Make your own free website on Tripod.com

A Survey of the Friesian Horse’s Predisposition to Colic and Other Health Issues

Kelsey Evans
Senior Applied Research Project
Sterling College, 2009

 The Friesian horse is a distinctive and ancient breed, originating from the Friesland region of the Netherlands. Throughout it’s history, the breed has experienced times of booming popularity and periods of near-extinction. During the latest population decline in the early 20th century, the genetic pool was severely affected, leaving the entirety of the current population of Friesian horses stemming from only three purebred stallions. Since the mid seventies, the breed’s popularity outside of the Netherlands has increased dramatically, particularly in North America (FHANA). However, because of this limited gene base, and the desire by many breeders to maintain true to breed type, the management of inbreeding has been a concern.

 With the rising population of Friesians in the United States and Canada, trends in their health and management needs have become more obvious. Inbreeding is commonly known to be a cause of health issues in animal populations (Keller & Waller, 2002), but very little is known in North America about particular issues to which the breed may be prone due to inbreeding or even simply breed characteristics.

 Some owners and caretakers of Friesian horses have found there to be a seemingly high proportion of Friesian horses dying in their prime years particularly from colic, one of the most common high-risk equine ailments. Very few scientific studies have been performed concerning the health of Friesian horses as a breed, and even a large proportion of general information is limited to articles written in Dutch. As a result, there are few resources for Friesian owners, either in the form of scientific studies or in layman’s knowledge about trends in Friesian health and management tips.

 This research project will explore through qualitative analysis, using accounts from owners, veterinarians, and registry records, whether any trends in the health of the Friesian breed exist, and if so what they are. In the event that trends do exist, it is the hope that enough information can be gathered to warrant a full scale scientific study to examine the issue, whether it may be connected to breeding, management or other factors.

 History of the Friesian Horse Breed

 The Friesian horse originates from Friesland, a culturally distinct area of northern Europe which is now the northwest province of the Netherlands. The breed is quite ancient, with accounts noting this antiquity tracing back to the Roman historian Tacitus in the years AD 55-120 (Edwards, 1994). Mention of the Friesian is made throughout history, from carrying knights in the Crusades to pulling hearses in 19th century London (Gordon, 1893). In the mid-1500’s, the breed began to become more refined with the introduction of Spanish Andalusian blood during the Eighty-years War between Spain and the Netherlands. It’s popularity as a versatile and good-tempered driving, riding and farm horse led to it becoming foundation or contributing stock to later European breeds such as the German Württemberger and Oldenburger, the Norwegian Døle Gubrandsdal, and the British Shire, Dales and Fell (Edwards, 1994).

 In the early 20th century, the Friesian breed was nearly outcrossed into extinction due to the popularity of Dutch trotting races at which the breed excelled. Crossbreeding with the Friesian for the sole purpose of creating a superior trotting horse became the goal above all others, resulting in fewer and fewer purebred Friesian breeding. Despite the creation of a studbook in 1879, by 1913 only three Approved purebred Friesian stallions were left: Prins 109, Alva 113, and Friso 1171 (Kasperek, 2009).

 According to Edwards, the breed was brought back from near extinction during World War II, when fuel and vehicle shortages forced Dutch farmers to revert to their native horsepower to work the land. The Friesian was bred away from carriage type toward a heavier draft in order to fill this niche, but with the return of mechanization in the 50’s, the breed again began a decline. Luckily, in the 1960’s and 70’s interest began to renew in recreational riding and driving, and the Friesian began to gain notice outside of Europe. In the 1970’s, the first Friesch Paarden Stamboek (FPS) registered Friesians were imported into the United States (Kasperek, 2009). In 1978, only 2058 horses were registered with the FPS worldwide (Bouma, 1979), mostly in Europe with a handful in the United States and South Africa. Today, there are over 45,000 registered Friesians, with 4000 registered in the United States alone (FHANA).

 It is worth describing briefly the selection methods used by the FPS to retain the defining characteristics of a breed which has endured so many threats to it’s survival. The typical breed characteristics are described in the FPS rules and regulations as:

 The Typical Friesian Characteristics may be found in a horse that is harmoniously built and properly proportioned. The noble head has clear, intelligent eyes and small, alert ears with the tips pointing slightly toward each other. The neck is of adequate length and is lightly arched. A strong back joins a croup of good length which doesn't slope too steeply. The shoulder is strong, long and sloping and the body has good depth and well sprung ribs. The feet and legs are strong with a well developed forearm and proper stance. A height of 1.60 meters (15.3 hands) is considered ideal. The horse has fluid, elegant and suspended gaits which are emphasized by feathering on the lower legs, a fine mane and beautiful, long tail. Jet black is the preferred color. This is a horse of luxurious and proud appearance, full of personality, honest and eager to work (“FHANA Rules & Regs”, 2.1.2.).

 In order to breed horses to this ideal, the FPS requires that horses applying for registration within the studbook undergo a series of evaluations by trained inspectors from the FPS to grade individuals against the breed type. Most horses are evaluated twice in their lives. Individuals are first presented as foals by their mother’s side, where they are evaluated for conformation and movement and awarded a first, second, third or no premium, or “premie” in the FPS Foalbook. A more serious evaluation is performed when a horse turns 3 years old, and they are again presented before inspectors to be evaluated 40% upon their conformation and 60% on their movement at the walk and trot for entry into the main Studbook. Mares and geldings are again awarded first, second, third or no premium and those of the highest quality are awarded additional designations indicating their superior quality themselves against the stated registry ideal, or their quality as a breeding individual. Some of these designations include Ster, Crown, Model and Preferent.

 Stallions must undergo a particularly rigorous testing and evaluation process before they are approved by the studbook for breeding use. The offspring of any stallions which are not approved by the registry are not recognized as purebred Friesians by the FPS studbook. Stallions must be evaluated first with other 3 year old horses being inspected for studbook entry. Only stallions of highest quality in conformation and movement will be chosen to move on to the next round of evaluations, all others will remain in the Foalbook. In the second round of evaluations, a video of the stallion is evaluated by a panel in the Netherlands, and the horse must undergo a series of physical evaluations including soundness x-rays, semen analysis, and blood typing. If the stallion passes all of these exams, he is passed onto the third round, the 70-day Stallion Central Proving. During this time, all eligible stallions are put into training and evaluated at the walk, trot, canter, performance under saddle, performance as a driving horse (to demonstrate obedience), performance pulling a sledge, performance as a carriage show horse (to demonstrate action), character and temperament, stable manners and training manners. At this point, stallions receive preliminary approval and are granted a temporary breeding license. When a stallion’s first offspring reach three years of age, a random selection is evaluated for quality, and again when the offspring reach five years of age. Only if the offspring are found to be of sufficient quality, showing positive characteristics from the sire and carrying on the breed type, will the stallion be finally approved for breeding purebred FPS mares.

 Inbreeding

 The use and meaning of the term “inbreeding” can be found to differ depending upon the context of it’s use, particularly when comparing the study of natural reproduction systems with the practice of human-controlled animal breeding systems. Even dictionaries seem to differ widely, though one well-rounded definition provided: “The mating of closely related individuals, as cousins, sire-daughter, brother-sister, or self-fertilized plants, which tends to increase the number of individuals that are homozygous for a trait and therefore increases the appearance of recessive traits” (inbreeding, n.p.).

 Scientists recognize that inbreeding alters the genetic diversity within populations of animals, which can lead to consequences in the health of the resulting offspring. “Data from bird and mammal populations suggest that inbreeding depression often significantly affects birth weight, survival, reproduction and resistance to disease, predation and environmental stress” (Keller & Waller, 2002, p.230).

 However, among breeders of domestic animals, inbreeding is a commonly used technique which has effectively created many of the numerous breeds of animals we know today. Through this method, a breeder will mate animals based on desired traits, sometimes breeding individuals with close kinship who display those traits in order to increase the likelihood of the offspring displaying those characteristics. Inbreeding may vary greatly from close: the breeding of full siblings or parents and offspring, to distant: the breeding of half-siblings or cousins (Sponenberg, Christman, 1995).

 According to Sponenberg, inbreeding is only as beneficial or detrimental as the genes being combined. Ideally, a breeding program that includes inbreeding either through planning or inherently small populations, also consists of a strong selection process with which to ensure positive traits within the breeding population (Sponenberg, 1995, p. 26). This is the case with the Friesian, whose breeding horses and stallions in particular go through extensive testing and evaluations before being approved for breeding purposes. Part of the process of managing an inbred population is the tracking of the inbreeding coefficient. According to Sponenberg (1995), “The inbreeding coefficient is the geneticist’s calculation of the proportion of genetic variants (or alleles) in an individual that are likely to be identical” (p.75). General guidelines in animal breeding suggest keeping the inbreeding coefficient of each new generation at or below 5%. Formulas are available which allow breeders to calculate the inbreeding coefficient of their herd so that matings can be planned which stay below this suggested percentage. However, inbreeding calculation in general, though mathematical is based upon certain assumptions about genetics, and is not known to be completely accurate. Variation within the population obviously helps with genetic diversity, and is particularly influenced by the number of males used within the breeding program. Because males are able to produce a large number of offspring every year in comparison to a female, low numbers of sires can have a detrimental effect upon the expansion of genetic diversity within the population, more so than would a low number of dams.

 In the Friesian horse, inbreeding first became an issue when the population dropped so low that only three viable purebred stallions were left. Since then, the KFPS has been employing many of the recommended methods for breeding from a small stock population.

 Overview of equine colic:

 While colic is known within the horse industry as one of the most common of serious equine ailments, the term ‘colic’ actually refers to the symptom of abdominal - usually intestinal - pain. Colic symptoms may be attributed to a range of actual causes, from parasite infestations to overfeeding.

 Tim Hawcroft’s A-Z of Horse Diseases and Health Problems identifies five types of colic, though more specific terms of diagnosis may occur within each of these general categories.

 Flatulent colic is caused by the, “Formation of large volumes of gas mainly in the large intestines - due to excess feeding on lush green pasture, clover, and other legumes” (Hawcroft, 1990, p.177).

 Gastric dilation may be caused by the consumption of large volumes of low quality feed such as moldy hay or grain, coarse straw, maize, etc. Consumption of such can cause large quantities of gas to build up, causing distention in the bowels, and further causing ‘muscles around the inlet and outlet of stomach to close, preventing escape of food and gas...” (Hawcroft, 1990, p.178). As the stomach continues to distend, fluid from the stomach lining flows into the stomach, causing further distention.

 Impaction colic is essentially the constipation of of the small and large intestines. This may be caused by a hurried consumption of low grade forage, which does not digest fully and forms into balls of undigested material, causing impaction.

 Obstruction colic is often the most serious form of abdominal problems in horses. It may be caused by, “a foreign body - twisted bowel - strangulated intestine resulting from hernia - intussusception (telescoping of one section of bowel inside another section of bowel)” (Hawcroft, 1990, p.179).

 Spasmodic colic is caused due to the rapid contraction of muscles in the intestinal wall. This may be caused by poor tooth care; if neglected the horse may find it difficult to grind feed. Poorly digested feed upsets intestinal motility, as may excitement, exhaustion or migrating red worm larvae.

 Causes and Risk factors for colic:

 According to DC Archer and CJ Proudman, colic is the most common form of death in some horse populations. In this study, the author reviewed the results of papers which identified risk factors for colic. Geography was found by studies to have little impact on the prevalence of colic, with the exception that “horses living in or originating from a particular geographic area are at increased risk for developing specific types of colic” (Archer, 2006, para. 2.1). An example was given of an increased incidence of sand colic in regions with sandy soil. The season of the year is a possible factor, with multiple studies finding a higher rate of colic cases in the spring, although according to Archer, “It is important to consider that seasonal incidence of colic may not be associated with weather factors alone but other potentially alterable management factors common to that time of the year such as stabling, quantities of feed or exercise levels” (Hillyer et al., 2001 and Archer et al., 2004).

 Intrinsic traits of an individual horse, such as cribbing, wind-sucking or a previous history of colic are likely a contributing factor to the onset of colic but are inherently difficult to measure due to the large number of variables. Unfortunately, this is often the case and narrowing down susceptibility to gender, age and breed are similarly difficult. “Some types of colic may be gender-specific in nature (e.g., inguinal herniation in stallions, and uterine torsions in mares) but overall there is no clear association between gender and colic” (Archer & Proudman, 2006). Studies of differences in colic susceptibility due to age are conflicting, with different age groups at increased risk for different forms of colic. Numerous studies have shown the breeds of Thoroughbreds and Arabians to be at increased risk colic. Again, Archer mentions that other factors are possibly involved, including the management practices of certain breeds and the fact that there may be a bias in the breeds brought to veterinary clinics. Also, certain breeds may be more susceptible only to certain types of colics, such as large Warmbloods to dorsal colon displacement. According to Archer, genetic predisposition to colic is possible in some cases, “Enterolithiasis is particularly prevalent in certain breeds such as Arab horses and Morgans making a genetic predisposition to the disease possible” (Cohen et al., 2000 and Hassle, 2004).

 In contrast to these slightly uncertain variables, the presence of parasites in the gut is a well known cause of colic. In recent years however, incidences of parasite-caused colics are largely reduced due to the availability and frequent use of anthelmintic drugs (Archer & Proudman, 2006).

 Another commonly known cause of colic symptoms is related to types of feed and feeding practices. Quality, freshness, and regularity of feed and changes in any of these factors, either roughage or grain, may be factors in the contraction of colic. “These studies demonstrate that change in feeding practices is significantly associated with increased risk of colic, supporting historical belief that change to new types or amounts of feed should be gradual” (Archer & Proudman, 2006).

 Exercise, especially strenuous forms such as racing may heighten the risk of colic. Horses who spend most of their time in the pasture are less likely to contract colic than those who spend large amounts of time in the stable. However, stabled horses may be under better observation and be more likely to be diagnosed with colic. Changes in living situations may also be a cause. Transportation poses a risk as well, though studies suggest this may be associated with a lack of water while in transit. Certain vaccinations have also shown an increased risk for colic for a certain period after being administered.

 Archer’s study demonstrated that a wide range of factors are present when evaluating the risk for colic ailments in individual horses. Evaluating contributing factors from an individual horse has proven difficult, but studies identifying management practices which may increase the risk of colic seem to have steadfast conclusions. Overall, changes in the diet and routine of a horse have shown to increase their chances of contracting a case of colic.

 Other Medical Issues:

 The Friesian horse has been noted to be predisposed to other health issues, sometimes due to their general body or breed type, sometimes due to more specific causes. Here is a partial list of ailments which some people have suggested may be common occurrence in the Friesian breed. Please note that like colic, these ailments have not been scientifically studied in the Friesian breed and as yet there is no conclusion that Friesians are more prone to these ailments than other breeds.

 Scratches, or pastern dermatitis is a common minor condition in the Friesian breed and other horses with pronounced fetlock hair or “feathers”. It is a skin irritation, usually found on the feathered lower legs, beneath the pastern and fetlock and sometimes running up the cannon bone and behind the knee. Severity can range from mild, with only a few scabs, to severe, with swelling of the leg and oozing scabs or sores. The cause of scratches may vary, from a mite infestation to fungal growth due to moist, dirty conditions of the fetlock hair.

 Osteochondritis Dissecans, or OCD, is a degenerative joint disease often found in young, rapidly growing horses who will mature to a large size (over 15 hands). Symptoms include lameness or swelling in the fetlocks, hocks, or stifles and is caused by the break down of cartilage in the joints, which harden into partially attached or free-floating bone cysts which may irritate the joint. This is usually brought on by increased activity in young growing horses and is not uncommon in the early training of larger horses. Similarly locking stifles, or the upward fixation of the patella, is often a short term problem for the joints of young growing horses, and in some cases may be caused by OCD.

 Dwarfism is known to occur to some degree within the Friesian breed, though in general the occurrence is rare in most horses. According to research done by the Australian Friesian Warmblood Association, reports from early 20th century Holland make note of certain stallions producing a large proportion of “midget foals”. At the time these vet reports were made, numbers of dwarf foals born to Friesian mares were significantly higher than they are today, perhaps indicating that the changes in breeding selection suggested in the report were at least partially successful in reducing the incidence of dwarfism within the breed.

 Retained placentas are also a recognized problem in the Friesian breed, and are one of the few ailments that have been studied particularly in relation to the Friesian. A retained placenta is the delayed expulsion of the fetal membranes after a mare has given birth. If the placenta is not expelled within three hours of birth, the mare may begin absorbing toxins and bacteria from the uterus (Thomas, 2009). Numerous studies performed by M. Sevinga and colleagues have suggested that a high incidence of retained placentas occur in Friesian mares and that they are at higher risk of the condition than other breeds (Sevinga, 2004).

 Research Questions:

 In researching the health issues of the Friesian breed, certain specific questions arise which I hope to at least broach in my studies. Firstly, what are the primary health issues effecting Friesian horses in the North American population, and how frequently do these issues occur? Secondly, what are the causes of these health issues, and are they preventable? And finally, if any of these ailments are preventable, how may they be prevented in the Friesian population as a whole?

 Methodology:

 In an effort to begin to answer some of these questions, I propose to use surveys and interviews to collect first hand accounts about Friesian health from Friesian owners across North America. I will contact large animal veterinary hospitals and request information from them on frequency and manner of cases concerning Friesian horses. If possible I will request information from the Friesian Horse Association of North America and possibly the Friesch Paarden Stamboek of the Netherlands on death certificates for registered Friesian horses. I will conduct interviews with breeding and training facilities which have dealt with health issues in purebred Friesian horses. Information will be collected in part through an online survey made available through my website, Friesiancrazy.com. First hand accounts will be verified where possible, and given less credibility if verification is unavailable.

 Accompanying the survey will be information notifying participants of the nature of the study and the use to which their data will be put. Participants will have the option of choosing the level of confidentiality of their information, ranging from complete anonymity, to complete disclosure of details in any final written report.

 Information will be collected on as many variables in the horse’s care and condition as possible so as to determine trends or connections between ailments and the horse’s lifestyle, besides the commonality of breed. Please see Appendix I for a potential example of a Friesian health survey.

 Conclusion

 So the questions remain, why does it matter what health issues affect this breed of horse, and how will this research be of any benefit? Firstly, to the many owners, trainers, caretakers and fans of the Friesian breed, the well-being of these horses is of utmost importance. Not only do individuals wish to protect the health of their own horses, but also the future of the breed itself. The Friesian horse is an ancient and unique member of the equine family, easily identified by their distinctive black color, proud carriage, luxuriant mane and tail and easy temperament. Deliberate care has been taken over the years to ensure the successful continuation and quality of this breed, and though their population size has increased, vigilance is still necessary to ensure that the Friesian horse so many have come to love will continue to thrive. The research proposed here will ultimately attempt to aid in that preservation, and if successful, may result in a methodology which can be used for other recovering breeds or species.

 Timeline May - June: Develop online survey and begin distributing/asking Friesians owners for participation. Specifically spread survey through e-mail lists. Also contact vet hospitals.

 July - Using FHANA Membership directory, begin contacting individuals through alternative methods.

 August- Continue distributing survey. Begin compiling results/stories. Define list of most common health issues.

 September - Organize results to find possible similarities in management or breeding that may cause health issues.

 October - Sort results by reliability and relevance, and begin consolidating into results.

 November- Finish up research, decide whether results may be posted online.

 December - Done research.

 References

 Archer, D.C., & Proudman, C.J. (2006). Epidemiological clues to preventing colic. The Veterinary Journal. 172, 29-39.

 Bouma, G.J.A. (1979). Het Friese Paard. Drachten & Leeuwarden, Netherlands: Friese Pers Boekerij.

 Cohen, N.D., Vontur, C.A., & Rakestraw, P.C. (2000). Risk factors for enterolithiasis among horses in Texas. Journal of the American Veterinary Medical Association. 216, 1787-1794.

 Edwards, Elwyn H. (1994). The Encyclopedia of the Horse. New York, New York: Dorling Kindersley Publishing Inc..

 FHANA, (2009). Rules and regulations. Retrieved April 28, 2009, from Friesian Horse Association of North America Web site: http://www.fhana.com/regulations/details.php?unid=71#2.1.2

 Gordon, W.J. (1893). The Horse World of London. R.T.S..

 Hassle, D.M., (2004). Update on enterolithiasis. In: Proceedings of the American College of Veterinary Surgeons veterinary symposium, Denver, Colorado, 2004, pp. 156–159.

 Hillyer, M.H., Taylor, F.G., & French, N.P. (2001). A cross-sectional study of colic in horses on thoroughbred training premises in the British Isles in 1997. Equine Veterinary Journal. 33, 380–385.

 inbreeding. (n.d.). Dictionary.com Unabridged (v 1.1). Random House, Inc. Retrieved April 28, 2009, from Dictionary.com website: http://dictionary.reference.com/browse/inbreeding

 Kasperek, L. (2009). Friesian Timeline. Retrieved April 29, 2009, from Friesian Horse Association of North America Web site: http://www.fhana.com/timeline/ Keller, L.K., & Waller, D.M. (2002). Inbreeding effects in wild populations. Trends in Ecology & Evolution. 17, 230-241.

 Sevinga, M., Barkema H.W., Stryhn H., & Hesselink J.W. (2004). Retained placenta in Friesian mares: incidence, and potential risk factors with special emphasis on gestational length. Theriogenology, 61, Retrieved April 28, 2009, from http://www.ncbi.nlm.nih.gov/pubmed/14757471

 Sponenberg, D. Phillip, & Carolyn J. Christman (1995). A Conservation Breeding Handbook. Pittsboro, North Carolina: American Livestock Breeds Conservancy.

 Thomas, H.S. (2009, February). Foaling complications: Part one. California Thoroughbred. Arcadia, California: California Thoroughbred Breeders Association. p 78.