I saw Nubble again yesterday. She is doing fine for now. The blood in her right eye seems to have subsided a little, although the iris is still ruddish. The vet apparently claimed that she’s still blind in that eye, but this can’t be entirely true because when I waggled a thumb a couple of inches away from that eye, she blinked in response. The reaction was not quite as strong as that in her left eye–I could have my thumb about twice as far away on that side and still induce a blink reaction–but she’s definitely seeing shadows and movements out of her bad eye, at least. Anyway, I doubt she’s concerned with her own depth perception at this point. I’ve been functionally blind since the day I was born in my own right eye and it doesn’t limit me, as I have no aspirations of being in the military anymore and don’t plan to fly any jetliners or bat clean-up for A-Rod.
The disease Nubble has been diagnosed with is histiocytic sarcoma of the spleen, an all-too-common malady in certain breeds, including Goldens, Bernese Mountain dogs (beautiful things, those) and Rottweilers. (Forgive the Comic Sans font in that link; the info is still good.) That term demands several answers. “Histiocytic” refers to histiocytes, a kind of macrophage that participates in immune responses by engulfing foreign objects, such as bacteria. “Sarcoma” refers to a malignancy originating in the mesoderm, one of three embryological “germ layers” (endoderm, mesoderm, ectoderm) and is associated with connective tissue, e.g., bones and ligaments. The spleen is an organ that serves more or less as a warehouse for red blood cells and immune cells of various types, recycling and deploying them as needed. People and other vertebrates can get by just fine without one, although this is not an ideal situation.
When Nubble underwent the diagnostic tests that spelled cancer, I was tempted to hold out hope that the techs had fumbled the histology and that there was something more benign going on. Unfortunately, as I remember from my own microbiology course, the stark difference between normal spleen cells and afflicted ones is all but impossible to miss. A tissue slide of cancerous spleen is characteristic, with the presence of excess numbers of multinucleated giant cells and marked pleomorphism, which are fancy terms for big cells with more than one obvious center and cells that don’t look at all alike, respectively. A first-year med student could pick up on this, so it’s hard to doubt an experienced veterinary physician and his or her lab rats.
Normal canine spleen, surface shot:
A dog with histiocyctic sarcoma–pay attention to the interior of the cells, even if you’ve never used a microscope:
And an image of a cancer-ravaged dog spleen on gross appearance:
Sadly, there is little room for error here. The pathologists have done their thankless job, and we just have to hope for a batch of comfortable weeks for Nubble, who is nicely doped up at the moment.