4/21/2010 Euthanasia

 Vet tip of the Day: Thinking about Euthanasia

I would like to introduce the topic of euthanasia with a few stories.  The first is one about an experience I had as a resident, and the second is about PipSqueak, a wonderful patient of mine

I completed a large animal internal medicine residency at the University of Georgia School of Veterinary Medicine.  I was on call to receive emergency patients into the hospital every 3rd weeknight and every other weekend for 5 consecutive years.  That's a lot of emergency admissions.  The sad reality of referral equine medicine is that we see a lot of very sick horses and many of them don't make it out of the hospital.

One weekend early in the first year of my residency I didn't sleep for 48 hours.  During that time I received 8 emergency patients.  Four of them were critically ill and over the course of two days I administered a lethal dose of sodium pentobarbital (euthanasia) to all four when it became clear that they had no hope of survival. Right there you come up against one of the more difficult concepts in the decision for euthanasia: no hope.  We all know that there always is hope, we just choose under certain circumstances to consider that hope too small to warrant the continued suffering of the really sick or the really old.  And let's face it, economic concerns and practical concerns influence the decision to end animal's lives as well.

That particular weekend in 1989 when I was a resident was very difficult for me. In the five subsequent years I never had to face the death of some many horses in such a short period of time.  I was exhausted, I was a new resident and I didn't have a lot of experience coping with the grief, guilt and confusion often experienced by owners when making the decision for euthanasia of an animal they love. At that stage of my career I also didn't have a lot of experience pushing the plunger on the syringe of "blue juice" that ends an animal's life.  I don't really remember all the details of that weekend.  I do remember that moment, just before performing each injection, when I wondered if perhaps there was hope, if perhaps I had misinformed the clients, if in fact the horse might survive if I could just do one more thing to turn its condition around, if I was making a terrible mistake.  None of these things was true, but the thoughts ran through my head nevertheless.  And I remember on Sunday afternoon, after I had humanely destroyed the fourth horse, sitting on the floor of the recovery stall outside the equine surgery suite and thinking, if one more horse comes in and requires euthanasia before tomorrow morning, someone else is going to have to push the plunger, I just can't take any more life today.

The second story is about PipSqueak.  PipSqueak was a grey arabian gelding who I took care of for 13 years, from the time he was 14 until his death.  Over these years PipSqueak belonged to 4 different owners, all of whom he taught the skill of riding after hounds, or foxhunting.  PipSqueak was a remarkable horse, an outstanding athlete, and a very wise soul.  Toward the last years of his life he was retired and turned out to pasture by his then owner.  His care was not adequate and he lost weight and began to have trouble getting up.  One of his previous owners, who by now was a teenage girl, saw PipSqueak's condition and reclaimed him.  She had owned PipSqueak when she was 8-12 years old and had ridden him all over the desert of Northern Nevada.  Now 15 years old, she brought PipSqueak home and fattened him up and took great care of him for another 9 months.

Although he was back in great body condition, PipSqueak's degenerative joint disease progressed to the point that he sometimes struggled for as long as 20 minutes attempting to rise, raising himself on his front legs but unable to lift his hind end to a standing position.  He was treated with joint supplements and anti-inflammatories, his hocks were injected, he was put on special footing and had special foot care, but his condition continued to deteriorate.  Finally his owner's grandmother called me one day to schedule an appointment for PipSqueak's elective euthanasia.

I arrived at the appointed time to find the entire family waiting with PipSqueak.  The horse had been bathed, his mane and tail brushed to a shimmering white, hoof dressing applied to all four feet, and he wore a beautiful new halter.  We all walked out with PipSqueak to the area where he was to be buried.  PipSqueak walked comfortably because his owner had given him one last whopping dose of bute that morning along with a bucket of grain so that he would be comfortable and feel especially spoiled in his final hours.  As we walked we shared stories of PipSqeak's many exploits over the years.

PipSqueak stood patiently while everyone said their goodbyes.  As I injected the sodium pentobarbital PipSqueak's family stood close by, speaking to him gently.  As soon as he fell to the ground we followed his descent, everyone keeping a hand somewhere on his neck or head.  We were very quiet,  his young owner began to cry and arms encircled her in her grief.  PipSqueak passed from life to death very swiftly, in the company of humans who loved and respected him, and who took the responsibility of ending his life squarely on their own shoulders, with compassion and grace.

I find the topic of euthanasia very complex, and will discuss it in more theoretical, and practical terms, over the next few days.  Please feel free to comment on this blog entry with your own thoughts and experiences concerning this topic.


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

4/20/2010 Spring Breeding - the Transitional Period

Vet tip of the Day: The Mare's Transitional Period

It's the time of year when I get lots of calls regarding breeding mares.  In the past week I've also had several  about performance mares exhibiting unusual behavior and brood mares showing irregular heat cycles.  Both of these problems are related to the seasonal nature of mare's reproductive cycle, and may be particularly evident this year because of our unusual weather patterns. Today I am going to briefly review the mare's estrous cycle with emphasis on the transitional period that affects many mare's between January and April.

Seasonal variation in the duration of daylight has a profound influence on mare reproductive performance.  The horse is a seasonal breeder - increasing daylight improves the mare's reproductive efficiency while shortened days results in poor reproductive regulation.  Daylight is believed to act by stimulating the production of melatonin by the pineal gland, located within the brain.  This melatonin in turn causes the hypothalamus to release GnRH (gonadotropin releasing hormone).  GnRH acts on the pituitary, causing production of FSH (follicle stimulating hormone) and LH (luteinizing hormone) which influence the ovaries to develop and release follicles. In order for successful conception to occur, a mature follicle, or egg, must be fertilized by healthy sperm and then arrive in a uterus which is ready to accept and nourish it as it develops into a budding embryo. 

The transition from the short days of winter when most mares stop cycling all together, to the long days of June, when fertility is at its highest, is a gradual, progressive process.  During the spring and fall, mares enter a period of anovulatory receptivity, or the transitional period.  At this time, they often exhibit erratic estrus behavior, and while they appear to be in standing heat and accept a stallion, there often is not an associated ovulation of a mature follicle.  Even if a transitional mare does ovulate appropriately, it is also likely that the hormonal sequence necessary to maintain the early critical days of pregnancy will not be in place and the conceptus is lost.  Particularly in the spring, this transitional period is characterized by long, erratic heat cycles without ovulation. 

During the transition period performance horses often exhibit irritable behavior and are difficult to train.  It is during this time that trainers are often looking for ways to suppress reproductive activity so that their mares will behave appropriately in the show ring.  There are many oral supplements available over the counter which claim to improve the demeanor of irritable mares. The effectiveness of these supplements is debatable.  The only way to know if one will help your cranky mare is to try.  For years people have used cattle subcutaneous hormonal implants to control mare's heat cycles, but multiple research trials have been performed using these implants and no one has ever been able to show that they have any real effect on the mare's hormonal regulation.  Injectable progesterone in olive oil can be used intramuscularly to prevent mare's from cycling during the transitional period with variable success.  The only truly reliable means of controlling a mare's reproductive system and preventing cycling is the daily administration of  oral Regumate liquid (a synthetic progesterone).

Once the transitional period is over and mare's are cycling regularly, reproductive efficiency rapidly improves.  The "normal" mare has a 21 day heat cycle.  She is not receptive for 14-15 days (diestrus), then comes into heat for 4-7 days (estrus), ovulating 12-24 hours before behavioral signs of estrus disappear. Regarding performance horses, some mares continue to be difficult during the days close to ovulation, but in general the number of days when undesirable behavior is exhibited are markedly reduced, and can be predicted based on following the heat cycle.

So, when your mare is acting like a maniac and its February or March, remember that part of her behavior may be attributed to the "raging hormone" condition that we all recognize in each other from time to time.  Mares, just like people, are very individual in their reaction to their own internal chemistry.  Some have placid dispositions and do not seem affected by the ups and downs of hormonal transitions while others are truly distressed during these transitional phases and should not be punished when they are at the mercy of Mother Nature's nasty tricks.  If you own a mare you are trying to breed in the early spring, or a performance horse with seasonal behavior problems, speak with your veterinarian about management practices that may improve your breeding success or help your mare's disposition. 

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

Prepurchase Exam III: Diagnostic tests

Vet tip of the Day: Prepurchase Part III - Additional Diagnostics
Key Words: Radiographs, ultrasound, endoscopy, blood work 

Today we will discuss the final aspect of a prepurchase examination: the decision to pursue further diagnostic tests.  Radiographs are commonly utilized to aid the veterinarian's evaluation of your prospective purchase.  In some cases, ultrasound, upper airway endoscopy, and blood work also may come into play.  Let's look at each individually.

There are two reasons to take x-rays.  First, to obtain further information about a specific anatomic region because of abnormal findings during the clinical portion of the exam.  A very common example would be a horse demonstrating a mild to moderate positive response to upper hind limb flexion, but no other signs of lameness.  Degenerative joint disease (djd) of the lower hock joints is very common in athletic horses (search blog entries for "hock" to review this subject) and often is quite manageable with appropriate medical therapy.  Therefore, hock radiographs are one of the most commonly obtained diagnostic series during prepurchase exams.

The second reason to obtain radiographs of the horse you are considering is to look proactively for radiographic abnormalities which may cause lameness problems in the future, or affect your ability to resell this horse, even though they are not causing clinical problems at this time. The most common anatomic areas investigated for these reasons are feet and stifles, but may also include fetlocks and carpi (front knees).

So how do you decide whether to request radiographs?  If your intended use for your new horse is pleasure riding or light competition, the horse is in full work and has a complete history, and the clinical examination of the horse is normal, you may choose to forego radiographic evaluation.  On the other hand, if you are buying a high level performance horse, if you are planning to re-sell the horse in the near future, if the horse has not been in full work prior to the prepurchase evaluation, or if there are any questions which arise after the horse's clinical evaluation, then you should seriously consider additional diagnostic tests based on consultation with the veterinarian conducting the examination.

One final word on radiographs: they sometimes open a can of worms that may be confusing to you.  While some radiographic abnormalities are straightforward, many are open to various interpretations.  If the horse you are looking at has abnormal radiographic findings in the absence of a corresponding clinical unsoundness, the veterinarian must give you their best professional opinion on the significance of the x-ray findings, but remember: they don't have a crystal ball! Once again, this brings up the importance of having a good performance record on your prospective purchase to help the veterinarian performing the evaluation interpret the significance of radiographic findings.

Ultrasound of the soft tissues of the distal limb, specifically suspensory ligament, superficial and deep flexor tendons, may be considered in higher level performance horses.  However, ultrasound imaging has not been standardized to the same extent as radiography, and ultrasound actually is not a sensitive tool for determining subtle changes in soft tissues.  I do not recommend ultrasound as part of a routine prepurchase examination.

Upper airway endoscopy usually is reserved for upper level performance horses such as race horses and upper level endurance horses.  During the exercise phase of the clinical evaluation, the veterinarian will ask the horse to canter long enough to elevate both heart rate and respiratory rate and will evaluate these systems immediately after exercise to look for any indication of upper airway problems indicating a need for endoscopic evaluation.

Blood work is not a bad idea.  Although very unusual, it is possible for a horse to be harboring a chronic inflammatory or infectious condition without showing outward clinical signs.  A complete blood count and chemistry screen can rule out the possibility of an underlying problem.  A toxicology screen testing for sedatives, analgesics (pain killers), or other behavior modifying drugs may be indicated in certain situations.  If you request a "tox" screen, be sure to ask the veterinarian what how long it will take to get results of this test - it may be up to a week, and thus you must factor this delay into your negotiation with the seller.

So that's the story on prepurchase examinations.  I strongly recommend you have a veterinarian conduct at least a full physical examination and basic lameness evaluation on any horse you plan to purchase.  There are  many problems that may not be apparent to either the seller or buyer that a vet can identify for you and help you understand before you make the decision to bring a new horse into your life.

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

4/16/2010 Prepurchase Exam II

Vet tip of the Day: What to Expect in Your Prepurchase Exam 
Key Words: Lameness, Conformation, Physical Examination, Suitability

Before I begin, let me apologize for the gap in my blog entries.  Spring is here and as much as I enjoy writing, my clinical practice takes first priority and it has been consuming my energy lately.  Also, in all honesty, I've been focusing on my young jumper in preparation for his first horse show of the season, and putting him ahead of writing time as well over the past week.

Back to the prepurchase exam.  What should you expect to see happen when a veterinarian is evaluating a horse for you?  First, a complete physical examination from head to toe, including an eye exam with ophthalmascope, careful ausculatation of heart, lungs and gastrointestinal tract with a stethoscope, a brief oral exam and careful palpation of the entire horse will  take place. We are mentally running through a check list of body systems as we perform this initial examination.  Before diving into the musculoskeletal portion of the examination we are checking skin, lymph nodes, circulation, heart and lungs, intestinal tract.  We get a sense of the horse's systemic well-being based on heart rate, respiratory rate, rectal temperature, body condition, and oral mucous membrane color and moisture.  Having completed the overall systemic exam, the musculoskeletal portion of the exam begins.

The veterinarian will look at the horse carefully from front, back and each side before beginning the hands on exam.The horse will be examined for conformational defects, musculoskeletal symmetry, body condition and mobility of large muscle groups such as the neck and back.  Each limb will be carefully palpated and manipulated and hoof testers applied to the feet.  As we feel each limb, there are specific anatomic structures being evaluated systematically by palpation and visual assessment.  Each joint is assessed for fluid filling and mobility.  Tendons and ligaments are palpated for painful responses and palpable swellings or irregularities.    After a thorough examination of the horse at rest, he will be observed in motion.

The gait evaluation portion of the examination will vary depending on the intended use of the horse, the horse's age and training, and the facility where the exam takes place.  For performance horses, even lower level athletes, minimum evaluation includes observation on a longe line at walk, trot and canter on at least two surfaces: once in deeper footing and once on hard ground.  In some cases the horse will be observed under saddle as well.  After evaluating the horse on the longe line it will be observed in hand at a walk and trot in a straight line.  Various full limb flexion tests will be performed to see whether these stress tests produce any alteration in the horse's gait.

Flexion tests are theoretically intended to reveal subtle discomfort in joints or soft tissue structures (tendons & ligaments) that may not cause overt lameness at the time of the examination.  When a horse trots off lame after a flexion test, it may indicate the need for further diagnostic evaluation such as radiographs (x-ray) or ultrasound.  The interpretation of flexion tests is controversial.  There is considerable debate among veterinarians concerning the significance of flexion tests.  The problem is the wide variation from horse to horse in the response to flexion and variations of technique in performing flexion tests between veterinarians.  This is one of the many areas where an experienced trainer, and a veterinarian you know and trust, can be of great assistance in helping you interpret the findings of a prepurchase examination.

I put a lot of effort into trying to make explanations of my findings clear yet thorough when speaking to a prospective buyer during a prepurchase exam.  However, I'll be honest with you,  it is challenging to condense years of knowledge and experience of the anatomy, pathophysiology, and demands of a performance horse's life into simple formulas that adequately explain the implications of every abnormality revealed during a prepurchase examination.  And that is what we are trying to do, both for the benefit of the buyer and the horse.  Therefore, it is important that you ask questions until you feel comfortable in your understanding of the significance of the veterinarian's findings with respect to YOUR needs for THIS particular horse.  Finally, you must understand that as veterinarians, we are asked to look at a horse once, over the course of 45 minutes to a couple of hours, and determine whether it is going to stay sound and healthy for years to come.  Obviously this isn't possible, but remember from the last blog post, you are most likely to have a positive outcome if the horse you are looking at has a complete history and is in full work at a performance level close to its intended use for you.

In tomorrow's blog (and I PROMISE to write an entry tomorrow) we will discuss ancillary tests, such as x-rays, ultrasound, and blood work which may be part of your pre-purchase examination.  Until then, enjoy the sunshine and warmer weather!

Our practice e-newsletter will be going out soon.  If you would like to receive it, send your e-mail address to us at hidvet@gmail.com or send us a message via our Facebook page.




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

4/2/2010 - The Prepurchase Exam

Vet tip of the Day: The Prepurchase Examination
Key Words: Intended Use, Physical examination, X-rays

 Today I am going to discuss some theoretical considerations regarding prepurchase examinations.  Tomorrow I will go over the nuts and bolts of the prepurchase exam including what you should expect your veterinarian to do during the exam, and how to determine if x-rays or blood work are indicated.  Right now let's begin with a look at the issue of suitability.

Today I completed a prepurchase examination on a 15 year old arabian endurance horse.  The horse was experienced, with 5,000 competition miles and no history of lameness problems.  The buyers were looking for a safe, experienced horse to do 25 to 50  mile endurance rides, but not at a highly competitive level.  The horse had not been competing for the past two years, but had been consistently ridden as an athletic trail horse.

I share this information with you, and chose this picture of the little cowgirl riding her barrel patterns on what appears to be a very wise old mare, for a reason.  The arabian gelding I saw today, and the old quarter horse poking around the barrel are two very different horses, but each is appropriate for their rider's needs.

A prepurchase exam is a veterinarian's evaluation of a horse's physical well being based on a single evaluation which takes from 45 minutes to a couple of hours to complete. While a tremendous amount of valuable information can be gathered based on a thorough physical examination, lameness evaluation, and diagnostic imaging, even the most rigorous prepurchase exam cannot replace a good history on a horse's past performance record and a buyer's solid understanding of their goals in purchasing this horse.  Obviously the little cowgirl's horse needn't demonstrate the same athletic ability as the 15 year old endurance horse.

As a veterinarian, one of the most challenging situations when performing a prepurchase examination is trying to evaluate a horse with an unknown history which is not performing the job for which it is intended.  For example, last fall I was asked to evaluate a 9 year old thoroughbred mare being purchased as a children's show jumper.  The mare had done some showing as a 5 and 6 year old, and then for an unknown reason had become a brood mare.  She had 2 foals then didn't conceive last year and now was for sale. 

Evaluating a horse like this is really difficult.  She has not been in any kind of exercise program for 3 years and there is no explanation for her change from performance horse to brood mare.  She may have a perfect prepurchase examination on the day I look at her.  She may be sound, have good conformation and pass all my flexion tests and limb palpations with flying colors.  She may have normal x-rays of her hocks, and front feet.  From my perspective, she is a sound horse.  However, I always caution buyers of such animals that the horse is not performing at the level of intended use and has an incomplete history therefore it is impossible for me to have great confidence in assessing the horse's long term prospects for continued soundness.   In fact, when this mare was put back in regular work and began jumping she developed a hind limb lameness that was attributed to a suspensory injury, which very possibly had been the reason she became a brood mare in the first place.

The moral of the story is this:  when purchasing a horse, always look for an animal that is in work, and performing at least close to the level at which you intend to use it.  It is then much more likely that your veterinarian will be able to accurately identify issues of concern and discuss them with you.  Make every effort to obtain a history of the horse's past performance and ask the seller why the horse is for sale.

A prepurchase examination is a very important part of making a wise investment.  Often I identify problems during a prepurchase exam about which the seller was unaware - that is why we subject the horse to unusually rigorous conditions during the examination such as trotting small circles on very hard and very soft surfaces.  But at the end of the day, the ethical horse seller with a complete history on their horse can be equally as valuable as your veterinarian's assessment.  Tomorrow I will discuss in detail what you should expect from your veterinarian during a prepurchase examination.

The wind is howling - Mother Nature has been very restless throughout March and appears to be continuing her mood right into April.  Keep your head down and your spirits high.

4/1/2010 Protecting our Ecology

Vet tip of the Day: Homeostasis- Support the Water Wars

Today's vet tip isn't strictly about veterinary medicine, but it is about the most important concept behind practicing good medicine: Homeostasis.

Whenever I am treating a very sick horse, foremost in my mind is the concept of homeostasis, which is the natural balance of all the elements in the body which when present, produces a healthy organism.

This morning I received a call from a client who has been deeply involved in a fight in the area where I live to stop the exportation of dangerous amounts of water out of our delicate watershed by a land development consortium.  She asked me to post the following message on the blog on behalf of the Northern Nevada Citizens for Water Conservation.  For many of us, riding our horses in the exquisite high desert environment of Northern Nevada nourishes our souls in a manner that defies expression.  The exportation of water proposed by these developers threatens the homeostasis of this delicate ecological system.  Please read Helen's message and do anything you can to support NNCWC in their fight for our precious native ecology.

You are all probably aware that RRR LLC have filed an appeal to the

Nevada Supreme Court with regards to the Washoe County Commission's
decision not to allow them to export water from our valley.
RRR LLC has been denied this on three different occasions; at the
Community Advisory Board, Washoe County Commission, and most recently
in their request for a Judicial Review.
Northern Nevada Citizens for Water Conservation has organized and funded this
fight. We hired an attorney when the Judicial Review was requested, by
doing so we were allowed to have our testimony and concerns heard.
Legal fees have pretty much exhausted our funds. How far we have gotten
in our cause, on fundraisers and donations is remarkable.


NNCWC is working for everyone's water. We need money for round number
four, it's that simple. Please put your donation in perspective with
what you are at stake to lose; if your well levels drop and you are
forced to drill deeper, (hoping to find the diminishing water table);
how that will affect your property value or even your ability to
exist here...


One more thing, be aware that the State Water Engineer has been
severely chastised by the courts for allowing excessive water
exportation permits to the potential devastation of environments and
small rural communities. The message being that their interests are not
necessarily yours, nor are they looking out for you. Please help. Send
contributions to: NNCWC 448 Hill St Reno, Nv 89501.

To learn more about water issues in the West, log on to http://www.greatbasinwater.net/

Thank you,
Helen Mooney

3/31/2010 - Vaccination Reactions II

Vet tip of the Day: "Allergic" reactions to vaccination
Key Words: Urticaria, hives, hypersensitivity, anaphylaxis

Most importantly, remember that severe vaccination reactions are rare.  That's why it was difficult to find a decent picture - sorry for the quality of this one.  True hypersensitivity or anaphylactic reactions to vaccines, while rare, do occur and require immediate attention.  The physiology behind these reactions is very complex and poorly understood in horses. 

Anaphylaxis refers to a shock reaction by the body to some foreign substance.  In the case of vaccines, anaphylaxis can occur the first time a vaccine is administered.  An anaphylactic response can vary from mild hives that appear hours after a vaccine is given, to acute life-threatening cardiovascular collapse which can occur within minutes of vaccination.  Epinephrine is the preferrred initial treatment for severe anaphylasis.  It works by counteracting the immediately life-threatening components of the body's severe inflammatory response.  It is usually administered by intramuscular injection.  In the most severe cases, it may be given intravenously.  Administration may be repeated every 15-20  minutes if necessary.

Hypersensitivity and immune-mediated reactions to vaccines also occur and may have similar clinical signs to anaphylaxis.  When these reactions occur, they usually are less dramatic than acute, severe anaphylaxis.  Signs may include swelling of the muzzle, face and throat region, which can lead to respiratory distress, or may manifest as hives, or urticaria.  Depending on the severity and progression of the clinical signs, treatment may include steroidal or non-steroidal (phenylbutazone, flunixin/banamine) anti-inflammtory agents, and/or anti-histamines.

When a horse experiences an adverse reaction to vaccination, the question always arises, should the horse be vaccinated again?  If the reaction is a very sore neck, sometimes changing vaccine brands, and thus the adjuvant used, will help.  If the horse has a true anaphylactic or severe hypersensitivity response to vaccination, the problem is more complex and the decision to repeat vaccination should be made based on the severity of the reaction and consideration of the true risk of the disease against which vaccination is directed.

Finally, for those of you who adminster your own vaccines, be aware that storage conditions are extremely important for vaccines.  Vaccines that are not stored at proper temperatures are significantly more likely to cause adverse reactions than those kept cool at all times. Also, correct administration of intramuscular shots, both with respect to location of the injection and injection technique, play important roles in the safety of injections.  If you choose to vaccinate your own horses, be sure to obtain instruction from a licensed veterinarian or licensed veterinary technician concerning the correct administration of intramuscular injections.  And be sure that your vaccines have been properly stored before you purchase them, check the expiration date, and keep them carefully stored until they are administered.  Better yet, take advantage of the chance to visit with your vet and have a spring wellness check up and make an appointment with your veterinarian to give your spring vaccinations!

It's cold and snowy on March 31 in Northern Nevada.  What's it like where you are?  Looking forward to spring and good riding weather.