Decompensation is a term that describes the syndrome that occurs when pets (and sometimes people) seem to go downhill very suddenly.
Take Hunter (at left), for example.
Hunter came to see us today feeling and looking really bad. The obvious question was, “How did she get to feeling this bad this fast? All day Sunday she felt fine. Sunday night became lethargic and by today (Wednesday) she won’t eat and will hardly move around.”
In animals, decompensation has two components.
One comes from their natural instinct to hide illness and susceptibility from predators. Therefore, when a dog or cat is sick they instinctively want to keep from looking sick, injured, or otherwise vulnerable.
The other factor comes from the presence of redundancy or excess capacity designed into the body. For example, we have two eyes. If we lose one we lose binocular vision and depth perception, but we’re not blind.
Likewise we have excess capacity in organ systems. With two kidneys we can lose one and still have more than enough. In fact, we are born with about ten times as much kidney tissue as we need to do everyday work. We lose some of that as we age, and before laboratory tests can even detect that loss 90% of kidney tissue must be gone.
We and our pets have extensive redundancy in our livers, too. That’s why a person can donate a lobe (section) of liver and still live.
Pathogenesis is a term doctors use to describe the course of an illness. “Path” means illness or abnormality, “genesis” literally means the beginning, but in this word it is used to define the course of the illness from beginning to end.
Hunter has a urinary tract infection. The fact that she is so ill implies that she not only has infection in the urinary bladder, but also has ascending infection, meaning that the infection probably started in the urinary bladder, then went “upstream” through the ureters and into the kidneys.
When Hunter initially became infected she didn’t feel bad at all. As the bacteria multiplied, making the infection worse, she had discomfort, but could still continue to function normally. Eventually she began to have sufficient irritation that she felt the urge to urinate frequently.
Still, it wasn’t until the infection ascended into the kidneys that the body as a whole began to feel bad. Hunter then felt backaches and fever. Her immune system responded with an increase in white blood cells and humoral immunity in the form of proteins that have the ability to combat infection. Fever and inflammation took away her appetite and energy, making her lethargic and depressed.
Fascinatingly, Hunter felt better in less than 24 hours after beginning an oral antibiotic. We have submitted the following tests: Complete Blood Count, Chemistry Profile, Urinalysis and Urine Bacterial Culture and Sensitivity. Of course, the culture takes the longest to yield results, and when those arrive we will know whether to stay with the antibiotic therapy we have begun or change to a different antibiotic.
We will stay on top of her case until we know she is totally well and there is little risk of relapse. We do that by using our practice’s specialized computer software to remind us to call her owner at regular intervals.