Otto and Ellis visited the veterinarian last Friday. On the advice of the vet, we ran a full blood panel and multiple infectious disease tests on them.
Except for a slightly elevated phosphorus level in the blood, they checked out completely normal! Negative for exposure to FIV, FeLV, FIP, toxoplasmosis, and so forth. Since they've gotten their vaccinations, worming, and surgery, and they've both become socialized, I can more fully devote my efforts to finding them a good home! Yay!
The not-so-good news is that whatever damaged them is still unknown. What they both have could be a simple physical birth defect, brain lesion, nerve damage from exposure to a neurotoxin or other substance (in utero or postpartum), or so forth.
So the kittens definitely have ataxia. Based on what the vet and I have observed, it appears to be cerebellar ataxia rather than sensory ataxia, based on a) good response to tests relating to detecting the location of limbs, and b) the occasional presence of intention tremor. The important part is that while the specific agent which caused their ataxia remains unknown, all infectious disease testing has come up negative.
If the diagnosis is accurate, and they suffer from cerebellar ataxia, it's a particularly mild case. They still run, climb, jump, stalk, and leap. They don't have any litter box issues, other than needing a slightly larger litter box than some (they tend to splay their hind legs a bit for stability, more so than many cats). They clean themselves just fine, and Otto kneads just like any happy cat - with purring and enthusiasm!
Anything taller than the seat of a chair is beyond their jumping abilities. They tend to climb up when possible, rather than trying to leap up. When they jump down, they usually land heavily, and sometimes off balance. Otto is getting used to being picked up and put down, with the voice cue of "up" and "down." Ellis is still learning this, and still doesn't like being held as much as Otto does.
But both of them love being petted, and rubbed under the chin and along the jawline. They like sitting in your lap. Their favorite toy is still a crumpled up ball of paper! And they definitely purr when they're feeling happy.
Now, to find them a good forever home! I'd love to place them together, but if I have to place them separately to find them homes, I'll do it. But they've gotten so attached to one another that if I'm in the bathroom with Ellis, and Otto's in their bedroom, Otto will cry out occasionally until Ellis returns. And while they're separated, if Ellis hears Otto crying, he seeks the door and looks at me somewhat expectantly.
Wish me luck!!