Encephalitozoon Cuniculi (EC)

[InspectorMorse]

This is just a question being asked out of curiosity. How many of you have had cases of *active* EC in *different* Rabbits over the years ?

I have cared for 152 Rabbits over the last 26 years. During that time I have only had 6 cases of *active*EC. I can trace the origin of 4 cases. I took in an Adult Buck who must have been an EC carrier as he went on to develop active EC after about 2 years. His symptoms were hind leg paresis and renal failure.This was at the very start of my Rabbit keeping days and my ignorance led three accidental litters when I put the Buck in with 3 entire Does just two weeks after he was castrated and long before he showed any signs of EC.He was obviously still fertile as all three Does became pregnant. None of the Does ever developed active EC but 3 of their kits did, by the age of about 3. One of the three Does only had 1 kit. He developed symptomatic EC two weeks after he was castrated, so aged about 5 months. After the acute symptomatic phase he was left with ongoing seizures for his entire life, almost 8 years.

The two other cases came to me with symptomatic EC, occular symptoms in both cases.

Strangely only one of the 6 symptomatic cases had a head tilt as a symptom. The others had either renal failure, hind leg paresis or EC induced phacolytic uveitis. One going on to develop secondary glaucoma finally resulting in the need to have the effected eye removed.

Given how common EC is and how many Rabbits I have cared for I think I have been lucky to not encounter a lot more active cases. I am *not* suggesting it’s due to anything I am or am not doing regarding Rabbit care. But it’s just something I have often thought about when I see posts about EC. I don’t know enough about the disease.

I wish there were more recent and ongoing studies into it. Nothing seems to have changed or improved for many years with regards to treatments. There is no recent data of how many Rabbits carry EC or are symptomatic.

I thought there was a new study being done a few years ago, I believe a rescue who used to be active on here was involved but I can’t recall the specific details.

I am interested to hear accounts of your experiences with ‘EC Rabbits’ and details of how the disease affected the Rabbit, what treatment was given and what the longterm outcome was. Also, was the Vet you consulted well informed about treatment options ?

Finally, do you give a one off 28 day course of Fenbendazole to any new Rabbit you obtain? Has your Vet ever advised doing so ?

I remember when I had my first encounter with EC when I consulted the Vet I used back then at the RSPCA Animal Hospital in Putney she had never heard of EC. This was in about 1999.

 

[Shimmer]

I still do a 28 day course of Panacur for all my rabbits when there is a new one joining us as a matter of routine.

I've had 2 rabbits with obvious recurring EC over the last 27 years. Most of my rabbits were of unknown background. All neutered, vaccinated, living outside.

One was perfectly normal as she came in the house one night. By the time she had gone through to the kitchen, she had collapsed. It was like watching a slow motion nightmare as her legs gave up over those few metres. She was on very long term treatment and had a very severe head tilt (head was stuck to her shoulder), although the first symptom was her back legs. The head tilt did reduce to a minor one eventually, but she was on panacur & metacam pretty much for the rest of her life. She got most of the use of her legs back - just coudn't jump as much as she used to as her balance etc were slightly off.

The other had hind leg weakness which was the only issue. There were flares of EC - they temporarily resolved with a 28 day course of treatment. I had to watch carefully for the first signs of the legs going and start another course of treatment. I think it also ended up affecting the eyes. They had to be treated 2 or 3 times a year to keep on top of it.

I'm sure there have been a couple of others with suspected EC. They were treated but there were no long term issues.

None of the companion rabbits ever seemed to sucumb to EC, although they tended to get a course of Panacur at the same time.

For anyone with an EC rabbit, it can be a real rollercoaster ride but IME is a battle that can be won with persistence.

Wasn't FHB doing something a few years ago? Or I may be confusing it with something else. She asked for samples to be sent to her via vets for her study.

 

[InspectorMorse]

I still do a 28 day course of Panacur for all my rabbits when there is a new one joining us as a matter of routine.

I've had 2 rabbits with obvious recurring EC over the last 27 years. Most of my rabbits were of unknown background. All neutered, vaccinated, living outside.

One was perfectly normal as she came in the house one night. By the time she had gone through to the kitchen, she had collapsed. It was like watching a slow motion nightmare as her legs gave up over those few metres. She was on very long term treatment and had a very severe head tilt (head was stuck to her shoulder), although the first symptom was her back legs. The head tilt did reduce to a minor one eventually, but she was on panacur & metacam pretty much for the rest of her life. She got most of the use of her legs back - just coudn't jump as much as she used to as her balance etc were slightly off.

The other had hind leg weakness which was the only issue. There were flares of EC - they temporarily resolved with a 28 day course of treatment. I had to watch carefully for the first signs of the legs going and start another course of treatment. I think it also ended up affecting the eyes. They had to be treated 2 or 3 times a year to keep on top of it.

I'm sure there have been a couple of others with suspected EC. They were treated but there were no long term issues.

None of the companion rabbits ever seemed to sucumb to EC, although they tended to get a course of Panacur at the same time.

For anyone with an EC rabbit, it can be a real rollercoaster ride but IME is a battle that can be won with persistence.

Wasn't FHB doing something a few years ago? Or I may be confusing it with something else. She asked for samples to be sent to her via vets for her study.

Thanks for your input D, I think it was FHB who was going to do some research, not sure if that ever happened though as ‘life’ took over for her.

The Bunny I had who was left with daily seizures did have one suspected flare up which presented with hind leg weakness. He did develop a head tilt but that was attributed to a middle ear infection ( CT scan confirmation). His seizures only occurred in his sleep. He would suddenly lurch forward and scrabble about. Sometimes he would roll too. We tried anticonvulsant medication but nothing helped. Phenebarbital completely knocked him out, but he still had the seizures. They were distressing to witness, but he wasn’t fazed by them at all. They lasted for about a minute maximum and he’d then immediately go and find something to eat. Toward the end of his life the seizures did increase in duration and on a few occasions he needed rectal diazepam. He passed at home in his sleep whilst on treatment for a RTI. I didn’t think he’d make it to be 8 given that his EC became symptomatic at just 6 months of age.

 

[SarahP]

I'm always surprised more hasn't advanced in this area too. But then, I don't get the impression that much has advanced with small animal (medical) knowledge generally within the last 20 years.

 

[InspectorMorse]

I'm always surprised more hasn't advanced in this area too. But then, I don't get the impression that much has advanced with small animal (medical) knowledge generally within the last 20 years.

I agree. It’s disappointing given that Rabbits are the third most popular pet. I expect finding a Guinea Pig savvy Vet is as difficult as finding a Rabbit Savvy one x

 

[Shimmer]

None of mine ever had seizures - just a gradual worsening of their individual subtle symptoms over maybe a week before treatment restarted. None were ever tested officially for EC, but they were classic cases and my vet was heavily involved with the first one.

 

[~ILoveMyBunny~]

I've had two definite, confirmed active EC buns who both had repeated flares. Snowflake and Jazzie, both ended up in renal failure and ultimately I lost both to it after having them on paliative care for a number of months. No head tilt in either (though I couldn't tell for sure if Jazzie had a very minor tilt briefly) For both the main indicator that they were having a flare was weight loss and it was then diagnosed by blood test.
With Jazzie she was particularly difficult to control, with her numbers coming back extremely high every time we did an EC blood test. She was on panacur for a very extended period of time. The numbers tended to drop a bit with treatment, but still remained high so she ended up doing another round and so on. Despite all that she did incredibly well and far exceeded everyone's expectations. Both girls were incredible fighters.

Three others - Willow, Maple and Honey were unconfirmed, but EC was *strongly* suspected. With Willow she went into stasis and, as I recall, had balance issues and limb weakness. She was 11 but otherwise healthy for her age.
Maple was in my view definitely EC, though I cannot confirm as we didn't get as far as testing. She had sudden onset hind limb paralysis, weakness, bladder incontinence and was in stasis (though did try to eat for herself). She died at an animal hospital overnight and before we could get as far as running blood tests. She was found to have a heart murmur too so we dont' really know what happened. Unfortunately she passed before we could get back up there. She wasn't even 3yrs old.
Honey is another unknown, but suspected to have had it either as a cause or a secondary factor in losing her. She had facial paralysis but we didn't know the cause. Some time later she suddenly developed a cataract seemingly overnight just a few weeks before we lost her (she was only just 6 so not likely to be age related) and had been placed on panacur as this was around the same time Snowflake had an active infection if I remember correctly. Either way we had good reason to suspect EC at the time I remember. Unfortunately I came in to do her medications one day and she collapsed against me and had difficulty breathing. I did everything to get her to a vet urgently but the taxi company let me down and she passed whilst I was waiting to get her there in a very traumatic way. Out of all of them that is ingrained in my memory the worst. I did try CPR on her but to no avail.
None of those three had a head tilt either.

Another two have possibly had EC but again unconfirmed.
Cody had a severe stasis espisode that nearly killed him and dramatic weight loss around the same time as Maple. He was hospitalised only days after we lost her. Thankfully he pulled through, though a blood test was never recommended and back then I didn't know to ask for one. But when he saw our normal vet she did think EC was very likely, especially given what had just happened with Maple. She strongly believed Maple had had EC.
Cody died years later just after being placed under GA for an ear abscess. He was with a trusted exotics vet team so all was done correctly. When I asked I was told the potential for him having had EC could have been a possible factor in losing him, though there were other circumstances so we'll never know for sure. This was 3 months after losing Snowflake too so could well have been that he was reinfected without my knowledge, though they were housed apart and I always took precautions with disinfecting etc. He had no symptoms at the time so it's a bit of an uknown with him. Again no head tilt at any point.

Harley is a very confusing one who I believe has had EC settled on as a diagnosis, despite him constantly having tested negative.
He had a severe head tilt, nystagmus, loss of coodination, rolling etc only a little while after we got him. He's seen numerous normal vets, at least 4 different exotics specialists, including a leading rabbit expert vet and has had his case discussed with Richard Saunders too. He's proven to be something of a mystery to them all.
He had multiple EC blood tests during and after onset of symptoms and every one came back negative. He also had several x-rays and a CT scan which ruled out other potential likely causes such as ear disease or even a brain tumour. He stumped everyone. However a good 5yrs on and with amazing care from our wonderful exotics vet who took over his case and never gave up on him he's now thriving. He has a pretty severe permanent head tilt but is otherwise a happy, healthy, bouncy little boy (aside from a current eye infection on his down eye) with no other symptoms present anymore. As I understand it I think it was decided EC was the likely cause despite him having had so many negative blood tests. He's been a real mystery to everyone though!


Out of 13 buns over the years there are two definite confirmed EC cases, three very likely but unconfirmed and two who were/are in question.
I have nothing but hatred for this evil disease. I know it has definitely stolen at the very least two of my girls from me, and very likely at least 3 more. I know technically myxo and rhd are 'worse', but this is the one I have a seething, personal hatred for. It's stolen my girls from me before their time. If not for EC they'd still be here. And having their precious lives cut short, stolen from them and stolen time for us together is something that I hate from the core.
If only rabbits were given the priority they deserve maybe we'd have more effective treatments or even preventions by now.

I have no idea with mine whether they had it from birth, acquired it before they came to me or caught it from each other.
I did treat most with panacur when they came to me as a precaution, but I guess if it's dormant it could still resurface at a later date. A few of my earlier buns came from pet shops so I wouldn't be at all surprsied if they picked it up there, given the volume of rabbits they have in and out. There's no way they throroughly disinfect in between batches of rabbits. They're just products to them.
I always took extreme precautions with the ones I knew or suspected had EC. I had very thorough disinfecting protocols and whilst they had active infections I even changed my clothes after handling them. The floors they ran on were disinfected, they were housed apart from the others, hand washing.. every precaution you could think of. We probably overdid it. However there's little you can do about the air aside from opening windows so I guess you can't fully prevent it.
I do really hope it wasn't a case of them catching it from each other.

 

[beki]

Potentially 2 cases out of 5 bunnies I have ever owned.

Bertie is now 10. When I adopted him I didn’t treat him with panacur (I can’t remember why as I treated my previous paring with panacur). He went to live with Ruby whose previous partner has recently died of a tumour. Ruby was 5 and perfectly healthy and had had occasional doses of panacur during ownership.
Within 2 months of the bonding, Bertie had a rupture in the lease of his eye which the vet believed to be EC (I can’t remember if he was tested or not, it was 9 years ago) and ruby had developed head tilt. We tried many treatments with ruby but she kept rolling and was getting very distressed so she was pts as nothing was working.
Berties eye got better and then ruptured again. He now has a cateract in it. He is still going strong at around 10 years old (I’ve had him 9.5 years). He had regular panacur treatments for a while and I treated both with I bonded him with his new partner, Betsy.
No further incidents of EC, head tilt or eye issues since then. Betsy and Bertie have been bonded 8.5 years.

I believe that Bertie gave it to Ruby, I don’t know why he didn’t give it to Betsy, but I expect as his eye hasn’t been an issue since he was bonded with Betsy, the EC went dormant again