The SDMA Kidney Test: The Canary in the Coal Mine

He really is man's best friendMost pet owners would probably not get much out of their veterinarian talking about symmetric dimethylarginine .  Abbreviated SDMA, this is a newer test for use in dogs and cats, operating on the presence of a biomarker that shows up earlier than traditional blood tests (BUN-blood urea nitrogen and creatinine) when kidneys either age or are affected by pathology.  On average, SDMA can detect kidney disease onset up to 17 months earlier than the traditional blood tests.


So a pet owner might ask, “why is this potentially relevant to my pet?”  Let’s start with the fact that once kidneys lose their tissue, they cannot regenerate or replace it.   So, the earlier a veterinarian is on to the fact that a pet is “slipping” with regard to kidney function, the sooner pre-emptive measures can be taken to preserve the kidneys.  Recommendations include lower protein (yet high quality protein) diets, phosphorous-binding drugs and potassium supplements to help the longevity of these pets affected.  In our clinic we recommend Hill’s K/D (simply standing for “kidney diet” in both dogs and cats.  Veterinarians at Hill’s have shared with me that dogs and cats that have been diagnosed with chronic kidney disease have twice the longevity when on K/D food, versus feeding commercially available diets.

Just as in humans, as go the kidneys, so goes the duration of life.  It is estimated that half of all cats over the age of 10 suffer from chronic kidney disease.  Kidney failure is the number one natural cause of death in cats, and in the top three of dog causes as well.

My first discussion concerning SDMA was three years ago, when the test was being released from the research level to the commercial laboratory level.  The chance meeting I had was with one of the research team members from Oregon State University, at a veterinary conference in Tampa.  No, it was not in a lecture hall, but at a lunch table.  Complete strangers, we were taking our lunch break at the same time and we sat together at a table getting acquainted.  Once he heard I was in practice, he asked me if I had heard of the SDMA test.  When I told him yes-I had read something about this early detection test, he proceeded to tell me all about the work he and his team were up to on SDMA.  He said that it would no doubt be on every senior pet profile before long.

Waiting for ChristmasWell, you guessed it.  Fast-forward to 2017, and SDMA has become the “third” kidney function test.  SDMA is now included on all our dog and cat send-out blood panels from IDEXX labs. Moreover, since this biomarker enzyme acts as an early detection vehicle regarding kidney function, it is often showing higher-than-normal values before BUN and creatinine values rise.

When I interpret these tests for pet owners, I simply refer to SDMA as the “canary in the coal mine” regarding kidney disease.  SDMA will surely sniff out renal disease prior to the other blood tests!

Dr. Chris Duke

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We Just Can’t Put The Canine Distemper Virus To Bed In Mississippi

For years now, we have had pockets of canine distemper outbreaks in dogs, raccoons and foxes in our region.  These outbreaks at first scare our local residents, because these disoriented animals are at first rabies suspects.  What people are observing is what veterinarians refer to as the “neurological” stage of the disease progression, when distemper virus has unfortunately reached the point of no return.

Dog Jack Russell Terrier and a Nova Scotia Duck Tolling Retriever lying on grass

Just this past week, the Mississippi Board of Animal Health put out a bulletin to Mississippi veterinarians that canine distemper virus is on the rise, not only in 2017, but reportedly on the increase in reported cases each year since 2013.

In 2013, 18 suspected cases were submitted to the state diagnostic laboratory for testing.  Fortunately, only six of the submissions turned out to be positive while 12 were negative.  By 2015, 67 total suspected cases were submitted, and although 42 were negative, 23 were positive.  In 2016, there were 30 positive cases, and this year already, there have been 46 confirmed cases of canine distemper-and we’re not even to the halfway point yet.

Canine distemper is a serious disease caused by a virus that attacks the respiratory, gastrointestinal and eventually the nervous systems of the animals affected.  There is no reliable cure once the symptoms are manifested in the nervous system.

The Mississippi Board of Animal Health has the following recommendations for Mississippians regarding animal care and handling during this spike in canine distemper virus cases:

-Make sure all puppies and adult dogs are current on their distemper vaccination.

-Any suspected case in a dog should be seen immediately by a veterinarian (cats are exempt, luckily).

-Please do not handle wildlife, especially those animals that might not be acting normal.  It is unfortunate, but despite the name of canine distemper virus, other animals that might be in contact, like wolves, coyotes, foxes and raccoons can be affected by the virus.  Possums, armadillos and squirrels are not thought to be affected as much, if at all by it.

-If anyone is bitten by an animal that has these types of disorientation from neurological disease, please contact your local health care provider immediately.

-Do not shoot neurological animals in the head, because that is the tissue used for viral testing.

-For further information or questions, call the Mississippi Board of Animal Health at (601)-359-1170.

As for our surveillance locally, I’ll keep our readership posted in upcoming columns.  In the meantime, let’s all enjoy the outdoors this summer.  Everybody stay safe!

Dr. Chris Duke

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Red Hot Information On Heartworms – The Votes Are In!

Every three years, the American Heartworm Society puts out its heartworm incidence map, which reveals much in the way of where heartworm disease is being diagnosed in America.  Over 4500 veterinary clinics and shelters submitted data to this project, and at the end of 2016, there were some eye-opening conclusions regarding both the incidence and spread of heartworm disease in dogs nationally.

Family pet enjoying the nice weather and grassy field.

Let’s start with one broad overall statement:  heartworm disease is being diagnosed in all 50 states.  There are some clinics that only diagnosed one (or even no) cases a year, but many (mainly along the gulf coast and up the Mississippi River) diagnose over 100 cases a year.  The reasons for spread of heartworm disease vary-there are theories that include people migration (with their dogs in tow), and mosquito migration, since mosquitoes are the primary vector.

The top five states in heartworm incidence are Mississippi, Louisiana, Arkansas, Texas and Tennessee-all states that have been in the top 10 since 2001.  Nationally, approximately seven of eight surveyed veterinary practices diagnosed heartworm-positive pets during the 2016 calendar year.

While the 2016 AHS heartworm incidence map may not look too much different than the last published map from 2013, there has been an overall increase in the number of heartworm positive cases diagnosed in the U.S..  Within the data, 18 % of clinics noted a decrease in cases of heartworm positive dogs, but the number of heartworm positive diagnosed cases have outpaced that statistic, therefore expanding the reported cases and their respective zones on the incidence map.  Veterinarians surveyed noted a 21.7 % increase in the average number of heartworm cases per clinic since the previous survey three years ago.

So how did our clinic fare versus three years ago?  We do keep the data, as our veterinary hospital has contributed data on both dog and cat heartworms since 1998.  Our data reflected a 12 % increase in heartworm positive as compared to 2013.

So what are my theories that heartworm disease is not just on the rise locally, but nationally overall?   Aside from the mobility issue, it comes down to pet owner awareness and pet owner compliance.  To put it another way, pet owners must be keenly aware that heartworm disease is real and preventable.  However, the product must be given and maintained on a regular dosing schedule.

It’s kind of ironic in that we have more and more good heartworm prevention products on the market every year-pills, liquids, injections and even combination products that kill fleas as well as protect pets from worms and heartworms.  Yet, we still are still in pursuit of reducing the case incidences of heartworms in both dogs and cats despite these many tools.

Dr. Chris Duke

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Our Own Bienville AMC Veterinarian Elected To American Heartworm Society Board

beinville-dr-dukeDr. Chris Duke of Bienville Animal Medical Center in Ocean Springs, MS was recently elected to the Board of Directors of the American Heartworm Society.  The board is composed of representatives from academia, industry and veterinary practice.  Dr. Duke was elected to a three-year term on the board as an at-large member at the American Heartworm Society Triennial Symposium in New Orleans in September.

Dr. Duke, co-owner of Bienville Animal Medical Center, is a 33-year veteran of veterinary practice and has been heavily involved in professional, church and civic organizations for many years.  He is also a member of the American Society of Veterinary Journalists and writes weekly columns and blogs on veterinary-related topics.

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Is There A Correlation Between Gulf Hurricanes And Heartworm Cases In Dogs?

At first glance, I know that you’re wondering….say what?  I thought that the problem with heartworm disease was that a larval-carrying mosquito bit a vulnerable dog (not on a preventive), and that was the way the process started.  What does wind and water have to do with this?  Aside from maybe a bit of heat and humidity and a transfer vector, what else does dirofilaria immitus need to thrive?

At the recent Triennial Symposium of the American Heartworm Society in New Orleans, Dr. Clarke Atkins, DVM, DACVIM (SAIM, Cardiology), addressed this seemingly off-beat topic.  After communicating with inland veterinarians in places like Shreveport, LA and Oxford, MS, Dr. Atkins found that positive diagnoses of heartworms and adulticide treatments became more prevalent in the year after hurricanes affected the gulf.  The core question of course is why?

According to Dr. Atkins, as we as coast people know, when there is a shake-up of our structures, like homes, fences and neighborhoods from damages, pets roam free.  Atkins called it post-storm “chaos”.  Dogs went free, and in the case of Katrina, many were rescued and relocated to inland shelters.  From that point, many were vaccinated, heartworm tested, dewormed and adopted out.  It is estimated that 250,000 dogs from the greater New Orleans area and up to 100,000 from South Mississippi were processed in this manner.  Of course, many dogs were found to be heartworm positive-so we’ll call this pre-existing disease.

Then, Dr. Atkins cites the point that refugia-native animal populations- contribute to the problems well.  In the Mississippi delta, other canine and canine-type hosts (wolves, coyotes, wild dogs, etc.) also enhance the spread of the disease.  Once again, just as with unprotected domestic dogs, these hosts are just as dangerous as any to propagating more potential for the spread of heartworm disease.

Then there’s water.  This is not to blame our coastal flooding but waters to our north.  The increased rain from the hurricanes contributes to not only standing water problems, but even significant rises in lake levels.  After the storm-laden hurricane season of 2005, Lake Sardis near Oxford even rose to record levels after Katrina, Rita and other named storms from that year.  Do mosquitoes love standing water?  Oh yeah.  There’s your connection.

Dr. Atkins had a chart that showed the lag effect of positive heartworm cases diagnosed after Hurricanes Elena (1985), Georges (1998), Lili (2002), Ivan (2004), Katrina (2005), Gustav (2008), and Isaac (2012).  The same chart showed the quiescent periods of lower heartworm diagnostic rates in the times when we had no hurricanes in the previous year.  Although there was a question as to whether the “delta” should be singled out as a local hotbed for heartworms, I personally think that the three main reasons Atkins cited stand on their merits whether we focus on that specific area of Mississippi or use broader parameters.

So what about the people who adopted and had these dogs treated?  Should pet owners in Massachusetts or Pennsylvania be concerned that the risk of heartworm disease goes up in their region once these dogs are transferred up?  Dr. Atkins says yes, because the presence of a heartworm positive dog greatly increases the potential for the disease, especially if the area is vulnerable (mosquitoes present and unprotected dogs).  That statement really re-framed my thinking, as for years I have always held that without the bite of a vector-host (mosquito), direct communicability of heartworms from dog-to-dog was never believed to be a problem.  My thinking has indeed expanded on this subject.

I guess this old dog needed to learn a new trick.

Have a great week with your pets!

Dr. Chris Duke

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Kidneys – Most Vital Organs

Often times in veterinary practice, pet owners ask me about the most common reasons that we lose pets.   Certainly, being hit by an automobile takes the lives of many pets.  So also are attacks by other animals (and occasionally man).  Yet, I often surprise pet owners when asked about the most common natural causes of pet death.  Sure, the answer may lie in heart disease topics.  Yet, kidney failure is right up there with the heart when it comes to veterinary cases.

Particularly in cats, kidneys are the #1 cause of natural death by organ failure.  This often happens in conjunction with tissue aging, or as a nephrologist might say, “loss of functional nephrons”, or cells of the kidney.  Yet, these paired organs, which much rid the body of excess internal fluid waste can cause a problem in the prime of life from other causes.  For example, poisonings and infectious disease can also lead to loss of functional kidney tissue.  Occasionally, the tissue may turn upon itself in the unusual circumstance of autoimmune disease.

For the most part, we as veterinarians try to actively treat the entire spectrum of kidney diseases when we are faced with the challenge.  Commonly, we utilize intravenous fluids to not only rehydrate the dehydrated pets, but to also re-activate dry, dormant tissues of the kidney.  In the case of infectious disease, we commonly use antibiotics systemically, as long as they are kidney-friendly in nature.  We also control symptoms such as nausea, anorexia and diarrhea, which can often accompany kidney disease.

Once the patient can get to the point of eating food voluntarily, kidney tissue is further spared by using a special diet like the k/d food.  One such food is the k/d food (a.k.a. “kidney diet”) from Hill’s.  Veterinarians often request that blood tests, which were used to diagnose the case originally are repeated once the therapy progresses.  In that manner, improvement can be measured.  Unfortunately, not all kidney case treatments are successful.

The cases such as the aforementioned, brought on by failing kidneys from old age and poisonings causing irreparable damage often yield a poor prognosis.  Try as we may, veterinarians must prepare pet owners properly for these tragic outcomes.  Transplantation is impractical in veterinary medicine at this time because of lack of donation banks and also because many canine and feline patients are at such a high risk for the procedure by the time the patients are presented and diagnosed.   Some veterinary teaching hospitals have succeeded in transplantation on selected patients and at a great economic expense.

The truth to the matter is that when it comes to kidney treatments in pets, there needs to be clear communication between the pet owner and the veterinarian.  Owners need to be cognizant of the risks inherent to these cases, and veterinarians need to be cautious about outcome.  Establishment of a proper diagnosis and prognosis is the key in the client-veterinary relationship while the storm of pet kidney disease is being weathered.

One way to stay ahead of kidney disease is through blood and urine testing, especially once your dog or cat reaches senior age (over 7 years of age).  In that manner, early detection of kidney disease may take place, and kidney-sparing measures instituted.  Ask your veterinarian to explain the laboratory results, and if your pet seems to be at risk for kidney disease.

We all want the same thing:  A long, quality life for your beloved pet.

Have a great week with your pets!

Dr. Chris Duke

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So What Do You Do With Your Pets If A Hurricane Comes Our Way?


As I compose this column, there have already been seven named storms (one is still active), and several “invests” that our local weather personalities have pointed out to us as potential threats.   This is not unusual for late August and early September on the Coast, as there is a spike in potential tropical storm and hurricane activity every year at this time.  I have been asked at least once daily by someone locally the central question about what to do with beloved pets should we get one of those nasty storms in the northern Gulf threatening us.  So here is my simple answer:

If at all possible, when you evacuate, take you pets with you.  You may think it strange that a veterinarian who runs a boarding kennel as well might give this advice, but I’ll enumerate five reasons why it’s the best answer.

  • If flood waters or excessive winds threaten your home and the people in your family, they also threaten animals. Those of us who weathered Katrina know firsthand about folks who stayed at home and had tragic losses.  We also know how well-meaning people may had left pets in their garages or sheds only to let them meet a demise that many didn’t see coming.
  • Realistically, there are not enough pet kennels or other animal shelters on the coast to house all the pets that might have a need. On top of that, some veterinary clinics and kennels have even shied away from boarding during hurricanes because of liability issues.
  • There is no guarantee that a veterinary clinic or kennel building will still be standing after a hurricane. Sure, we were fortunate here at Bienville AMC with Katrina, in that our building sustained very minimal wind damage and was above the flood line.  However, less than a half a mile away from us, an associated tornado severely damaged the former Ocean Springs High School and local businesses around it.  One of the saddest signs I saw after Katrina was a posted sign on the front door of a colleague’s flooded out clinic that read “I am so sorry, but the pets here all perished because of the flood waters.”   Just because our clinic has weathered several storms over the years, there is never a guarantee that all will be well.
  • There are more pet-friendly hotels than ever before that want to help. Frankly, it’s getting to the point that the more common way to ask the question is “you do take pets here, don’t you?”.  Certainly I would call or reserve on-line ahead to be sure you and your pets can be accommodated.  Of course, if you evacuate to the home of a family member inland, that it always a good option as well.  If you do hit the road, remember to also take your pet foods, medicines, and vaccination records for proof if you go to a hotel or out-of-town kennel.
  • Who knows how long you will be away, or when the veterinary clinic or kennel will re-open. This may sound like a minor point, but it is quite emotional to some pet owners.  After Katrina, cell and land line communications were down for days.  Even though we had re-opened and were operating with a skeleton crew (whoever we could get back to work), many clients couldn’t get through to us.  Some clients didn’t return for their beloved pets until weeks later.  And from our perspective, even though we re-opened for business fairly quickly, that extra day we were closed seemed like an eternity for a few local people.

So there you have it.  I was trying to count the number of named storms I had witnessed since I began practice 33 years ago.  While I lost count, the five or six memorable ones always bring me back to this same advice.  If you love ‘em, take ‘em with you!

Dr. Chris Duke

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A News Flash: Labs Eat a Lot (But There’s Scientific Evidence Why!)

Labrador retrievers.  They are playful, active and energetic dogs for sure.  If their owners claim that they beg for food a lot, well, they must be quite astute.  Researchers in the U.K. and England have linked a gene alteration specific to these dogs that proves that they possess food-motivated behavior.  The variation occurs frequently in Labradors chosen as assistance dogs.

This study was published in the May 3 issue of Cell Metabolism, and reported by the E-newsletter Newstat.

Starting with an initial group of 15 obese and 18 lean Labrador retrievers, the researchers selected three obesity-related genes to examine, all of which are known to affect weight in humans.  The first analysis turned up a variation in a gene called POMC.

In more of the obese dogs, a section od DNA was scrambled at the end of the gene.  This deletion was predicted to hinder the ability to predict a dog’s ability to produce neuropeptides B-MSH and B-Endorphin, which are usually involved in switching off hunger after a meal.

In a larger sample of 310 Labrador retrievers, the researchers discovered a host of canine behaviors associated with the POMC deletion.  Not all labs with the DNA variation were obese (as some were obese without the having the mutation), but in general the deletion was associated with greater weight.

Additionally, according to an owner survey, affected dogs were more food-motivated: they begged their owners for more food more frequently, and paid more attention at human mealtimes, and scavenged for scraps more often.

On average, the POMC deletion was associated with a 4.6 pound weight increase in the affected dogs.

“We’ve found something in about a quarter of pet Labradors that fits with the hardwired biological reason for the food-obsessed behavior reported by pet owners”, said Eleanor Raffan, PhD, from the University of Cambridge and one of the study’s authors.  Yet, the POMC deletion was present in 76 % of assistance dogs.  “We had no reason to believe that assistance dogs would be a different cohort”, says Raffan.  “It was surprising.  It’s possible that these dogs are more food-motivated and therefore are more likely to be selected for assistance-dog breeding programs, which historically train using food rewards”.

So there you have it.  As an owner of two labs that are not service dogs, I can tell you that I highly suspect the gene variation in Jake and Flo.  Those two will knock the doors down twice daily when they think the grub is overdue.  Food-motivated?  That’s an understatement!

Dr. Chris Duke

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An 83 Year-Old Man Looks To Graduate Veterinary Technician School…And That’s Not All!

Occasionally a human-interest story from within your profession grabs your attention.  In this case, reading about this special man touched not only my mind, but my heart.  I thought I’d share this story with local readers, because it is special on many levels:

This month in Suffolk County New York, Leonard Marino will be graduating with his veterinary technician degree from Suffolk County Community College.  As reported recently by trade journal DVM 360, this amazing man will work in his son Dominic’s veterinary practice as a certified veterinary technician soon.  The twist?  Leonard Marino is Dr. Leonard Marino, a retired pediatrician since 1995.

The elder Dr. Marino has not been resting on his laurels since medical practice retirement.  He had practiced pediatric medicine in Plainview, New York for 31 years, beginning in 1964.  Soon after retirement, he began working in his son’s practice, Long Island Veterinary Specialists (LIVS) for a time, helping edit the practice’s newsletter and assisting in surgery.  He still serves as editor of the practice’s newsletter.  His interest in better understanding the technical content of the newsletters, coupled with a desire to work more closely with his son led him to pursue the veterinary technician option.  Says Dr. Leonard Marino “initially I was in the on-line training classes, but switched to the in-person classes.  I missed that hands-on element that I used to feel in pediatrics.”

The younger Dr. Dominic Marino (DVM, DACVS, DACCT, CCRP) is not only the hospital chief of staff, but performs a lot of surgery in the practice.  The elder Dr. Marino says that his favorite part of working with his son is the time in surgery.  He helps by setting up the drapes and equipment, use the suction and cautery, and assist directly in the procedures.  He also helps post-operatively in these surgeries.  In all, he says that he has assisted his son in over 500 hip replacement surgeries.

Dr. Leonard Marino has no plans for slowing down after he picking up his diploma as a veterinary technician.  He plans to continue assisting his son in surgeries and editing the practice newsletter for years to come-or as long as he is able.

After all, Marino shares, ”my father lived to be 100, so I have some time left in this profession.”

Have a great week with your pets!

Dr. Chris Duke

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Corticosteroids In Veterinary Practice? Think “CIA”

It really depends on who you talk to.  The use of corticosteroids in veterinary medicine can be a blessing or a curse.  A wise old veterinarian once shared with me that “although antibiotics may be the heart of your practice, steroids are its soul”.  But we also must heed the lyrics of Barry White when he once shared “too much of anything isn’t good for you baby”.  Perhaps the answer lies in-between:  judicious situational usage is the key when discussing corticosteroids.

In the trade journal DVM 360 this past month, Daniel Fletcher, PhD, DVM, DACVECC shared with us that the acronym “CIA” was an easy way to justify the use of corticosteroids in the veterinary patient.  For definition purposes, think of any anti-inflammatory drug ending in –one, like dexamethasone, prednisone, prednisolone, triamcinolone and the like (but not hormones or anabolics like testosterone).  With this in mind, what is the “CIA” advice about?  Let’s take a look:

C-Cancer.  We all know that although corticosteroids don’t kill cancer cells, they serve many ancillary purposes in the cancer patient.  They help with associated secondary inflammation, can stimulate the appetite in the anorexic patient, and give a sense of well-being through at least palliative therapy.  Even when chemotherapy is in play, corticosteroids have a role in the overall treatment plan.

I-Immune-mediated disease.  Corticosteroids are at the heart of the treatment on immune-mediated thrombocytopenia, autoimmune hemolytic anemia and the autoimmune skin diseases.  No ifs ands or buts on this.

A-Actually, Fletcher calls them the “Five A’s”.  Atopy, asthma, anaphylactic shock, Addison’s disease and allergies.   I’ll say that whenever confronted with any of these five situations, I have reached for corticosteroids in the past.  However, on that last “a”, there are more alternatives as opposed to corticosteroids in recent years.  Some of these newer antihistamines have changed the game regarding the use of so many corticosteroids on “itchy skin”.  The often-reported side-effects, like drinking excessive water and excessive urination can discourage pet owners and veterinarians alike from choosing this option so quickly.  So have innovative diets, like Hill’s Derm-Defense food, a new player in specific realm of canine atopy.

Beyond these categories, veterinarians have to be careful in situations like gastroenteritis, trauma, back problems and heat stroke.  Many veterinarians are on the fence when corticosteroid usage is discussed when treating snake bites.  While many have justified the use of corticosteroids in many of these emergency-type situations, longer-term repercussions, like immunosuppression must be thought through.

In my experience, the benefits versus the risk in an individual situation must be weighed out.  In my 33 years of practice, I have seen some wonderful results as a result of corticosteroid usage.  However, I have seen a few disasters as well.   Most importantly, the choice to use corticosteroids in marginal situations must be offered and accepted as part of the therapy by the pet owner.  In that manner, the veterinarian and the pet owner are in partnership on the decision as whether to treat the pet with or without corticosteroids.

The bottom line?  Begin with “CIA” in mind!

Have a great week with your pets!

Dr. Chris Duke

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