The Accidental Veterinarian
Page 9
Yellow
After writing “Rainbow of Poo,” it was only a matter of time before I turned my attention to the colour of pee. It should be obvious that I will not be talking about rainbows here.
Pee is yellow. This much you know. But why is it yellow? Do you know? Do you even care? Quickly then, a bit of science (cue the booming voice echoing “science, science, science” like in an ’80s educational show). Urine is yellow because of the presence of urobilin. Urobilin is a breakdown product of bilirubin, which also gives bile its yellowish colour. And bilirubin is in turn a breakdown product of hemoglobin. As red blood cells are constantly being turned over (in the average human, 100 million red cells die each day, but fortunately 100 million are born each day as well), there is a constant stream of urobilin waste the body needs to get rid of.
Urine is full of all sorts of other waste products as well, most notably urea, which is a by-product of protein metabolism. These other waste products are colourless, though, and the urobilin is excreted at a more or less constant rate, so the only variable in how yellow the pee is is how much water is being excreted. More water means more dilute urobilin and less yellow, and less water means more concentrated urobilin and more yellow. Logical, yes?
So now that you know this, what can you do with this information? The first thing to understand is that urine concentration will vary from day to day, so one really clear pee or one really dark yellow pee doesn’t mean much. If, however, your dog (I’ll get to cats later) is producing very clear pee day after day, there may be something wrong. There may be. It may also be that he just loves to drink water and his body is getting rid of the excess. But definitely get it checked out to rule out diabetes, kidney disease, adrenal gland disease, etc. If your dog is producing very dark yellow pee day after day, he may be dehydrated, and you should call your veterinarian to discuss.
That’s all well and good for dogs, but what about cats? You’ll only see the colour of your cat’s pee if you are invading their privacy much too closely, or if you are unlucky enough to have the pee appear on a white towel or bedsheet. However, if you use clumping litter, you can use the size of the clumps as a way to guess at concentration, because as volume goes up, concentration tends to go down, and vice versa. If the clumps start getting much larger, the urine is possibly becoming more dilute and you should contact your veterinarian. By the same token, if the clumps are getting smaller, make sure dehydration is not an issue.
What about other colours? Red is the only one worth talking about. Any redness or pinkness in the urine could indicate a problem such as an infection or inflammation or stones and needs to be brought to your veterinarian’s attention. Also, if it is April 1, collect a normal sample, put some blue food colouring in it and drop it off at your clinic.
Finally, a few random facts about pee:
Many people assume that a pet in kidney failure will stop producing urine. The opposite is in fact true. Up until very close to the end, kidney failure patients produce a lot of dilute urine. The kidneys are failing to concentrate the urine, not failing to make it.
Urine kills grass because the urea being excreted is high in nitrogen. It’s like dumping a bunch of nitrogen fertilizer in one spot.
Stinkier dog pee usually just means more concentrated pee (unless you’ve fed your dog asparagus or something strange). I actually get this question a lot. Infection is a possible cause too, but generally there are other symptoms, such as accidents, urgency or straining.
Dogs and cats can tell large numbers of other specific dogs and cats apart by their urine scent, so all that sniffing your dog does on a walk is about figuring out who was there and whether they know them. A longer, deeper sniff usually means that it was an unfamiliar animal. It’s a pretty darned exciting day for Orbit, my dog, when I come home from work after being peed on.
Bread and Ears
Whack, whack, whack — the metronome of Timmy’s tail kept striking the wall beside him, speeding up as I approached with the expected liver treat. You know how some dogs smile? Timmy definitely smiled. An ultra-wide, happy black Labrador retriever smile.
“He really loves those treats!” Mrs. Singh said.
“Timmy doesn’t just love these treats,” I thought, regarding his beer-keg-shaped torso. But he was a happy dog and a good patient, and we weren’t going to discuss his weight again today. Today we were going to discuss his ears again.
“So, his ears are bugging him again?” I asked as I crouched down to scratch Timmy’s neck and then carefully lift up his right ear flap. The tail metronome slowed down a little.
“Yes, he started shaking his head again yesterday, and I don’t have any drops for him anymore.”
Timmy’s right ear was bright red, and the ear canal was filled with a sharp-smelling black substance. I gently inserted the tip of my otoscope to look a little deeper down the canal. The whack, whack, whack of Timmy’s tail stopped entirely. He wasn’t smiling anymore either, but he stayed still and let me perform the examination. When I was done I straightened up, gave Timmy another treat and told Mrs. Singh, “I’m afraid it’s a yeast infection again.”
Often I will swab the ear and look under the microscope to make sure that I know what is growing in there, but in this case it was so characteristic, and it had happened so many times before, that it wasn’t necessary. Mrs. Singh was horrified the first time Timmy developed a yeast infection because she associated it with yeast infections in people, but it is a very different situation in dogs’ ears.
Yeast are normally resident on their skin and in their ears in low numbers. We all have a beneficial ecosystem of bacteria and yeast living on us in balance with our system. The yeast are, however, similar to baker’s yeast in that they will multiply rapidly in warm or moist conditions. If a dog’s ear canal becomes inflamed, it is like turning the oven on when you’re getting ready to bake bread. This is especially true for dogs with big ear flaps (closing the oven door!). Dogs with more erect ears do occasionally also get these sorts of infections, but they are much less common. As the yeast multiply, they create that strong, smelly, waxy discharge, and they further inflame the ear, creating a vicious circle of ever-worsening inflammation and yeast infection.
OK, you say, that makes sense — but why are the ears inflamed in the first place? In a word: allergies. While there are some other triggers, allergies account for the great majority of these inflammations. This sometimes surprises people because they were unaware that dogs could have allergies, and they are surprised that the allergies would only affect the ears. Regarding the first surprise, indeed dogs do have allergies. Do they ever! Allergies are in fact extremely common, especially in some breeds. There is a whole separate lengthy conversation that can be had about allergies, but for the purposes of the ear discussion, suffice it to say that they are usually environmental allergies to house dust, pollen or mould, and occasionally food-related allergies to the primary source of protein in the diet. Allergies can come on at any age and can change over a pet’s life. And with respect to only affecting the ears, in part this is because the ears have the most sensitive skin in the body, and in part it is because the closed-oven-door feedback loop makes allergies there far more obvious. Incidentally, you’ll recall that I mentioned that moist conditions can also encourage yeast to grow, so occasionally we will see these infections after a dog has been swimming or been bathed.
I had explained all this to Mrs. Singh before, but she found she just couldn’t stick to a diet for Timmy to try to address a possible food allergy, and she wasn’t that interested in going down the more complex path of pursuing environmental allergies. The drops worked well, and she preferred to just refill them as needed. I explained again the need to clean the ears regularly as the normal self-cleaning mechanism had been damaged by the repeated infections. And I explained again the need to finish the entire course of drops rather than stopping as soon as the symptoms subsided, but I could see that she wa
s beginning to tune me out. I was refilling the drops, and that’s what she’d come for. And you know what? To be honest, it’s not like I follow each and every piece of advice my doctor or dentist gives me. Just ask me about flossing . . . Everyone just does their best. All we doctors can do is try to nudge the definition of “best” a little further along.
Now that the poke, poke, poke and the blah, blah, blah had stopped, the whack, whack, whack began in earnest again. Timmy knew we were done, and he was wagging and smiling and so clearly hoping for a goodbye liver treat that I had to smile right along with him.
Cough, Hack, Wheeze
There are four exam rooms along the hall leading to my office. The other day when I arrived at work, two of the four had signs on their doors stating “No Dogs!!” No, this does not mean that we are transforming into a cat clinic (although there are moments during heartworm season when this starts to sound attractive). Instead it means that we are going through another outbreak of “kennel cough” and have to sanitize some rooms.
Kennel cough is an unfortunate name as it is misleading. Being a nerd, I prefer the far more accurate “infectious tracheobronchitis,” but we nerds are an embattled and misunderstood minority. The main problem with the name kennel cough is the kennel part. Dogs can contract this disease any time they are in close contact with disease carriers, especially indoors, but not just in kennels. The easiest way to understand this disease is to think of it like the human common cold. Sure, schools and daycares (i.e., kennels for kids) are really easy places to pick up colds, but anywhere you are mixing with other people can do the trick. The cough part of the name is occasionally also misleading as some people perceive their dog to be choking or gagging or retching, rather than coughing. This can be even more confusing because a violent coughing fit can lead to hacking up some phlegm or saliva, which can easily look like vomiting to the anxious pet owner.
But all of that notwithstanding, I am not going to change the minds of thousands (ha!) with one essay, so for the sake of clarity, let’s keep calling it kennel cough. Now I suppose I should explain what it is. I already tipped my hand above when I compared it to the human common cold. Humans with colds may sneeze more than cough because their nasal passages are targeted whereas dogs almost exclusively cough because it preferentially hits their windpipe and bronchi, but otherwise the analogy is useful in several ways.
Like the human cold, kennel cough
Is very contagious, but not all individuals will be affected the same way as some have immunity.
Is caused by a large number of different organisms. In humans, it’s only viruses. In dogs, it’s mostly viruses plus one bacterium (Bordetella) and something wacky that is neither virus nor bacteria, called a mycoplasma.
Usually runs a course of one to two weeks and requires no medical intervention.
Can occasionally develop secondary complications such as pneumonia or bacterial bronchitis, especially in the weak, the otherwise ill, the very young and the very old.
Consequently, if your dog is coughing but is still hoovering his food and racing around like the damn fool he is, please give your veterinarian a call before rushing down. We don’t want to spread the bugs in the waiting room and can often triage and give useful advice over the phone. (Colleagues, please don’t send me hate mail for suggesting this.) Sometimes we may recommend a cough suppressant if the cough is disrupting sleep or is otherwise distressing. However, we must see the ones that might have secondary complications. These dogs may be depressed, off their food and/or hacking up thick yellowish goo when they cough. In puppies, any vomiting, diarrhea or nasal discharge at the same time as the cough is also a reason to come down.
One distinction between kennel cough and human colds is that we have vaccines for kennel cough. These vaccines primarily protect against Bordetella and some also cover a couple of the viruses. Because of the number of potential causative organisms, these vaccines only help reduce the risk, they do not guarantee protection the way a rabies or distemper vaccine does. Nonetheless, risk reduction is still useful in high-risk scenarios such as, you guessed it, kennels, dog daycares and training classes. Many of these facilities require proof of vaccination because they want to reduce the chance that they’ll have 20 dogs coughing simultaneously. The risk in off-leash dog parks is variable and usually quite a bit lower although it depends on how nose-to-nose your dog gets. Think of it like daycares versus playgrounds for kids. The daycare is a petri dish sitting in an incubator, but in the playground your child will only get more colds if they lick the slide or wrestle with their friends rather than swinging quietly alone.
That Distemperment Shot
You don’t have to be in practice very long before you have someone come in with an out of control puppy, expressing relief that the puppy is about to get his “distemperment” shot. “He’s getting that distemperment shot today, right, Doc? I can’t wait until he settles down!”
“Um . . . yeah . . .”
To be fair, it is an odd and confusing name. Its origins reach back to before the advent of modern medicine. Before the mid-19th century the prevailing theory was that good health resulted from a balance between the four “humours,” also called “tempers”: blood, yellow bile, black bile and phlegm. You can still see it in the language today — melancholy is Greek for black bile, and indeed depressed people were thought to suffer from an imbalance of the humours with an excess of black bile. (For the record, actual bile is a greenish yellow, but you probably already knew that.) Dogs stricken with distemper were so profoundly ill and could potentially spew phlegm, bile and blood (in the stool), so they were thought to be dis-tempered.
And what is distemper actually? It is a disease caused by a virus that is related to the human measles virus, although the symptoms are very different. Dogs with distemper often have a constellation of symptoms including fever, heavy nasal discharge, breathing difficulties, vomiting, diarrhea, blindness and eventually nervous system symptoms up to and including seizures in some cases. It is spread through the discharge from a sick dog. The incubation period is up to about five days between exposure and first symptoms. There is no specific treatment, only supportive care, which often has to be quite intensive to prevent the patient from succumbing. Even so, about half of infected dogs will die.
Confusingly, feline distemper, more correctly called panleukopenia, is not related to canine distemper. It is in fact a close cousin of canine parvovirus.
Incidentally though, canine distemper can also spread to wildlife. Foxes, coyotes and wolves are definitely susceptible, and a mutated form has spread to seals as well, where it has devastated some populations. Oddly some marsupials are also vulnerable, and distemper is theorized to have played a role in the extinction of the magnificent Tasmanian tiger (also called the thylacine).
That’s all the bad news, but the good news is that the vaccines are extremely effective and safe. Consequently, distemper is now very rare in areas where vaccination is common, such as here in the city. When we do see cases, it is usually in puppies from remote communities. In the Arctic and in isolated First Nations, it is still rampant.
Actually, I lied. That wasn’t all the bad news. There is a worrying trend among some pet owners to refuse vaccination. How often to booster is a subject of some legitimate debate, but not to vaccinate at all is foolhardy (to be polite). It is still a small minority of pet owners who refuse to vaccinate, and fortunately their pets are protected by the fact that the majority of their neighbours are more sensible and responsible, so the virus cannot yet gain a foothold, but this could change. On the human side, whooping cough outbreaks are beginning to become more frequent in areas where vaccination rates are dropping. Whooping cough is sometimes fatal in babies.
Distemper is far deadlier than whooping cough.
And training is the remedy for “distemperment.” Now, if only we had a shot for that.
Spay Day
Assuming the
Hudson’s Bay Company’s lawyers remain quiet, every November, the Manitoba Veterinary Medical Association will sponsor a “Spay Day.” The event features significant discounts on spaying and neutering at participating clinics.
This is the perfect opportunity to explain what exactly spaying is and why we do it. Let’s start with that weird word, “spay.” It’s made a long journey from the Latin “spatha,” meaning broad sword (kind of alarming), from which we also get spade and spatula, to the Old French “espeer,” meaning to cut with a blade, and then over to England, where it turns up as “spaier” and “spaied,” which is where things get . . . weird. There it was first used to describe a specific way of dispatching a deer with a thin blade during the hunt, but in 1410 there also is reference to “oon spaied biche lesteth lengere in hure bounte than other ii that byn not spaied.” How they managed to “spaied” the “biche” and have her survive in 1410 is unclear, but henceforth, the word was associated with the removal of ovaries from prized hunting dogs, from which the evolution to the modern usage is obvious.
I’m sorry, that’s probably way more than you wanted to know about that, but I was on a roll. In any case, yes, it’s a weird word.
The technical term is clearer though: ovariohysterectomy. How is that clear? Just break it down: “ovario” means ovaries, “hyster” means uterus (ok, that bit’s not exactly clear) and “ectomy” means removal. In fact, this may be a useful thing to know. Any surgery ending in the suffix “ectomy” involves removing something. So when your own doctor starts saying “blahblahectomy,” pay close attention. For the record, the suffix “otomy” means making a temporary hole somewhere, and “ostomy” means making a permanent or semi-permanent hole somewhere. Come to think of it, you should probably also tune in when the doctor says “blahblahostomy.”