Spring News and Notes 2012

 High Desert Veterinary Service

Spring 2012 News & Notes     

Chrysann Collatos VMD, PhD, DipACVIM           HighDesertEquine.com

775-969-3495 (Office)                        775-742-2823 (Cell)       hidvet@gmail.com

* Vaccination Clinic Schedule

* New information on Pergolide

* Learning from the Brumbees

* What’s new with Us

I am excited  to share new knowledge and continuing relationships with you all in 2012.  Spring clinics always provide a rewarding opportunity for me to catch up with you and your animals.

I look forward to seeing you in March!

Spring Vaccination Clinic Schedule

As always I’m there to answer your questions, and offer routine health care services on clinic days. Routine spring health care includes vaccination against E&W Encephalitis, West Nile, Rabies, 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  Mar 3 

Rancho Haven/Sierra Ranchos2             Fri  Mar 9

Red Rock North/Silver Knolls 1              Sun Mar 4

RR North/Cold Springs/Silver Knolls 2    Fri Mar 16

SpanSprings/Palomino Valley 1             Mon Mar 5

SpanSprings/Palomino Valley 2             Sat Mar 10

Antelope Valley                                     Sun Mar 11

Golden/Lemmon Valley                         Sun Mar 11   

South & West Reno                        Tues Mar 13 

Golden/Lemon Val/South Reno               Fri Mar 23

Sierra Valley/California                            Sat Mar 17

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/Spring Exam          $18.00

West Nile (Prevenile)                $32.00

FluRhino                                    $27.00

Tetanus/ Encephalitis               $15.00

Rabies                                        $22.00

Intranasal Strangles                  $30.00

Ivermectin Deworm                   $14.00

Coggins Test                             $25.00

Sheath Clean w/sedation         $35.00

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

 New Information on Pergolide

Many of you are familiar with Equine Cushings Disease (PPID) and already are treating your affected horses with Pergolide.  Equine Cushings Disease is a disorder of the pituitary gland that affects the endocrine (hormonal) system.  It is slowly progressive, and puts affected horses at risk for laminitis (founder) and recurrent infections.  As the disease progresses, affected horses typically have long, shaggy hair coats (hirsutism) that do not shed out in the summer time,  drink and urinate excessively (PU/PD), and exhibit loss of muscles tone along their neck and back. Unfortunately, these clinical signs vary from horse to horse, making early diagnosis of the problem challenging.  The best way to test for Equine Cushings Disease is by measuring Adrenocorticotropin Hormone (ACTH) in your horse’s blood.

Pergolide, which stimulates production of dopamine in the brain, has long been an effective management tool to treat PPID.  There has been no FDA approved product for years, and so compounding pharmacies, which purchase and prepare non-approved chemical formulations of drugs, have been the only source of pergolide.  The price and quality of these preparations vary significantly.  Unfortunately in an effort to economize, many horses are receiving less expensive pergolide formulations that may not contain accurate or stable amounts of pergolide.

An FDA approved pergolide formulation, Prascend, is now available.  The cost is higher than some compounded formulations, but the concentration and stability of the drug is guaranteed.  If you have a horse on pergolide, or suspect that your horse may have Equine Cushings Syndrome, please contact me so that we can discuss the best diagnostic and treatment plan for your horse.  Go to our HighDesertEquine facebook page to find a link to more information on Prascend.

What’s new with us

All three of my assistants have had exciting years.  Hayley Rasmusen is waiting to hear any day now if she has been accepted to start vet school in the fall.  She had an interview at Washington State University last week and currently is on the waiting list at Oregon State University.  Join us in our hopes for a thumbs up from one of these institutions.

Jessie Racicot was accepted into and is finishing her first year in the Truckee Meadows Community College Certified Veterinary Technician program.  She is loving the veterinary related academics, but misses being able to spend as much time on the road with Dr. C

And when she isn’t winning barrel races Gina Valceschini continues in her undergraduate classes at TMCC.

 I am very excited to see these three talented individuals develop their career paths, and look forward to mentoring future HighDesertEquine assistants in the years to come. 

A New Perspective on the Mustang Hoof

Mustangs are widely used as a model for “natural” foot trimming.  This is based on the premise that their lifestyle promotes hoof health as a result of distance travelled on unimproved footing, a natural diet, and the absence of human intervention on hoof conformation.  I attended the 2011 International Equine Conference on Laminitis and Diseases of the Foot where Brian Hampson, working with Dr. Chris Pollitt of the Australian Equine Laminitis Research Unit, presented his studies on the feet of 100 Brumbies, the wild horses of Australia.

            Five groups of horses were studied, each living in a different environmental region of the Australian outback. The feet of 20 horses in each group were analyzed for conformation and pathologic changes.  Conditions ranged from rock hard arid strata to wet grasslands.  Brian’s hypothesis was that no single feral-horse foot model exists, and that it is incorrect to assume that because a horse survives in the wild that its feet are therefore healthy.

            It was discovered that each environment produced a different hoof conformation, and that 97/100 feet studied exhibited some pathologic abnormality.  Histologic evidence of chronic laminitis was observed in over half of the feet.  It was noted that “significant pathology was identified in the foot types most closely resembling the popular ‘mustang’ foot.”  In fact, characteristics such as thick hoof wall, thick hard sole and heavily worn distal wall promoting sole loading may actually be associated with pathology.         

Brian Hampson concluded that “there is currently no clear evidence to support the use of the extreme feral horse foot as a model for foot care.”  However, he went on to point out that when the varied characteristics of all 5 groups of horses were combined and analyzed, some consistent parameters were identified that may be important when considering the natural form of the equine foot.

            Research on the wild horse foot is ongoing.  See great videos and learn more about this work at www.wildhorseresearch.com.

Call 775-969-3495 to schedule your clinic appointment today!

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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.

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.

03/30/2004 - Vaccination Reactions

Vet tip of the Day: When Vaccinations go Wrong
Key Words: Vaccine, adjuvant, immune system, clostridium

Vaccination season is drawing to a close, but I thought I would return to this subject one more time to talk about vaccination reactions.  Of course I would like to tell you that I have never had a horse demonstrate an adverse response to vaccination, but that would be a big fat lie.  Fortunately, I can tell you that I have never had a horse suffer a serious vaccination reaction that didn't respond promptly to appropriate treatment. There are several types of adverse reactions to vaccination, and it is important that you understand how they differ, both in onset of signs, and seriousness of consequences.


By far the most common adverse reaction to vaccination is the simple sore neck.  I vaccinate hundreds (literally) of horses every spring, and this year to date I know of only two horses which developed significant signs of neck pain following vaccination.  Typically the day after vaccination the owner notices that these horses are unwilling to move their heads, show signs of pain if one of the vaccination sites is touched, and exhibit swelling at the vaccination site.  Occasionally the discomfort will be so severe that horses will not lower their heads to eat or drink, or will pull back if pressure is applied to a lead rope when they are haltered.  Years ago I had a client call to tell me that her horse was having a seizure when in fact the horse's neck was so painful that when the owner tried to lead her forward she reared over backwards in response to the pain.  The vast majority of inflammatory reactions after vaccination resolve within 48 - 72 hours with palliative therapy including warm compresses and phenylbutazone.

This "sore neck" reaction to vaccination is NOT an allergic response to the vaccine.  It is an exagerrated inflammatory response to the ingredient in the vaccine that stimulates the horse's immune system.  This ingredient is called an adjuvant, and is very important in causing vaccines to elicit a strong antibody response by your horse's immune system.  Without this response, the vaccine will not be effective in preventing the disease against which it is directed.  Drug companies spend a lot of time and money developing different adjuvants.  Their goal is to find an adjuvant that is a potent stimulator of the immune system but does not cause severe local soreness.  Over the years I have used many brands of vaccines, and have come to be a staunch supporter of Intervet vaccines.  I believe that their adjuvant causes very few advers reactions, and I have been impressed with the company's dedication to client education and with their committment to research and development of new products to protect horses' health, such as Prevenile, their DNA based West Nile vaccine.

When a horse develops a sore neck after vaccination, it is important to notice whether or not the horse is systemically ill.  Specifically, will the horse refuse food and water even when it is placed so that the horse can reach it without lowering its head? Is the horse's temperature over 102.5 degrees?  Is the swelling at the vaccination site severe and increasing over time?  When the swelling is palpated, is there a crackling feeling underneath the skin?  Does the horse appear markedly depressed?  If the answer to any of these questions is yes, then the horse should be examined by a veterinarian.  As stated earlier, the vast majority of inflammatory reactions after vaccination are not serious and resolve within 48 - 72 hours with palliative therapy including warm compresses and  phenylbutazone.  However, in rare cases, it is possible for a bacteria called Clostridium to grow deep in muscle tissue at a vaccination site. If this unlikely event does occur, it can be life-threatening.
Clostridial bacteria exist normally in the environment in a spore form which can only grow in the abscence of oxygen.  Even when a clean needle and syringe are used and the vaccination is administered correctly, it is possible for Clostridial spore sitting on the skin to be carried deep into the muscle tissue by the needle during vaccination.  When this happens it is a random, extremely unlucky event, and does not mean that the vaccine was administered improperly.  Clostridial infections can be life threatening and require prompt and aggressive treatment. The Clostridium bacteria grow rapidly in the abscence of oxygen and produce several toxins which invade the horse's blood stream and cause severe systemic illness which can be fatal. Therefore, it is always a good idea to contact your veterinarian if your horse has an adverse reaction to a vaccine and discuss your horse's specific clinical signs so that you and your vet can decide if your horse needs to be examined.  If you take your horse's temperature and do a physical examination (see blog on this!) and carefully observe your horse's behavior before you call your vet you will be best able to provide important information in making that decision.

In tomorrow's Vet tip of the Day I will discuss Allergic reactions to vaccination and the importance of careful storage and administration of  vaccines, for those of you who vaccinate your own horses.

Until then,

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

Sat. Feb 13, 2010: Vaccination Protocols

Vet tip of the Day: Selecting Appropriate Vaccines
Key Words: West Nile, Tetanus, Influenza, Rhinopeumonitis, Encephalitis, Rabies, Strep Equi

Diseases are like brush fires.  Some smolder for awhile and are easily extinguished, others flare up and have devastating effects.  Choosing vaccinations for your horse has a lot to do with the nature of each disease we are attempting to prevent.  Toward this goal, here are the answers to yesterday's questions.  

Note: The answers about likelihood of exposure are only pertinent to horses in Northern Nevada.  Consult your veterinarian for other geographic regions.

1.     How likely is it that this horse will be exposed to Disease A?

• West Nile:  Likely
• Tetanus: Unlikely
• Influenza: Very Likely
• Rhinopnuemonitis: Very Likely
• Encephalitis: Very Unlikely
• Rabies: Very Unlikely
• Strangles: Likely

2.     Is Disease A a deadly disease, such as Tetanus? (this assesses risk to this horse)

• West Nile: Yes, 40% mortality
• Tetanus: Yes, 80+& mortality
• Influenza: No
• Rhinopneumonitis: No, but high risk abortion in pregnant mares
• Encephalitis: Yes, 85+% mortality
• Rabies: Yes, uniformly fatal
• Stangles: No, 10% complication rate, with fatality uncommon

3.     Is Disease A highly contagious, such as Influenza? (this assesses risk to neighboring horses)

• West Nile: No, is not transmitted horse to horse. Disease is transmitted from infected bird, to mosquito, to horse
• Tetanus: No, is not transmitted horse to horse. Tetanus bacteria lives in soil and usually gains access to horse through deep puncture wound that creates an oxygen free environment where bacteria can proliferate.
• Influenza: Yes! Transmitted directly horse to horse by aerosole (cough) and direct contact.
• Rhinopneumonitis: Yes! As for influenza.
• Encephalitis: Moderately, disease is not transmitted directly horse to horse, but is carried from horse to horse by a "vector", which for this disease is the mosquito.
• Rabies: No, is not transmitted horse to horse
• Stangles: Yes! Primarily transmitted by direct contact horse to horse AND by contact with contaminated "fomites": halters, lead ropes, hands, feet, water buckets, etc.

4.     Is the vaccine used to protect against Disease A highly effective?

• West Nile: Yes, Intervet DNA vaccine extremely safe and effective with minimal side effects
• Tetanus: Yes, killed vaccine 95+% safe and effective
• Influenza: Vaccines against influenza currently available are moderately effective, with relatively short lasting immunity provided. 
• Rhinopneumonitis/Equine Herpes type I and IV: There are 2 main Equine herpes viruses that cause upper respiratory disease in horses. They are also responsible for abortion and a neurologic disease which can be fatal.  Currently available vaccines are very effective in preventing abortion, moderately effective in preventing upper respiratory disease, and of questionable efficacy against the neurologic form of herpes virus.  More discussion on this in a later vet tip post.
• Encephalitis: Yes, killed vaccine very safe and effective
• Rabies: Yes, killed vaccine very safe and effective
• Stangles: The intranasal vaccine against Strep equi bacteria is moderately effective, and of all the vaccines discussed here has the highest complication rate.  We will discuss Strangles in more depth in a later vet tip post.

5.     What is the cost vs. effectiveness vs. safety value of the vaccine for Disease A?

• West Nile: Excellent
• Tetanus: Excellent
• Influenza: Moderate
• Rhinopneumonitis: Moderate, except very good against Equine Herpes induced abortion
• Encephalitis: Very Good
• Rabies: Excellent
• Stangles: Fair

 With this information, consider the following:
Your horse's age: the young and the old are always more susceptible to disease
Your horse's lifestyle: travel, stress of competition, and exposure to other horses always increase the risk of disease


Now decide which vaccines you think are appropriate for your horse.


More on Monday.  Have a wonderful weekend.


Chrysann

Friday, Feb 12, 2010 - Vaccination

Vet Tip of the Day: Vaccination
Key Words/Phrases: Immunity, West Nile Virus, Influenza, Encephalitis, Veterinary Consultation

It is mid-February, almost time to begin gearing up for spring, which means administration of spring vaccinations.  For the next few vet tips, I would like to discuss some of the theory behind the practice of vaccination, in order to give you the tools to make informed decisions about appropriate vaccination strategies for your particular horses.  Rule #1: never be afraid to ask your veterinarian the basis for choosing your horse's vaccination program.  You deserve this attention.  However, I am as guilty as anyone else in this regard - the words "hectic" and "springtime" are virtually synonymous for equine practicioners.  We are usually scrambling to keep our heads above water during the months of March, April and May, from gelding colts, to getting mares in foal, to welcoming new babies into the world, to preparing performance horses for upcoming show seasons our days (and nights!) are already full, so we tend to be on the go when it comes time to administer routine vaccinations.

You may want to try this strategy: avoid trying to slow your veterinarian down to talk in the spring when they are most likely to be distracted.  Instead, talk to your veterinarian about routine health strategies such as vaccination during the quiet winter months.  Schedule a consultation appointment and let your vet know the topics you would like to discuss ahead of time.  This approach allows your veterinarian to sit down and focus on your questions in a relaxed fashion that will lead to a more thorough, rewarding information exchange.

To begin our discussion of vaccination strategies, let's determine how we decide whether a horse should receive a certain vaccine.  Consider vaccinating a horse against Disease A.  I ask myself the following questions:
1.     How likely is it that this horse will be exposed to Disease A?
2.     Is Disease A a deadly disease, such as Tetanus? (this assesses risk to this horse)
3.     Is Disease A highly contagious, such as Influenza? (this assesses risk to neighboring horses)
4.     Is the vaccine used to protect against Disease A highly effective?
5.     What is the cost vs. effectiveness vs. safety value of the vaccine for Disease A?

With these questions answered, I then can make an informed decision whether or not to recommend vaccinating this horse against Disease A.

The diseases against which we routinely vaccinate horses in the Western United States are listed below.  Test your own knowledge and try to answer the questions above for each of them - I will post the answers in tomorrow's Vet Tip of the Day.

West Nile Virus
Influenza, Rhinopneumonitis
Eastern & Western Encephalitis
Strep Equi (Strangles)
Rabies

Our new and improved website if coming on line.  It is like a fledgling chick pecking its way out of the egg - if you want to watch it emerge, then keep checking in over the next week or so.  If you'd rather just see the final product, wait a couple of weeks and then look.  Either way, you can now get to this blog through the website - it's an easier address to remember and the link to the blog is on the home page.  Just log on to HighDesertEquine.com


There is quite a bit of information on the website as well for your education. 


Finally, for my local clients, the spring vaccination clinic schedule will be posted by Monday, February 15th.

Enjoy,
Chrysann