JPH0725699B2 - Drugs for treating laminitis in equine livestock - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the treatment of equine livestock such as horses, donkeys, ponies, mules and the like.

One form of this invention is a glycopeptide antibiotic.
eptide antibiotic, or glycolipid anibiotic, or staphylomycin antibiotic, staphylomycin antibiotic, or polypeptide antibiotic (polypeptide anibiotic), or macrolide antibiotic (macrolide anibiotic) It is a therapeutic drug for equine livestock.

According to a preferred feature of the present invention, the drug is a drug for treating laminitis in equine livestock by suppressing the lactate concentration in the posterior intestine.

According to a preferred feature of the invention, the drug is in a particulate form that is resistant to enzymatic digestion in the upper gastrointestinal tract and enhances cecal uptake.

According to preferred features of the above features, the particle size is at least about 1 mm large.

According to a preferred feature of the above features, the particles are fibrous.

According to a preferred feature of the invention, the glycopeptide antibiotic comprises avoparcin.

According to a preferred feature of the present invention, the glycopeptide antibiotic includes vancomycin.

According to a preferred feature of the invention, the glycolipid antibiotic is flavomycin (banvermycin) [flavomyc
in (bambermycin)].

According to a preferred feature of the invention, the staphyromycin antibiotic comprises virginiamycin.

According to a preferred choice of the present invention, the polypeptide antibiotic comprises bacitracin zinc.

According to a preferred selection of the present invention, the polypeptide antibiotic is bacitracin methylene disalicylate.
methylene disalicylate).

According to a preferred selection of the present invention, the polypeptide antibiotics include virginiamycin S.

According to a preferred selection of the invention, the polypeptide antibiotics are polymyxins (B and E) [polmyixins (B & E)].
Includes.

According to a preferred feature of the invention, the macrolide antibiotic comprises tylosin.

According to a preferred feature of the invention, the macrolide antibiotics include spiramycin.

According to a preferred feature of the invention, the macrolide antibiotics include virginiamycin M.

According to a preferred feature of the invention, the macrolide antibiotics include josmycin.

According to a preferred feature of the invention, the macrolide antibiotics include spectinomycin.

According to a preferred feature of the present invention, the macrolide antibiotic includes erythromycin.

The digestive action of horses includes gastric digestion, where enzymes act on the ingested feed in the acidic stomach, then absorption of nutrients from the small intestine, and then fermentative digestion in the cecum, colon and colon. The volume of the caecum, colon, and large intestine is about 50-60, and in most diets the end product of fermentation in these parts of the intestinal system supplies more than half of the effective heat to the animal.
The main end products of fermentation are three volatile fatty acids consisting of acetic acid, propionic acid and butyric acid. To understand how modifying their relative importance, such as fermentation end products, enhances the performance of horses, an explanation of the process by which these acids are produced is required.

During microbial fermentation, carbohydrates including cellulose, hemicellulose, starch and sugar are first broken down into hexacarbon compounds (hexose sugars). It is then fermented and converted to volatile fatty acids via pyruvate. 1 mol hexose to 2 mol acetic acid, or 2 mol propionic acid, or 1 mol
It is possible to obtain molar butyric acid. 2 in the final product
A mole of propionic acid contains 3.08 MJ of heat and one mole of butyric acid contains 2.20 MJ, compared to 1.
Includes 75 MJ. Therefore, if the production of propionic acid is increased relative to the production of acetic acid and butyric acid, then more calories per unit of fermented carbohydrate will be available to the animal.

Volatile fatty acids are utilized by animals via different biochemical pathways in liver and living tissues. Acetic acid and butyric acid cannot be used for the synthesis of glucose. On the other hand, propionic acid is converted to glucose in the liver. Glucose is an essential nutrient for many living tissues such as the brain and kidneys, and is a basic compound of glycogen, which is a storage source of intramuscular biochemical calories. Glycogen is rapidly broken down into glucose as the animal exercises, as it is used in muscle. And its effectiveness can affect speed and / or the ability of the animal to endure. Thus, increased production of propionic acid in the cecum, colon may enhance glycogen accumulation.

When acetic acid or butyric acid is produced during fermentation, gas, carbon dioxide is also produced. Part of this carbon dioxide is converted to gas methane. Some of this, called gas, is absorbed through the gastrointestinal tract, but some is flatus. Under certain conditions, gas is produced more rapidly than it is removed, and the accumulation of gas causes the animal to distend the colon, which is the cause of severe abdominal pain (colic pain). One form of fermentation in which propionic acid production is increased results in the production of smaller amounts of gas, which reduces the amount of gas that is discharged and is expected to reduce the accumulation of gas that causes colic. Be done.

When the horse consumes cereals or other feeds containing starch or soluble carbohydrates, some of this is digested by fermentation in the cecum and colon. Starch and soluble carbohydrates provide substrates for rapidly fermenting bacteria. The immediate consequences of this rapid fermentation are the following changes: an increase in the rate of volatile fatty acid production; a decrease in pH (pH);
Accumulation of lactic acid. It is known that many adverse effects in horses are associated with high intakes of starch or soluble carbohydrates in animals. The effects of excessive carbohydrate intake on animals include harmful behaviors (eating timber and feces), increasing testosterone levels, lowering blood pH, decreasing blood bicarbonate levels, increasing body temperature, and blood lactate. Includes increased concentrations, laminitis, etc. leading to lameness. Chlamititis is an inflammation of the foot of a horse. A thin film is located between the bone and the crease, and the crease contains a blood vessel. When the thin film between the two parts becomes inflamed, the rigid surface swells, compresses, ache,
Causes tissue damage. Through the anterior venous shunt, the blood supply to the inflamed tissue is cut off, which results in a thin-film local ischemic gangrene in front of the fold. In severe cases, the hooves are likely to come off the lamina of the underlay, or the foot may undergo a downward rotation of the femur. It is not known about the biological pathways associated with carbohydrate overdose and chlorophyll, but it is clear that feeding large amounts of cereals or fresh green grass results in laminitis and lameness. The inventor has found that these adverse effects are closely correlated with low pH and high lactate in the cecum and colon. Therefore, it regulates low pH and high lactate levels in the cecum and colon, so that when starch or soluble carbohydrates are given as a major component of a defined diet,
It would be more desirable to reduce or eliminate adverse effects on animals.

Today, nutritional management of horses requires about half of the diet to be fed with forage and only small amounts of starch. This method of feeding is intended to avoid laminitis, which is well known to be associated with excessive starch in the diet. If it were possible to feed additional grain (starch) and less forage, then there would be many advantages such as scabbing.

(I) By reducing the amount of digestive material in the hindgut of the horse, reducing the total body weight of the animal without affecting the muscle mass.

(Ii) facilitate the implementation of a "carbohydrate burden" used in athletic horse nutrition management. This practice requires that the muscles be eaten with starch or soluble carbohydrates prior to the race or performance in order to spike glycogen reserves.

(Iii) Reduction of horse feed costs. Grains rich in starch are
High-quality roughage commonly used as horse feed (hay, cut straw)
It is a lower digestive heat source.

Lactate in horse blood and tissues can come from two sources (i)
When glucose is completely burned to carbon dioxide, it is formed by the muscle when glucose is used as a heat source due to the presence of insufficient oxygen. (Ii) Accumulation of lactate in the cecum and colon is absorbed and it contributes to the total lactate concentration in the blood. Accumulation of lactic acid in the blood causes the animal to lose its athletic capacity at all potentials and cause muscle pain. The secondary efficacy of blood lactate reduces appetite,
Thus reducing feed intake. Loss of appetite can be an important factor when a horse being trained requires ultra-high heat to maintain physical condition and maintain long-term training. Inhibition of lactate during fermentation of carbohydrates in the cecum and colon reduces the total concentration of lactate in the blood, thereby contributing to a reduction in the secondary effects of animal metabolites.

Much research has been done on the development and control of lactic acidosis in sheep and cattle by feeding excess fermentable carbohydrates. The main lactate bacteria are Streptococcus bovis.
cus vovis) and Lactobacillus sp.
p.). These are Gram-positive organisms and it has been shown that the accumulation of lactic acid can be suppressed by the use of a series of antibiotic compounds that are particularly active against Gram-positive bacteria. Nagaraja and colleagues reported that the ionofol compounds lasalocid or monensin could be used to suppress lactic acidosis in cattle (1981). Muir
Have used thiopeptin and related antibiotics on sheep,
Demonstrated suppression of wheat-induced acidosis (1980). And Aitchison and colleagues showed that sheep were given crushed wheat and aboccin was particularly effective at suppressing lactic acid in sheep (1986). In all these studies, the endpoint of lactic acidosis inhibition was the inhibition of lactic acid accumulated in rumen fluid. Chlamititis is not a major problem for ruminants, and in the above studies no observation of the effect of antibiotic treatment on the signs of lameness in the animals studied was reported.

In addition to the question of whether suppressing lactate production in the large intestine of horses could prevent laminitis, these antibiotics were used in equine livestock based on the use of certain antibiotics effective in ruminants. It is not certain that its use will be effective. Ruminants are anterior gastric fermenters, whereas horse fermenters are in the posterior gut. In the horse, all substances (feed, bacteria, antibiotics) pass through enzymatic digestion in the stomach and small intestine and reach the main fermentation chambers, the cecum and the large colon. The difference between these two types of animals is
Therefore, it is also to be expected in relation to the toxicity of antibiotics to the host (eg monensin is highly toxic to horses), the substrate to be fermented, and the composition of the fermenting microbial community.

A first object of the invention is to change the form of cecal, colonic fermentation in such a way that (i) little or no lactic acid is produced, (ii) and the pH remains within normal limits.

A second object of the invention is to increase propionate production relative to acetate, butyrate during posterior intestinal fermentation.

The following series of three reference examples and examples show (i) whether the use of antibiotics selective for Gram-positive organic matter can suppress lactic acid accumulated in the hindgut of horses.
i) Whether foliar inflammation can be suppressed by preventing lactic acid accumulation during starch fermentation, (iii) Propionate formation by the action of antibiotics active against Gram intestinal organic matter during posterior intestinal fermentation The objective of this study was to determine whether or not the increase was related to acetate and butyrate.

Reference Examples and Examples In Reference Examples, animals were administered with wheat slurry to which avopersin was added and without addition of avopersin. Lactic acid accumulation and lameness in the posterior gut occurred with or without avopersin. This effectively proved that the results obtained in ruminants are not necessarily inferred by events occurring in the hind or large intestines of horses. Based on this result, Examples 1-6 were performed to examine the efficacy of a series of antibiotics on the inhibition of lactate production in digests from the caecum and large colon of horses. In this experimental program, Virginiamycin was identified as a substance that reliably and effectively inhibits lactic acid accumulation. Examples 7 and 8 were conducted to investigate the effectiveness of Virginia myx in suppressing lactic acid and laminitis by feeding horses with a suppressed dose of ground wheat.

Reference Example 1 Avopersin in vivo Four horses were administered with 15 g wheat per kg body weight. The wheat fed to two contained 120 mg of avopersin per kg of wheat, and the other two were fed drug-free wheat. The animals were examined before administration and every 8 hours for 24 hours after administration. Body temperature and heart rate were measured at these times. Venous blood samples were taken for measurement of pH, blood gases, bicarbonate, D-lactate, L-lactate. Animals were also evaluated by Obel's criteria (19) summarized by Garner et al. (1977).
48 years) and examined for signs of lameness. Twenty-four hours later, all animals were sacrificed and digested samples were taken from the cecum and large colon for analysis of lactate, volatile fatty acids, and avopersin concentrations.

Three of the four animals used in this experiment showed signs of obel grade 2 lame within 24 hours of crushed wheat administration.
One horse showing no signs of lameness was D compared to other horses
-Lower lactate concentration, the stomach was also clogged with wheat at 24 hours. All three horses showing signs of lame showed high D-lactate levels in blood and colon digests (see Table 1). The data in Table 1 show D-, L in both the cecum and large colon.
-It shows that the lactate co-appeared at approximately the same ratio.

Avopersin was used to control lactic acidosis in sheep data [Aitchison et al.
(1986)], it is clear from this result that it is impossible to deduce the possibility of using avopersin in horses for the same purpose.

In addition, this result shows that animals treated with avopersin (2
The second and fourth horses) had lower antibiotic concentrations in the cecum than in the large colon. Lactate levels were significantly lower in the cecal content of animals given avopersin than in the large colon digestions of those animals. It is believed that the fine antibiotic particles do not stay there long enough to have a significant effect on the cecal fermentation morphology. This is an important point demonstrating the need to develop prescription work to obtain antibiotics in the cecum. The formulation may need to be particulate and / or fibrous to improve transfer to the cecum. It is believed that the size of the particles should be at least about 1 mm.

FIG. 1 shows changes in D- and L-lactate in blood with the passage of time after administration of crushed wheat. The D-lactate concentration peaked at 16 hours. And then, while retreating, L-lactate concentration continued to increase at 24 hours.

FIG. 2 shows the relationship between blood D-lactate concentration and bicarbonate concentration. Blood samples were collected every 8 hours within 24 hours after administration. Although the correlation coefficient (R ² ) of this relationship was 0.61,
In the relationship between blood L-lactate and the equivalent value of bicarbonate concentration, only R ² = 0.25. Body temperature is about 37.8 ° C at the beginning of the experiment
After 24 hours (average of all animals), the temperature rose to 40 ° C. Heart rate averages about 44 to 16 hours and 24 hours after administration
Increased to 60.

Examples 1-6 In Vitro Screening of Antibiotics for Inhibition of Lactic Acid Accumulation Cecum and large colon digests from recently slaughtered animals were filtered through nylon gauze (approximately 60 micron gap). Liquids were described by Bales et al. (1976)
Years) diluted 1: 1 with buffer and incubated with wheat corn starch (antibiotics and no antibiotics) at 37 ° C for 16-20 hours. 100 ml of digest sample diluted with 50 ml of buffer
Add to conical flask. Carbon dioxide was injected before the flask was sealed with a tightly fitted rubber lid. A 21 gauge needle was inserted into the rubber lid to allow gas escape during fermentation. Sub-samples were taken to measure the L-lactic acid concentration and pH immediately upon removal from the incubator.
Triplicate incubation flasks were used for each treatment or antibiotic level.

Example 1 Corn Starch Value Basic Experiment of Avopersin, Virginiamycin, Flavomycin Preparation of a series of corn starch concentrations: 0, 5, 15, 20 mg / ml
Digests (0-1 g cornstarch / conical flask) diluted with 1 were tested to determine the amount needed to form the form of fermentation at high lactic acid levels. Flasks were also incubated with 15 mg corn starch / ml incubation mixture, 0, 2,
Cornstarch and antibiotics were mixed to provide 4, 8, 16, 32 μg of avopersin, virginiamycin, flavomycin / ml incubation mixture. 37 ° C
After incubating for about 16 hours at 37 ° C, samples were taken for measuring lactic acid, volatile fatty acids and pH. The effects of different amounts of corn starch on the pH, L-lactate and volatile fatty acids of the incubated mixture are summarized in Table 2. There was a dose-related decrease in pH with increasing amounts of corn starch. A significant L-lactate concentration was then measured in flasks containing 10 mg corn starch / ml or more of the incubated mixture. Addition of corn starch maximized volatile fatty acids at 10 mg corn starch.

The effects of antibiotics on the in vitro fermentation of buffered colon digest and 15 mg / ml corn starch are summarized in Table 3. Avopersin only partially suppressed the accumulation of lactic acid even at 32 μg / ml, and virginiamycin and flavomycin completely suppressed it at a low concentration of 2 μg / ml. There was a significant increase in pH associated with the suppression of lactic acid by these antibiotics. For all Gram-positive antibiotics tested in this experiment, there was a significant increase in the ratio of acetic acid to propionic acid.

Example 2 Effect of Virginiamycin, Flavomycin, Bacitracin Zinc Antibiotics at Concentrations Below 2 μg / ml Incubation flasks were set up as described above with cornstarch (0.75 g) containing Virginiamycin, flavomycin or zinc bacitracin. Was done. Antibiotic feed was 0, 0.25, 0.5, 1.0, 2 μg / ml incubation mixture. These flasks were incubated for 16 hours. Also, the flask is 0.75 without antibiotics
It was equipped with g-corn starch and equipped with taps and sampling tubes for sampling from the incubation vessel at each time during fermentation. Start the sample at the start of incubation and
It was collected at 8, 12 and 24 o'clock. These L-lactate concentration, pH
Was analyzed.

The effects of the three antibiotics on L-lactate and pH are summarized in Table 4. All antibiotics significantly reduced lactate concentration, and pH increased significantly at all contents levels. Virginiamycin best inhibited lactic acid at a concentration of 1 μg / ml.

The changes in lactic acid concentration and pH are summarized in Table 5. Little or no accumulation of lactic acid was observed in corn starch until about 8 hours after the start of incubation. Again 16
There was no significant increase between -24 hours.

Example 3 Further screening of vapercin, virginiamycin, flavomycin plus bacitracin zinc using digests samples from four horses. Each of the four antibiotics above was incubated as described above.
15 mg corn starch and 2 μg antibiotic were given per 1 ml incubation mixture. One flask per test, each antibiotic was incubated in both caecal and large colon digests taken from 4 animals each. Incubation liquid samples were taken after 20 hours of incubation,
L-lactate and pH were analyzed.

After incubation for 20 hours, the average values of L-lactate concentration and pH of the incubated solution are summarized in Table 6. 2 in lactate production between untreated animals in the presence of starch
There was a significant difference within the range of 1.4-68.5 mmol /. Of the four antibiotics tested in this experiment, only Virginia myx gave a significant decrease in L-lactate concentration in the incubated fluid and a significant increase in pH. No significant difference was found in the reaction between the fermentation morphology of the antibiotics and the results obtained by combining the cecal digestion product and the large colonic digest product and both incubations. L-lactate concentration and pH in fermentation broth
Are closely related (R ² = 0.84), and due to antibiotic differences between horses, both parameters were similar. There was a significant difference between horses in the amount of lactate appearance following digestion and corn starch incubation (p <0.00.
1). There were significant differences (p <0.001) depending on the type of antibiotics used in terms of the amount of accumulated lactate in the incubation solution and the pH. Considering the results obtained from all horses, Virginiamycin alone reduced lactate levels (p <0.001) versus no treatment without drug treatment and against the other antibiotics tested, It was an antibiotic that increased pH (p, 0.01). Several other antibiotics have been shown to have an effect on lactate production and pH in some animals.

Example 4 Digestion Diets from Animals Fed Pellet Defined Diet With or Without Virginiamycin-Metabolites Before and After Incubation A total of 10 horses were used in this experiment. To 5 horses, 5 kg of pellet mixture (95.5% ground wheat, 5% ground Lucerne chaff, about 2.5 g Virginiamycin "Stafac 2.5%" 2.5 to supply
%) Was given. An additional 5 horses were fed a similar diet without Virginiamycin. Samples were taken from the cecum and large colon for analysis of pH, volatile fatty acids, Virginiamycin, L-lactate. Samples were incubated with corn starch (digest of 15 mg / ml diluted) prepared in buffer as described above (1 flask / sample).
After 20 hours of incubation, samples were taken and analyzed for L-lactate and pH.

Table 7 summarizes the results of measurements of blood, fresh digests and incubated digests from untreated animals and animals fed a diet containing Virginiamycin. Animals treated with virginiamycin reduced the molar fraction of acetate, butyrate, isovalerate, valerate, and propionate at lower total volatile fatty acid concentrations (p <0.001). The rate was more than double. No significant effect was seen on the pH of digestive juices from the cecum or large colon, but the L-lactate concentration in digestions from the cecum, large colon of animals fed Virginiamycin was higher (p < 0.05).

Following incubation with corn starch, digests from animals receiving Virginiamycin produced significantly less (p <0.001) lactic acid than no treatment. This difference was also reflected in the higher pH of the incubated digests of animals dosed with Virginiamycin. Lactate produced in the large colon incubation was significantly less than that produced in the cecal fermentation.

Example 5 Efficacy of tylosin against virginiamycin In vitro fermentation experiments were performed to determine the efficacy of tylosin against virginiamycin. A 16 ml sample of the filtered caecum and large colon contains 4 ml of glucose solution (60 μg / m
l) and various concentrations of 0, 0.5, 1.0, 2.0, 4.0 μg / ml virginiamycin or tylosin were co-incubated. A 25 ml container was incubated at 37 ° C for 24 hours. Experiments were performed 3 times for each treatment.

The binding is shown in Table 8. Tylosin can reduce the concentration of lactic acid during fermentation of soluble carbohydrates, but higher levels of tylosin than Virginiamycin are required for a similar decrease in lactate levels. At the antibiotic concentrations conducted in this study, tylosin did not reduce lactate levels as much as Virginiamycin.

Example 6 Therapeutic Uses of Virginiamycin In vitro experiments determine whether addition of Virginiamycin prevents subsequent lactate production even after cecal digests and glucose start fermentation. It was done for the purpose.

Samples of caecal and large colonic digests were prepared as described above (Example 5) but were subjected to the following treatments.

(Repeat experiment of each treatment 3) (a) Control standard-24 hours incubation (b) After 4 hours, a sample was taken, virginiamycin was added, and incubation was carried out for a total of 24 hours.

(C) Similar to (b), but sampled 8 hours later.

(D) Same as (b), but sampled 12 hours later.

Virginiamycin was added at 10 μg / ml.

FIG. 6 shows changes in the L-lactate concentration with the lapse of time after the start of incubation of the filtered digestive juice of the posterior intestine of the horse and glucose. The dotted line shows the change in L-lactate concentration after the addition of Virginiamycin (10 μg / ml) to the incubation solution. Virginiamycin was added 4, 8 and 12 hours after the start of incubation.

The results show that virginiamycin is still able to prevent lactate accumulation and laminitis, even when given after the animals have consumed large amounts of cereals. Start fermentation of glucose 8
By the end of the hour, it is clear that the addition of Virginiamycin prevents the accumulation of lactic acid. Starch is the main grain fed animal, which first needs to hydrolyze glucose. This means that the therapeutic use of Virginiamycin to prevent lactate accumulation is possible at a later stage.

All the antibiotics selected for screening in Examples 1 to 6 were active against Gram-positive bacteria and had a very similar antibiotic spectrum, but accumulated lactic acid during fermentation of starch. It is interesting to note that their biological activity is very different in the inhibition of spores. Given the very wide dosing range of the total mixture used in Example 1, there seems to be no cause for the difference in efficacy and dose rate of these antibiotics. And even at the highest concentrations of avopersin (about 32 times the lowest effective dose of Virginiamycin), it failed to completely suppress lactic acid. It is also clear that there are useful differences between horses in the amount of lactic acid produced during corn starch fermentation and the fermentation reactions of different antibiotics. This difference between the horses is probably explained why not all horses given crushed wheat develop high levels of lactate in the large intestine and why not all horses show signs of laminitis.

Examples 7 and 8 Biological study of the action of Virginiamycin Example 7 Preliminary study with two horses Virginiamycin was premixed in the diet and fed to these animals. 2 kg of the mixture is 1225 g of straw, 225 g of sugar,
It contained 450g of water and 100g of "STAFFAK 20". This provided about 2 g of Virginiamycin per day. The sugar was first dissolved in water prior to the addition of "Stafuck 20" and "Staffuck 20" was admixed into a homogenous suspension. This mixture was then added to millet and mixed for 20 minutes. When I gave this feed and did not eat it on the second day,
125g of "Staffuck 20" per head through the stomach tube to animals
(2.5 g Virginiamycin per head) was given. On the third day of the experiment, the animals received one dose of ground wheat. With this, weight 1k
About 6 mg virginiamycin was supplied per gram. Wheat was mixed in a slurry with water, and the same amount was divided into two portions and given at intervals of about 2 hours. Animals were examined and sampled every 8 hours for 48 hours as described in the Reference Example above. The time was taken from the time of the first dose of wheat.

One of two horses fed wheat slurry and Virginiamycin died 16 hours later. The cause of death was diagnosed at autopsy as a result of gas accumulation in the cecum. The results from this horse were combined with the results from the eight animals in Example 8 since the second animal did not show any pathological effects by administration.
Therefore, the data presented are 5 in the Virginiamycin treated group and 4 in the untreated group.

Example 8 Eight horses were used in this experiment. Four were given virginiamycin and the other four were treated the same but without virginiamycin. Animals fed virginiamycin were fed and fed the diet for 2 days prior to administration of the wheat slurry. 640 g of feed mixture, 495 g of Rusen chopped straw, 16.5 g of sugar,
Cornflower 8.3g, water 115g, "Staffuck 500" 4.9
5 g, which provided about 2.48 g Virginiamycin per day. The feed was prepared as follows. A slurry was prepared in which sugar, corn flour, water and "Staffuck 500" were mixed homogeneously, and Lucen chopped straw was added and mixed well in a cement mixer. The animals in the control group received 640 g of Rusen chopped straw without additives.
The dose of wheat given on the 3rd day was 12 g of ground wheat per kg of body weight, which was also given in equal amounts in two divided doses. Wheat fed to Virginiamycin-treated horses
"Staffac 20" (20 / kg) was included. This is weight 1
About 4.8 mg Virginiamycin per kg was supplied. Animals were examined and samples were taken every 8 hours for 48 hours as described in the Reference Example. After 48 hours, all animals were sacrificed and samples of cecum and colon digests were taken for L-, D-lactic acid, pH analysis.

None of the 5 animals treated with Virginiamycin showed signs of lameness. On the contrary, 3 out of 4 of the untreated group became obel grade 2 lame. As a result, there was a significant reduction in lameness in prior use of Virginiamycin and concatenated use of wheat slurry (p <0.
05).

FIG. 3 shows the changes with time of L- and D-lactate in blood. One group of horses (n = 5) was treated with Virginiamycin and the other group was untreated. Whereas untreated animals had a significant increase in D-lactate at 16 and 24 hours, animals fed Virginiamycin showed
There was a slight increase in D-lactate concentration at 16 hours. Regarding L-lactate, Virginiamycin-treated animals had significantly higher L-lactate concentrations at 8 and 16 hours. This trend was reversed after 24 hours and by 40 hours L-lactate concentrations were higher in untreated animals (p <.
0.05).

Fig. 4 shows blood bicarbonate and fecal pH after administration of wheat slurry.
The change with time was shown. One group of horses (n = 5) was treated with Virginiamycin and the other group was untreated. By 16 hours after administration of wheat, blood bicarbonate concentrations were significantly reduced in untreated animals, and levels were still lower at 32 hours compared to animals treated with Virginiamycin. A similar form over time,
It was also found in blood pH. With regard to fecal pH, the fecal pH of untreated animals dropped sharply at 24 hours (p <0.01) and returned to normal at 32 hours. Fecal pH of animals treated with Virginiamycin
There was no significant change in.

Significant relationship between blood pH and blood D-lactate (p <0.00
There was 1). However, there was no relationship between L-lactate and blood pH.

FIG. 5 shows changes in the heart sound rate over time after administration of the wheat slurry. One group of horses (n = 5) was treated with Virginiamycin and the other groups were untreated. Heart rate of virginiamycin-treated animals was higher than that of untreated horses during 16-24 h. After that, the heart rate returned to normal. Mean heart rate in untreated animals increased significantly between 24-48 hours.

The main finding of this series of experiments was that virginiamycin administration protected horses against the development of laminitis due to excessive carbohydrate consumption. The results show that administration of virginiamycin maintained low levels of blood D-lactate and also controlled all parameters of acidosis (blood bicarbonate and pH, fecal pH) in a normally marginal control. .

The results of in vitro fermentation differed from those measured in vivo, especially regarding pH. Although Virginiamycin reduced the marked decrease in pH, the pH of the incubated liquids decreased in vitro regardless of the presence of Virginiamycin. In contrast, animals treated with Virginiamycin showed no reduction in fecal pH and no evidence of changes in blood pH or blood bicarbonate levels. This is probably because in living organisms, volatile fatty acids are rapidly absorbed from the gastrointestinal tract and do not contribute to the acidity of the digest. On the other hand, lactate cannot be effectively absorbed until the pH of the digest is reduced to about 5.5 [Dunlop, 1965.
Year〕. In addition, virginiamycin reduced the concentration of total volatile fatty acids in vivo (Example 4). They also contribute to the higher pH of the digests of these animals.

Virginiamycin and other Gram-positive antibiotics appear to increase the molar proportion of propionate during posterior intestinal fermentation (Tables 2 and 7). Increased production of propionate may increase the effectiveness of the substrate for grape head synthesis, thereby increasing glycogen accumulation.

Animals dosed with virginiamycin represent more gas production during the initial rapid fermentation of carbohydrates. This was seen in animals that died of gas accumulation in the cecum, and also in L-lactate elevated between 16 and 24 hours (Fig. 3). The reason for this accumulation of gas is probably due to the fact that volatile fatty acids, rather than lactate, are continuously produced during starch fermentation in Virginiamycin-treated horses. When volatile fatty acids, acetates and butyrate are produced, carbon dioxide and hydrogen are also produced. They also combine to produce methane. There is no gas associated with the formation of lactate or propionate. It should be emphasized that the carbohydrate overload model used here is capable of supplying easily fermentable carbohydrates in very large amounts in a very short time, and under more physiological conditions gas accumulation does not occur. . In fact, virginiamycin increased the production of propionate as compared to acetate and butyrate (Table 7), and under normal conditions of fermentation based on volatile fatty acids, gas production increased Expected to decrease.

In fact, once virginiamycin has been given to the digestive inclusions, the fact that lactate concentration accumulation does not persist
Virginiamycin can be administered even after the animal has inadvertently consumed large amounts of high starch carbohydrates, indicating that this method can prevent lactic acid accumulation and laminitis. From the data shown in FIG. 3, only D-lactate appears to be significantly elevated about 16 hours after wheat administration. This indicates that it is expected that treatment with virginiamycin within 12 hours after accidental ingestion of high levels of starch will prevent laminitis.

[Brief description of drawings]

Figure 1 shows blood D- and L- of four horses treated with crushed wheat.
Changes in lactate with time, Fig. 2 shows the relationship between blood D-lactate and bicarbonate of four horses treated with ground wheat,
Figures 3A and 3B show changes in D-lactate and L-lactate in horse blood over time measured after administration of ground wheat, and Figures 4A and 4B show that after administration of ground wheat. Changes in bicarbonate and fecal pH in horses over time, Fig. 5 shows changes in heart rate of horses over time following administration of ground wheat, and Fig. 6 shows rear intestine of horses filtered. The change in the L-lactate concentration over time after the start of the incubation of the digestive juice and glucose is shown, and the dotted line shows the change in the L-lactate concentration after the addition of Virginiamycin (10 μg / ml) to the incubation solution.

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Claims (13)

[Claims] 1. A therapeutic agent for laminitis in equine livestock, which comprises a glycopeptide antibiotic, a glycolipid antibiotic, a staphyromycin antibiotic, a polypeptide antibiotic, or a macrolide antibiotic. 2. The drug of claim 1, wherein the drug is provided in particulate form that can withstand enzymatic digestion of the upper gastrointestinal tract and increase cecal uptake of the drug. 3. The drug according to claim 2, wherein the particles are fibrous. 4. The drug according to any one of claims (1) to (3), which comprises a glycopeptide antibiotic. (5) The drug according to any one of (1) to (3), which contains a glycolipid antibiotic. 6. A staphyromycin antibiotic is contained.
The drug according to any one of claims (1) to (3). 7. The drug according to any one of claims (1) to (3), which comprises a polypeptide antibiotic. 8. The drug according to any one of claims (1) to (3), which contains a macrolide antibiotic. 9. The drug according to claim 4, wherein the glycopeptide antibiotic comprises avopersin. 10. The drug according to claim 5, wherein the glycolipid antibiotic comprises flavomycin (banvermycin). 11. The drug according to claim 6, wherein the staphyromycin antibiotic comprises virginiamycin. 12. The drug according to claim 7, wherein the polypeptide antibiotic consists of zinc bacitracin. 13. The drug according to claim 8, wherein the macrolide antibiotic consists of tylosin.