Clinical signs of chronic uterine torsion in mares may be vague and include inappetence and signs of depression; signs of colic may not be evident.Transrectal palpation is considered essential to diagnose uterine torsion; however, findings may be inconclusive in chronic uterine torsion.Prognosis for life can be good after treatment by ventral midline celiotomy, cesarean section correction of the torsion, and ovariohysterectomy.

treatments the cows were randomly assigned to two groups. One group of cows (n= 281) was fed 0.5 mg of melengestrol acetate (MGA) per head per day for ten days while the other group of cows (n= 257) served as controls. All cows were bled for progesterone concentrations at the beginning of the MGA feeding (d -21), before the SMB treatment, and at the time of artificial insemination (AI). Twenty-eight days after AI, cows in both groups were examined for pregnancy using transrectal ultrasonagraphy. MGA feeding increased (P=.02) synchronization rates in the estrouscycling females; however, MGA feeding did not improve (P>.01) pregnancy rates. In summary, MGA may be used to improve synchronization rates of estrus-cycling females, but the improvement is likely not warranted unless higher pregnancy rates are observed. For example, if the overall pregnancy rate would have been 55%, the improvement in synchronization would have yielded a 4% overall increase in pregnancy rates.

were used in this experiment. All cows were administered Syncro-Mate B® (SMB) for estrus synchronization and were bred from a timed AI about 48 hours after SMB implant removal. Blood samples were collected from all cows on days 0 (AI), 5, 14, 22, and 24 via jugular venipuncture and analyzed for progesterone concentrations using a validated ELISA. Progesterone data was used to determine estrus-cycling status and to monitor corpus luteum development and function. On day 5, one half of the cows were administered an intravaginal progesterone insert (IPI) containing 1.9 g of progesterone. Pregnancy was determined on day 28 via transrectal ultrasound examination. Pregnancy data was analyzed as a 2 x 2 factorial with estrus-cycling status and treatment as the main effects. IPI treatment improved (P = .03) pregnancy rates in estrus-cyclin g cows, but there was a tendency (P = .06) for pregnancy rates to be lower in treated cows that were previously anestrous.

This study was designed to evaluate the haemostatic suture as a means of preventing haemorrhage from the hysterotomy in mares after caesarean section. At 2 university hospitals 1982-1994, 48 mares had caesarean section for dystocia, 10 as an elective, and 8 mares concurrently with colic surgery. The haemostatic suture was used in 31 of 66 mares (47%) and surgery period was significantly (P<0.05) shorter when it was not applied. Anaemia (PCV<30%) was recorded in 13 (22%) of 58 mares, excluding the colic group, and the haemostatic suture did not after this proportion of mares that had anaemia. Anaemia was 5 times more probable following caesarean section than vaginal delivery, evidence that bleeding from the hysterotomy is a serious and common complication of caesarean section in mares, Severe uterine haemorrhage was recorded in 3 mares that had an haemostatic suture (10%) and in 2 mares that did not (6%). The latter two mares died of haemorrhage. The suture, therefore did not eliminate post operative anaemia and severe uterine haemorrhage. If omitted, the hysterotomy should be closed with a full thickness pattern that is sufficiently tight to compress vessels in the uterine wall.

Data from 116 mares that had caesarean section or vaginal delivery at 2 university hospitals were analysed in 5 groups, as follows: dystocia corrected by caesarean section, Group DCS (n = 48); elective caesarean section, Group ECS (n = 10); caesarean section concurrently with colic surgery, Group CCS (n = 8); assisted vaginal delivery, Group AVD (n = 22); and controlled vaginal delivery under general anaesthesia, Group CVD (n = 28). Survival rate in all mares that had caesarean section, excluding Group CCS, was 88% (51/58). All mares in Group ECS survived and Group CCS had the lowest survival rate (38%). In 98 mares with dystocia, Groups DCS (15%) and AVD (14%) had significantly lower (P<0.05) mortality rates than Group CVD (29%). There were no differences between groups for duration of dystocia. The placenta was retained in 75 (65%) of 116 mares, and for a longer period following elective caesarean section than following assisted vaginal delivery. Multiple complications (> or = 3) were recorded in 6 mares in Group CVD but not in the other groups. Of the 102 foals delivered from 98 mares with dystocia, 11 (11%) were alive at delivery and 5 (5%) survived to discharge. Survival rate for foals was 38% in Group CCS, and 90% in Group ECS. Under conditions similar to those in this study, it is calculated that caesarean section is preferable to CVD if dystocia is protracted and great difficulty and trauma is involved, even if CVD allows delivery of the foal.

A controlled test was conducted to assess the efficacy bioequivalence of a single dose of 0.5% fenbendazole (FBZ) top dress pellets to a 10% FBZ suspension formulation (Panacur suspension 10%, Hoechst Roussel Vet). Thirty horses with naturally-acquired parasite infections, in replicates of three, were used. Strongyle egg per gram counts were not significantly different (P>0.1) between groups pretreatment, but FBZ treated groups were significantly different from the control group post-treatment. At necropsy, which occurred seven to nine days post-treatment, two methods of nematode recovery were compared to assess whether a small aliquot can be used in a control test to determine efficacy against large as well as small strongyles. Both post mortem worm recovery techniques revealed similar efficacies of both formulations (>95%) against small and large strongyles, but large differences in the number of worms recovered. Six species of small strongyles comprised 96% of all the small strongyles recovered: Coronocyclus coronatus, Cylicocyclus insigne, Cylicostephanus longibursatus, Cylicocyclus brevicapsulatus, Cylicocyclus nassatus, and Cyathostomum catinatum. The results of this study demonstrated therapeutic bioequivalence between FBZ formulations and also the need to sample at least a 10% aliquot to accurately estimate number of large strongyles. No adverse reactions to treatment were detected.

Fourteen mares were included in a study to determine the effect of altrenogest treatment to early postpartum mares on the reproductive performance of the mares and health, growth and development of the foals. Mares were assigned to one of three groups :group 1- no treatment (control group), group 2- orally administered altrenogest for the first 7 days postpartum and group 3- orally administered altrenogest for the first 15 days postpartum. On days 1-30 postpartum, mares were tested daily with a stallion to determine estrus. Foals were monitored daily for general health and weighed and bled for serum chemistry concentrations on days 1, 5 10, 15, 20 25 and 30 of age. Foals nursing mares orally administered altrenogest grew as rapidly as foals suckling untreated mares (P>.20). Furthermore, serum chemistry of foals nursing mares orally administered altrenogest were not adversely affected and none of the foals became ill during the first 30 days of age. As anticipated, the foal heats were delayed (P<0.05) in the mares orally administered altrenogest for the first 15 days postpartum. No adverse effects on the reproductive performance of the mares were detected. In summary, administration of altrenogest to early postpartum mares had no adverse effects on the reproductive performance of the mares and on the health, growth and development of the suckling foals.

Two trials involving 85 heifers and 67 cows were conducted to determine the effect of estrous cycle stage at the time of Syncro-Mate-B® (SMB)b treatment on interval to estrus following implant removal and on conception rate at the synchronized estrus.In Trial 1, 57 beef and 28 dairy heifers were treated with SMB on each representative day of a 22-d estrous cycle (estrus = Day 0). Beef heifers were artificially inseminated approximately 48 h after implant removal, whereas dairy heifers were inseminated 0 to 12 h after detection of estrus. Inseminations were scored by the inseminator according to their difficulty. Interval to the onset of estrus was not different between heifers treated early (≤ Day 11) in the estrous cycle (31.3 ± 7.4 h) and heifers treated late (> Day 11) in the cycle (35.2 ± 7.2 h). Conception rate at the synchronized estrus was slightly higher in early-cycle heifers (2247 = 47%) compared to late-cycle heifers (1438 = 37%, P = 0.2). Heifers that were difficult to inseminate had lower (P < 0.01) conception rates (211 = 18%) at the synchronized estrus than heifers considered normal (2151 = 41%) or easier than normal to inseminate (1323 = 57%).In Trial 2, of the 131 beef cows synchronized, 67 that were estimated to be either early or late in the estrous cycle by progesterone analysis were utilized. Cows were treated with SMB and inseminated without regard to estrus 48-h after implant removal. Inseminations were scored as in Trial 1. Calves were separated from cows from the time of implant removal to insemination. Conception rate was higher (P < 0.05) in cows treated with SMB early (≤ Day 11) in the estrous cycle (2032 = 62.5%) compared to cows treated late (> Day 11, 1635 = 46%). Cows that were difficult to inseminate had a lower (P < 0.01) conception rate (08 = 0%) than cows that were normal (4394 = 46%) or easier than normal to inseminate (1329 = 45%).

A clinical trial carried out over 98 days was done to evaluate treatment of horses with moxidectin gel for efficacy as measured by (1) reduction in the production of parasite ova post treatment, (2) a comparison of the posttreatment parasite egg count suppression of moxidectin to ivermectin, and (3) assessment of the field safety, animal acceptance of the moxidectin formulation, and the utility of the moxidectin delivery device. One hundred and fifty Standardbred horses with naturally acquired parasite infections were used in the study. Moxidectin had more prolonged and greater suppressive influence than did ivermectin on reappearance and magnitude of strongyle egg counts post treatment. Differences were not observed between the capability of ivermectin or moxidectin to reduce and suppress low Parascaris equorum egg counts. Adverse reactions to treatments were not observed, and the utility of the moxidectin delivery syringe and animal acceptance of moxidectin treatment were satisfactory.

The bioequivalence of Strongid® C and generic pyrantel tartrate was determined in a controlled study using 30 horses with naturally acquired endoparasitic infections. Three horses were randomly allocated to each of ten replicates based on quantitative nematode and ascarid egg counts and fecal larvae culture results. Horses within each replicate were randomly assigned to one of three treatment groups. Horses in Treatment Group 1 received only oats; horses in Treatment Group 2 received generic pyrantel tartrate pellets (2.65 mg pyrantel tartrate kg−1) mixed with oats; horses in Treatment Group 3 were fed Strongid® C pellets (2.65 mg pyrantel tartrate kg−1) mixed with oats. Horses were treated daily for a 30 day continuous treatment period. At the termination of the study the horses were necropsied and endoparasites recovered, identified, and enumerated. In all instances, no significant difference (P>0.05) in mean numbers of parasites recovered existed between horses treated with generic pyrantel tartrate and Strongid® C. Numbers of gastrointestinal parasites recovered from horses treated with generic pyrantel tartrate or Strongid® C were shown to be significantly different (P<0.05) from numbers of gastrointestinal parasites recovered from non-treated controls for the large strongyles (Strongylus vulgaris, S. edentatus, and Triodontophorus spp.), small strongyles (Cyathostomum spp., Cylicocyclus spp., and Cylicostephanus spp.) and fourth-stage Parascaris equorum. Numbers of adult P. equorum recovered from horses treated with Strongid® C were also significantly different (P<0.05) from those from non-treated controls. Numbers of adult P. equorum recovered from horses treated with generic pyrantel tartrate were not significantly different (P = 0.0761) from those from non-treated controls. The determination of bioequivalence was based upon the 95% confidence interval of the difference between the mean number of parasites recovered from horses treated with generic pyrantel tartrate and the mean number of parasites recovered from horses treated with Strongid® C. For all instances in which the numbers of parasites recovered from horses treated with either Strongid® C or generic pyrantel tartrate were significantly different from the numbers of parasites recovered from non-treated controls, bioequivalence was demonstrated.

A study was conducted to 1) determine differences in the inflammatory response following bacterial challenge between normal mares and mares with chronic endometritis and 2) to determine if enzyme activity in uterine fluid can be used to evaluate degree of inflammation in the equine uterus. Six normal mares (Group 1) and four mares with chronic endometritis (Group 2) received an intrauterine infusion of beta-hemolytic streptococci on the second day of estrus. Neutrophil concentration as well as lysozyme and alkaline phosphatase activity were determined in uterine secretions obtained by placing tampons in the uterus of mares. All mares had a similar inflammatory response following bacterial challenge of the uterus, as indicated by a neutrophil response of the same magnitude. Neutrophil numbers, lysozyme and alkaline phosphatase concentrations were all increased 12 h postinoculation and declined rapidly to normal preinoculation values by 48 h after inoculation. In spite of the similarity of the clinical signs, neutrophil concentrations and enzyme activity, mares in group 1 demonstrated a markedly higher ability to eliminate the infection than mares in group 2. It is concluded that factors other than neutrophil numbers, lysozyme and alkaline phosphatase activity account for the inability of the mare to eliminate uterine infections.

Eighteen pony foals inoculated with 1,500 +/- 109 infective Parascaris equorum eggs were given 0.02 ml of ivermectin vehicle (liquid)/kg of body weight, PO, (control); 0.2 mg of ivermectin paste/kg, PO; or 0.2 mg ivermectin liquid/kg, PO, on postinoculation day (PID) 28. Foals were euthanatized on PID 42, and the small intestinal contents were examined for P equorum larvae. The mean number of fourth-stage P equorum larvae in foals treated with ivermectin paste and liquid were 3.5 and 6, respectively. Significantly (P less than 0.01) higher mean numbers of larvae (1,250) were detected in foals treated with ivermectin vehicle. Larvae recovered from foals treated with ivermectin vehicle were of significantly (P less than 0.002) longer mean length than those from foals treated with ivermectin paste or liquid. Gross examination of lungs and liver revealed similar pathologic changes from the migration of P equorum in all foals. Adverse reaction to treatment was not observed.

A controlled test was carried out on 15 pony foals inoculated with 1,500 +/- 108.8 infective Parascaris equorum eggs. The foals were assigned to 3 treatment groups. Treatments given on postinoculation day 11 included 0.2 mg of ivermectin/kg of body weight, formulated as paste (n = 5), or liquid (n = 5), or no treatment (controls; n = 5). The foals were euthanatized on postinoculation day 25, and examined for larvae in the small intestine, lungs, and liver. Larvae were not found in foals treated with ivermectin liquid or paste, whereas significantly (P less than 0.05) higher mean numbers (960.9; range, 379 to 1,736) of 4th-stage larvae were found in the controls. Histologic and gross examination of lungs and liver revealed pathologic changes attributable to P equorum migration that were similar in all foals. Adverse reactions to treatment were not observed.

Chloramphenicol was administered by constant IV infusion to 7 healthy postpartum cows at rates predicted to approach a steady-state plasma concentration of 5 micrograms/ml. After 8 hours of constant IV infusion, uterine tissues were removed surgically and were assayed for chloramphenicol concentrations. Mean plasma-to-tissue ratios of chloramphenicol concentrations were 3.05, 3.63 (6 cows only), and 3.22 for caruncles, endometrium, and uterine wall, respectively. Plasma-to-tissue ratios of the 3 tissues were not significantly different (P greater than 0.10). Intrauterine (IU) injections of chloramphenicol (20 mg/kg of body weight) were administered to 3 healthy post-partum cows. The mean value of the fraction of the drug absorbed from the uteri of these cows was 0.40. Mean concentrations of chloramphenicol were 43.8 micrograms/g in caruncles, 34.6 micrograms/g in endometrium, 2.8 micrograms/g in uterine wall, and 2.9 micrograms/ml in plasma 8 hours after IU injections. Chloramphenicol has now been banned for use in food-producing animals in the United States because of its potential for causing toxicosis in human beings. It is illegal to use chloramphenicol in food-producing animals in the United States and in some other countries as well. This includes use by the IU route of administration because chloramphenicol and most drugs are absorbed from the uterus into the bloodstream and are distributed to milk and tissues.

Twenty ponies less than 18 months of age and infected with Parascaris equorum were treated with either 0.2 mg of ivermectin/kg of body weight (n = 10) or a placebo (n = 10; controls). Five control and 5 ivermectin-treated ponies were euthanatized 14 and 35 days after treatment, respectively. At necropsy, the small intestinal contents, lungs, and liver were examined for larvae and/or adult P equorum. Significantly (P less than 0.02) higher mean total numbers of P equorum were found in the small intestinal contents of the controls on day 14 (51) and on day 35 (21) than in the ivermectin-treated ponies on days 14 (0) and 35 (3). The efficacy of ivermectin in removing adult and intestinal larvae of P equorum at 14 days after treatment was 100%. The efficacies of ivermectin in removing adults and intestinal larvae of P equorum at 35 days after treatment were 100% and 76.9%, respectively. Gross examination of liver and lung tissues revealed damage as a result of P equorum infections in all ponies. The Baermann technique used on liver and lung tissues did not yield any P equorum larvae. Adverse reactions attributable to treatment were not observed.

Fifteen pony foals were inoculated with 1,500 +/- 298.7 infective Parascaris equorum eggs. The foals were assigned to 3 treatment groups. Treatments included 10 mg of fenbendazole/kg given once on postinoculation day (PID) 11, 10 mg of fenbendazole/kg given daily on PID 11 to 15, and no treatment (controls). The foals were euthanatized on PID 25 and examined for P equorum larvae in the small intestine, lungs, and liver. Significantly (P less than 0.05) lower mean numbers of P equorum larvae were found in the small intestine of foals treated on PID 11 to 15 (1.4 [range, 0 to 6]) than in the small intestine of foals treated on PID 11 (428.2 [range, 0 to 777]) and in controls (500 [range, 284 to 802]).

Fifty horses from a herd known to have benzimidazole-resistant small strongyles were treated with febantel (6 mg/kg), combinations of febantel (6 mg/kg) and piperazine citrate (25 or 55 mg base/kg), thiabendazole (44 mg/kg), or placebo (0.6 ml of water/kg). Pretreatment and 7-day posttreatment fecal examinations were done. Fecal cultures, strongyle egg per gram (epg) counts, sugar flotation fecal examinations, and in vitro testing for benzimidazole resistance were performed. Results of fecal examinations before treatment were similar in all horses, and results of testing were positive for benzimidazole resistance. Horses treated with febantel and piperazine at all dosages had significantly lower mean strongyle epg counts and greater percentage reduction in mean strongyle epg counts (99.7% to 99.9%) 7 days after treatment, compared with those determined for horses treated with febantel, thiabendazole, or placebo. Adverse reactions to treatment were not observed.

Plasma glucose and serum insulin concentrations in Thoroughbreds administered xylazine hydrochloride (1.1 mg/kg; IV) and ketamine hydrochloride (2.2 mg/kg; IV) at dosages sufficient to induce short periods of recumbency and anesthesia were measured. Samples of blood were collected from 6 adult horses before, during, and after the anesthetic period. Plasma glucose (mg/dl) was significantly increased above control (-30 minute concentration) from 15 to 150 minutes after xylazine administration with the peak value occurring at 30 minutes. Serum insulin (microU/ml) was significantly decreased from control from 5 to 90 minutes after xylazine administration, with the nadir occurring at 15 minutes. The alterations in plasma glucose and serum insulin concentrations in xylazine-ketamine-anesthetized horses were similar to the changes in xylazine-sedated horses.

The activity of fenbendazole and febantel was evaluated in 12 pony foals whichwere inoculated with 2600 P. equorum eggs. The foals were not maintained free of parasites before or after inoculation. Once patent for P. equorum, the foals were randomly assigned to groups and treated one time intraorally with either 0.5 ml corn syrup/kg of body weight (controls; n=4), 10 mg fenbendazole/kg (n=4), or 6 mg febantel/kg (n=4). Foals were necropsied and examined for parasites 10 days after treatment. Fenbendazole and febantel were highly effective against adult and immature P. equorum. Grosslesions attributed to P. equorum were evident in all foals. P. equorum were not foundin any of the fenbendazole-or febantel-treated foals. The mean number of adult and immature P. equorum found in the controls was 66.8 (15–166) and 65.0 (21–147), respectively. Strongyle infections were insufficient for efficacy evaluations to be done. Neither anthelmintic was effective against mature Drasehia megastoma, mature Habronema majus, immature H. muscae, Gasterophilus intestinalis or late 4th-stage larvae of Strongylus vulgaris. Adverse side effects due to treatment were not observed.