Sunday, July 5, 2015

Sunday Stills



River, Rubrico and Oskar


Tony and Thomas


Ritchie





Foggy morning pictures; Renny


Mick


Taco


Mick and Renny


Taco, Renny and Mick having a 3-horse grooming session


herding mares and ponies in for breakfast; Traveller, Silky, Cuffie, Lily, Calimba, Cinnamon, Norman and Dolly


Norman and Silky


2.5 inches (6.3cm) in the rain gauge this morning, and Jason had dumped an additional inch (2.5cm) out yesterday. I'm happy for all the rain but it would be great if the rainfall could spread itself out over more days. It would be a lot more useful that way.


this section of our creek is normally dry this time of year but 3.5 inches of rain (almost 9cm) has it flowing nicely for a few days



Maisie and Traveller


Cuffie and Norman



Merlin and Duesy


Thursday, July 2, 2015

Cushings/PPID Primer, Part II

Welcome to Part II of the Cushings/PPID primer. If you have not already read the first post on this subject it would be very helpful to read it first before continuing with this post. You can find Part I of the Cushings/PPID primer here, and in that post I explained what Cushings/PPID is. I also want to emphasize again that I am grossly oversimplifying my explanations in order to make the big picture easier to understand. This series of posts will not be submitted to a veterinary journal.

Now that we know what PPID is how do we recognize the signs? As I mentioned in the first post there is a lengthy list of signs that can point to PPID. Many of them are easily attributable to other causes so it is easy to to miss the early signs of PPID. I also find that when these signs are seen in younger horses people often do not want to test because in the past PPID/Cushings has always been thought of as an "old horse" disease. This assumption is patently false. It has now been clinically proven that PPID can occur in horses as young as five years old. 

This meme makes me giggle. As soon as I tell someone I think their horse should be tested for PPID (or any other disease) the emails with all the internet theories often start.  I understand why, I've presented my small animal vet with a lot of internet theories. The problem with internet theories in regards to PPID is that a lot of old theories about PPID in horses have been shown to be false (hence the name change in horses from Cushings to PPID). Thus, much of the information someone is reading on the internet is not current, even articles from vet journals that are only a few years old. The irony that I am posting this picture on the internet with some information about PPID is not lost on me.


One reason that PPID was thought of as a disease only for older horses was the lack of a test sensitive enough to give a positive result if PPID was still in the early stages in a horse. It wasn't that many of the younger horses that tested negative for PPID didn't actually have the disease, it was simply that there was no test sensitive enough to diagnose them, and many would maintain there still isn't a test sensitive enough. As one of our vets once said, the tests we have for PPID don't give us a positive result until the disease has essentially reached Stage 4 cancer in many horses.

For us, the most common sign that tips us off that a horse should be tested for PPID is abnormalities with the haircoat. The hair doesn't shed properly, the horse sheds very late, the hair is very long and dry, or maybe all of the above. The second most common symptom we see is excessive water consumption. We've had more than one horse whose only sign of PPID was their constant trips to the water trough. Their coats looked good, they had shiny hair, they shed normally, but they drank an excessive amount of water. Other symptoms we've seen have included muscle loss, abnormal fat deposits, excessive sweating and/or abnormal sweat patterns, lethargic attitude and symptoms one might associate with a suppressed immune system such as chronic skin issues or runny eyes. Laminitis is also a common symptom of PPID although it isn't one we've dealt with.

Maybe you have noticed that your horse is exhibiting one or more of these symptoms. What should you do? Call your horse and get them tested for PPID by your veterinarian. But before you do that have an understanding of the tests that a vet might choose to use. There are some tests even older than the ones I discuss below, but for the most part any vet is going to mention one of the following three tests.

1. The DST or Dexamethasone Suppression Test - In the dex suppression test blood is drawn to measure blood cortisol levels. The horse is then injected with dexamethasone and blood is drawn again 19 hours later to measure cortisol levels. A normal horse should respond with a very low blood cortisol concentration after injection of dexamethasone. This is due to negative feedback whereby high circulating levels of steroids (from the dexamethasone) signal the body to suppress the release of cortisol. Horses with PPID lack this normal response and will continue to have normal to elevated cortisol concentrations (failure to suppress).

There are a lot of weaknesses to the DST. Number one is the test cannot be accurately performed during the fall because cortisol levels in the horse are naturally higher at that time. Also the test is not sensitive and will give false negative results in early onset cases. If this is the only test your vet is using to diagnose PPID at this time then they are not current on diagnosing PPID.

Negatives aside this test was used for a long time because it was the test we had. Then the baseline ACTH test came along. However it could only be done during certain times of the year at first. Thus, depending on the season horses were tested using the DST or a baseline ACTH test. We no longer use the dex suppression test test at our farm.

2.  Baseline ACTH Test or Plasma ACTH Concentration - These two terms are often used interchangeably to describe the same test. For a baseline ACTH reading your vet will draw blood in EDTA (purple top) tubes. The blood is chilled then the plasma is separated from the blood cells and sent for testing. 

In horses positive for PPID the plasma concentration of ACTH is considerably higher than in non-affected horses. For a few years there wasn't enough reference data to perform the ACTH test year round. Thankfully that eventually changed and the test can now be done at any time of the year. In our experiences we saw fewer false negatives with this test as compared to the Dex Suppression Test. However we still had horses with negative results to this test that showed clear clinical signs of PPID. 

3.  TRH Stimulation Test (our test of choice) - TRH stands for thyrotropin-releasing hormone.  To perform the TRH stim test your vet will first draw blood to measure baseline ACTH levels as described above. Your vet will then administer TRH via IV injection, wait ten minutes, and then collect another blood sample that will be used to measure the post-TRH level of ACTH. Thus you get two ACTH levels with this test, a baseline reading and a post-TRH reading.

In our experience the TRH stim test appears to be the most sensitive test for PPID available at this time. Horses at our farm that have presented with a negative result after a baseline ACTH test have tested positive using the TRH stim test. Thus, this test is our test of choice at this time. The big drawback is that, just like it used to with the baseline ACTH test, there is currently only enough reference data to perform this test in the months of December through June. Outside of those months we have to settle for the baseline ACTH test, and if we get a negative result will retest using the TRH stim test during the December - June period.

Researchers in the field of PPID freely admit that there is still not a test sensitive enough at this time to pick up many of the early stage cases of PPID. Thus, if your seven year old horse has clinical signs and a negative test, he probably has PPID. This theory has been proven true through necropsies of young horses with clinical signs but negative tests. 

What happens if your horse does test positive for PPID? I'll cover that in my next post on the topic.

_______________________________


Apollo and Hemi


Asterik and Gus


Homer and Levendi


Mick and Lighty


Moe


Rubrico


Grand, Elfin and Rip


Hesse, Remmy, Duesy and Merlin

Tuesday, June 30, 2015

Cushings/PPID Primer, Part I

Cushings Disease is something that we have a lot of experience with. In fact we have so much experience in identifying, treating and managing Cushings horses we have spent the last few months participating in a clinical study with one of our veterinarians and the manufacturer of the drug Prascend. Many people get confused when they hear the name Prascend, however the actual drug in Prascend is pergolide mesylate, which has been the drug of choice for treating Cushings in horses for many years.

Since we test, treat and live with so many horses with Cushings (more appropriately known as PPID now) we spend a lot of time discussing this with our vets and our clients. I decided it was time to write a series of blog posts that contained the answers to the questions we get asked over and over. Keep in mind in these posts that I will be attempting to explain things in layman's terms, thus I am grossly oversimplifying many of these explanations to allow for ease in understanding of the big picture. In today's post, Part I, am going to attempt to explain what this disease is.

Cushings is one of the most common metabolic disorders, or disorder of the endocrine system, in horses. Cushings disease is now officially called PPID (Pituitary Pars Intermedia Dysfunction) in horses, although most people generally still refer to it as Cushings. In horses Cushings is now referred to as PPID since it was discovered that the mechanism of the disease is different of that in people in dogs. 

PPID causes the pituitary gland to overproduce hormones. The pituitary gland, which is sometimes referred to as the master gland, is located at the base of the brain and is made up of three lobes in a horse: pars distalis, pars intermedia, and pars tuberalis. PPID  specifically affects the pars intermedia lobe of the pituitary gland, hence the name Pituitary Pars Intermedia Dysfunction.

Under normal circumstances the pars intermedia acts to regulate and suppress the secretion of certain hormones. One of the hormones that is kept regulated via a suppression mechanism is ACTH. PPID is initiated when hypothalamic dopamine producing neurons fail. When this failure occurs the suppression mechanism of the pars intermedia fails. 

The failure of the suppression mechanism leads to an increased hormone production in the pars intermedia. The result of this increased hormone production means the hormone levels within the pars intermedia, including ACTH, can be up to 100 times higher than that in a horse that does not have PPID. The cells in the pars intermedia divide and enlarge without regulation, causing the pars intermedia to increase greatly in size.  At the same time that the pars intermedia lobe of the pituitary gland is expanding, it forces the other two lobes of the gland to become compressed.  

Thus a PPID horse has a greatly enlarged pars intermedia lobe that is busy over producing hormones. This overproduction leads to a variety of symptoms in horses, and rarely do two PPID horses present with exactly the same symptoms. The most common initial symptom we see are issues with the haircoat. The hair is overly long and/or very dry, or the hair doesn't shed properly or shedding is delayed, or some combination of these. The second most common symptom we see is an over-consumption of water. The third most common symptom we see are a poorly functioning immune symptom, or better put as an increased susceptibility to infection. The horses might be prone to skin infections, have chronically puffy and/or runny eyes, and other such symptoms that are easy to write off and attribute to weather and other factors. There are a lot of other symptoms we've seen as well including irregular fat deposits, a lethargic attitude, muscle wasting, etc. 

We've seen these symptoms presented very subtly and sometimes in very obvious ways. Sometimes the horse might have only one subtle symptom, other horses start presenting more than one symptom, and some pretty much scream at you "I have PPID, begin treatment now." We've had horses in their early teens test positive as well as older horses. One extremely common misconception is that PPID/Cushings is an "old horse" disease. This has been soundly disproven clinically. As a horse ages the odds of having PPID continue to increase, but PPID has now been clinically verified in many horses as young as five.

In my next post on the topic I'll discuss testing and treatment. I want to state again that in an effort to make my explanations easy to understand I am grossly oversimplifying many things. My point isn't to turn all of us into clinical experts on all aspects of PPID, but simply to help us all understand what it is, how to test for it, treat it and manage horses with it. I hope the information will be helpful to at least a few people!

_________________________________


Lofty and Faune having a particularly relaxing day with George, Gibson and Flyer


a closer look at Lofty and Faune (and George)


Dutch, Blu and Murphy . . . 


. . . didn't bother to lift their heads as the turkeys strolled past them


Kennedy and Oskar


Duesy and Remmy (Bruno in the background)


Gibson


Walden, Hesse and O'Reilly


pony power; Norman, Traveller and Cuff Links


Donovan, Oskar and Johnny


Rocky, Largo and Clayton

Sunday, June 28, 2015

Sunday Stills


Blu and Nemo


Johnny and Sebastian


Bruno, Lucky and Lightning


Griselle and Sparky


Calimba and MyLight hanging out



Tony and Baby


Flyer and Faune


Cocomo and George having a foggy morning grooming session


Thomas doing his routine pre-meal stretch with Homer watching


Romeo and Lotus


Thursday, June 25, 2015

At Least The Grass Is Free

We all hear certain things that, for whatever reason, really push our buttons. A comment I hear from time to time is something along the lines of "your expenses must be so low most of the year because the grass is free."  When someone makes a comment this stupid (sorry to be harsh but it is true) I generally don't respond. Sometimes I'll make a half-hearted attempt at correcting their overwhelmingly wrong interpretation of what it takes to run our farm, but usually I don't bother and just try to change the subject.  As I was watching Jason mowing in one of the pastures yesterday it made me think about how "free" the grass is.

In case you haven't picked up on where this is headed grass is not free. In fact grass is expensive in both money and time. First of all you have to pay for the land. Even when purchasing cheap land at $3,000-$5,000 an acre that means we have $6,000 - $10,000 per horse tied up in land costs as we allow two acres per horse. After we've purchased our free grass, I mean land, then you have to fence it. Four board wood fencing in our area costs between $6-$7 per foot, with gates costing double the amount per foot. The variation in cost depends on if each post is set in concrete or if the posts are just pounded in and some other factors. So to fence off one pasture you are looking at another $10,000 minimum, and that is for a pretty small pasture. 

Jason using some of our free equipment to maintain our free grass


Then your free grass needs some run-in shelters at about $7,000 per shelter.It would be so nice if the fence maintained itself and the horses didn't scratch their butts on it, crib on it, and do other horsey things that break boards. So after you've paid for the fence you get to keep paying for it as you replace boards. And those replacement fence boards (free of course) are all cut with a $600 chain saw. Why do you need an expensive chain saw? So it will run when you need it to. Anyone who has used chain saws on a regular basis will know what I mean by that. 

Then we have this free grass that has to be maintained. We have two tractors and three bush hogs. Our critics could rightly point out that three bush hogs is overkill and they wouldn't be wrong. However we actually do need two of them.  The 15 foot wide bat wing mower is essential, and one of the two smaller bush hogs is necessary as well to get to the few places that are a bit too tight or awkward for the big bush hog. We have an 8 foot as well as a 4 foot bush hog for the tighter areas. We really only need one of the two smaller ones, and I'm not sure which Jason would pick if he were choosing between the two. The bigger tractor was about $50,000 when purchased, and the big bushhog was about $20,000. Between one tractor and one mower that is $70,000 in equipment for maintaining the free grass.  We also have a 500 gallon sprayer used for weed control and chain harrows used for dragging the pastures. 

And just like any other piece of equipment this stuff all has to be maintained, belts and chains have to be replaced, tires have to be replaced, fluids need to be changed, they run on that free diesel fuel, etc. Then you need a place to park this free equipment. The best part is that the free equipment runs itself. There is no manpower at all involved in servicing and maintaining it, much less hooking it up and mowing over 150 acres. I'm sure Jason is having a good laugh over that right now. 

The next expense in your free grass is keeping it looking nice and keeping it at optimum nutritional levels. This means we take multiple soil samples from all over the farm and have it analyzed on a regular basis. From these results we determine when to lime and when to fertilize. We fertilize at least once a year, sometimes twice. Lime is not applied yearly but every few years depending on soil tests. Each round of lime and fertilizer costs a few thousand dollars. It isn't necessary to do either of these and grass will still grow, but if you want the grass to have optimum nutritional value then you need to help out. We also re-seed various areas depending on need each year. Grass seed if of course free at as well, if you drive up to the co-op and ask for 100 bags of grass seed they load it in your truck and never expect you to actually pay for it.

Allowing horses to continuously graze pastures is incredibly hard on grass. Horses are pasture destroyers by nature. They do not graze evenly and are terrible spot grazers because they can thanks to their two rows of teeth. They like to return to the same place and over and wreck them, using their top and bottom teeth (many other grazing species don't have two rows of teeth) to eat the grass down to the ground. We do our best to mitigate their damage by re-seeding, liming, fertilizing, mowing and controlling weeds. Not to mention when it is really wet and they decide to gallop through the pastures, seriously damaging the free grass with every step. Throwing in the sliding stop, especially when wet, is just the icing on the cake for pasture damage.  

The hardest part to take with all of this free grass is when the weather thwarts all of your efforts anyway. We had a record breaking drought seven years ago that did serious damage to our pastures. It took about three years of intensive inputs and management to recover from that record breaking drought. I would be absolutely fine if we never experienced a drought like that again. As a general rule I find participating in record-setting weather events to be unpleasant experiences. I will never forget the defeated feeling I had while looking at our brown and yellow pastures that we had put so much time and money into.

Grass can be done much more inexpensively. It does not have to be mowed, fertilized, limed, have weed control,  be re-seeded, or anything else. You can put up cheap barb wire to fence in your grass. However, if you want to have pastures that look decent, and ours look at least decent most of the time, and have horses living on them year round, grass is expensive in money and time. 

To summarize it would be a lot cheaper to have much smaller pastures and allow the horses to over-graze them and feed hay year round. MUCH cheaper. So the next time any of you are talking to any farm owner, please skip the comment about how the grass is free. 

_______________________________


Stormy and Rocky


Clayton, Walon and Johnny


Maisie and Lily


Renny, Dutch and Murphy wandering in for breakfast


B-Rad, Alex and Mick


Rip, Grand (sticking his tongue out), Elfin, Ritchie and Tony (Apollo is hiding behind Ritchie and Tony)


Romeo, Lotus and Donneur


Trigger having a stressful morning



Leo and Chance


Homer, Tony and Baby dozing in the shade