Aging Horses

The past several decades have seen an increase in the proportion of older horses. It is now estimated that horses greater than 16 years of age make up 16 percent of the horse population. 

The aging of the horse population can be credited to improved nutrition, preventative care, and health management.  Additionally, owners have adjusted their expectations of their older equine partners, thus allowing the horses to continue contributing their experience in the years after peak athletic performance is no longer possible.

Aging is a gradual, irreversible process that affects all body systems. It is estimated that at least 70 percent of horses greater than 16 years of age have a medical problem that requires veterinary attention to maintain health or comfort.  

Regular dental care, body condition evaluation, and physical examination are important components of ensuring a healthy, comfortable old-age for your horse.

Common problems seen in the older horse include:

• Declining immune function

• Declining vision

• Poor thermoregulation

• Musculoskeletal problems

                -Sagging of topline and pendulous abdomen

                -Osteoarthritis

                -Suspensory ligament degeneration

                -Laminitis

• Dental problems

                - Missing or broken teeth

                - Malocclusion

• Alterations in body condition

                -Weight loss due to declining feed efficiency, bad teeth, loss of appetite, or concurrent          disease

                - Weight gain due to decreased activity or Equine Metabolic Syndrome

• Altered internal organ function

                -Kidney disease

                -Liver disease

                - Cushing’s Disease (Pituitary Pars Intermedia Dysfunction)

                - Equine Metabolic Syndrome

Below are some additional resources on aging horses

http://extension.uga.edu/publications/detail.cfm?number=B1368 

http://edis.ifas.ufl.edu/an253 

http://esc.rutgers.edu/fact_sheet/care-for-the-older-horse-diet-and-health/ 

http://extension.psu.edu/animals/equine/news/2015/older-horse-care 

http://www.unce.unr.edu/publications/files/ag/2000/fs0009.pdf

Equine Pregnancy: Why Things Go Wrong

Many horse breeders know that it can be a challenge to get a mare pregnant and keep her pregnant. There are a number of factors that can lead to a loss of pregnancy, making it important for the breeder to take steps to prevent pregnancy loss and/or be prepared to handle such events.

Problems Preventing Pregnancy First, you have to get your mare pregnant. Below are some challenges you might face during that time.

Endometritis is an inflammation of the uterine lining. Mares that have this will very seldom show any clinical signs.  Because of this, it is important to check for endometritis in advance of breeding with enough time to get the problem cleared up. Doing an endometrial culture and cytology is a simple way of detecting this issue.

The timing of insemination with the mare’s ovulation is critical. The ovum, or egg, loses viability six hours after ovulation, with almost no viability by 24 hours after ovulation. Semen viability is highly variable depending on the stallion and if you are using fresh or frozen semen. The majority of semen will maintain its viability for up to 48 hours after insemination, while some may last four to seven days or just a few hours. Mares ovulate 24 to 48 hours before the end of estrus (heat), with estrus lasting anywhere from two to eight days. If insemination happens too early or too late, the mare has little chance of becoming pregnant.

The mare’s body condition score (BCS) at the time of breeding can also prevent pregnancy. The ideal BCS at breeding is 5 to 6 on the 1 to 9 Henneke BCS scale. Mares being too thin or over weight have decreased reproductive efficiency. Prior to breeding, make sure your mare is in good health and good weight.

A mare’s age also plays a role in becoming pregnant. By 18 years old, a mare’s egg quality begins to decline. As she ages her uterus becomes less healthy, compared to a young mare. Vulva conformation issues can additionally become a concern because it can lead to contamination of the reproductive tract.

Choosing to breed at the wrong time of year will furthermore prevent pregnancy. Mares are seasonal breeders, meaning for a portion of the year they are not cycling. May through August is the natural breeding season and when the mare will most likely be cycling. October through November and April through March is when the mare is going through a transitional period and is unlikely to become pregnant because she is not ovulating as reliably. December through February is when mares are anestrus, or not cycling, making chances of becoming pregnant almost nonexistent. Most breeders want to get mares pregnant as close to the beginning of the year as possible and to achieve this they use artificial light and sometimes hormones to encourage the mare to begin to cycle sooner.

Pregnancy Loss So you got your mare pregnant, but she lost the foal before she was full term. Why did this happen?

Most losses occur within the first couple months of the pregnancy. The early embryonic losses are most likely due to embryonic abnormalities, genetic defects, or stress related. Stress related incidents include severe illness, long distance transport, extreme weather conditions, poor nutrition, and too heavy of a work load.

There can also be later term loses. Some common culprits are equine herpes virus, inflammation of the placenta, umbilical cord abnormalities, and twinning. If twins are caught by ultrasound between 10 and 15 days, which is before placental implantation, a veterinarian should be able to successfully reduce the pregnancy to a single embryo, increasing the chances of a fruitful pregnancy.

Parturition Loss You got your mare pregnant and she has carried her foal to full-term and is in the process of foaling, but you still lose the foal. What went wrong?

Losing a foal during the birthing process is usually due to dystocia, or difficulty birthing. The majority of the time, the umbilical cord gets cut off, causing oxygen deprivation to the foal. Dystocia is generally caused by the foal being in the wrong position and the mare being unable to push it out on her own. When this happens it is imperative to get the foal out ASAP. If this happens quickly enough there is a good chance of saving the foal. Dystocia can also occur because the foal is too big to fit through the birth canal. This issue may be able to be avoided by selecting a stallion that is known to produce smaller foals.  

Steps to Take to Be Successful

Here are some tips on how to help your mare have a successful pregnancy.

• Consult with a veterinarian prior to breeding so you have a game plan
• Research the stallion you are going to use. Know his pregnancy success rate for fresh and/or frozen semen (whichever you are using)
• Plan for using multiple straws of semen if you choose to use frozen semen – not all mares will take with one straw
• Have your veterinarian check your mare for endometritis, make sure she is up to date on all vaccines and that she has been dewormed prior to breeding
• Ensure your mare is a BCS of 5 to 6
• Have your vet do an ultrasound 14-16 days after breeding to check for twins
• Schedule a pregnancy check at 60 days after breeding to make sure your mare is still pregnant
• 10 months into gestation get you mare her core vaccines to improve her colostrum quality
• Throughout pregnancy allow your mare to have some exercise, don’t keep her locked in a stall 24 hours

As always, if you have any questions about this topic or anything else, contact your local Extension agent.

When to Increase Fat in a Horse’s Diet

Recently, my sister called me asking how to add weight to one of our horses that she has with her in Missouri.  She told me she is feeding free choice hay and 3 lbs. of 14% CP/5% Fat pelleted grain twice a day along with access to grazing.  This particular horse is an 8 year old 16.3 hh Appendix Quarter Horse gelding used for barrel racing competitions.  We have owned him since he was a 4 year old and he has always been a thinner type of horse.  He is very lean and muscular and most of that comes from his bloodlines and the work he is doing.

This is a photo of the gelding mentioned in this article.  I am shown here barrel racing him in a competition.

We know that horses can utilize up to 20% fat in its diet where we typically feed 3-5% fat.  Horses that are candidates for increased fat consumption are older horses that cannot keep weight on, frequently exercised/competition horses, and horses that have foundered in the past.  So, if we want to increase fat in his diet to add weight (especially going into the winter) what are our options?  We can select feedstuffs that are naturally higher in fat content e.g., rice bran or flax seed or we can add supplemental fats, e.g., vegetable oils, hydrolyzed animal fats or dry granular fats. Feedstuffs that are naturally higher in fat contribute other nutrients that must be taken into account. In contrast, the supplemental fats are greater than 98% fat and do not contribute other nutrients. The vegetable oils tend to be more palatable than animal fats and have less likelihood of containing impurities. Probably the most common method of increasing the fat content is to top dress the grain with corn oil or soybean oil.

So, what did I recommend to my sister in her given situation?  I recommended top dressing grain with a vegetable oil.  I felt that she was already feeding enough grain per day at the cost she could afford, so the oil was a great low cost option to help increase weight.  I also suggested that she deworm the horse in case he has a load of internal parasites preventing him from keeping on weight.  Remember, increasing the fat content of a horse’s diet should be done gradually.  Also, careful attention should be paid to not providing excess energy as this can result in an overweight horse.

Reference: http://www.extension.umn.edu/agriculture/horse/nutrition/feeding-fat-to-horses/

Watch out for Foxtail in Hay

Most horse owners in eastern NC are familiar with sandbur, also called sand spurs or sand stickers. These are irritating to human and animal alike. If you've ever stepped on one in bare feet, you learned a painful lesson! Obviously, such an object in hay would cause injury to the horse's mouth, lips and gums, at the very least. However, horse owners should also be observant for foxtails in hay, and this applies to horse owners in a much greater portion of our readership area.

Foxtails of the Seteria species are quite common throughout NC. The seeds of foxtail have small barbs that can lodge in soft tissue of the lips and gums, and can even cause irritation of the gastrointestinal tract. Foxtails in NC are usually either Green Foxtail, Yellow Foxtail, or less frequently, Giant Foxtail. All are warm season annuals. For pictures of the seedheads, click this link to a University of Tennessee website.
https://extension.tennessee.edu/WebPacket/Pages/WP-2015-12-Horsesandfoxtail.aspx

It should be pointed out that the seedheads are the problem. If foxtail is present in a hayfield, but it is mowed frequently enough to prevent seedhead formation, the grass itself is of little concern. (Although, from a nutrient standpoint, foxtail is not generally as digestible and nutritious as most improved grasses.) Chemical control of foxtail can be difficult. In fescue and other cool season grasses, there are no options for broadcast control of foxtail, so it would have to be controlled by spot spraying with a non-selective herbicide. In bermudagrass, Pastora has fairly good activity on foxtail, but may require multiple applications for satisfactory control. For more information about control and management, contact your local Cooperative Extension office.