Evaluation of dietary and management risk factors for enterolithiasis among horses in California

Enteroliths are intestinal calculi that result in intestinal obstruction and colic in horses. Equine enterolithiasis occurs worldwide, but the disease is particularly prevalent in some geographic locations, including California. The objectives of this study were to evaluate dietary and environmental risk factors for the disease. This was accomplished through a case–control study by comparing horses with colic from enterolithiasis presenting to the University of California, Davis VMTH, to horses with colic of other causes. Data were collected on 61 horses with enterolithiasis and 75 controls via evaluation of patient records and questionnaires completed by owners at the time of admission. Following multiple logistic regression analysis, the following factors were found to be significantly associated with enterolithiasis: feeding 50% of the diet as alfalfa; feeding <50% of the diet as oat hay; feeding <50% of the diet as grass hay; and lack of daily access to pasture grazing.     

Risk factors for enterolithiasis among horses in Texas

OBJECTIVE: To identify risk factors for enterolithiasis in horses. DESIGN: Matched case-control study. ANIMALS: 26 horses with enteroliths, 104 horses with other causes of colic that underwent surgery (52 horses, surgical control group) or were treated medically (52 horses, nonsurgical control group). PROCEDURE: Medical records were reviewed for horses with enteroliths and control horses. Information collected included signalment, anamnesis, and findings on physical examination and clinicopathologic testing at admission. Horses with enteroliths and control horses were compared by means of conditional logistic regression to identify factors associated with enterolithiasis. RESULTS: Horses that were fed alfalfa hay, spent < or = 50% of time outdoors, or were Arabian or miniature breeds had an increased risk of developing enteroliths. Horses with enteroliths were more likely to have been hyperbilirubinemic and to have had clinical signs > 12 hours prior to admission. CONCLUSIONS AND CLINICAL RELEVANCE: Breed and diet appear to influence the risk of enterolithiasis; other management factors also may influence development of enteroliths. Duration of clinical signs may be longer and signs may be less severe among horses with enteroliths, compared with horses with other causes of colic.     

Dietary risk factors and colonic pH and mineral concentrations in horses with enterolithiasis

A prospective, unmatched case control study was performed to identify dietary and environmental risk factors for enterolithiasis in horses in California and to determine whether colonic ingesta analyses differed between horses with and without enteroliths. Forty-three horses with enterolithiasis were compared with 19 horses with surgical colic attributable to nonstrangulating obstruction of the colon without enteroliths. Colonic ingesta samples were collected at surgery from horses with enteroliths and control horses. Colonic pH and colonic concentrations of magnesium, phosphorus, sulfur, sodium, calcium, potassium, and nitrogen were measured. Questionnaires were distributed to owners to determine diet and management practices. Student's t-test and Mann-Whitney tests were used to evaluate differences in pH, dry matter content, percent nitrogen, and mineral content. Associations between dietary and management risk factors and enterolith occurrence were quantified by odds ratios. Mean pH of colonic contents from horses with enterolithiasis was significantly higher than for control horses. Horses with enterolithiasis had significantly lower percent dry matter in colonic fecal samples and higher mean mineral concentrations than controls. On the basis of reported feeding and management practices, horses with enterolithiasis were fed a significantly higher proportion of alfalfa in their diet and were less likely to have daily access to pasture grass than horses without enteroliths. Results suggest that decreasing alfalfa consumption and allowing daily access to pasture grazing might reduce the risk of enterolithiasis. Dietary modifications promoting acidification of colonic contents and dilution of minerals might be beneficial as preventive measures for enterolithiasis in horses.     

Feeding practices associated with colic in horses.

OBJECTIVE: To determine whether specific feeding practices were associated with development of colic in horses. DESIGN: Prospective matched case-control study. ANIMALS: 364 horses examined by veterinarians in private practice in Texas because of colic (cases; n = 182) or any other reason (controls; 182). PROCEDURE: Participating veterinarians were sent forms at the beginning of the study to collect information on signalment, feeding management practices, farm management practices, and preventive medical treatments. Case and control horses were compared by use of conditional logistic regression to identify factors associated with colic. RESULTS: Risk factors for colic were a recent change in batch of hay, decreased exposure to pasture, a recent change in type of grain or concentrate fed, feeding > 2.7 kg (6 lb) of oats/d, feeding hay from round bales, and Thoroughbred breed. Recent anthelmintic administration decreased the risk of colic. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that certain changes in diet (eg, change in batch of hay, change in type of grain or concentrate, feeding hay from round bales) and management (eg, decreased availability of pasture) increase the risk of colic in horses.     

Influence of diet and water supply on mineral content and pH within the large intestine of horses with enterolithiasis

To determine the effects of two diets and water supplies on intestinal pH and mineral concentrations in the colon of horses, and to identify whether differences in these parameters exist in horses with and without enterolithiasis, surgical fistulation of the right dorsal colon was performed in six adult horses, three with and three without enterolithiasis. Each horse underwent four feeding trials: grass hay and untreated water, alfalfa hay and untreated water, grass hay with filtered/softened water, and alfalfa hay with filtered/softened water. Samples of colonic contents were analyzed for pH, dry matter, and mineral concentrations.Horses with enterolithiasis had higher calcium, magnesium, phosphorus and sulfur concentrations and higher pH in colonic contents than controls. Horses fed alfalfa had lower colonic sodium and potassium, higher calcium, magnesium, phosphorus and sulfur concentrations, and a more alkaline pH than those fed grass. Grass hay consumption leads to reduced concentrations of select minerals and a more acidic colonic environment compared with alfalfa, probably beneficial in the prevention of enterolithiasis. Under controlled dietary and management conditions, horses with enterolithiasis have differences in colonic mineral and pH parameters that may be consistent with physiological differences between horses with and without the disease.     

Dietary and other management factors associated with colic in horses.

OBJECTIVE: To determine whether dietary and other management factors were associated with development of colic in horses. DESIGN: Prospective matched case-control study. POPULATION: 2,060 horses examined by veterinarians in private practice in Texas for colic and noncolic emergencies. PROCEDURE: Each month for 12 months, participating veterinarians were sent forms to collect information on 1 horse with colic and 1 horse that received emergency treatment for a condition other than colic, information collected included signalment, farm management and characteristics, diet, medical and preventive medical factors, transport, and activity or use. Case and control horses were compared by means of conditional logistic regression to identify factors associated with colic. RESULTS: Recent change in diet, recent change in type of hay, history of previous episode of colic, history of abdominal surgery for colic, recent change in weather conditions, recent change in housing, Arabian breed, administration of an anthelmintic during the 7-day period prior to examination, failure to receive regular deworming, age > 10 years, and regular exercise (vs pastured at all times) were associated with increased risk of colic. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that changes in diet (particularly in type of hay fed) contribute to increased risk of colic. A regular program for administration of anthelmintics may reduce the overall frequency at which colic develops, but recent administration of anthelmintics may predispose some horses to colic. Arabian horses may have an increased risk of colic, and horses at pasture may have a decreased risk of colic.     

Effect of Feed Processing Method on Average Daily Gain and Gastric Ulcer Development in Weanling Horses

The present study evaluated the effects of two different methods of feed processing on growth and gastric ulceration in 16 weanling Standardbred horses. The two diets were composed of identical ingredients that were processed differently and fed at a rate of 3% body weight per day. The hay and grain diet (diet HG) consisted of 50% alfalfa hay cubes and 50% commercial texturized grain mix fed as is, without any further processing, with the cubes and grain fed in separate containers. The complete pelleted diet (diet CP) consisted of the same proportion of hay cubes and grain mix, which was ground, pelleted, and fed in a single container. The horses were divided into two groups and the study was divided into three periods of 30 days each. During period 1, all 16 horses consumed only free choice alfalfa hay (diet H). Group 1 was given diet CP during period 2 and diet HG during period 3. Group 2 was given diet HG during period 2 and diet CP during period 3. The horses were endoscopically examined for the baseline number and severity of stomach ulcers at the end of period 1, then again at the end of each treatment diet feeding period. Horses on diet CP in periods 2 and 3 had greater ulcer numbers (P = .0135) than diet HG. However, there was no significant difference (P = .30) in ulcer numbers when making a direct comparison between diets CP and HG. Despite the gastric ulceration found in horses on diet CP, the average daily gain was significantly greater (P = .016) for diet CP than for diet HG. Both diets containing grain were observed to cause gastric ulceration.     

Plasma Concentration of Glucosamine and Chondroitin Sulfate in Horses after an Oral Dose

This study was conducted to study absorption of glucosamine (GlucN) and chondroitin sulfate (CS) in horses immediately after feeding. Six mature mares were used in a replicated 3 × 3 Latin-square-designed experiment. The experiment consisted of three 15-day periods, which included 10 days of diet adaptation followed by a 5-day sampling period. Blood was drawn after feeding on one day during each sampling period. Horses were fed a control diet (40% hay, 60% concentrate) balanced to meet NRC requirements for maintenance of mature horses (NRC, Nutrient requirements of horses, 1989). In one experimental diet, 2.0 g CS and 5.5 g GlucN were added to the basal ration at each feeding. In the other experimental diet, 3.5 g CS and 8.5 g GlucN were added to the basal ration at each feeding. After collections, blood was centrifuged and plasma was harvested and stored until analyzed for the presence of each compound. Analyses for plasma GlucN were performed using high-performance liquid chromatography. CS in the plasma was analyzed using a color reagent, dimethylmethylene blue, followed by ultraviolet spectrophotometry. There were no significant differences (P < .05) in the concentration of either CS or GlucN in plasma, when comparing the three different diets. This leads to a conclusion that these compounds were not absorbed intact through the intestinal wall into the bloodstream. This poses a question as to whether oral forms of these compounds are absorbed and are able to migrate to joints through the blood to improve joint function.     

Effects of feed form on growth and blood glucose in weanling horses

Eight weanling Standardbred horses were used to evaluate the effects on growth and plasma glucose of two differently processed diets with identical ingredients fed at a rate of 3% of body weight, as fed, daily. The daily ration was divided into two equal feedings at 7:00 am and 7:00 pm. The hay and grain diet (diet HG) consisted of 50% alfalfa hay cubes and 50% of a commercial growing horse texturized grain mix fed as is, without any further processing, with each part fed in separate containers. The completely pelleted diet (diet P) consisted of the same proportions of the hay cubes and grain mix that was ground, pelleted, and fed in a single container. Two groups of four horses were fed either diet P or diet HG for two 21-day periods such that each horse consumed each diet for 21 days. On the last day of each feeding period, 7-mL blood samples were drawn into heparinized evacuated blood tubes for determination of plasma glucose concentration. Blood samples were drawn 30 minutes before the afternoon feeding, immediately before, and every 30 minutes thereafter for 5 hours. Analysis of variance found greater (P = .027) average daily gain for horses fed diet P versus diet HG. A nonsignificant difference was seen in feed efficiency (P = .057) for horses fed diet P versus diet HG. Plasma glucose changes were compared across treatments using area under the curve analysis. No difference (P > .05) was found in the postprandial plasma glucose changes between diet treatments.     

Analysis of Sodium Carboxymethylcellulose Administration and Related Factors Associated with Postoperative Colic and Survival in Horses with Small Intestinal Disease

Objective— To analyze the effect of the intraoperative use of sodium carboxymethylcellulose (CBMC) and related perioperative factors on postoperative colic and survival in horses that had abdominal surgery for colic.
Study Design— Retrospective study.
Animals— Horses (n=203) that had surgery for small intestinal disease; 33 horses had intraoperative administration of CBMC.
Methods— Information was obtained from medical records for 170 horses that had surgery for colic before use of CBMC and 33 horses that had intraoperative CBMC. Kaplan–Meier survival curves were used to estimate median survival time and a Cox proportional hazards model was used to estimate the hazard ratio for the effect of CBMC and other perioperative variables on survival.
Results— Seventy-five percent of horses administered CBMC survived to 180 days, whereas 75% of untreated horses survived 8 days (median survival time=18 days). Horses not administered CBMC were twice as likely to die compared with horses administered CBMC. Horses that had postoperative ileus (POI) were 1.4 times more likely to die than horses without ileus. Similarly, horses with signs of colic after surgery were 1.3 times more likely to die than horses without postoperative signs of colic.
Conclusions— CBMC administration is seemingly protective against death and prolongs survival when used intraoperatively in horses with small intestine disease, particularly horses with postoperative colic or POI. Both POI and colic increased risk of death after surgery.
Clinical Relevance— Intraoperative administration of CBMC in horses that have surgery for small intestinal disease may improve survival, possibly by reducing early adhesion formation.     

Food and water intake and selective feeding in rabbits on four feeding regimes

Diet plays an important role in maintaining rabbit health. Feeding an incorrect diet, particularly a low fibre diet, has been linked with digestive, dental and urinary tract disease. However, food intake and dietary requirements have been poorly studied in pet rabbits. This study assessed the effects of two commonly fed pet rabbit diets [extruded nuggets with hay (EH) and muesli with hay (MH)] alongside hay only (HO) and muesli only (MO) on food and water intake in 32 Dutch rabbits. Dry matter (DM) intake was greater in the HO group and lower in the MO group than in the EH and MH groups (p < 0.001). The portion of the diet made of hay was greater in the EH group than in the MH group (p < 0.001). Water intake was positively correlated with DM intake and was greatest in the HO group (p < 0.001). Selective feeding occurred in all rabbit groups fed muesli, whether or not hay was also available. Pellets were rejected, and grains and extrudates selected. The presence of selective feeding in all rabbits fed muesli leads to the consumption of an unbalanced diet. In addition, hay intake and water intake were lower when muesli was fed. Conclusions drawn from this study are based on general recommendations for pet rabbits, and clinical disease may have developed by feeding the study diets over a longer time period, as many diet‐related conditions typically present in older rabbits. However, the study demonstrates that the feeding of muesli diets cannot be recommended.     

The Effect of Hay Net Design on Rate of Forage Consumption When Feeding Adult Horses

Modern horse management systems tend to limit a horse's opportunity to forage. The objective of this experiment was to investigate the effect of hay net design on the rate of forage consumption when feeding horses. Eight adult horses were fed in individual stalls in a replicated Latin square design, with two horses per treatment per week. Horses were fed hay off the stall floor (control), or from one of three hay nets: large (15.2 cm openings), medium (4.4 cm openings), and small (3.2 cm openings). Horses had access to hay for two 4-hour periods each day. When horses could not consume all forage from the medium and small hay nets in 4 hours, a second study using a crossover design gave horses an unlimited amount of time to feed from the hay nets. Stopwatches were used to calculate time to consumption and dry matter intake rates (DMIR). Mean time to consumption was 3.1 and 3.4 hours for the control and large hay net, respectively, in study 1, and 5.1 and 6.5 hours for the medium and small hay nets, respectively, in study 2. Mean DMIR during the 4-hour feeding period were 1.5, 1.3, 1.1, and 0.9 kg/hr for the control, large, medium, and small hay nets, respectively; all treatments were different (P < .0001). These results demonstrate that hay nets were effective at decreasing the rate of forage consumption when feeding adult horses. Long-term studies are warranted to determine if horses will adapt to feeding from hay nets.     

Risk factors of colic in horses in Austria

A hospital‐based case study was conducted at the University of Veterinary Medicine Vienna for a 1‐year period. The purpose of this study was to determine possible alterable and non‐alterable risk factors of equine colic in Austria. The investigated parameters were obtained from hospital medical records (individual factors, duty of the horse, deworming, change in diet and water intake), from questionnaires (feed intake, watering types, housing and pasture practices) and from http://www.orf.at (weather‐related factors). Moreover, 221 collected feed samples were investigated through hygienic quality sensory evaluation and mould, yeast and bacteria presumptive samples were confirmed by microbiological investigation. Variables that were observed from the hospital medical records and found to be significantly associated with colic in a univariate analysis were included in multivariate analysis and the only remaining risk factor was decreased water consumption (p < 0.001, OR = 5.025). Consequently, a total of 2743 horses and 366 cases of colic were observed during the study period. The risk factors for colic in Austria were identified for the first time in this study and these increased risk factors were decreased water consumption, high amount of concentrate intake (p = 0.037), low hygienic quality of hay (p = 0.027) and high temperature on the arrival date (p = 0.003). Results suggest that the occurence of colic may not stop, but may decrease with better feed management practices in Austria.     

Factors associated with development of ileal impaction in horses with surgical colic: 78 cases (1986-2000)

Deal impaction is prevalent in the south-eastern USA, where feeding of Coastal Bermuda hay has been implicated as a risk factor. Alternatively, infection with the tapeworm Anoplocephala perfoliata has been identified as a risk factor for ileal impaction in the UK. We hypothesised that feeding Coastal Bermuda hay and failure to administer routinely an anthelmintic with efficacy against tapeworms would place horses at risk of developing ileal impaction in the USA. Seventy-eight horses, with surgically confirmed ileal impaction and 100 horses admitted for colic that did not have an ileal impaction, were selected retrospectively for logistic regression analysis. Using odds ratios (OR) as an index of risk, feeding Coastal Bermuda hay (OR = 2.9) and failure to administer a pyrantel salt within 3 months of admission (OR = 3.1) placed horses at risk of development of ileal impaction. This study confirms the belief that feeding Coastal Bermuda hay places horses at risk of ileal impaction, although the quality of the hay may also play a role. Periodic administration of anthelmintics with efficacy against tapeworms should be considered to reduce risk of ileal impaction.     

Surgical Reduction of Ileal Impactions in the Horse: 28 Cases

Objective —To evaluate the seasonal influence, signalment, type of hay consumed, clinical examination findings, and outcome after surgery for horses with ileal impaction. Study Design —A retrospective study. Results —Between 1988 and 1993, 28 horses had surgical correction of ileal impaction. There was a significantly higher rate of ileal impaction during the Fall (September-November, P= .0041). Mean duration of clinical signs of abdominal pain before referral was 15 hours. Transrectal palpation was used to localize the impaction in 11 horses. The ileal impaction was reduced by extraluminal massage aided by admixing of intestinal fluid oral to the impaction or injection of fluids intraluminally and then movement of the ingesta into the cecum alone in 24 horses. A total of 26 horses recovered from surgery; 24 horses were discharged from the hospital and eventually returned to previous use. Two horses had fatal postoperative complications: jejunocec-ostomy dehiscence and development of extensive small intestine adhesions after manual reduction of the impaction. One horse initially treated by manual reduction required jejunocecostomy twice for management of recurrent ileal impaction. Follow-up information was obtained for 21 horses, of which 20 were alive 1 year or longer after surgery. A total of 27 of 28 horses were fed Coastal Bermudagrass hay as the primary type of hay consumed. A total of 9 horses continued to be fed Coastal Bermudagrass hay as the only roughage source, whereas 6 horses were fed Coastal Bermudagrass with at least 50% other hay, and in 6 horses, Coastal Bermudagrass hay was entirely eliminated from the diet. Conclusion and Clinical Relevance—Ileal impactions can be successfully reduced by celiotomy and extraluminal massage and injection techniques to soften the ingesta for passage into the cecum without enterotomy or bypass techniques in most horses. Changes in weather and feeding practices in the Fall may account for an increased risk of ileal impaction in horses in the southeastern United States at that time of year.     

Nutritional considerations for horses with colitis. Part 1: Nutrients and enteral nutrition

The equine colon is the primary site of fibre digestion and water absorption. It is therefore not surprising that colitis and associated colonic dysfunction can result in severe nutritional derangements, which can be exacerbated by reduced feed intake in affected horses. Dietary management of colitis is important for optimum recovery. In broad terms, it should prioritise provision of nutrients to horses that otherwise have reduced appetites. In some forms, such as right dorsal colitis, as well as those with chronicity, nutritional recommendations include restricting or eliminating long‐stem roughage from the diet and feeding a complete pelleted diet. Voluntary enteral nutrition is preferred, but horses that are not ingesting enough to meet the minimum recommended requirements as outlined, should be fed via nasogastric tube (if tolerated – no reflux, no ileus and no colic present; faecal output present). Parenteral nutrition may be necessary in some cases, as some colitis cases do not tolerate enteral feeding for reasons such as colic, intestinal dysmotility or abdominal distension. Timing and constitution of nutritional intervention is vital and should be tailored to the individual patient to prevent further complications of the disease process.     

Fat Supplementation to Alfalfa Diets for Refeeding the Starved Horse

The objective was to examine the metabolic responses of chronically starved horses using two isoenergetic diets consisting of either 100% alfalfa hay (AH) or 80% alfalfa hay with 20% corn oil (AO), on a caloric basis. Two 10-d trials were conducted using 14 emaciated, but otherwise healthy, horses with an initial mean body condition score of 1.8 ± 0.9 and mean BW of 336 ± 31 kg. The initial DE intake of 50% of maintenance was gradually increased to 100% during the 10-d refeeding period. Two of the horses receiving the AH diet were euthanized, thus 12 horses (AH, n = 7; AO, n = 5) survived the 10-d study. One preprandial and four postprandial venous blood samples were collected daily. Dietary effects (P<0.01) were shown for blood serum or plasma free fatty acids (FFA), phosphate, magnesium, and 2,3-diphosphoglycerate (2,3-DPG), but not glucose, insulin, or potassium concentrations. The response of insulin and FFA during the 10-d study showed differences (P<0.05) between AH and AO diets. Serum phosphate concentration in horses on both diets exhibited a general slow decline with concentrations below normal reference range during d 5 through 10, thus indicating hypophosphatemia. Serum magnesium increased in horses consuming the AH diet, whereas concentrations in horses consuming the AO diet consistently were below reference range, leading to mild hypomagnesemia. Hypokalemia did not develop in either treatment group, as all serum potassium concentrations remained in the normal reference range. The substitution of corn oil in isoenergetic alfalfa diets was not advantageous in minimizing or preventing hypophosphatemia or hypomagnesemia for refeeding starved horses. The AH diet is recommended as more supportive in refeeding starved horses because of the greater intake of dietary phosphorous and magnesium.     

The Influence of Stable Management and Feeding Practices on the Abnormal Behaviors Among Stabled Horses in Malaysia

The present study aimed to provide preliminary data on the prevalence of oral stereotypic, locomotory stereotypic, and redirected behaviors as well as their associations with stable management and feeding practices. In this cross-sectional study, a total of 207 working horses used for leisure riding, equestrian sport, polo, endurance, and patrolling were selected from seven equine facilities. Data on the stable management and feeding practices were obtained through the stable records, interviews, and on-site monitoring visits, whereas the prevalence of abnormal behaviors in the studied population was determined using the instantaneous scan sampling method. Most horses in the present study worked for more than 8 hours per week (n = 93). In addition, more horses were fed three times per day (n = 65) with different amounts of hay, concentrate, and chaff. Among the study population, oral stereotypic behaviors had the highest prevalence (n = 281; 54%), followed by redirected behavior (n = 181; 34%), and locomotory stereotypic behaviors had the lowest prevalence (n = 63; 12%). The oral stereotypic behavior was found to be significantly influenced (P < .05) by the working hours, amount of hay, and amount of concentrate. Both locomotory stereotypic and redirected behaviors were found to be influenced (P < .05) by the number of feedings per day and the amount of hay. In summary, the present study has proven that the stable management and feeding practices could influence the prevalence of different abnormal behaviors in the majority of working horses, with oral stereotypy being the most common abnormal behavior in this country.     

Small intestinal obstruction associated with wood chewing in two horses

Although wood chewing by horses is recognised as a common vice, there are few reports of specific disease associated with the habit. Two cases of acute obstruction of the small intestine by solid aggregations of wood splinters are described in horses which were both habitual wood chewers. Details are presented of the clinical findings in these cases, including the surgical treatment of acute colic. Both horses returned to full working fitness. The authors review the syndrome of enterolithiasis in horses, and discuss the causes and significance of wood chewing as a stable vice.     

Colic in geriatric compared to mature nongeriatric horses. Part 1: Retrospective review of clinical and laboratory data

Reason for performing study: It is the impression of some surgeons that geriatric horses have a lower survival rate compared to mature nongeriatric horses following colic surgery. One possible reason for this is that geriatric horses may be more critically ill at admission and have more severe disease than mature nongeriatric horses. Objective: To compare admission historical, physical examination and laboratory data for geriatric and mature nongeriatric horses referred for signs of colic. Methods: Medical records of horses admitted with a presenting complaint of colic between 2000 and 2006 were reviewed. Geriatric horses ≥16 years (n = 300) and mature nongeriatric horses 4–15 years (n = 300). Information obtained included duration of colic prior to admission, admission level of pain, heart rate, intestinal borborygmi, packed cell volume (PCV), plasma creatinine and blood lactate concentrations and peritoneal fluid total protein. Data were analysed using a Chi‐squared test or an analysis of variance. Level of significance was P<0.05. Results: There was no difference between geriatric and mature horses in the duration of colic prior to admission or in admission heart rate, PCV, or plasma creatinine or blood lactate concentrations. However, geriatric horses were more likely to be moderately painful and less likely to be bright and alert than mature horses; and less likely to have normal intestinal borborygmi than mature horses. Peritoneal fluid total protein concentration was higher in geriatric than mature horses. Conclusions and potential relevance: Geriatric horses presenting with signs of colic had a similar admission cardiovascular status based on heart rate, PCV, and plasma creatinine and blood lactate concentration to mature horses. Geriatric horses, however, may have different causes of colic, which may be more serious than mature horses based on pain, lack of intestinal borborygmi and peritoneal fluid total protein concentration.