More Info from U of MN

Just got off the phone with the folks at U of MN. Super nice and helpful folks there; can't say enough good things about them. They have answered all my questions and sent me PDF files of their articles. Pretty much anything I could have thought of. I'm going to try to jot down the highlights of our conversation very quickly, perhaps in a less organized manner than usual, so I don't forget them or get called away to something else.

1. EIC, of all forms studied, is generally characterized by an increased sensitivity to heat and humidity. It has been known to occur in colder conditions and even in retrievers doing water retrieves in cold water but that is in the minority of cases.

2. A current working hypothesis is that there may be a variety of different mutations that result in a similar phenotype across different breeds/types of dogs. The underlying connection being that these mutations increase the temperature sensitivity of processes involved in neurotransmission, specifically in the CNS and not at the NMJ, of affected dogs resulting in a similar collapse phenotype. The differences between the specific breed/type syndromes being more specific to the actual mutation involved as opposed to the collapse. In general, dogs' ability to thermoregulate and dissipate heat is reduced compared to other mammals.

3. There are some identifiable differences between EIC in Labradors (for the duration of post EIC_L refers only to Labs) and what has been termed Border Collie Collapse (BCC):
  A. EIC_L results in a collapse involving relaxed, almost flaccid muscles, particularly in the back legs
  B. BCC results in a stiff-legged, rigid movement and ultimately collapse
  C. In almost all cases of BCC studied so far, the dog shows some evidence of disorientation, e.g. does not respond to name or other commands or may actually lose consciousness in more severe cases
  D. EIC_L results in a loss of patellar reflexes upon collapse

I also asked them specifically about one of the observations the vets made the other day when I worked Gata between cardiology evaluations - the constricted pupils and slight delay in return to normal function (reactivity to light stimulus). At this time, that was not a feature that they recognized as being characteristic of either of the collapse conditions that they have worked on.

We talked about potential treatments a little. They are encouraging people to try a low dose of Phenobarbital with their dogs. Two lines of reasoning for this - 1. in BCC it is looking like a seizure disorder; 2. it is the only thing that has worked in a few EIC_L. We talked briefly about other options and she suggested "calming drugs" but said she wasn't sure about which or the appropriateness of that since she is a bench scientist and not a vet. Maybe that's why I enjoyed talking with her so much :-)

Talked more about a video. They feel that they have everything that they need on her case. Dr. Eeg's office sent them the entire file on all the diagnostics that we have done so far. She said that they are always happy to have more video but not to "go out of my way to cause a collapse just for a video". What a nice thing to say after some of the "crap" that I've gotten from other folks. We both agreed that if it is some form of EIC that there will be plenty of unavoidable collapses to get video of in a few months.

About the BCC study: The have nearly completed the physiology portion of the study and are preparing a manuscript for publication. They have DNA samples from over 100 dogs but they do not have the funding to start the full genome analysis to identify the mutation. So it will probably be quite awhile to get that work done.