I took Puff to a veterinary neurologist today, and confirmed my suspicions that his inability to walk is of neurological rather than arthritic origin.

Here's the what the neurologist said:

At examination today Puff seems to be in good general health except for the marked weakness and loss of position sense in the rear limbs. Spinal reflexes and muscle tone are decreased in the rear limbs. Anal sphincter reflexes are diminished. Signs are consistent with dysfunction of the spinal cord in the lower back (the mid-lumbar spine). Most likely diagnostic candidates include tumor or type II intervertebral disc protrusion. Additional diagnostic pursuit by means of MRI is recommended for a firm diagnosis.

In lieu of a firm diagnosis an ongoing course of medical management is recommended. This course includes a prednisone trial as outlined above. Please call in 5-6 days to discuss Puff's response to the treatment. The medication may or may not bring improvement in the condition. If improvement is seen the medication may continue indefinitely. If no improvement is seen, we will suggest a decreasing course over time.

The bladder should be emptied 2-4 times daily by catheterization. This should help to keep Puff at least clean and dry. Please call if you see any sign of pain or any sign of increasing weakness. In that instance further evaluation is more strongly recommended.

Please call if you have any problems or questions.

Interestingly enough, I've used this type of catheter once before. A day or so after giving birth, a female dog I had bred managed to find and eat some toxin or another which was lying around an adjoining construction site. It didn't kill her, but it made her severely ill, causing her to lose her milk -- along with any semblance of maternal instinct. She turned on her own pups, killing two and was intent on killing the rest of them when I realized what was happening, yanked her away and put her in the kennel for the next six weeks. I had to raise the pups by hand, and it would have been impossible without catheters like this one:

That's called a "Feeding tube and Urethral Catheter." Whether they're putting stuff in or taking stuff out, it's the same item. It's hollow inside with a hole on the side of the tube near the end (which is a rounded tip), and the larger end fits on a syringe coupling. When I was raising the litter, I mixed a formula of eggs, milk and yogurt, which I loaded into 100cc syringes. The wide end of the catheter went onto the end of the syringe, and each blind, helpless puppy in turn had his meal delivered through the catheter, which I coated with butter and gently threaded down the throat until it stopped in the stomach. The mixture was slowly injected directly into the tiny tummy -- much the same way you'd fill an empty print cartridge with ink. The puppies would make instinctive sucking movements with their lips while this was going on, and they'd twitch with satisfaction. Finally, when the belly was full, I removed the tube, then rub the anus and genitalia with a warm wet Q-tip to stimulate excretion the way the mom would with her tongue. Just as they are unable to eat normally, neonate puppies are unable to relieve themselves without help. They'd oblige, of course. And it was on to the next puppy, until all six were fed and "relieved." Starting when the pups were a couple of days old, I went through this routine every four hours until finally I was able to start weaning them at around four weeks. (To them I was "mom," of course...) I'm proud to say I didn't lose a single pup out of the six.

Anyway, Puff now has a very similar catheter. I don't plan to use it all the time, but it ought to help if I have to go out at night, or for long periods. His "signal" mechanism isn't the same anymore, and if I don't drag him out every couple of hours he can lose control (which seems to embarrass him greatly; glad he can't read the blog!)

I sure hope Puff gets a boost from the change in meds. We'll see. He's still loaded with life, and the vets agree that at this point there's no reason to consider putting him down. Besides, Coco keeps him plenty busy....