Understanding Equine Colic

May 2009 Understanding Equine Colic Gene Parker Jr. DVM OSU Extension Veterinarian Colic in horses is so common that most horse owners either have dealt with it in the past or will deal with it in the future. Colic is a major cause of death and suffering in today s horse population. It is not a disease, but is a condition that results in abdominal pain. Any type of colic should be considered abnormal. If mild and moderate colic cases are left to run their course they often result in major colic episodes due to complications. Causes of Colic The following are some of the common causative agents frequently associated with colic. Parasites Parasites can cause colic by attacking the walls of the major blood vessels that supply the digestive system and reducing the flow of blood to the extent that the tissues of the intestinal tract start to die. In young horses large roundworms, can become so numerous that they form a physical blockage to the passage of foodstuffs along the digestive tract. Dietary changes The horse s digestive tract has several areas where the gut goes from a large diameter to a small diameter (similar to a funnel) and/or turns back sharply on itself in a short distance. Horses become accustomed to the physical nature of their diet and if allowed to, will consume feed (especially roughage) at a slow but steady rate. Any sudden change in diet or feeding schedule can result in colic due to the formation of blockages at these locations. The gut is very well provided with stretch receptors and any condition that causes distention due to material or gases being backed up will cause extreme pain. Be sure to make any required dietary changes very gradually over several days to allow the horse s system to adjust. Insufficient water intake Horses need water as a nutrient, as a cooling agent, and also to help lubricate the contents of the gut to move along steadily and freely. Horses need large quantities of water and under some conditions they may not be drinking enough to ensure that all the requirements are met. Problems occur when water is hot or dirty in the summer or cold or frozen in the winter. Also horses, when traveling, may not drink enough water if the taste is different from what they are used to at home. This problem can be overcome by using a mild flavoring agent such as small amounts of flavored gelatin or soft drink in the water before leaving home, so that you can then mask any foreign taste. Insufficient roughage Today it is common to feed horses concentrates such as grains and grain products as a portion of their daily ration. It is important to remember, however, that horses are designed to utilize forages as their primary feed source. When feeding to maximize growth or performance it is easy to get too many concentrates and not enough roughage in the diet. Always make sure that horses have access to either good quality pasture or another source of roughage such as baled hay because many cases of colic result when the diet does not contain enough bulk from roughages. In 18 years of large animal practice I never saw a horse colic that had continuous access to plenty high quality forage

(grass or hay) and unlimited exercise. Putting a horse in a stall and feeding grain out of a sack is what causes most cases of colic in horses. Ingestion of toxins Many chemical and naturally occurring poisons and toxins can cause colic. Mold found in feedstuffs can frequently cause digestive disturbances. A toxin found in the bodies of dead blister beetles in baled alfalfa causes colic symptoms by severely damaging the digestive and urinary systems. Blister beetle toxicity can be avoided by using alfalfa that was harvested before the middle of May or after September, or harvested without using a crimper. Sand impaction When horses are fed on the ground in areas with sandy soils small amounts of sand can be picked up with the feed and gradually build up in the digestive system until they interfere with the passage of ingesta and cause distention with ingesta or gases that are formed behind the blockage. Clinical Signs of Colic Signs of colic can be categorized as behavioral or physiological. While behavioral signs will probably be your first notice that something is wrong, the physiological signs will help you to define the severity of the attack and if reported to your veterinarian will help assess the situation. Behavioral signs These signs are all associated with the horse s response to his stress and pain. He will be off feed. The horse usually will be circling, laying down, and may be violently rolling. He probably will turn his head to look back at his abdomen and may try to bite or kick at his flank. He may stretch out as if trying to urinate. Other signs include pawing, pacing, and nervousness. Physiological signs Horses in the midst of a colic episode will have increased heart and respiration rates. Dry, purple, or brick red mucous membranes indicate circulatory problems that are associated with severe colic. Capillary refill time greater than two seconds also suggest shock associated with severe colic. The longer the refill time, the more serious the situation is. Lack of gut sounds or very violent gut sounds are usually associated with colic. What to Do Until Help Arrives Techniques used in assessing and treating routine colic cases usually include passage of a nasogastric tube, rectal examination, abdominal fluid tap, treatment with prescription medications, and occasionally surgery. Consequently, this is the domain of licensed veterinarians. If you are in doubt as to your need for assistance, contact your veterinarian early in the episode; give him the signs you have observed, and let him decide on the best course of action. There are, however, some things you can do to help while you are waiting for assistance. Allow free choice to hay and water. Remove all feed. Try to keep the horse quiet. Allow the horse to lie down if he remains calm, allow the horse to roll if he is not being violent or causing physical injury to himself. Light and intermittent hand walking is usually helpful, but do not allow the horse to become exhausted. Do not administer any drugs unless directed to do so by your veterinarian. Drugs can mask the symptoms and interfere with the proper diagnosis and treatment. The old cowboy saying is true: A rolling horse will not cause a twisted gut; but a horse with a twisted gut will always roll. 2

Two New Livestock Disaster Programs in Farm Bill Daniel Skipper Area Extension Ag Economic Specialist There are two new livestock disaster programs in the Food, Conservation, and Energy Act of 2008 (the 2008 Farm Bill) under the title Supplemental Agricultural Disaster Assistance. These programs are the Livestock Indemnity Program (LIP) and the Livestock Forage Disaster Program (LFP). They are designed to assist livestock producers in the case of some form of disaster. Livestock Indemnity Program (LIP) LIP compensates producers for livestock death losses in excess of normal death due to adverse weather that occurs between January 1, 2008 and October 1, 2011. Producers will be compensated 75% of the fair market value as determined by the Secretary of Agriculture for each specific livestock category. No formal disaster declaration has to be made. Eligible adverse weather events include: Blizzard Tornado Lightning Ice storms Earthquakes Flooding Extreme cold Extreme heat Wildfire must be related to a weather event Disease must be related to or exacerbated by an eligible weather event Eligible livestock include: Adult/non-adult beef cattle Sheep Goats Swine Adult/non-adult dairy cattle Alpacas Llamas Poultry Adult/non-adult buffalo and beefalo Emus Deer Elk Horses used as a part of the commercial operation Reindeer Non-eligible livestock include: Show animals Pleasure animals Rodeo stock Pets Animals kept for home consumption Hunting animals Producers will need to file a notice of loss with the Farm Service Agency within 30 days of the loss of the livestock. Proof of death of the livestock may also be requested in the form of but not limited to rendering truck receipts, veterinary records, private insurance documents, or a measurement service as requested by the producer and completed by FSA. LIP will pay up to $100,000 annually including any benefits received from SURE and LFP. Livestock Forage Disaster Program (LFP) LFP provides financial assistance to producers who suffered grazing losses due to drought on or after January 1, 2008 and before October 1, 2011. To be eligible for LFP producers must meet each one of the following conditions: 1. Obtained crop insurance or Non-insured Crop Disaster Assistance (NAP) coverage on the pasture or grazing land that suffered an eligible loss. 2. Be an owner, cash or share lessee, or contract grower of covered livestock that provides pastureland or grazing land for livestock. 3

3. Provide pastureland or grazing land that is physically located in a county affected by a D2 or larger drought. A drought is determined by the U.S. Drought Monitor. A signup period will be announced when the following drought levels are reached: D2: 8 consecutive weeks in any area of a county during the normal grazing period. D3: 4 consecutive weeks in any area of a county at any time during the normal grazing period. D4: any area of a county at any time during the normal grazing period. The payment rate will be determined by the severity of the drought. D2 drought receives 1 monthly payment per head, D3 drought receives 2 months payment per head and a D4 drought receives 3 months payment per head. The drought monthly payment rate is equal to 60% of the lesser of the monthly feed cost for all covered livestock using a feed grain equivalent or the monthly feed cost calculated using the normal carrying capacity for the grazing land. The feed grain equivalent is determined by the National Office for the various type of livestock based on the pounds of corn using an adult cow as the base. Eligible livestock include: Adult/non-adult beef cattle Sheep Goats Swine Adult/non-adult dairy cattle Alpacas Llamas Poultry Adult/non-adult buffalo and beefalo Emus Deer Elk Horses used as a part of the commercial operation Reindeer Note: Only livestock that normally graze are considered eligible livestock. Livestock must be owned, leased or purchased for 60 days prior to the beginning date of the qualifying drought. LFP will pay up to $100,000 annually including any benefits received from SURE and LIP. Implanting Nursing Calves Bob LeValley Area Extension Livestock Specialist Implants have a long history of use in the beef cattle industry. The first commercial implant was introduced in 1955. Since that time, the use of implants has been widely adopted by the cattle feeding and stocker sectors of the beef industry. According to a 1999 survey, 99% of all feedlot cattle are implanted one or more times during the finishing phase. Two recent Oklahoma studies surveyed 729 producers that received the Beef Cattle Manual. Thirty-seven percent of cow-calf producers with larger operations (more than 100 cows) indicated that they implanted their steer calves, while only 9% of cow-calf producers with smaller operations (fewer than 100 cows) implanted their steer calves. 4

Implant products are available for calves weighing less than 400 lbs. Implants cleared for use in nursing calves contain a lower dose of the active ingredient compared to products cleared for use in older cattle. These implants are typically administered when the calves are between two and four months of age. Research has shown that implants given during the suckling phase will increase ADG of steer calves by approximately 0.10 lb/day. Most calf implants are designed to payout in approximately 100 to 120 days. In some circumstances, the suckling period is long enough that reimplanting would be appropriate. Steer calves that were implanted twice with zeranol or estradiol benzoate/progesterone implants gained approximately 0.12 lb/day more than nonimplanted control animals. The additional implant did not appear to have as much effect as the initial implant. Many producers follow the practice of leaving bull calves intact rather than castrating them at birth or two to four months of age. The idea is that hormones produced increase ADG and weaning weight of the calves. Numerous research trials have shown that implanted steer calves gain at a rate equal to, or greater than, bull calves. Castrating bulls as small calves, as opposed to weaned calves, reduces overall stress on the calf. The stress and hormonal effects of castration at weaning can reduce post-weaning gain potential and the calf s ability to withstand diseases typically associated with weaning and marketing. This difference in post-weaning performance of bulls versus steers is recognized by cattle buyers, as indicated by the fact that steers will command a $3 to $6 per cwt premium over intact bull calves. Producers wanting to maximize the value of male calves at weaning should consider early castration at birth or at two to four months of age and use an implant approved for nursing calves. Refer to the Oklahoma Beef Cattle Manual, for additional information on implanting heifers as well as general implant information. Summer Crops and Fall Wheat Forage Mark S. Gregory Area Extension Agronomy Specialist What do these have in common? In most years, maybe nothing, but this year the connection may be soil moisture. Any growth we get on a summer crop, whether it is a hay crop like sorghum-sudan or sunflowers or sesame, will remove soil moisture from the soil profile. Most of us have received rain, and moisture recharge in the soil surface may have occurred, but did it sink into the subsoil? Water running off of fields was not water being retained to recharge subsoil moisture. So what does that have to do with fall wheat forage production? 5

If we grow a summer crop, that crop will remove soil moisture. If we remove enough soil moisture without it being replenished during the summer, it will affect a fall planted wheat crop. If we don t replenish the moisture removed by a summer crop, we may get September rains adequate to get wheat to emerge and become established. But roots won t grow into dry soil. Therefore, if we have planted a summer crop that removed subsoil moisture, even if wheat gets established in the fall, lack of subsoil moisture may limit the amount of fall forage we can produce, which would also limit the amount of forage we carry into winter for grazing. Early Summer Alfalfa Stand Establishment Reminders By Mark S. Gregory Exerpts from www.alfalfa.okstate.edu/webnews/stand10.htm Good planning is critical to reliable alfalfa stand establishment. The exact steps required for success vary from farm to farm and from year to year. However, the following keys included in the Alfalfa Establishment Checklist below include most of the critical activities for this time of year. Producers expecting to plant alfalfa this fall should check off the listed keys to determine if they will be ready. Each of these items are discussed in OSU Extension Facts No.2089 which is available at county extension offices. Alfalfa Establishment Checklist: *Site Selection - Choose a deep, fertile, well-drained soil. *Soil Test - Fertilize and lime according to a reliable soil analysis. *Land Preparation - Plow, level, and drain low areas well before sowing. *Seedbed Preparation - Develop a level, mellow, firm bed with small clods. Don t forget to consider any herbicides used on a previous wheat crop (or any other crop) and the effect those herbicides might have on a seeding stand of alfalfa. Additional Information: Alfalfa Stand Establishment Questions and Answers. OSU Extension Circular E-949 Alfalfa Stand Establishment. OSU Extension Facts F-2089 6

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