Veterinary Networking

Veterinary Networking

     Last week a local veterinarian called me to discuss a horse he was treating for metabolic syndrome.  The horse had been treated with a specially designed diet and exercise program for the past 6 months to address a problem of abnormal weight gain, high blood sugar and insulin levels.  She was being re-evaluated and the veterinarian had some questions about interpretation of her latest laboratory values.  He called me because I am a diplomate of the American College of Veterinary Internal Medicine, which means I successfully completed a 3 year clinical large animal residency training program and a rigorous examination process to ensure my advanced knowledge and experience diagnosing and treating internal medicine problems in large animal species.

      I stopped by to visit with Dr. Shane Miller at Comstock Large Animal Hospital yesterday.  Shane is a diplomate of the American College of Veterinary Surgeons.  I had taken some x-rays of a foal with an unusual stifle lameness and had some questions about the abnormalities I had seen on the radiographs.  Shane and I sat down and looked at the films together.  He gave me his opinion on the radiographic changes and some suggestions on treatment options for the foal. 

     This type of congenial exchange of information goes on all the time behind the scenes as a routine part of your animal's care. In addition to consulting with local specialists, there are larger networks we utilize to keep up with the constantly expanding subject matter concerning veterinary medicine.

    I allocate a portion of every day to reading two listserves that I follow on line- one is supported by the American College of Large Animal Veterinary Internal Medicine, the other by the American Association of Equine Practicioners.  These internet based conversation groups provide a wonderful, interactive forum for veterinarians to discuss cases they are treating and get input from colleagues worldwide.

    The variety of problems presented to the ambulatory veterinarian is enormous, and maintaining this network of colleagues is a critical part of my service to you.  After 22 years as a practicing veterinarian, the majority of patients I see exhibit clinical signs with which I am familiar, and diagnostic and treatment plans are relatively routine.  However, when an animal presents with an unusual history or presenting complaint, it is wonderful to have a network of specialists to consult.  Sometimes the initial conversation with a specialist leads to the referral of the patient for advanced diagnostics or treatment.  

Last month I sent a patient to the UC Davis Veterinary Teaching hospital not only for advanced diagnostic services, but also to ensure a level of intensive care treatment and monitoring that could not be provided in the field.  

     Deciding when to consult or refer with a specialist is not always a cut and dry matter - a crucial part of my job is to be sure to keep lines of communication open, and to present all your options to you as a horse owner.  If you ever have unanswered questions about your horse, discuss them with me until you are completely satisfied, and ask for a referral for a second opinion if you feel it is warranted -  I am happy to comply.
    There are 21 specialty colleges of veterinary medicine recognized by the American Veterinary Medical Association. In the greater Reno area we have 2 board certified surgeons practicing on horses, 1 large animal internist, and a board certified ophthalmologist who sees both large and small animal patients.  UC Davis is 3 hours away and offers specialists in most of the large animal disciplines.  To learn more about veterinary specialists, google AVMA specialty organizations.

   

I believe that education is the key to evolution. I believe that animals are the key to compassion. I believe the learning never stops.

Going the Distance - 

to a Happy Ending

     I think of it most commonly in murder mysteries.  You know, the Sherlock Holmes guy who recognizes the connection between several apparently unrelated events that no one else thinks are important and the next thing you know - voila! the murderer is exposed. This story is a bit like that.  It is about Spring, a 9 yo mare who has beaten the odds, thanks to an observant veterinarian and a dedicated owner.  

       Last summer  I was called out to see Spring twice because she had a severe dermatitis affecting the white part of her muzzle.  I treated her for photosensitization, a common problem in northern Nevada where horses with white skin fed alfalfa have a dramatic reaction to sunlight that results in a painful, sunburn like inflammation, seen most commonly on the nose and white areas of the lower legs.  In January Spring's owner called me because once again the white skin of Spring's nose was severely inflamed.  At this point I became concerned about an underlying problem.  A few things didn't make sense: 1) Spring's diet had been carefully managed to eliminate consumption of ingredients, such as alfalfa, that might contribute to photosensitization, and 2) it was January - the days were short and we had had lots of bad weather, meaning there wasn't enough sunshine to trigger a typical episode. I began to wonder about the health of Spring's liver.  

      The liver plays an important role in detoxifying phylloerythrins, the photodynamic substances that cause photosensitization.  Thus an unexplained episode of this problem may be an early sign of liver disease.  Consequently we began an extensive evaluation of Spring's liver, which included serial blood work, hepatic ultrasound and finally a percutaneous liver biopsy.  All the news was bad.

     Spring had persistent elevations in the active hepatocellular enzymes that indicate ongoing damage to liver cells.  Her biopsy showed extensive fibrosis, or scarring of the liver, indicating that the disease process had been going on for a prolonged period of time.  Ultrasound revealed that her liver was smaller than normal. There are several diseases that result in the findings observed in Spring.  The one that fit Spring's findings most closely  is called Chronic Active Hepatitis (CAH).  It is a poorly understood disease process, most likely immune-mediated. It carries a very poor prognosis for long term survival, and in general does not respond well to medical treatment.

     If you received our most recent e-news letter, you read my article on veterinary networking.  Spring's case is a wonderful example of how networking makes us all smarter.  I presented Spring's case to the American College of Veterinary Internal Medicine Specialists' list serve and asked for input from my colleagues.  Most agreed that a diagnosis of CAH was correct and treatment with steroids and anti-fibrosing agents should be attempted, but the outcome was not hopeful.  However, one of my colleagues and mentors from the University of Georgia where I completed my residency and PhD program, suggested another possibility.  Dr. Michelle Barton wondered about the possibility of a stone in the common bile duct, which would not be visible on ultrasound.  Although Spring's diagnostic findings did not fit this picture perfectly, Dr. Barton pointed out that this was the only disease she could have with any hope of treatment, and that the only way to rule it out would be an exploratory surgery, because in the horse the common bile duct can only be visualized and fully examined at surgery.

       Horses don't have gall bladders.  The liver makes bile, which is excreted through the common bile duct into the small intestine.  In order to access the bile duct, the horse is placed on its back under general anesthesia.  A large incision is made along the midline of the abdomen - the same incision made for colic surgery, but much longer, extending forward almost to the sternum.  The surgeon must lift much of the gastrointestinal organs out of the abdomen, then reach far down and forward into the abdominal cavity to find the bile duct as it exits the back of the liver along with the hepatic vein and artery.  It is a very difficult surgical exposure. 

    Now Spring's owner had to make a really tough decision. The odds of Spring having a bile duct obstruction that could be resolved at surgery were small.  The anesthesia and stress of surgery could precipitate a crisis and push Spring from a state of compensated liver disease into full blown liver failure which would almost certainly be fatal.  On the other hand, if Spring did have a bile stone that the surgeon could loosen up and move from the bile duct into the small intestine, Spring's prognosis for long term survival would improve markedly.  I spent a long time talking to Spring's owner, explaining the options, looking at things from various perspectives, talking about possible outcomes, and listening to her owner's thoughts and concerns about Spring's quality of life.  My recommendation was to go forward with surgery because it provided the only hope of a significant positive impact on the disease process progressing in Spring's liver.  

      The picture at the top of the page tells the story.  I took it during Spring's surgery, conducted by Dr. Shane Miller, a board certified equine surgeon. At surgery the liver was found to be small, with a markedly fibrotic right lobe.  Dr. Miller did not feel a discrete bile stone in the bile duct, but the duct was very firm on palpation, and Dr Miller massaged and manipulated the duct in hope of freeing any bile "sludge" that might be occluding the flow of bile through the duct.  At surgery we all were pretty disappointed, and thought that our best hopes of improving Spring's outcome had not been realized.

     After surgery everything began to change. Spring had no difficulty at all related to the surgical procedure.  She recovered uneventfully from anesthesia and had no problems with her large surgical incision.  Her liver enzymes were carefully monitored for 3 days post-operatively for signs of deterioration secondary to the stress of surgery.  Surprise surprise surprise.  The enzymes that indicate bile obstruction and active liver cell damage began to decrease immediately after surgery and continued to move toward normal numbers.  Four weeks after surgery Spring's blood work is normal!  Just like mud in a hose, the firm material that Dr. Miller felt on palpation of the bile duct was most likely stagnant, thickened bile "sludge" that he loosened up with his manipulation at surgery.

    Currently Spring is being maintained on a grass hay and beet pulp based diet, which is rich in branched chain amino acids, readily metabolized by the liver.  She also is receiving pentoxyphylline, a medication that acts to reduce fibrosis.  She looks great and can't wait for her incision to finish healing so that she can be turned out to pasture and then get back to work!

    Spring's story is far from over, but at this point I cannot thank all the people involved in the Spring network enough for their contributions to her diagnosis, treatment, and recovery.  First of all her wonderful owner, who listened, digested and formulated her decisions with only one thing in mind: her horse's well being.  And then to the team of veterinarians, especially Dr. Barton and Dr. Miller, who contributed their knowledge, experience and clinical expertise to Spring's case.  It truly does take a Village. 

    

 

I believe that education is the key to evolution. I believe that animals are the key to compassion. I believe the learning never stops.

Gear up for Spring

Time to Gear up for Spring

 

Here’s to Spring in February! What a winter – Jessie, Hayley, Gina and I were working in our shirtsleeves during Mother’ Nature’s generous gift of a warm early February and now winter is having her last go at us again. I hope you were able to take advantage of those beautiful days to get out with your horses. The ups and downs in temperature have been a bit hard on our equine friends this winter. I’ve been treating an unusual number of impaction colics, most of them mild and responding well to treatment.

They are a reminder of how important it is to keep after hydration during the winter months. On these warm days excercising horses and blanketed horses tend to sweat – loosing precious body water – then the temperature drops at night, water freezes, horses drink less and risk dehydration. Horses require 10-12 gallons of water daily. This amount increases substantially in the face of body fluid loss through sweat. Horses have been shown to decrease their voluntary water intake when the temperature drops below 45 degrees.

In addition, before the weather became warm, we had that nasty stretch of freezing snow that made it difficult for horses to move around comfortably. Lack of exercise also contributes to colic through decreased gut motility and processing of fiber through the intestinal tract.

Finally, while it is true that horses burn more calories during cold weather, erratic increases in grain can cause problems. Sudden change in carbohydrate load to the digestive system can cause gas accumulation, bowel distension, and subsequent abdominal pain. Put it all together and winter is a challenging time for good management. Keep these basics in mind:

1) Check your horse’s water source 2x daily – be sure it is clean and free of ice

2) Exercise your horse – even if it is just taking him out for a nice 20 minute hand walk – even in the worst weather!

3) Make feed changes gradually – good quality hay is always the safest thing to feed – be sure there is adequate fiber in your horse’s diet!

Here is the best news of all – Winter is Almost Over! Thanks for being part of the HIghDesertEqine.com family – I look forward to seeing you on a clinic day in March. See clinic schedule below.

Gratefully,
Chrysann Collatos VMD, PhD, DACVIM
High Desert Veterinary Service

                          Spring Vaccination Clinic Schedule.

 As always I’m there to answer your questions, and also offer routine health care services on clinic days. Routine spring health care includes vaccination against E&W Encephalitis, West Nile, Tetanus, Influenza and Rhinopneumonitis plus deworming, an oral exam and sheath cleaning for geldings.

Call the office to reserve an appointment.

BE SURE TO LEAVE THE FOLLOWING INFORMATION:

Name, Phone #,  Date you request, Number of Animals, and the Services needed.

We will return your call three days before your clinic with an estimated time of arrival at your address.  Please be sure horses are caught and haltered 30 minutes beforehand.

Location                                               Date

Rancho Haven/Sierra Ranchos1              Sat  March 5

Rancho Haven/Sierra Ranchos2              Fri  Mar 11

Red Rock North/Silver Knolls 1                Sun Mar 6

Red Rock North/Silver Knolls 2                Fri Mar 11

SpanSprings/Palomino Valley 1              Mon Mar 7

SpanSprings/Palomino Valley 2              Sat Mar 12

Antelope Valley                                          Sun Mar 13

Golden/Lemmon Valley                            Sun Mar 13    

South & West Reno                                  Tues Mar 15

Golden/Lemon Val/South Reno               Fri Mar 4

For additional savings, you can schedule your own mini-clinic as long as you have at least 10 horses at a single location.  Call the office to make such arrangements.

Price List – Clinic day only

Farm Call/Fall Exam              $17.00              

West Nile (Prevenile)              $32.00

FluRhino                                   $26.00

Tetanus/ Encephalitis             $14.00

Intranasal Strangles                $32.00

Rattlesnake Vaccine*             $32.00*

Ivermectin Deworm                 $14.00

Coggins Test                           $22.00

Sheath Clean w/sedation       $35.00

* 2 boosters are required after this initial dose – call the office or e-mail us if you have questions.

Ask Dr. C what vaccines are best for your horse based on age, environment, and activity level.

Spider Bites

I think of winter as a time when bugs and snakes and things that cause nasty bite wounds are asleep.  While this is mostly true for our friend the rattlesnake, I learned last week that it is not so for spiders, when I was called out to see Venus, a 12 yo thoroughbred mare.
 
Venus was fine the night before when her owners closed up the barn, but they came out Sunday morning to find her standing in her stall with her head down, breathing heavily, unwilling to move, with a severely swollen hind leg.  On my arrival, initial examination revealed an elevated heart rate (80 beats per minute/normal 40), respiratory rate (24 breaths per minute, normal 12), and temperature (104.5 F, normal on a digital thermometer 99-100).  Venus was exquisitely painful - her breathing was shallow and panting, when forced to move she hopped on her right hind leg, and the leg was 3x normal size, from the pastern to the stifle.  The swelling in her leg was warm and very painful to touch.  After careful examination of the leg, I discovered a tiny red spot on the lateral aspect  of her metatarsus (outside of the cannon bone).  The skin immediately surrounding this spot was weeping a clear yellow fluid.

The rule outs for acute, severe swelling and lameness in a limb are abscess, infection, and fracture.  The most common is a foot abscess.  However, it would be extremely unusual for a hoof abscess to cause swelling extending this far up the limb and such a high fever to develop in just 12 hours.  Nevertheless, I pulled out my hoof testers and performed a careful examination of the hoof before crossing this one off the list.  Next to eliminate was fracture of the tibia or femur.  These bones in the upper limb, when broken, may be associated with severe swelling of the surrounding muscle masses.  However, the presence of a high fever was not consistent with fracture, and once Venus was brought out of her stall and moved around a bit, she did bear full weight on the leg when standing.  This did not completely eliminate the possibility of fracture, but made it less likely.  Upon discovery of the red spot with serum oozing around it, the high fever, severe pain, sudden onset of swelling and lameness were most compatible with a diagnosis of cellulitis of unknown origin.

Cellulitis literally means inflammed cells.  It describes a condition where something - trauma, bacteria, virus, toxin, cancer - sets off a cellular reaction that causes the body to release fluid, white blood cells, and a wide variety of small chemical molecules into a region of the body in response to the insult.  This is the body going to war - these factors are the body's soldiers and weapons that it uses to kill invading organisms.  Unfortunately, as in any war, there is collateral damage, and the body not only attacks the enemy, it also attacks itself.  The result is swelling, heat, pain, and redness, the four classic signs of inflammation (rubor, calor, tumor & dolor in latin - these signs have been recognized since ancient times).

The yellow fluid leaking through Venus' skin was serum - as the cells in her skin and underlying interstitial tissues fell apart, the blood and lymph vessels in the area also lost their integrity, allowing the fluid that should be retained within the body's plumbing system to leak out.  The damage to Venus' leg was so severe that this liquid was exuding through her skin - the body's final and most important barrier to the big bad outside world.

Whatever the initiating cause of cellulitis, the destruction of the body's intricate array of barriers to the external environment allows immediate invasion of infectious organisms that always are lurking about- primarily bacteria.  In a barn setting, these bacteria are everywhere because they love to live in warm organic matter - manure, bedding, wet spots under water buckets - I'm sure you can  imagine many more if you look around your barn and paddocks.  Although to us hairless humans winter feels very cold, in our climate prolonged deep freeze is actually rare - and if you dig to the bottom of the manure that's been accumulating since November in the corner of a pen, you'll likely find some warm, wet spots that are the bacterial equivalent of our mid-winter Baha vacation haven.

So, let's take a step back and decide what to do for Venus.  Although at this point we have not determined the definitive cause of her clinical signs, we have put together the fever, painful swelling, and serum leakage as indicators of cellulitis as the most likely primary problem.  We have reasoned that cellulitis is associated with inflammation and infection, therefore our initial treatment should be directed against 1) pain 2) inflammation 3) infection.  On a scale of 1-10, I gave Venus' condition a clinical score of 8 - very severe.  When choosing medications, we must chose oral, intramuscular or intravenous routes of administration, and we must choose drugs according to their strength and spectrum of activity.  Venus needed the big guns - so she was given intravenous flunixin meglumine (Banamine - anti-inflammatory/analgesic), Gentocin (antibiotic) and Potassium Pencillin (antibiotic) as well as an intramuscular tetanus toxoid.

The next concern was hydration and nutrition.  I decided to monitor Venus' reponse to therapy for 24-48 hours.  She did improve, but it was not logistically possible to continue frequent intravenous antibiotic adminstration and Venus did not eat or drink well over the next 48 hours, so the decision was made to hospitalize her where she responded rapidly to intensive medical therapy.  She returned home a healthy, sound horse, although she continued to loose hair and some skin on the affected leg for 10 days after the initial insult.

What happened to Venus?  The owners reported finding a Black Widow spider in the tack room next to Venus' stall a few days before her adventure began.  They have had problems with these spiders in the past.  Although we cannot know for certain, I believe that Venus was bitten along the side of her cannon bone (the red spot leaking serum) by a Black Widow.

We have two spiders in our area that cause toxic bite reactions.  The picture at the top of the blog is a Brown Recluse.  The actual Brown Recluse species is rare in Northern Nevada, but we do have a closely related species.  The bite of the Brown Recluse and its relatives causes a severe, localized, necrotizing reaction, but not a generalized response. The site of brown recluse bites initially is warm and painful, and over the subsequent 3-7 days may develop into a deep, debilitating open wound with massive loss of tissue and secondary infection.

The Black Widow bite contains a neurotoxin.  It travels through the body and tends to cause more systemic signs which can range from muscle pain to neurologic signs, depending on the site of the bite and the size of the victim.  While dogs are quite resistant to the affects of Black Widow toxin, horses are very sensitive. To learn more about these two spiders, visit Slideshow: Black Widow Spider vs. Brown Recluse Spider on eMedicineHealth.com 


I believe that education is the key to evolution. I believe that animals are the key to compassion. I believe the learning never stops.

The Will to LIve

The Will to Live

     

     Three years ago, Angel was born dysmature and septic.  Angel could not stand, could not suckle, and had a bacterial infection (neonatal septicemia) affecting her entire body.  Hospitalization in a neonatal intensive care unit was not an option due to financial constraints.  Under the best of circumstances the likliehood of survival in this situation is 20%.  In an at home care setting, it is drastically reduced.  Somebody forgot to tell Angel.

We set up a MASH unit in the outdoor paddock where Angel and her dam lived.  Angel’s human family basically stopped eating or sleeping for the next 10 days.  I provided Angel with an intravenous catheter and a nasogastric feeding tube, and administered initial aggressive treatment to address the immediate issues of failure of passive transfer, sepsis, inadequate caloric intake, toxemia, and possible cerebral anoxia, and gave the owners a crash course on IV medication and fluid administration, feeding tube maintenance, and neonatal foal nursing care.  Remember, Angel couldn’t stand  – she could barely lift her head.

     Angel required around the clock care and she got it.  As day 1 became day 2, then 3…6…10 I watched amazed as Angel’s owners gave life to this gritty little filly.  As the caregivers began to look increasingly weak and exhausted, Angel did just the opposite – by 2 weeks of age she was a bouncing, active, clinically normal foal.  We all danced for joy (well, her owners watched with bleary eyes while I danced – they were just too wooped to jump around) and Angel set off to live a normal life.

     Turn the clock ahead to late summer, 2010.  Angel is now 3, and has been sent off to spend some time with a cowboy trainer.  She went on a slow cattle drive and had some great experience just learning to be out and about with other horses.  Unfortunately, there was an outbreak of Strangles on the ranch while she was there.  Strangles is a strep bacteria: Streptococcus equi sp. equi.  It is highly contagious.  A typical case of Strangle goes like this: the horse is exposed to the bacteria.  Three to five days later the horse is depressed and has a fever.  This may go unnoticed.  By day seven the horse has a thick yellow nasal discharge.  Over the next week to ten days, the horse develops swelling just behind the cheek bones (retropharyngeal) or between the jaw bones (submandibular) caused by lymph node abscessation.  These abscesses break open and drain, the horse recovers and that’s that.  An uncomplicated case of Strangles is not treated with antibiotics, and has no long lasting consequences for the horse.

     Complications occur in about 10% of horses with Strangles.  These include abscesses that compress the airway and interfere with breathing or swallowing, pneumonia, formation of internal abscesses within the abdominal cavity, and an uncommon immune mediated disease called purpura hemorrhagica.  All complicated cases of Strangles require intensive medical treatment and are potentially fatal.

     Angel didn’t handle her Strangles well.  By the time her owner was notified and came to see Angel she had been sick for 3 weeks.  She had multiple abscesses on the left side of her face and neck, she had pneumonia, she was suffering from severe malnutrition, and to top things off, she had multiple foxtail abscesses under her tongue and in her throat.  This picture was taken the day Angel came home.  She was weak, staggered as she unloaded from the trailer, had long strings of saliva falling from her mouth, and stood with her head extended, her eyes half closed.  Her heart rate, respiratory rate and temperature were elevated and she had difficulty breathing.  Her hip bones and back bone were prominent – I estimated her weight loss over the 3 weeks at over 100 pounds.

      Once again, the MASH unit was organized.  However, instead of a 65 pound neonate, the owners were now trying to manage a critically ill adult.  I placed an intravenous catheter and we began intensive antibiotic, anti-inflammatory and fluid treatment, but when Angel’s initial blood work came back from the lab, it was obvious that we were not going to able to provide adequate care at home.  She was suffering not only from a critical bacterial infection, but also from severe cachexia.  Our bodies burn many additional calories when we are ill.  Angel’s ability to prehend, chew and swallow had been compromised for 3 weeks, and to compound this problem, she had been competing for food in a group of horses.  In her increasingly weakened condition she had been left with the poorest quality hay to try and consume.  Her blood protein levels were alarmingly low – her body was consuming itself in an effort to fight the infectious process and it was losing the battle. 

     Angel’s owners and I sat down and had a heart to heart.  None of us were willing to give up on Angel, even though it was clear that she once again was facing an immediately life-threatening situation with a guarded prognosis for recovery.  I called UC Davis and arranged for an emergency referral.  Angel’s owners loaded her up and off she went.  Angel , whose normal body weight is 950-1000 pounds, weighed 760 pounds on arrival at the University hospital .  Diagnostic testing including ultrasound and endoscopy confirmed the presence of pneumonia and multiple upper airway abscesses.  Under the excellent care of Dr. Dawson, a senior medicine clinician and her staff, Angel once again defied the odds.  She was in the hospital for close to 3 weeks, and continued her treatment at home for another month.  By Christmas Angel had recovered completely from her second brush with death.  Here she is, head up, bright eyed, and round barrelled.

     It takes a village.  Angel has a tremendous will to live.  She also has a family who loves her and doesn’t hesitate in the face of adversity.  Grandma, grandpa, grand-daughter, the entire medicine staff at UC Davis, the benefactors who support the UC Davis Emergency fund, the Care Credit organization, myself and my assistants, all played roles in Angel’s survival. 

     These days we see and hear a lot of stories of loss, of animals suffering because the money isn’t there, because people give up.  Angel’s owners are not wealthy, but they were willing to look for help when they needed it, and to roll up their sleeves and work themselves to the point of exhaustion to care for their horse.  Their dedication and Angel’s desire to survive are insipirational.

I believe that education is the key to evolution. I believe that animals are the key to compassion. I believe the learning never stops.