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A healthy mare-foal bond is critical for growth, provides nursing and warmth, and supports foal development and socialization. A strong bond sets the foundation for the foal’s behavior and interaction with humans and other horses.
Foal rejection occurs when a mare and her foal fail to bond after birth. As a result, the mare may show disinterest, fear, or even aggression towards her newborn foal.
The precise cause of foal rejection is often unknown, but may stem from various mare-related factors or disruptions during the critical bonding period immediately after birth.
In many cases, foal rejection is treatable through appropriate management of the mare. Management may include:
- Restraining the mare to allow the foal to nurse
- Behavioural modification techniques
- Pain medications
- Sedation
If foal rejection continues, or if the mare is overtly aggressive towards the foal, the foal must either be raised as an orphan or transferred to a nurse mare. Both processes can be costly and require extensive hands-on management for success.
Normal Mare-Foal Interactions
Research suggests that maternal bonding in horses begins when the mare smells the placenta and associated fluids after birth. This gives her a strong smell to associate with her foal, a process that continues as the mare licks the foal shortly after delivery. [1][2]
Initial maternal behaviours mares display towards the newborn foal include: [2][3]
- Nuzzling the foal
- Licking the foal
- Flehmen response
- Scraping the foal with her teeth
- Avoiding walking or laying on the foal
- Encouraging nursing
- Positioning herself between the foal and humans
Maternal Bonding
The behaviours most associated with development of the maternal bond are: [2][3]
- Sniffing the placenta and birthing fluids
- Nose-to-nose sniffing with the foal
- Nuzzling or licking the foal’s perineum while the foal nurses
These behaviours are most common in the first three hours after foaling, but can continue for up to three days.
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Signs of Foal Rejection
Foal rejection refers to a situation where a mare does not exhibit normal maternal behavior towards her newborn foal. Rejection results in a lack of nurturing, protective behaviours, and bonding. This abnormal behavior can hinder the foal’s ability to nurse and receive maternal care.
The manifestations of foal rejection can vary. The main types of foal rejection include: [1][4][5]
- Mares that seemingly ignore the foal (ambivalence)
- Mares that avoid the foal or display fear or anxiety
- Mares that do not allow the foal to nurse
- Aggressive mares that attack the foal
Distinguishing Rejection from Normal Behaviours
Breeders should not mistake normal maternal behaviours during initial bonding as foal rejection. Truly aggressive mares often attack the foal unprompted, and may bite, shake, or throw the foal. [1]
During initial nursing attempts, or if the foal is aggressively bunting the udder, normal mares may display behaviours such as: [1][5][6][7]
- Squealing
- Nipping or gently kicking at the foal to stop nursing
- Pinning ears at the foal
- Stepping away from the foal during the first nursing attempt
Many investigators report seeing domestic and feral mares stepping away from their foals when the foal first attempts to nurse, even if the mare and foal have bonded normally. This behaviour may teach the foal to follow the mare as part of the bonding process. [2]
Additionally, mares during early lactation frequently walk away from their foals while the foal is still nursing. [2][7] This appears to be a normal behaviour which has been described in many breeds, and should not be confused with foal rejection. [2]
Causes of Foal Rejection
The main causes of foal rejection are: [1][5]
- Mare factors
- Disrupted maternal bonding
- Abnormal foals that do not encourage maternal instinct in the mare
- Pain in the udder during nursing
In many cases, the underlying cause of the rejection is unknown. [1]
Mare Factors
Studies show that certain mares have a higher risk of foal rejection. Commonly identified risk factors include: [1][6]
- Maiden mares, who are inexperienced in foal care
- Older mares
- Mares raised around foals
- Arabian mares, particularly mares from Egyptian breeding lines
Mares that reject their foals may have differences in postpartum estrogen and progesterone fluctuations when compared to normal mares. [8] Progesterone is a key hormone in the equine reproductive cycle, playing a crucial role in maintaining pregnancy. It may also have a role in priming maternal behaviour.
The specific causes of differing hormone fluctuations in some mares during foaling are not fully understood.
Disrupted Maternal Bonding
Foal rejection may be caused by disruptions to the maternal bonding process due to: [1][5]
- Excessive human interaction in the early neonatal period
- Abnormal deliveries, such as dystocia, where the mare and foal may be unable to interact immediately after delivery
The initial six-hour period following delivery is critical for the development of the maternal bond between a mare and her foal. This bonding process is largely facilitated by the mare smelling and tasting her newborn.
Disruptions during this crucial time can hinder the natural bonding process, potentially leading to foal rejection. [1]
One study showed that removing the placenta from the mare’s stall too early increases the risk of foal rejection, highlighting the importance of minimizing human interference. [1]
Abnormal Foals
Foals stimulate the mothering instinct in their dam through nickering, nuzzling, and nudging their mother. Once the foal can stand, udder-bumping and suckling continues the maternal bonding process.
Any foal showing signs of illness at birth has the potential for rejection. Common causes for foal illness include: [1]
Sick foals often require intensive care, which can further disrupt maternal bonding through excessive human interaction. Additionally, certain medications may change the foal’s smell, which may also affect the maternal bond. [1]
Painful Udders
Udder pain can initially cause a mare to prevent their foal from nursing. This may progress to aggression or fear towards the foal if the mare associates the foal’s approach with pain. Pain in the udder can occur due to: [1]
- Rapid onset of lactation causing pain and tenderness
- Agalactia from fescue toxicosis
- Mastitis
Strong postpartum uterine contractions can also cause abdominal discomfort, which the mare may associate with the foal suckling. [1]
Treatment
The first step in managing foal rejection is ensuring the foal’s safety. Signs of overt aggression from the mare require immediate removal of the foal. [1] Most truly aggressive mares are not manageable in a way that supports a healthy foal.
The next pressing matter is the foal’s colostrum intake. Since rejected foals are unable to nurse, they do not receive colostrum– the mother’s first milk. Colostrum contains antibodies that the foal needs to establish their immune system and fight against infections.
If early attempts to allow the foal to nurse are unsuccessful, foals will need donor colostrum within 6 – 8 hours of birth. [1] Conducting an immunoglobulin (IgG) test is key to ensure that successful passive transfer of immunity has occurred.
In cases where mares are not overtly aggressive, steps may be taken to encourage a relationship between a mare and her foal. There are several strategies to help stimulate the maternal bond, depending on the type of foal rejection displayed.
However, breeders and veterinarians must weigh the risk of human intervention further disrupting the developing maternal bond.
Ambivalent Mares
When a mare is ambivalent towards her foal, it means she is showing a lack of interest or a neutral attitude instead of the expected maternal instincts. In such cases, a healthy mare-foal bond may be encouraged by: [1][4][9]
- Restraining the mare while encouraging the foal to nurse
- Reintroducing the placenta for the mare to smell
- Administering pain medications to reduce discomfort that may distract the mare from her foal
Some mares ambivalent towards their foals only start to develop a maternal bond when there is a perceived threat to the foal. [5] Potentially threatening stimuli that can be used to trigger the maternal bond include: [5]
- Separating the foal from the mare
- Bringing a leashed dog into the area, as many mares respond strongly to canines
- Turning the mare and foal into a paddock adjacent to other horses
Mares Preventing Nursing
Mares that do not allow the foal to nurse are typically experiencing udder pain. Treatments can include: [1][4]
- Cool compresses applied to the udder
- Pain medications
- Oxytocin administration to encourage milk production
- Hand-milking to reduce pressure within the udder
Mares that nip or bite their foals during nursing attempts may require a grazing muzzle for the foal’s safety. Hobbles can be used on mares that kick at their foals. [1][4][10] Some facilities may have breeding stocks available that can allow the foal to nurse while preventing the mare from turning and biting or kicking at the foal. [1]
In most cases, mares only require restraint for 3-7 days before they will allow the foal to nurse on its own. [2][5]
Other Techniques
Behavioural Modification
Some mares may respond to behavioural modification training, such as positive and negative reinforcement. To effectively implement these strategies, a good understanding of behavioural modification is necessary to prevent the mare’s behaviour from escalating. [9]
The mainstay of behavioural modification techniques is positive reinforcement through gentling stroking and rubbing of the mare’s neck or offering a food incentive when the mare allows the foal to nurse. [9] Over time, the mare associates the foal with positive outcomes, which overrides the fear or anxiety that she may have experienced previously.
Negative reinforcement should be used very judiciously, as it can increase the mare’s negative attitude about the foal. In most cases, negative reinforcement is only used for mares who are actively aggressive towards their foal. [9]
Physical punishment should be avoided. Instead, producing an aversive condition (such as a loud noise) when the mare attacks can interrupt the behaviour and reduce its frequency.
Pharmaceutical Intervention
As a last effort, some mares may require sedation to allow the foal to nurse. [1][4] Mares may also benefit from administration of altrenogest, a synthetic progestin that raises the threshold for aggression. [1][4]
Prostaglandin administration (cloprostenol or dinoprost) is also effective at treating foal rejection. [9][11] Discuss medications with your veterinarian to determine the best treatment approach.
Foal Management
While trying to bond the mare and foal, it is important to ensure that the foal’s nutritional needs are met. Foals require 10% of their body weight in milk per day to maintain a steady growth rate. [1] This milk can either be collected from the mare, or provided by a milk replacer product. [1]
Bottle feeding will maintain suckling and udder-bumping behaviours in the foal, which allow the foal to transition back to their dam when ready. [1]
Successful Bonding
Behavioural tests are used to determine whether successful bonding has occurred. The easiest test is to remove the foal from the dam’s sight. The mare should respond with anxious behaviour and vocalization. [1]
Mares displaying this behaviour, and who allow the foal to nurse regularly, are likely successfully bonded to their foal.
Bonding Failure
Unfortunately, some mares never develop a maternal bond towards their foals. These foals can either be managed as an orphan foal, or can be fostered onto a nurse mare.
Nurse mares are preferable in many cases, as they will raise the foal on their own once they accept the foal. [5] However, finding a nurse mare on short notice, or inducing lactation in a non-pregnant mare, can be challenging.
Orphan foals require a significant time investment, as foals must nurse every two hours during the first week of life. [5] Milk replacers are also expensive and may be difficult to acquire. [5] Finally, orphan foals may be more difficult to handle as adult horses, due to their close relationship with humans. [5]
Preventing Foal Rejection
The main recommendation for preventing foal rejection is to allow mares to deliver their foals in an undisturbed environment with limited human interaction. [2] Other strategies that may reduce the risk of foal rejection include: [2]
- Moving the mare into the foaling stall several weeks prior to delivery for familiarity
- Using foaling stalls in quiet areas of the barn away from human or equine traffic
- Leaving the placenta and reproductive fluids with the foal for several hours
- Leaving the foal in sight of the mare during any medical procedures
- For bottle-fed foals, holding the bottle in the mare’s inguinal region during feeding to encourage normal behaviours for both mare and foal
For maiden mares, an additional strategy to prepare them for mothering is desensitizing her flanks and udders. [1][10] In this process, one person touches the flanks and udders of the mare, while another person provides a food or scratch reward for the mare accepting the contact. [1]
Mares that have previously rejected foals may benefit from altrenogest administration immediately after delivery, rather than waiting to see if she rejects the foal. [1]
Frequently Asked Questions
Here are some frequently asked questions about mare–foal bonding and foal rejection:
A mare that is bonding well typically sniffs the placenta and birthing fluids, nuzzles the foal, licks the foal’s body, and performs the flehmen response (a behavior where the mare curls her upper lip and inhales to draw scents into a special organ in the nasal cavity, helping her detect and recognize the foal’s smell). She often positions herself between the foal and people or other horses and encourages the foal to nurse. These actions usually occur within the first few hours after birth and help the mare learn her foal’s scent and strengthen the maternal bond.
During the foal’s first tries at nursing, a mare may squeal, pin her ears, gently nip, or even step away. These brief reactions are common, especially if the foal is bunting the udder, and they usually help the foal learn to follow the mare and refine its nursing technique. As long as the mare allows nursing shortly after these moments and does not show true aggression, these behaviors are not signs of rejection.
Foal rejection is more likely in maiden mares, older mares, or mares with certain bloodlines such as some Egyptian Arabians. Disruptions during foaling—like difficult deliveries or excessive human interference—can also interfere with bonding. Foal illness at birth, such as dummy foal syndrome or sepsis, may reduce the normal cues that trigger a mare’s maternal instinct.
Horse owners can support bonding by keeping the foaling environment calm, leaving the placenta in the stall for a few hours, and limiting early handling so the mare can smell and lick her foal. If a mare is ambivalent, gentle restraint to allow nursing or reintroducing the placenta for scent association can help. For mares that show pain or aggression, a veterinarian may recommend pain relief, sedation, or hormonal treatments such as altrenogest or prostaglandins, but these should be used only under veterinary guidance.
Summary
- Foal rejection can lead to ambivalence, fear, or even aggression in the mare towards her foal.
- The underlying causes are often unknown, but may stem from maternal factors or excessive human interaction.
- Some cases of foal rejection are treatable with appropriate mare management.
- Mares and foals that fail to bond properly require the foal to be raised as an orphan or transferred to a nurse mare.
References
- McKinnon, A. O. et al., Equine Reproduction. Wiley-Blackwell, 2010.
- Grogan, E. H. and McDonnell, S. M., Mare and Foal Bonding and Problems. Clinical Techniques in Equine Practice. 2005. doi: 10.1053/j.ctep.2005.07.004.
- Houpt, K. A., Formation and Dissolution of the Mare–Foal Bond. Applied Animal Behaviour Science. 2002. doi: 10.1016/S0168-1591(02)00111-9.
- Dascanio, J. J. et al., Eds., Equine Reproductive Procedures, 2nd edition. Hoboken, NJ: Wiley-Blackwell, 2020.
- Žurek, U. and Danek, J., Foal Rejection - Characteristics and Therapy of Inadequate Maternal Behaviour in Mares. Annals of Animal Science. 2012. doi: 10.2478/v10220-012-0011-9.
- Juarbe-DÃaz, S. V. et al., Prevalence and Characteristics of Foal Rejection in Arabian Mares. Equine Veterinary Journal. 1998. doi: 10.1111/j.2042-3306.1998.tb04513.x. View Summary
- Crowell-Davis, S. L., Nursing Behaviour and Maternal Aggression among Welsh Ponies (Equus Caballus). Applied Animal Behaviour Science. 1985. doi: 10.1016/0168-1591(85)90034-6.
- Berlin, D. et al., Post-Partum Concentrations of Serum Progesterone, Oestradiol and Prolactin in Arabian Mares Demonstrating Normal Maternal Behaviour and Arabian Mares Demonstrating Foal Rejection Behaviour. The Veterinary Journal. 2018. doi: 10.1016/j.tvjl.2017.12.007. View Summary
- White, M. S. E. and Scoggin, C. F., How to Manage Foal Rejection. Proceedings of the AAEP Annual Convention. 2014.
- Houpt, K., Equine Maternal Behavior and its Aberrations, in Recent Advances in Companion Animal Behavior Problems, IVIS, 2011.
- Barker, K. et al., Prostaglandin F2 Alpha–Induced Maternal Behaviour for Fostering Orphan Foals and for Mares Demonstrating Foal Rejection. Equine Veterinary Journal. 2019. doi: 10.1111/evj.03_13152.
