Wednesday, May 9, 2012

Rodenticides

We could all hear my next patient in the waiting room.  His cough sounded deep, wet, and painful.  I guessed before I even saw him that something was very wrong.  This was not the dry hacking cough we have become accustomed to hearing in dogs with infectious tracheobronchitis (kennel cough).  There was a sinister pitch to this that told me he had fluid in his lungs and a hard time breathing without going into a coughing fit.

When my assistant and I walked into the room, you could see a little bit of smeared blood on his white feet.  The owner told us that "Bubba" vomited a little bit of blood the evening before.  He had just started coughing 24 hours ago.

I have extolled the virtues of a complete physical exam in previous posts.  This story has a different moral... Accurate and pertinent history.  Early in my veterinary education, I saw a young puppy that presented for lethargy and limping.  I asked questions about the limp, the food, coughing, sneezing, vomiting, diarrhea, etc.  I whisked the puppy away to visit an orthopedic surgeon to see if she could help me localize the limp.  When I came back and spoke with the owner, I saw tears welling up in her eyes and she produced a bag of rat bait from her purse.  She then told me that he had eaten half of the bait.


A "Rodent Of Unusual Size" from The Princess Bride

This moment of combined shock, frustration (at myself for not asking the right questions and at the owner for not just telling me what the problem was), and revelation has stuck with me ever since.  Anti-coagulant rodenticide can present with a myriad of signs, the best way to diagnose it is by asking the owner the right questions.  

When I asked Bubba's owner if there was any chance that he had eaten any rodent poison, she laughed and said, "no, that was my other dog... and that was about a week ago.  We watched him very closely afterwards and nothing really happened".  This brings me conveniently to the main point of this post:

Most rodent baits do not cause any signs for three to five days... sometimes even longer.  If your dog ingests rodenticide and seems fine the next day, he/she could still be in grave danger of lethal poisoning.


Given the possible exposure to the poison and his clinical signs, I told the owner we should check his coagulation times to see if his blood was clotting appropriately.  Anticoagulant rodenticides essentially rob the body of it's ability to form blood clots.  As a result, animals will bleed inappropriately.  Prolonged blood clotting times and a history of possible exposure to anticoagulant rodenticide is highly suggestive if not diagnostic of poisoning.


This coughing dog was essentially bleeding into his lungs.  This creates a bad situation for two different reasons.  First is the obvious loss of blood, second is the loss of usable lung volume (due to blood filling). Toxicologists will tell you that bleeding into the airway or into the central nervous system creates a poor prognosis.  Our treatment for anticoagulants sometimes does not work quickly enough to stop bleeding into areas that cannot sustain prolonged bleeding.


I administered a vitamin K injection and wrote a prescription for all of her other dogs.  We had a long discussion about plasma transfusions and advanced care.  The story is not quite finished for this dog.  The last time I spoke with Bubba's owner, she said he seems to be doing much better.  He is not out of the woods yet.  The newer generations of these poisons have very long half-lives and can stick around at lethal blood levels for weeks.  However, so far so good for Bubba. 

Wednesday, February 1, 2012

Scabies: Balou and Tundra

The stack of papers hit my desk like a ton of bricks.  These files were faxes received from other vet clinics containing the records for two dogs that I was to see for a "5th opinion".  There were two malamutes in the same family with a large history of dermatopathology (skin disease).  When presented with such a case, I tend to go a little goofy.

First off, derm disease is fiendishly difficult and expensive to treat with the tools that we have available to us.  Owners most often get frustrated long before completely exhausting options, and even when we have the diagnosis nailed maintenance of these dogs can be extremely difficult.  Our professors back in school used to tell us that derm disease would be the number one reason that clients would seek out a second opinion (or fifth opinion)

Secondly, what the heck was I going to find that four other veterinarians could not?  I don't hold myself in such esteem as to think that what had evaded a number of other experienced veterinarians would be painfully obvious to me.  The records were all over the board; skin scrapings, food trials, antibiotics, antifungals, Veterinary Information Network threads about zinc responsive dermatitis, etc.  It seems that pretty much anything I could think of had been tried.

I made note of the receptionist that decided to put this heap in my column... it had just become obvious that she didn't really like me all that much.  All joking aside there was little in the stack of files to make me hopeful that I was going to make any difference in these dogs' lives.

When Balou and Tundra hit the doors with their owners, everyone cringed.  They looked awful.  There was little hair to be seen on Balou, and his sister Tundra was heading that way.  You could see depression in their eyes.  They had the look of a couple dogs that were just not enjoying life and had not been for some time.  I sent in my assistant to get a history while I worked on another patient... not at all looking forward to this.

Balou at his first visit to ITAH

The assistant came out of the room with an obvious assessment; the dogs look like hell.  Beyond that, the story became much more interesting.  To my relief the owners were very nice, realistic, and observant.  These three qualities make the veterinarian-client-patient relationship rewarding for all.  They described a progression of disease that started with the introduction of Tundra to the family via a rescue organization.  Previous veterinarians had done skin scrapings for mites, and had given mite treatments to one but not both dogs.  Antibiotics and antifungals were of limited use, as were shampoos and novel foods.  These dogs were itchy to the point of self mutilation and nothing really seemed to make a whole lot of difference.

The number one nagging part of the history which I just couldn't let go was the fact that it all started after Tundra arrived.  It just screamed infectious.  It screamed sarcoptic mange.  The only issue was that the mites were not seen on previous skin scrapings, and they had technically been treated to no avail.

I started discussing differentials, and told them I just couldn't let go of the idea of mites.  I decided to do another skin scraping.  Sarcoptic mange is caused by the burrowing mite, Sarcoptes scabiei.  The mite is very difficult to find via skin scraping.  Frequent false negatives are a hallmark of infestation.  Whenever veterinarians suspect the disease, we treat for it... which had sort of been done already.  Balou and Tundra had both received ivermectin and Frontline a couple times during their workup.

I chose two spots on Tundra and three spots on Balou for scraping.  I had three slides and a whole lot of wishful thinking.  If I didn't find the mites, I didn't know exactly what I was going to do.  Should I try treating again?  Would the owners go for it?  What should I do in the mean time?

Luck was on my side that day, and I found one little mite on one of the slides (and I checked for a good 15 minutes before I found it).  Bingo.  This was what we were looking for.  We could throw out everything else about the case, and deal with the devil we knew.


Sarcoptes scabiei (from wikipedia)


I went back into the room elated, and told the owners who were similarly elated.  This was the best of all possible outcomes.  Sarcoptic mange is a curable disease.  I explained that I thought we should probably be a little more aggresive this time and treat both dogs concurrently with ivermectin injections and topical Frontline.

Upon further research I found that with very advanced cases of Sarcoptic mange, 6 weeks of treatment are needed to fully kill off the mites.  We set a schedule of weekly injections.  The difficulty in treating mange is that it is the immune system's reaction to the dead and dying mites that causes the worst signs.  In severe cases, the patient will appear worse rather than better during the initial treatment, leading the clinician and owner to think that treatment is failing.  Complicating this is the fact that most of the time we don't have a definitive diagnosis when we are treating.


Balou after 6 weeks of treatment


After 6 weekly injections of ivermectin, the dogs were obviously looking and feeling much better.  Within two weeks of stopping treatment, Balou returned with some sores on his paws and red irritated skin.  I performed another skin scraping and did not see any mites.  Tundra, it was reported, was back to normal.  I was faced with a dilemma again... is this failure of treatment?  Does he concurrently have some other skin disease?  What to do?

Everything I have ever learned about Sarcoptic mange from texts and the Veterinary Information Network said that after 6 weeks of treatment, the mites should be gone.  Anything that pops up after that should be considered a different problem.

However, the severity of disease on initial presentation made me want to just extend treatment another 6 weeks.  We gave Balou another ivermectin injection and ordered a whole new bottle for the owners.  His skin improved within a couple days, and the owners continued weekly ivermectin treatments for 6 more weeks.

I have seen him a couple times since that day, and every time he looked like a whole new dog.  However, the most recent time I saw him was the most striking.  He is one of the most beautiful dogs I have seen.  He has all of his hair back (with the exception of a little bit on his tail), and he feels terrific.



Balou's most recent photograph


Balou and Tundra's story was a big lesson for me and one of my proudest moments as a veterinarian.  Rarely can we offer a complete cure for such a striking disease.  Sarcoptic mange is extremely difficult to deal with.  It is sneaky, and like so many other things in medicine, does not always act in accordance with the books.  

I know that if I had not seen the little mite with my own eyes, I would not have stayed the course with treatment for as long as I did.  Plagued with doubt and second-guessing, I would have been grasping at straws with exotic diseases and arcane treatments.  I would have been doctor number five with a few pages of my own stacked on top of the rest of the file on another veterinarians desk.

Simba

"He's doing fine, no coughing, sneezing or diarrhea... just drinking more, and occasionally peeing outside the box... which he has always done"  This was the run-down from the veterinary assistant as I was about to go see Simba and his brother for their yearly physicals and vaccines.  The owner, as many owners do these days, had expressed financial concerns before even making the routine appointment.  Luckily the owner had decided to make the sacrifice and get a thorough  exam and vaccinations for her cats despite her financial situation.  In this economic climate, it is a rare week that we don't have someone tell us that "we don't need an exam, we just need shots".

It is a shame that the physical exam is the most underrated and overlooked diagnostic in veterinary medicine.  Somehow, we as a profession have failed to communicate the benefit of or necessity for physical examination in pet healthcare.  In our enthusiasm for products (vaccines, flea preventatives, dewormers, drugs) our services (physical exams and procedures) have been unintentionally minimized.  When we send out reminders for vaccinations, we reinforce this mindset.  People almost always call because "Fluffy" needs shots, not because "Fluffy" needs a physical exam.

I digress... The point of this story is to illustrate just how strikingly useful physical examination can be for the detection of disease.  Simba's occasional poor litterbox habits did not set off any alarm bells in my mind as I put my stethoscope around my neck.  Many cats occasionally pee outside the box and there can be a myriad of reasons, many of which are fairly benign but difficult to diagnose.  Drinking more water, however, can be a bad sign in cats.  

I examined Simba's brother, Bear, first.  He was a stray that had adopted the owner as his new provider.  The owner was interested in getting him neutered... As (poor) luck would have it, he was cryptorchid (had an undescended testicle).  For anyone who does not have an excess of money to spend, that is bad news.  A routine cat neuter is a relatively simple procedure.  A cryptorchid surgery is at best much more complicated, and at worst an invisible easter egg hunt.  I broke the news to the owner and started explaining what she was into.

Simba was next, and while the owner was digesting the news about his brother, I started going through Simba's history with the owner looking for clues.  He was finicky with his food.  He was drinking more water.  He seemed irritable when she picked him up.  I listened intently as I conducted my physical head to toe.  When I came to abdominal palpation, something felt very wrong.  Just as I felt a hard mass in his cranial abdomen, he turned around to bite me.

I had my assistant scruff Simba as I went back to feeling his abdomen.  Sure enough, there was a big hard something in his abdomen that most certainly did not belong there, and he did not want me touching it.  Now, this was a difficult situation.  I knew that something was desperately wrong with Simba, but also knew that diagnosing and treating this was going to be an issue.  I explained to the owner what I felt, and offered to run the ultrasound over his abdomen to see what was there.  She agreed, and we took Simba to the back.

The ultrasound was unrewarding... the ultrasonic waves do not travel through air well, and there was gas interference from his guts.  I decided to take an x-ray.  What I saw on radiographs I could not begin to explain.  I had the other two doctors feel him and look at the x-rays.  No one could tell what was going on.  Right in the cranial abdomen was a big globoid something that looked like it was full of radio dense worms or spaghetti (neither of which would show up on an x-ray like that).  I showed the owner, and told her that I didn't know what it was but was confident that it didn't belong and most likely needed to come out.

The owner agreed and we scheduled surgery for early the next day.  That afternoon we started taking bets on what it was.  I felt that it was in fact a mass of intestinal worms (perhaps mildly calcified) in the stomach (where they don't belong).  Other bets were cancer, foreign body, and cyst.


The next morning, as the owner waited in the lobby, I conducted an exploratory surgery on Simba.  After I entered the abdominal cavity, a large hard stomach just about jumped out of the incision.  I could feel hard densities contained within and knew that I found my target.  Upon opening the stomach, I was greeted by a tangled mass of rubber hair-ties filling the tubular organ.  Removal of the ties was trivial, and closing the stomach and body wall was routine.


The owner was surprised when I explained my findings.  Simba had eaten those months ago.  Luckily, they had not yet made it past the pylorus into the small intestine.  Once there, they could have caused all kinds of unpleasantness and even death.  Simba went home later that day, and was up eating normal wet cat food within 24 hours.


I guess the moral of this story is that while vaccines, deworming, and tick/flea products may seem like the "reason" to go to the veterinarian, they are really just the icing.  The real meat and potatoes of your pets' visit is the physical exam.  Most veterinarians are experts at physical examinations.  The reason is that the physical exam is sometimes our only modality for detection of disease.


Friday, January 6, 2012

Welcome

Once again... Welcome to the new Indian Trail Animal Hospital blog!  We are excited to be offered this opportunity to communicate with our clients and the community about points of interest and importance in the world of veterinary medicine.   Please feel free to comment or make suggestions as this blog matures.

After a season filled with cakes, sweets, and enormous meals, many of us have new year's resolutions concerning physical fitness (as cliche as that may sound).  Physical fitness is as important for our four legged companions as it is for us.  Which brings me to my unofficial resolution: To exercise with my dogs more this year.

My dogs need two things that are often overlooked in my busy schedule; exercise and quality time with me.  Taking the dogs for good long walks three times a week can go a long way to fulfilling these needs.  It gets them (and me) out of the house, and provides them with a chance to enjoy some exercise, training, and one-on-one time.

If you have a high-energy dog who is hard to control or is on the "naughty" side when it comes to obedience, exercise should be the cornerstone of your training regimen.  A tired dog is a good dog.  Living in north Spokane, we are blessed with many opportunities for outdoor recreation with our dogs.  Taking advantage of the trails around Riverside State Park or the long rolling Centennial Trail is a relatively easy way to start an exercise program.

I started out taking walks around my neighborhood with my Corgi and Great Dane.  The walks have now been extended to two hour hikes over rough terrain.  I get up early on Saturday and Sunday and head out before the trails get busy.  I have been working on commands while off leash, and the pups are able to obey commands and stay behind me without the use of a leash.

I used to be a runner and regular at the gym.  However, with my busy work schedule and family, I don't have the time to devote to physical fitness I once did.  Taking the dogs for a short walk with a ball session used to be an "extra activity" that I would fit in on lazy mornings.  Now, exercise with my dogs is the basis of my workout schedule.  We are all better off for it!



Welcome to the new Indian Trail Animal Hospital Blog!