Horses are very adaptable and typically can handle significant temperature swings. It’s when we alter their natural condition and confine them or haul them from one climate to another that they tend to struggle.
When the mercury rises or drops dramatically, will your horse be prepared?
In October 2013 South Dakota livestock and farmers were experiencing balmy 70- and 80-degree temperatures when a storm moved in from the Rockies and a cold front from Canada. The collision of the air masses created heavy rain, winds up to 70 mph, and a dangerous blizzard. Many cattle drifted with the storm, piling up against fences, getting covered with snow, and freezing to death because they were soaked with rain before the snow and cold temperatures set in. Though there were some equine losses, outdoor horses generally fared better than cattle because they’re more adept at finding windbreak and shelter. But horses with no reprieve from the elements likely suffered cold stress and frostbite.
Similarly, albeit not so drastically, horses might have a tough time adjusting to the elements when moving from a cold climate to a hot one (or vice versa) or when body-clipped during a serious cold snap.
Giving medications to pregnant mares is never without risk and should always be discussed with your veterinarian.
Which drugs are safe for use in pregnant mares?
My pregnant mare is colicking … can I give her Banamine? She needs a laceration sutured … is it safe for her to get a sedative? What about her fall vaccines?
Which common drugs and medications are safe for use in pregnant mares is a huge topic with more questions than answers, says Margo Macpherson, DVM, MS, Dipl. ACT, professor of large animal reproduction at the University of Florida’s College of Veterinary Medicine, in Gainesville. This is primarily because very few drugs have been thoroughly evaluated and validated for use in this population.
Begin administering chest compressions immediately to any foal born not breathing and without a heartbeat. Photo: SallyAnne L. Ness, DVM, Dipl. ACVIM
It’s bad news when a foal enters the world without taking a breath. But there’s some good news: Many foals born with beating heart and pulse, but who fail to breathe, can be revived via cardiopulmonary resuscitation (more commonly known as CPR). And there’s more good news: Both owners and veterinarians can perform CPR on a foal in need. The key is to be prepared in advance and not to wait until it’s too late to learn this potentially life-saving skill.
To that end, SallyAnne Ness, DVM, Dipl. ACVIM, reviewed how to perform CPR on newborn foals at the 2015 American Association of Equine Practitioners’ Convention, held Dec. 5-9 in Las Vegas, Nevada. Ness is an internal medicine specialist at Cornell University’s College of Veterinary Medicine, in Ithaca, New York.
Be Prepared
Ness said many veterinary clinics keep portable neonatal crash kits prepared and handy. These kits should contain the products needed to deliver life-saving oxygen to foals that fail to breath upon delivery.
She also recommended that veterinarians have on hand the injectable medications that can aid resuscitation when a foal’s heart rate gets too low or stops beating—epinephrine (adrenaline) and vasopressin (a hormone that raises blood pressure and helps maintain blood flow to the heart and brain). She also suggested printing a dosing chart ahead of time to prevent errors if medications are drawn up and administered in a hurry.
When the Foal Arrives
Ness said veterinarians and foaling attendants should rapidly assess any foal that fails to move and/or breathe upon delivery. She recommended:
Placing him in a sternal position (on his abdomen with tucked-under legs) and clearing the airways;
Identifying any rib fractures and/or congenital deficits;
Auscultating (listening with a stethoscope) the lungs and heart; a healthy foal’s respiration rate should be 20 to 40 breaths per minute and pulse should be 60 to 80 beats per minute, she said;
Palpating for pulses; and
Clamping the umbilicus.
This assessment should take less than a minute. She suggested giving several people specific jobs—one team leader, one to listen to the heart and lungs, etc. She also said attendants should be prepared well in advance for high-risk pregnancies or foalings.
The foaling team’s job is easy if the neonate’s heart is beating and he’s breathing properly. If he’s not breathing, however, it’s time for them to begin attempting resuscitation.
First, rub and dry the foal, she said. Sometimes tactile stimulation helps prompt the foal to breathe. Poking the muzzle and nostrils with straw can also incite a reflex that prompts the foal to take a breath. If he isn’t breathing after 10 to 15 seconds, he’ll need ventilation.
Ness said intubation is the easiest option and can be approached either through the foal’s nasal passages or his mouth. In this instance, the veterinarian will extend the foal’s neck and pass an endotracheal tube into the trachea. Then, he or she will inflate a cuff to seal the tube within the trachea and connect an Ambu Bag, which allows the veterinarian to administer breaths to the foal.
Alternatively, veterinarians and foaling attendants can use a non-intubated approach. Ness said in this case, the attendant can use a mouth-to-nose approach. To do this, Ness instructed, “You block the lower nostril (the one closest to the ground as the foal lies) with your hand and blow into the upper nostril.” Another non-intubated option is a mask with a self-inflating air pump made specifically for foals. This last option is probably the easiest and safest choice for foaling attendants and nonveterinarians, she added.
Regardless of which option the veterinarian or attendant uses, Ness said the goal is to apply 10 breaths per minute, holding the first inspiration for three to five seconds and then using quick, short breaths after that. She recommended reassessing the foal after 30 to 60 seconds.
Handling Foals Without a Heartbeat
“A foal born not breathing and without a heartbeat for any length of time is unlikely to respond to CPR,” Ness said. “But you have nothing to lose doing CPR on a dead foal. It’s doing something instead of nothing. Some can come back if the arrest began right at birth.”
She recommended beginning chest compressions immediately. The veterinarian should maintain a straight back and locked elbows and place one hand on the other on the widest part of the foal’s chest wall. Then, using his back and core muscles, begin applying 100 to 120 compressions per minute, aiming to compress the chest by one-third with each compressions. Ness noted that an easy way to get an appropriate compression rhythm is by mentally singing Stayin’ Alive by the Bee Gees and compressing along with the beat. Ironically, she laughed, Another One Bites The Dust by Queen has a similar beat and could also be used to achieve an appropriate compression rhythm. She recommended having the foaling team take turns performing compressions in two-minute cycles to prevent fatigue.
Ness said the foal should receive 30 compressions for every two breaths. If the animal is intubated, she said the compressor doesn’t need to stop. If he’s not intubated, the compressor should stop every 30 seconds so breaths can be administered. Additionally, veterinarians can administer epinephrine every four minutes to aid in revival, she said.
When to Stop
Ness recommended continuing CPR until the foal is breathing on his own and has a heart rate over 60 beats per minute. She recommended that foals that do respond positively should still be monitored closely for relapse.
She noted that if a foal fails to respond after 15 minutes, success is unlikely.
Take-Home Message
Knowing CPR and being prepared in advance to administer it to foals in need is essential for both veterinarians and foaling attendants.
“CPR is a rewarding and life-saving procedure that can result in a positive outcome when delivered quickly and with proper technique,” Ness relayed.
Erica Larson, news editor, holds a degree in journalism with an external specialty in equine science from Michigan State University in East Lansing. A Massachusetts native, she grew up in the saddle and has dabbled in a variety of disciplines including foxhunting, saddle seat, and mounted games. Currently, Erica competes in eventing with her OTTB, Dorado.
Most deliveries transpire smoothly with no ill effects. But when a problem does occur—even a simple issue such as an easily correctable dystocia (difficult birth)—things can go south rapidly.
For some breeders, the waiting game starts as soon as the mare is inseminated. For others, it starts when she’s confirmed in foal. Still for others, it starts when she her belly grows large. Whenever that waiting game starts, all breeders want to know: When will my mare foal?
Igor Canisso, DVM, MSc, PhD, Dipl. ACT, Dipl. ECAR, previously of the University of Kentucky Gluck Equine Research Center and now an assistant professor of equine theriogenology at the University of Illinois College of Veterinary Medicine, offered some tips on how to predict when a mare will foal.
Most deliveries transpire smoothly with no ill effects. But when a problem does occur—even a simple issue such as an easily correctable dystocia (difficult birth)—things can go south rapidly, Canisso said. Additionally, “in certain situations, we don’t want let the foal suckle on its dam due to risk of developing a condition such as neonatal isoerythrolysis,” or acute hemolytic anemia caused by ingesting antibodies in the mare’s colostrum and milk that are directed against the neonate’s red blood cells, he said.
“That’s why each foaling should be attended,” he explained. “If there is a simple problem, it can easily be corrected by an experienced foaling attendant. Or, if there is a more serious condition, the mare can be referred to a clinic, or a veterinarian can be called to check the mare.
“Usually, it is best not to wait (to call the veterinarian), as after 30 minutes from ‘water break,’ every 10-minute delay in foaling decreases the foal’s survival rate by 10%,” Canisso said.
And because the vast majority of foalings take place between 6 p.m. and 6 a.m., he said, it’s important to know when you might want to start brewing coffee for overnight foal watches.
Here are some of the options owners and veterinarians can use to predict when a mare will foal.
Estimated Foaling Date—The average equine gestation length is between 335 and 345 days. So you should be able to easily calculate your mare’s estimated foaling date if you know when she was bred. For example, if your mare was bred on Feb. 10 and has an average gestation, you can tentatively expect a foal between Jan. 12 and Jan. 22 of the following year. Canisso cautioned, however, that gestation length varies substantially between breeds, time of the year (it’s usually longer when the mare is due to foal in the late winter and early spring), and individual mares, so use this method only as a guide.
If you’re unsure of when your mare was bred, your veterinarian can perform an ultrasound exam to estimate the mare’s stage of pregnancy and calculate an estimated foaling date.
Physical Signs—As the mare’s due date approaches, start watching for physical signs indicating she’s preparing to foal, including:
Tailhead relaxation—Canisso noted this is harder to identify in overweight, heavily muscled, or maiden mares;
Vulva relaxation and elongation—Canisso cautioned that some older mares might have very pronounced vulvar relaxation well before foaling while others mares will show minimal or no appreciable changes, so don’t rely solely on this factor to predict foaling; and
Mammary gland enlargement—Canisso said most mares’ mammary glands will begin getting larger about a month before their due date, with the most notable changes in the last two weeks prior to foaling. Maiden mares might not show substantial udder enlargement until close to parturition, he said.
Canisso cautioned that maiden mares might not display the same physical signs as seasoned broodmares.
Mammary Gland Secretions—For the last three decades many veterinarians and breeders have used mares’ mammary gland secretion electrolyte levels to predict foaling. In the normal mare, the mammary gland secretion’s calcium and potassium levels rise while sodium decreases closer to foaling. However, measuring these electrolytes to predict foaling requires a machine to analyze the levels and serial measurements. Canisso said that, commonly, breeders and veterinarians have submitted these electrolyte samples to a laboratory, which can be expensive and prohibit the practice’s use for mares not located close to a laboratory–essentially, most mares in most regions.
Because calcium is the most reliable and commonly used electrolyte, commercial kits are now available for breeders to use to estimate the mammary secretions’ calcium carbonate content and, thus, help predict when the mare will or will not foal. The commercial calcium carbonate test’s limitations include the costs and required dilutions to obtain an accurate reading, said Canisso.
Recently, Canisso and colleagues tested another method by which to predict foaling using mammary gland secretions. This time, however, they measured the secretions’ pH levels. Using commercially available pH test strips, owners can test the mammary gland secretions once daily; when the normally slightly basic secretions (pH> 8) drop to below 7 on the pH scale, the mare will likely foal within 24 hours, Canisso said. In his recent study, 11 of 14 mares foaled within 24 hours when their mammary gland secretion pH levels were 7 or lower; the remaining three study mares foaled without significant pH changes, he said.
In the same study, Canisso and colleagues compared the secretions’ pH levels with their calcium, sodium, and potassium concentrations. They found that the pH measurements were equally as effective as electrolyte measurements at predicting foaling, suggesting that pH can replace electrolyte measurements, he said. Canisso also noted that measuring pH is advantageous over electrolytes because the tests cost less; are more practical, as no dilutions are needed to determine pH; and require only a small drop of secretion to complete—this is especially beneficial for maiden mares, he said, as many maiden mares have a very small amount of pre-foaling mammary gland secretions, making electrolyte measurement very difficult.
Electronic Devices—Next, Canisso described some electronic devices breeders can use to alert them to impending foaling:
The Foal-Alert is a magnetic device that a veterinarian sews into the mare’s vulva. When the magnets are separated as the vulva expands during foaling, an alert is sent to a pager or cell phone, or an alarm sounds in the barn. Canisso said while this device can be used successfully, it can also cause many false alarms. Additionally, the alarm might not sound if the foal is malpositioned in the uterus or if its feet don’t penetrate the mare’s vulva.
The Breeders’ Alert is a position-monitoring device shaped like a small box that attaches to the mare’s halter and sounds an alarm when it detects that the mare is in lateral recumbency (the position in which they deliver a foal) for more than 15 seconds. Like the Foal-Alert, Canisso said, this device causes a lot of false alarms.
The last device Canisso described is the Birth Alarm. Like the Breeders’ Alert, the Birth Alarm monitors a mare’s position; however this device is located on a surcingle. When the mare lies down for more than about 8 seconds, an alert is sent to the individual monitoring the mare. As with the other two devices, Canisso said this can throw false positives, and it might be cost-prohibitive for some breeders.
Video Monitoring Systems—Finally, Canisso noted that many breeders and veterinarians employ video monitoring systems that allow them to keep an eye on the mare for signs of foaling from afar.
So which method should breeders select? Canisso said many breeders opt for a combination of the available options to give themselves the best chance to accurately predict when a mare will foal.
“Since there isn’t a single and perfect way to predict foaling in all mares, the best approach is to combine different strategies to maximize the results,” he said.
Erica Larson, news editor, holds a degree in journalism with an external specialty in equine science from Michigan State University in East Lansing. A Massachusetts native, she grew up in the saddle and has dabbled in a variety of disciplines including foxhunting, saddle seat, and mounted games. Currently, Erica competes in eventing with her OTTB, Dorado.
Begin administering chest compressions immediately to any foal born not breathing and without a heartbeat. Photo: SallyAnne L. Ness, DVM, Dipl. ACVIM
Most deliveries transpire smoothly with no ill effects. But when a problem does occur—even a simple issue such as an easily correctable dystocia (difficult birth)—things can go south rapidly.
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