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!!

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!

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!!