Our four-year-old, twenty-pound Fox Terrier, Zip, was dying. My husband and I were devastated. She was not only an excellent squirrel dog, she was our house dog, our best friend.

For days, we had noticed a subtle change in her. She had gone from a bright, vigorous new mom of seven weaned pups to one whose eyes had lost their sparkle. Her hair, which had always been shiny and thick, was starting to shed more than usual. She looked tired and her eyes were watery. Something was wrong. We started trying to build her immune system with a high protein dog food and raw eggs. She ate and drank well, so we blamed her diminished state on the toll a litter of pups had taken on her system. But by the weekend, she took a turn for the worse. Her nose was warm and dry and her whole body was hot to the touch. By bedtime, we were very concerned and called our vet, Tom, who also happens to be a good friend.

I told him all about Zip's symptoms, trying to keep it light-hearted. I didn't want to sound like an overprotective mother.

"Could be a cold or sore throat," he said. "Have you got any of those antibiotics left over from last year?"

We did have a couple of refrigerated syringes left over from an upset stomach.

"Go ahead and give her those over the weekend plus one baby aspirin a day. Maybe that'll do it. If not, let me know."

Although her fever went down at times, by Sunday night her left eye was completely inflamed. We had her in Tom"s clinic as soon as it opened Monday morning.

"Blastomycosis," Tom said at first glance. "We"ll have to run a test to be sure, but I"m almost positive she has it." As he continued, I strained to hear one bit of optimism in the tone of his words. There was none.

"Her left eye is already gone," Tom said. Her eye was swelling, pushing it out of its socket. If it moved to the other eye, she could lose her sight completely.

Tom explained that the disease is actually a fungus that is breathed into the lungs and then attacks the internal organs. He told us the disease was not uncommon in dogs who like to dig in wooded areas hunting for mice or moles. Zip's first love was squirrel hunting, but she also loved to locate vermin by listening to the ground and then digging for her prize. This particular year, she had become a victim of one of the hottest, dampest years in recorded history. Our Kentucky bottom-land farm had been a haven for Blastomycosis, with rotting vegetation providing the perfect breeding ground for the deadly fungus.

Tom gave Zip a couple of shots to help her fight the infection, but told us that they were just a temporary fix. It wouldn't kill the fungus, but, until the test came back, it was all he could do.

Now, Zip's life hung in the balance. My mind kept going back to the day we got her from the Amish man who raised Fox Terriers. Black and white, skinny as a rail, she had quickly worked her way into our hearts.

We waited two days for the test results and sure enough, our vet was right.

"There is a treatment that has been proven to be very effective, but it's also very expensive," he said.

"Don't even ask. Just get it," my husband replied. Zip was a dog of a lifetime. On his daily walks around the farm, Zip was there by his side every step of the way. There was never a question we would do whatever it took to save her life.

We went to our local pharmacy to get the prescription filled for Itraconazole and started it right away. She got worse before she got better. Her left eye actually bled from the corner. I couldn't hold back the tears every time I looked at our beautiful dog, once so poised and strong. My husband doctored her religiously and never lost faith in her. She started responding at the end of one week. Her progress was slow, but steady.

Today, she's on her way to a complete recovery. She's adjusted well to losing the vision in her left eye and she's hunting with the same vigor as before. But the disease is stubborn and we realize she's still not out of danger. She will have to be retested periodically. We are just thankful our vet identified the disease quickly and recommended a medication that works.

In the meantime, we are teaching our pups-in-training to look up for squirrels, but never to dig in the ground. The inherent nature to dig can be controlled. These guys are smart and want to please. Digging may be fun for them and fun for us to watch, but it could be as deadly as poison.