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Do pigeons cause Pigeon Fever?

Aug 4, 2012 | Ailments, Pests

 

I was hanging out on the counter the other day when a client came in asking about Pigeon Fever.  My ears perked up at the thought of chasing pigeons but it turns out this conversation had nothing to do with birds.  Pigeon Fever is a syndrome cause by a very specific bacterium, Corynebacterium pseudotuberculosis, which leads to abscesses.  This bacteria hasn’t been a big problem for Floridians since it prefers dry weather but this year has been different!

Let’s start with a little bit of learnin’.  Pigeon Fever or Dryland Distemper or Lymphangitis is a relatively common problem in the hot, dry regions of our desert southwest.  For reasons the experts don’t really understand the organism has been marching its way across the country to wetter regions.   C. pseudotuberculosis is perfectly content to live in soil until drought conditions occur.  At that time it seems to begin looking beyond the ground for somewhere to live and reproduce.   The bacteria is readily spread by common insects like the stable fly and infects horses through any small wound.

The most common appearance of Pigeon Fever is a large swelling of the chest, so the horse looks like a pigeon, or underside of the belly.  Upon further examination the swellings turn out to be large abscesses.  Another, less frequent problem, is what’s known as ulcerative lymphangitis.  This is a big swollen, oozing infection of the leg.  Even rarer is an invasion of the internal organs such as the kidney and liver by the organism.

Once Dr. Lacher has decided that a C. pseudotuberculosis abscess is likely to be the problem she will start treatment by draining the abscess and flushing the area.  The tricky part is any pus that hits the ground can contaminate the entire area so all pus must be contained and disposed of properly.  Dr. Lacher said she tries to open them on concrete so bleach can be applied to the area.  Opened and regularly flushed abscesses generally heal rapidly with minimal scarring.  However, ulcerative lymphangitis can be very difficult to treat.  These horses are placed on aggressive antibiotic therapy with both injectable antibiotics and highly concentrated therapy into veins in the affected leg.  The leg is kept bandaged to help reduce swelling, absorb drainage, and keep antimicrobial ointments in place.  Unfortunately chronic scarring of the leg and repeated infections are often left over effects of this form of the disease.   Infection of the internal organs is treated with rest and aggressive antibiotics with a full recovery the usual outcome.

Prevention is aimed at controlling insects in the stable area and making sure any wounds are regularly addressed.  The very bottom of the abdomen is a common area for us to see insect bites leading to open skin and excellent entrance sites from many diseases.  SWAT fly ointment is the best way Dr. Lacher and her team has found to prevent this problem.  Several groups are working on a vaccine but so far they have had no luck.  The good thing in Florida is that Pigeon Fever time of year and scratches or dew poisoning time of year are not the same.

The biggest lesson I learned is, once again, if in doubt about what is going on with your horse:  Call Springhill Equine!  And in the meantime May your litter box be clean and your food bowl full!!

 

Exciting new eye med!

Jun 3, 2012 | Ailments

 

Hallo there! Another day in the world of Tony here (just waiting for the Monday to come so I have all my people paying attention to me again). This weekend, watching the vets prepare another edition of our monthly newsletter, The Naughty Pony, I was amazed at what Dr. King had to share about a new eye medication called Equitrx Corneal Repair drops (from Bayer). I mostly stole this week’s blog from the newsletter, because I think as many people as possible need to know why they need to call us quickly when their horse’s eye becomes painful.

The vets at Springhill Equine have experienced recent success in treating ‘fresh’ corneal ulcers, thanks to a new medication. Corneal ulcers – defects or scratches on the outermost surface of your horse’s eye, are a serious problem for you and your horse. The new medication is for ulcers recognized in the first 24 hours, so we encourage you more than ever to call us IMMEDIATELY if you notice your horse has a painful eye.

Dr. King first learned about the medication, called Equitrx Corneal Repair drops, when a Bayer representative presented at a University of Florida Equine Club meeting (UF SCAAEP). She has subsequently prescribed the medication to appropriate cases with great success. Corneal ulcers are a particularly frustrating and potentially expensive problem for horse owners in Florida. The cornea, the outermost clear surface of the eye, not only is part of the sphere that keeps the eye inflated, but is the window to the eye. It contains no blood vessels and no water, thanks to special water pumps inside corneal cells – and this is how this thin layer stays so clear. An ulcer is a disruption in this outer surface – from a bump, poke (hay and grass heads are common culprits), or who knows what. Sometimes the defect heals quickly over in the face of infection, and what is called a ‘stromal abscess’ results.

The cornea itself is made up of three layers – akin to a hamburger (meat between two buns). A corneal ulcer disrupts some portion of the top bun and the meat, but can erode down and or/through the bottom bun. A stromal abscess is in the meat with both buns intact. It can rupture into the eye, or out. The scariest part is that the bottom bun is only 2 CELLS thick! The corneal layers are extremely sensitive to pain – which is why if you try to poke a horse in the eye, he reflexively shuts it. This ‘corneal reflex’ is one of the last reflexes to leave a horse when it dies, and can be used by veterinary staff to measure depth or level of anesthesia.

If your horse suddenly has one painful eye (squinting, eyelid drooping, tearing), a corneal ulcer is suspected until proven otherwise. If we see your horse, we will look in the eye, and can often see the defect in the surface, and in later stages blood vessels and/or surrounding edema. Blood vessels and edema obscure the window, making it hard for your horse to see. We will stain your horse’s eye with florescein, a bright green dye, which binds to the meat of the cornea. The amount of stain will show us how big and where the ulcer is. It can also help differentiate a corneal ulcer from a stromal abscess.  Florescein does not bind to either bun, so in the worst cases, there is no stain in the middle of the ulcer (bottom bun), and a ring of green where the meat is exposed. These are medical emergencies and generally are treated surgically, which is usually close to and potentially significantly more than $5,000 by the time the ulcer has healed (usually weeks to months). Appropriate medical treatment for the average ulcer can easily reach $700-$1200 in 1-2 weeks of treatment, if hospitalization is elected (and strongly recommended) at Springhill Equine or a referral facility.

The first medication used to treat corneal ulcers is an antibiotic ointment applied directly to the affected eye. This allows the ulcer to heal free of infection, which will constantly and continuously work against and erode the healing cornea. Another significant potential for infection comes from fungi, which are unfortunately abundant in Florida! Fungal infection results in a ‘melting ulcer’ – where the cornea literally appears to be melting away (droplet-like) from the site. These are extremely difficult to deal with, aggressive antifungal treatment is necessary (eg, hourly, 24/7) to save the eye, otherwise surgical treatment may be required (removing the eye as the battle fails).

Atropine is also used as a topical eye ointment, to dilate the eye keeping it more comfortable. Banamine is used as well to keep the horse comfortable (it appears to work better than bute). A variety of other topical medications can be added into the regimine based on severity. However, without corneal healing, these treatments are for naught. This new product, which contains hyaluronic acid (a viscous fluid that we inject into joints), provides a scaffold over which the healing corneal cells can move. Dr. King has seen healing within 24 hours in 4 out of 5 horses she has prescribed it to (the 5th was particularly large/severe and required several weeks to heal). These cases all fit the appropriate criteria for the company recommends for treatment (eg, they were certain to have occurred in the last 12-24 hours).

I am convinced, as is the rest of Springhill Equine, that this new product holds a great deal of promise for horses attended within 24 hours of injury. We recommend, now more than ever, that you please call us IMMEDIATELY if you notice your horse has a painful eye, to save you and your horse a potentially long and painful process! Thanks for reading, and may your litter box be clean and your food bowl full!

 

Bot, oh Bot!

May 25, 2012 | Ailments, Pests

 

Ever wondered what those tiny yellow dots are at the end of the hairs on your horse’s chest, legs, and undersides? While many people have heard of ‘bots,’ they are often mismanaged and can seem to be a never ending problem, particularly in year-round warm of Florida.

The life-cycle of the bot-fly is centered on the horse – a bot is the larval stage of the adult bot-fly. They can be extremely irritating, and the irritation the horse experiences perpetuates the life-cycle.  The cycle begins when the bot-fly (which resembles a small yellow honeybee) lays the small yellow eggs on your horse’s coat.  When the horse licks, rubs, or bites the area of the coat where eggs are laid.  Irritation by the horse stimulates the larvae in the eggs. The threadlike juveniles move into the horse’s mouth, where they burrow into the gums. Here they remain, nestled between teeth, for about four weeks.  Then they move into the stomach, where they attach to the walls and grow to a fat red bean covered in rows of black spines. They mature and move through the remainder of the digestive tract, emerging with the feces when they are ready, and burrowing into the ground until adulthood is reached. One complete cycle takes approximately a year. Thanks to the Florida weather, what it typically a seasonal nuisance is a year-round infestation.

Bot-fliescan affect humans as well as animals, so diligence is important when caring for a horse with a bot problem.  There are three species:  the common bot (Gastrophilus intestinalis), the throat bot (Gastrophilus nasalis), and the nose bot (Gastrophilus haemorrhoidalis). They each tend to lay eggs in a particular area. The common bot lays eggs over the body, the throat bot’s eggs are generally under the neck and jaw, and the rare nose bot focuses on the lips. Ulcers (or larvae) can sometimes be found in and around the mouth, and teeth may be loose or have nearby pus pockets. Colic and gastric ulcers can be caused or exacerbated by bots, whether from direct damage or blockage from a mass of larvae. Inappetance, diarrhea, choke, weight loss, lethargy, and general unthriftiness can result from infection. Other complications include anemia, stomach rupture, and peritonitis (infection in the abdominal cavity).

Diagnosis is by simple fecal exam – they can collect a sample at your appointment, or you can drop a fresh ‘apple’ by the office for Danielle & Michelle to process. You can collect it with a zip-lock bag within 2-4 hours of passage, and store it in your fridge (up to 24 hours) until you can bring it to us. Sometimes larvae are discovered in the soil, or in your horse’s feces, mouth (eg, during a dental). Worms are easily identified in the stomach on gastroscopy (putting a 3 meter camera into the stomach), or rarely in the gastric reflux when tubing during a colic.

Treatment is simple enough, ivermectin usually does the trick – but wait until the average temperature is above 80 degrees F. Prevention is more difficult – good fly control measures and careful removal of eggs. Again, be aware – bot-fly larvae have been found in the skin, eyes, and stomachs of humans. Eggs should be removed from the skin with a bot knife, which is used to scrape the side of the skin to remove the eggs without injuring the skin. A grooming stone/block, pumice stone, and clippers also work well. As many eggs and hairs should be caught and disposed of as possible – preventing eggs on the ground from being ingested. Keep these simple tricks in mind, and you will find it is a problem worth managing!

As always, may your litter box be clean and your food bowl full!

 

The Flies Have It!

May 20, 2012 | Ailments, Feed, Pests

 

This week I thought I would blog a bit about that dreaded summertime pest:  the fly.  Teenie and I were having a movie night and I chose The Fly in preparation for this blog.  She smacked me, told me I had poor taste in movies, and stomped off to sit at the front desk.  Girls.  I just don’t understand them.  Oh well here goes, all I have learned about flies while hanging around the office.

To start with the most common species we see are the stable fly and the house fly.  The house flies are annoying, spread disease, and are generally a pain in the rear.  Stable flies are all that and they live off blood so they bite us and our horses.  Each of these critters enjoy having babies in a mixture of hay or straw, feces, soil, and grain.  Sound familiar?  During my inspections of the stalls at the office I have found this combination of things are quite common around horses.  The stable fly can go from egg to fly in as little as three weeks and the house fly can do the same in as fast as ten days in the summer!

I see many people spraying their horses with loads of sprays trying to keep the flies away but my keen cat sense has determined that this doesn’t work very well.  My research found that sprays work well to knock down adult flies but don’t have much residual effect to keep them away.  Some sprays contain scents that flies find mildly offensive but this approach is better for gnats and mosquitoes.  One insecticide option that can work with flies are products like QuickBayt.  This product is sprinkled on the floor or can be mixed with water and sprayed on vertical surfaces like walls or posts were flies hang out.  When flies come in to contact they are killed.  The product is very safe for children and animals.  Dr. Lacher has proven this at her house when her dog ate a few mouthfuls before realizing QuickBayt tastes horrible.  The manufacturer did this on purpose to minimize the risk of dogs and children thinking it tastes great.

So what does work?  The best way to minimize flies is to minimize their breeding grounds.  Keeping stalls meticulously clean and dry is the most important first step.  It is extremely helpful to remove any hay mats left over after round bales are finished.  Lift one of those mats up and you will find a fly baby making machine!  Composting, when done properly, kills the fly eggs before they can mature.  There are numerous web sites with excellent tips and tricks for composting (hmm future blog?).  One excellent link is http://www.puyallup.wsu.edu/soilmgmt/composts.htm  Spreading manure helps dry the manure quickly and, well, spread it out making less fly friendly.  Managing manure has to be the first step in fly control.  None of the other methods can overcome poor manure management.

Feed through controls.  There are two main brands out available:  Solitude and SimpliFly.  Solitude contains a compound called cyromazine.  Cyromazine is not active until it passes through the intestinal tract and is deposited in the manure.  From there it is eaten by the larval stages causing them to die.  Cyromazine is generally considered safe for all ages of creatures.  SimpliFly contains a compound called diflubenzeron.  This compound is a little trickier to pin down on safety but is generally considered safe for adult animals.  Diflubenzeron prevents the larva from making chitin so they can’t progress in their life stages to adulthood.  The big advantage to feed through control is it delivers the compounds around the farm.  Anywhere your horse “goes” your feed through goes.  They are also very easy to administer since both are in an alfalfa pellet base.

Isn’t there a way to manage flies without chemicals?  Why yes there is I say.  They are called fly predators.  These are tiny relatives of the big wasps we all see.  They selectively lay their eggs inside fly eggs and their kids eat the baby fly.  I love these critters!  They can’t quite keep up their end of the baby making equation so you must spread extras around every month to keep up.  Fly predators do a pretty darn good job as long as proper numbers are used.

I have to add one more management method:  let the cat chase them. I find this to be the most fun of the options even if it isn’t very effective.  If you find flies are driving you and your horses mad, call us for help finding an entomologist who can help you determine the best plan for your property.  And that’s a wrap for this week.  May your litter box always be clean and your food bowl full!

 

Vaccine Clinic Cliff notes and Dr. Lacher’s Itchy horse update!

Apr 30, 2012 | Ailments, Pests

 

I had a really great week this week.  Thursday evening we had a seminar on vaccines here at the office.  I LOVE seminars.  It gives me a chance to meet my adoring fans up close and personal.  I also enjoyed a bit of cheese from Villagio’s pizza and we all know Villagio’s is never a bad thing.  For those of you who missed out on the seminar I thought I would summarize what Dr. Mackenzie covered.  Next week I will return to my breeding for dummies series.

Dr. Mackenzie covered several topics regarding vaccinations.  She divided it up in to three main categories:  Evaluating the horse to be vaccinated, geographic specific differences, and biosecurity.

The most important category is the evaluation of the horse.  Dr. Mackenzie talked about evaluating the age of the horse.  Dr. Lacher and Dr. King are always talking about this very thing around the office.  They say that while age is not a disease it is very important when picking vaccines.  Young foals must begin with a series of vaccines to prime the immune system.  The timing of this series is very crucial.  It turns out all those good things foals get from mom’s milk can also interfere with our vaccines!  Knowing a history on the mom whenever possible makes our doctors’ job much easier.  Senior horses may need vaccines more often as well if they are experiencing signs of Cushings disease or are otherwise down on their health just a bit.  Dr. Mackenzie emphasized how important is to have Dr. King and Dr. Lacher give your horse a good check-up to determine they are in good health.

Next Dr. Mackenzie discussed the differences around the country and the world.  For instance, here in Florida we have to vaccinate for the mosquito born encephalitis much more frequently than our more northern friends.  One reason is the presence of mosquitoes all year! But we don’t have diseases like Botulism or Potomac Horse Fever.  Geography also involves your horse’s lifestyle.  A horse that doesn’t leave the property doesn’t necessarily need vaccination for Rhinopneumonitis and Influenza.   Once again Dr. Mackenzie emphasized a partnership with Dr. Lacher, Dr. King, and you to determine your horse’s health and what vaccines are required based on your lifestyle.

The last topic was biosecurity.  Here Dr. Mackenzie emphasized taking temperatures! A lot of taking temperatures!  She talked about taking daily temperatures to establish what is normal for your horse and then again after any trips or exposure to new horses.  We also talked about the importance of quarantines.  New horses should be kept separate for at least three weeks.  She also recommended nasal swabs to determine if they are shedding any viruses and fecals to check for parasites. Dr. Mackenzie sure sounded a lot like Drs. Lacher and King when she talked about making sure you have your own water buckets at group events, making sure the hose doesn’t touch the water in the bucket, and limiting nose to nose contact with strangers.

A few other points Dr. Mackenzie covered concerned the nature of vaccines.  She pointed out that vaccines contain two main components: antigen, or the disease we are vaccinating for, and adjuvant, the part that notifies the immune system.   Most of the vaccines we give our horses are killed vaccines.  This means the organism has been inactivated and then combined with an adjuvant.  These vaccines are very stable and cheap.  However, they don’t stimulate an immune response for very long so we have to give these vaccines at least every six months.   We do use one vaccine that is modified live and that is the Intranasal flu.  Modified live means the organism has been altered so that it grows in the horse a very small amount once given.  These vaccines don’t require an adjuvant and offer long lasting protection.

Overall I really enjoyed Dr. Mackenzie’s talk and learned a lot about how, why, and when we give vaccines.  And I once again, learned how important Dr. Lacher and Dr. King are to our horse’s healthcare!

Completely changing topics briefly.  I spoke with Dr. Lacher this week about her horse, Angie’s, response to immunotherapy (allergy shots).  Dr. Lacher tested Angie with our new intradermal skin testing and found she was allergic to all kinds of weeds and trees.  This explains why Angie was still very itchy despite all Dr. Lacher’s efforts to control her culicoides, or gnat, allergy.  Angie has been on allergy shots for about three weeks and is much more comfortable!  Dr. Lacher said Angie normally has her mane and tail itched out by now even with a full fly sheet, fly mask, and daily fly spray.  Now she looks great and no more daily fly spray.  Though Angie still wears a fly sheet and mask for turnout.  Dr. Lacher was very excited about the results!

Well that’s all I have for this week.  May your litter box be clean and your food bowl full!!

 

Heaves – What’s happening in your horse’s airways

Heaves – What’s happening in your horse’s airways

Apr 1, 2012 | Ailments, Feed

 

From my counter, I watch Florida horse owners grapple with a number of issues that are particularly difficult to manage in our climate – from gnats to fungal infections, and of course the non-sweaters. Among these, there is one disease in particular that gets Florida horses (and their owners) down – heaves. I hear so much about it, that this week I stole Dr. King’s Naughty Pony article that explains heaves, inside and out!

Heaves, formally known as Recurrent Airway Obstruction (RAO), is an allergic respiratory disease similar to asthma in humans. Like with asthma, the primary symptom is that of respiratory distress. The high load of plant and mold allergens, exacerbated by the intense heat, makes life especially tough for a ‘heavey’ horse living in Florida. Heaves was first recognized as being associated with horses that were stabled in dusty barns and fed hay. The organic dusts associated with bedding and hay – containing molds, allergens, endotoxins, and small particulates, initiate the inflammatory cycle in the airways. In Florida, plant allergens alone can get your horse heavey – symptoms are usually worse in the fall for this reason (although the summer heat doesn’t help either).

The first response is for the airways to constrict – termed bronchospasm, which is the primary response with human asthma. The airways also produce mucus to try to trap the allergens, and move them back out of the airway. However, in the narrowed airways of the lungs, these mucus plugs lodge, closing off the path to the downstream air sacs (alveoli). As the horse attempts to move air into the alveoli, where oxygen can pass into the blood, the mucus plugs dislodge and re-lodge. This action is the root of the name Recurrent Airway Obstruction, changed from the old name COPD (chronic obstructive pulmonary disease). Over time, the muscle layer and fibrous scar tissue around the airways thicken, making the lungs less elastic, and less likely to recover. This means that the longer heaves goes unmanaged, the harder it will be to manage down the road. A recent study found that horses with RAO have a more intense response to the histamine control during Intradermal Skin Allergy Testing (ISAT), indicating that histamine is an important component of the allergic response with heaves.

Heave Line

Horses with heaves develop a characteristic appearance. The respiratory rate is increased (normally 12-24 breaths per minute), and the nostrils are wide open and flaring with each breath. The horse’s expression often appears anxious or distressed. With chronicity, the horse uses the abdominal muscles to try to move air, and a double breathing effort is seen in the flank. Over time, the horse develops a “heave line” just under the edge of the ribs from this motion (black arrow). Wheezing, first only heard with a stethoscope, becomes audible just by standing near the horse. The horse is losing weight by this point, and may extend the head and neck in its attempt to move air. Early signs may only be seen with exercise, particularly in dusty arenas. These include coughing, reduced exercise tolerance, and a delayed recovery from exercise (eg, respiratory rate does not return to normal in 5-10 minutes).

Diagnosis is generally straightforward, characteristic wheezing on expiration is heard with a stethoscope. A rebreathing exam (performed with a trash bag over the horse’s nose) and/or exercise may be required to bring these sounds out to an audible level. Definitive diagnosis is performed with a BAL (bronchoalveolar lavage), where a small amount of fluid is put into then recovered from the deep airways. The cells from the fluid are examined for the presence of inflammatory cells. Intradermal Allergy Testing, now offered by Springhill Equine, is an important diagnostic step to management and therapy of heaves.

Management of heaves is multi-factorial and challenging (that means there is no miracle shot). Housing is an important consideration – on pasture is usually preferable to stabled, however, it is important to know the source of the horse’s allergic response. For example, a horse who is allergic to dusts and molds should be managed differently from a horse allergic to trees and weeds – and this is where Intradermal Allergy Testing comes in (see story above). Another benefit of allergy testing is immunotherapy – an individualized prescription program developed based on the findings of your horse’s intradermal test. These tiny shots teach your horse’s immune system to hold its’ horses when responding to these everyday particles.  Once we know what your horse is most allergic to, targeted avoidance also becomes easier. For example, you can walk your pasture knowing that it’s crucial to get up all the pigweed. Or, you can improve ventilation and soak your hay for 5-15 minutes prior to feeding to minimize molds and dusts. Other management techniques to reduce dusts include reduced sweeping (which stirs up dust), watering arenas, and removing roundbales. Rolled or processed grains should be replaced with soaked pellets. Alfalfa pellets and cubes, as well as whole grains, have lower amounts of dusts. However, consider your horse’s response to alfalfa during the allergy test – food allergies exist in horses too!

Finally, the mainstay of heaves management is steroid therapy. Whether using dexamethasone, prednisolone, or triamcinolone, our last desperate attempt to quiet the allergic response is to suppress the immune system with steroids. Side effects, which include worsening or inciting laminitis or infections, make steroid use less-than-ideal in many patients. However, they work much better than non-steroidal anti-inflammatories, like ‘bute’ (phenylbutazone) and ‘Banamine’ (Flunixin meglumine). We reach out to aerosolized steroids like Beclomethasone and Fluticasone in some cases – administered via a specialized horse mask. Attempts to manage heaves with other medications, such as antihistamines like hydroxyzine, have had variable success. Bronchodilators, like clenbuterol or albuterol, are generally only used as rescue medications for acute attacks, or prior to administering aerosol medications. However, the new evidence regarding the histamine response in ISAT indicates that antihistamine therapy may be worth reconsidering when managing the challenging heaves horse.

In summary, heaves (RAO) is a challenging and debilitating disorder to which horses in Florida are especially at risk. We hold renewed hope in managing it with the introduction of Intradermal Allergy Testing at Springhill Equine, allowing us to not only identify allergens to avoid, but also to provide an immunotherapy prescription for your horse.

Please contact Springhill Equine if you have any questions regarding management of heaves, or regarding allergy testing your horse!  As always, may your litter box be clean and your food bowl full!