pain? can we baby him and comfort him now with any medications...we truly love this guy..but don't want to keep him going if he is in pain....any hope?
SONIA
Tuesday 7th of May 2019
I will love to see if you can send me a pic of the bottles of the medicine, I dont have a near by vet and definitely not one that come to my place :'( I will love to show them what they prescribed for our alpacas to see if they can do the same for mine, please?
SONIA
Tuesday 7th of May 2019
I am sorry for your alpacas!!!