Usually, this time of year I like to talk to you all about mares and foals and breeding your mare. Recently, however, we have had a few stallions come through the clinic and so I figured there is no time better than the present to talk about stallions and semen. I guess, I typically avoid the subject because, well, I lost my stallion status at a young age, and lets be honest, no one ever fully recovers from that. But alas, I must address the subject because, maybe you have a stallion and someone has approached you about breeding to him, or maybe you have your eye on a stallion that you would like to breed your mare to.  The desire to breed is the first step, however, stallion collection and semen evaluation and shipping involves many more steps.

Collecting

Live Cover

First lets talk about the semen collection process. More and more frequently stallion owners are shying away from live cover, unless you’re a breeder of thoroughbred race horses, but thats a topic for an entirely different blog. Live cover for any horse is a very risky process. No just for the stallion but for the mare as well. I’ve met my fair share of mares and let me tell you, they can have CATtitude. Those girls are sassy, they will kick and bite for not reason. I can only imagine if they have a horse trying to mount them how they would respond but from what I heard, they can be very quick to kick. If a mare kicks a stallion in the genitals, that could be career ending for that stallion. If an owner choses to allow their stallion to live cover, they may require that the mare be sedated or placed in hobbles or both. This is not just for the stallion’s safety but for the mare’s as well. Think about it, 1000-1200+ pounds of pure muscle trying to mount her and she moves, the next thing you know she has a hoof to the head, or teeth taking a chunk out of her side. The other downside to live cover, is there is rarely any way to evaluate the semen quality as an entire ejaculate is deposited directly into the mare’s vagina.  Live cover is risky business. There are benefits of live cover as well. For one, there is no question that the correct stallion and correct mare are being bred. There is also no need to use semen extenders to help keep the semen alive as they are already in their second favorite home, the mare’s reproductive tract.  Live cover also allows for the mare to be exposed to the stallion several times while she is in season as opposed to other methods in which there is often only 1 dose of semen available.

Phantom

A more common way to collect semen is to use a phantom. If you’ve been to my clinic you’ve probably seen our phantom. You may have even thought it was used from something such as bull riding practice. You would be wrong.  That is in fact our phantom that we use when my docs collect stallions for semen processing and breeding.  The first step of collecting a stallion using the phantom is to train them to mount the phantom. Luckily, instinct is on the docs side and most stallions want to mount something when exposed to a mare.  My docs use a tease mare to get the stallion ready to mount.  They keep the stallion on the opposite side of a wall to protect himself and the mare. Once the stallion is ready, they clean his penis with warm water. Once he is clean, he is teased to the mare again. Then he is introduced to the phantom.  He is encouraged to mount the phantom from the back and wrap both front legs around the phantom on either side.  Often times my docs will place some urine from a mare on the phantom to encourage the stallion to mount and stay on the phantom. 

Once the stallion has mounted the phantom my docs use what is referred to as an artificial vagina (AV) to collect the stallions semen. The AV is prepared with a  protective liner inside and filled with warm to hot water based on the stallions preference, and yes, apparently stallions have a preference.  Picky, picky boys.  While on the phantom, the stallion’s penis is placed into the AV and semen is collected through a filter into a dark container since semen does not like light.

As you can imagine, teaching a stallion to be collected artificially and learning their preferences is not always an easy task and often dangerous, however, once the stallion learns his job, the whole process becomes routine for the stallion and my docs.

Processing

Semen Evaluation

Now that my docs have collected semen from the stallion, it is time to evaluate and process the semen.  The first step in evaluating semen is to figure out the volume of semen collected. Once a volume is measured, a sample of semen is used to evaluate the concentration of sperm in the semen. A stallion may have produced a large amount of semen, but there may be a very low sperm concentration, or conversely, there may be a small amount of semen that has a very high concentration of sperm. Either way, my docs can determine the concentration, and from there they can use their fancy shmancy math and determine the appropriate dose of semen to use to breed a mare. During semen evaluation, my docs will also look at a sample under the microscope. While looking at the sample they evaluate how the sperm are moving, in what direction they are moving, and if there is a high ratio of dead to live sperm present. All of these factors play a role in what my docs determine is the correct dose of semen to breed a mare with.

Cooled Shipped vs Frozen

When semen is collected artificially it must be processed before breeding the mare. This is done to extend the lifespan of the semen and allow for transport of semen throughout the world.  There are two ways in which semen can be processed, it can be cooled and shipped immediately, or it can be frozen and stored for later use.  Once the semen has been thoroughly evaluated by my docs, they will then add in a semen extender which has nutrients for the semen to live off of for a couple of days prior to being inseminated into a mare.  The benefit of cooled semen is, a stallion owner can obtain several doses of semen to send to multiple mares from only one collection of the stallion. On the mare owners end of things, cooled shipped semen is very popular as they can get semen from almost anywhere in the world to use with their mare.  Compared to live cover, a concentrated dose of semen is inseminated directly into the uterus whereas, with live cover, semen is deposited into the vagina and has to find its way through the cervix and into the uterus.  Frozen semen is a completely different ball game and involves the use of liquid nitrogen, storage tanks and a lot more steps than this cat cares to know about.  However, frozen semen allows for stallions to be collected and their semen stored indefinitely even once the stallion has died. Once a mare owner has decided to use a dose of frozen semen, it is thawed, and inseminated in a similar manner as cooled semen.

Fertility rates are decreased with the use of semen extenders and in the cooling and freezing process. However, with appropriate mare and stallion management, conception rates can be as high as 33%, meaning that with one breeding cycle the mare may become pregnant. Given the technology and medications available for use by my docs, 33% change of a pregnancy in 1 go around, seems pretty darn good to me.  Although all of this collecting, processing and breeding stuff, is way to much for this cat, I think I am thankful that my stallion status was removed all those years ago, I can spend so much more time sleeping. 

But, if you have a stallion that you think you want to collect and may want my docs to spend a few days teaching him about the phantom, give my minions a call and they will get your stallion on the schedule for a date with the phantom. 

Until next week,

~Tony

 PS- If you’d like to know more about breeding check out our Podcast on breeding here. 

It’s the first half of the year, and around here that means it’s everyone’s favorite time of year: Fecal Egg Count Season! I know, my humans are weird. They celebrate strange things, and they are very, very passionate about their fecal egg counts. Let me tell you all about the strange rituals involved, and the deep meaning behind all of it. Get ready for me to drop some serious knowledge on you, and save you some money. Learning, and saving? Sounds like a great combination!

First, the Bad News

The bad news is the deworming drugs on the market now are all we’ve got. There are no new ones in the works, which means a minimum of 10 years before we could even see a new drug. Even more bad news: there’s resistance reported to every one of those drugs right now. This means you humans better be good users of the drugs you’ve got! Most of you aren’t old enough to remember what it was like before easy, safe dewormers were available, but I hear it involved some seriously scary colics, and some pretty toxic chemicals. None of you want to go back there, I promise, so read the rest of this week’s blog very carefully.

Let’s talk life cycle

We’re going to mostly talk about the two biggies: small strongyles, and ascarids. These are the ones fecal egg count season revolves around. I’m also going to touch on tapeworms, large strongyles, and onchocerca and haemophilus. I’m a very knowledgeable cat. 

Small strongyles begin life as an egg in the pasture. They enjoy cool, but not cold temperatures, reasonable to high humidity, and really don’t like temperatures over 85F. When the weather meets these requirements, they hatch and crawl to the top of some nice tasty grass in a drop of dew. Here, your horse eats them, giving them a free ride to the intestinal tract. Once in the large intestine, the baby worms crawl into the lining to grow up. Here they have choices. If they can’t handle the pressure of growing up to be an adult, they can hibernate in the mucosa for a while as an encysted larvae. If they’re ready to make grown-up choices and have kids, they can mature to adults and head to the intestinal lumen. Once there, the adults do what adults do and make eggs. These eggs exit in the manure so that the circle of life can continue on. The adults carry on until they die of old age at about 8-10 months. 

Ascarids are the big reason for the fecal egg count season, although they allow us to carry the joy on for the entire year! Yay!! Ascarids start their life as eggs in the pasture, as well. These guys are the Ironman of the parasite world, though. Nothing kills these eggs. They handle heat, cold, dry, wet. You name it, they’ll survive. They also take a much more scenic route to adulthood than the small strongyle. 

After being eaten, ascarid larvae migrate from the intestinal tract through the body to the lungs or liver. If they are lucky enough to make it to the lungs, they cause the horse to cough them up, where they are then swallowed back into the intestines. Now they are ready to grow up to be adults and have kids. And boy do they have kids. They aren’t as reliable as small strongyles at constant egg laying. This means a few fecal egg counts may be necessary to find them. Fun ascarid fact: they kinda look like short, fat spaghetti noodles. You won’t miss these guys when they die and come out in the poop! 

The important thing about the life cycle of ascarids and small strongyles is they’re really fast! They can happen multiple times during a year. For tapeworms and large strongyles, life moves at a more cat-nap-like pace. This will be important later! Onchocerca and heamophilus get their eggs laid by flies in open wounds so fecal egg count season doesn’t apply to them. They get their own season called Summer Sore Season. You can look that one up in the search bar above. Trust me, I’ve blogged on it several times. 

Just deworm all the horses

“Well Tony,” you say, “sounds like I should just throw wormer at everyone!” First, it’s dewormer. We are taking the worms out, not putting them in. Second, under no circumstances should this be your thought process! This is why I have to save you humans from yourselves all the time. Do you remember earlier when I said we only have the drugs we have, and the parasites have learned how to evade all of them? The way you guys keep those drugs lasting as long as possible is to only deworm the horses that need it. Guess how you know which horses need it? Fecal egg counts! Here’s the fecal egg count rules:

1. Everyone over the age of 12 months gets one between January and July.
2. Everyone under the age of 12 months gets one at about 6 months, and again around 9 months. 
3. If anyone has a high fecal egg count, they get dewormed with an appropriate product (stay tuned for more on that), and then recheck in 14 days to be sure there’s none of that dreaded resistance. 

Simple, right? Yep. Super simple. Side note from my humans: when bringing them a sample to test, they want ONE, and only ONE fecal ball taken from a fresh pile, and placed in a plastic baggie in a cool, dry place until it can be delivered to the clinic. As long as it is kept cool in your fridge (the butter spot in the door works great) you can take up to 7 days to get it to them. 

You may now deworm… Maybe

Now that you have results, you may deworm the horses that have more than 350 eggs per gram of poop. Now, most of the time in an adult, you’re going to use plain old ivermectin. It still works great most of the time, it hits all the bugs we want, and it’s pretty safe. The rest of the drugs out there just don’t work very well on small strongyles, so don’t waste your money or your time. 

Notice in the rules I said if you’re under 12 months, you get a fecal twice! That’s because ascarids are generally only found in horses under 18 months old, and usually under 12 months. Once the adult immune system kicks in, it gets to work kicking those ascarids out of town! That same adult immune system is why some horses don’t have high strongyle egg counts. Their immune system kills the little buggers before they can lay eggs. 

Back to ascarids. My docs do start deworming foals for ascarids around 4-5 months old. Drug choice depends on your farm, and your history, so I recommend a chat with them rather than winging it off what Dr. Google said. Dr. Google went to a really crappy vet school. Don’t trust it for anything! 

Why no egg count in the Fall?

Remember earlier when I said small strongyles live for about 8-10 months? We’re about to take advantage of that. One way to make worms more susceptible to dewormers is to hit them when they’re sick, or stressed, or…..old. We’re going to take advantage of the fact that most of them are old around late Fall, and push them into their little worm graves. Horses also need to be dewormed once yearly with an ivermectin to kill large strongyles, and praziquantel to kill tapeworms, so our Fall deworming plan does all the things we need a good deworming plan to do. 

Don’t want to remember any of this? Sign up for a Wellness Program, and my Docs will take care of it all. From fecals to deworming, done. Crossed off the list. No worrying. Seems like a no brainer to me! You can even sign up at 3 a.m. from the website. Seriously, what’s not to love about this thing? Did I mention no emergency fees? If you haven’t already, go to the menu bar, go to the Wellness page, sign up, be happy. 

Until next week,

~ Tony

P.S. If you want to advance to cat-level knowledge on deworming, you should listen to the podcast my docs did on the topic. It will give you all the information you need to convince your hard-headed friends to stop contributing to the drug resistance problem! Find it on our Podcast Page.