Young Ponies Research Articles

A Positive Start: Backing a Horse Using Positive Reinforcement

Abstract This case study delves into the transformative approach of starting a horse under saddle using a positive reinforcement technique (clicker training). Grounded in the ethos of respect, trust, and cooperation, this methodology emphasises fostering a strong bond and effective communication between horse and handler. The presented case study aims to showcase practical demonstrations highlighting the theory and application of positive reinforcement in initiating the riding training of a young pony. Throughout this case study, we will explore the foundational principles of positive reinforcement in horse training, emphasising empathy and a holistic understanding of the horse’s perspective. It will detail the step-by-step process of introducing the saddle, bridle, and mounting, employing clicker training and shaping techniques. Practical demonstrations will illustrate the gradual introduction of equipment, the use of clicker training for reinforcing desired behaviours, and the shaping of responses to riding cues. Through these demonstrations, the case study seeks to exemplify how positive reinforcement techniques can establish a willing and confident young horse, laying the groundwork for a harmonious and trusting relationship between horse and rider. Information © The Author 2024

Colocephalectomy for the Treatment of Capital Physeal Fracture of the Femoral Head in Pony

Background: Femoral capital physeal fractures occur in young animals and are generally associated with trauma. They have a poor prognosis and surgical therapy is the most indicated. There are few studies describing surgical treatment and postoperative results, so the objective of the present report was to present the first case in Brazil of a colocefalectomy for the treatment of femoral capital physeal fracture in a young pony, the post-surgical and the results obtained with the technique employed.Case: An 18-month-old pony, male, not castrated, , weighing 136 kg was referred to the Veterinary Hospital of the Federal University of Paraná (HV-UFPR) with a history of trauma for 4 days. On physical examination, the animal presented lameness grade 5 of the right pelvic limb, shortening and lateral deviation of the limb, crackling and painful sensation on abduction, and slight atrophy of the gluteal muscles on the affected side. In the radiographic examination, a femoral capital physeal fracture was found in the oblique ventro-dorsal projection. Once the diagnosis was performed, a colocefalectomy was realized, as the patient is a light and short horse. The patient underwent general anesthesia and was placed in the left lateral position. The access to the coxofemoral joint was made through the lateral face of the right hindlimb. The muscles of the region were incised and deviated, so a partial myotomy was performed in the deep gluteal and vastus lateralis. This procedure allowed to visualize the fracture, where the head of the femur remained congruent to the acetabulum. A hammer and a curved osteotome were used to section the round ligament, allowing the dislocation of the femoral head and with the aid of an oscillating orthopedic saw was performed the femoral neck ostectomy. Previously to the synthesis of the muscular planes and the skin, a passive tubular drain was fixed, in order to avoid the accumulation of exudate and consequent dehiscence of stitches, which was removed on the 6th postoperative day. For postoperative analgesia, epidural morphine was administered for 6 days and intravenous phenylbutazone for 3 days. Antibiotic therapy was performed with Ceftiofur and Metronidazole. The stitches were removed on the 15th postoperative day, after the correct healing of the surgical wound. The patient’s return to activity was gradual and he was pasture sound on the 42nd postoperative day. After medical discharge, contact with the owner was kept until the fifth postoperative month, and he related that the animal remained walking well and maintaining his reproductive function.Discussion: Femoral capital physeal fractures can occur in young animals, and are not common in clinical surgical care. Clinical signs are crackle of the joint on manipulation and presence of swelling in the affected region. The patient in question, in addition to evident lameness, had crackling and painful sensation during the abduction of the limb, but there was no local swelling, but an atrophy of the musculature of the limb, that occurs in cases of chronic femoral injury. Surgical intervention is the indicated method of treatment and should be performed as soon as possible after the injury has occurred, avoiding the worsening of bone and joint degeneration. Femoral head ostectomy is more suitable for animals less than 12 months old and weighing up to 100 kg. The technique has as a postoperative complication the contamination of the surgical wound, however the implantation of the passive tubular drain allowed rapid evolution of healing. Physical rehabilitation in the postoperative period is variable according to the progress of the animal’s locomotion. Therefore, the colocefalectomy technique aims to maintain the patient’s quality of life, even as in the case reported, it allowed the animal to maintain the reproductive function.

Ascorbic acid status in pony mares and young pony foals

Ascorbic acid status in pony mares and young pony foals

From abandonment to rehabilitation

I ncreases in the numbers of abandoned horses in the UK has been widely reported since 2008. This trend has been reflected at Redwings Horse Sanctuary by the number of new arrivals being brought into the welfare charity’s care whose owners cannot be traced, despite the best efforts of the field officers involved. In 2012, for example, 16 separate abandonment incidents resulted in 73 equines coming into Redwings’ care, and 21 cases of abandonment the following year brought in 27 horses and ponies. Individual horse rescues included Stephen, a foal believed to have been deliberately thrown into a river in Essex; Blackbird, an emaciated and pregnant mare shut in a barn without light, food or water; and Simon, found with gaping, infected wounds in his neck. Similarly, in one twomonth period multiple groups of young ponies were found abandoned in South Wales, requiring a huge multi-agency effort from charities and councils to secure their rescue and future care. Invariably, little or nothing is known about the history of abandoned equines, how they have been kept, what food and water they have had access to and any treatments or pseudo-treatments they may have received. This means that when attending an abandoned equine, Redwings’ welfare vets are faced with walking a fine line between assessing and meeting the immediate clinical needs of the animal and adhering to the core tenet of ‘do no harm’, meaning the team must always be mindful of an equine’s fragile health status and any undiagnosed conditions that could be exacerbated by otherwise positive interventions. It can take weeks or even months of carefully planned treatment to make significant rehabilitative progress.

What can I give to calm this stallion down?

What can <scp>I</scp> give to calm this stallion down?

Evaluation of a commercially available modified-live Streptococcus equi subsp equi vaccine in ponies

To evaluate a commercially available modified-live Streptococcus equi subsp equi vaccine for safety and persistence in vaccinated ponies and to detect recombination or reversion events in the vaccine strain. 5 ponies that were 1.5 to 8 years old (group 1) and 4 ponies that were 6 months old (group 2). Ponies were vaccinated, with a subsequent booster vaccination 2 to 3 weeks later, and monitored for 50 days. At booster vaccination, an equal amount of a tetracycline-resistant wild-type strain of S equiwas administered. Recovery of all strains was performed by use of bacteriologic culture and PCR assays. Ponies in group 1 had background antibody titers against S equi antigen before vaccination despite the lack of known exposure to S equi. Ponies in group 2 were immunologically naïve. Increases in anti-S equi antibody titers were detected in both groups. Ponies in group 1 did not have clinical signs of disease caused by S equi. In group 2, all ponies developed abscesses in retropharyngeal lymph nodes; 1 pony developed severe clinical disease and was euthanized. The vaccine strain was recovered from ponies in group 2 for up to 24 days after vaccination. Although the vaccine was successful in inducing IgG antibodies against S equi in all ponies, findings suggested that the vaccine may have caused substantial morbidity and some deaths in the young ponies. In young ponies, the vaccine strain persisted in tissues for weeks; however, no evidence of recombination was detected.

Benign Peripheral Nerve Sheath Tumor of the Perianal Region in a Young Pony

A 20 x 10 cm, lobulated mass was present in the perianal region of a 4-year-old Dales pony. Histopathology revealed an unencapsulated, loose arrangement of sheets and whorls of narrow mesenchymal cells, situated in the deep dermis. Intervening areas had a myxomatous appearance. The whorls were often arranged around a central structure resembling an axon or a vascular structure. Immunohistochemistry revealed that the elongated mesenchymal cells and central axon-like structures expressed vimentin, S-100, and neuron-specific enolase, but not pancytokeratin, glial fibrillary acid protein, and the neurofilament markers, NR4 and 2F11. On the basis of the histopathology and immunohistochemistry, a diagnosis of benign peripheral nerve sheath tumor (schwannoma type) was made. This case was unusual in that the concentric laminations of Schwann cells were very loosely arranged, with an intervening myxomatous stroma (Antoni type B appearance) and despite its benign histological appearance, the mass extended deeply to the proximal sacral vertebrae. Its exact origin was unclear; it may have arisen from cutaneous nerves with deep extension or from neural structures in the sacral region. Due to the incomplete surgical removal, regrowth of the mass occurred.

Morphologic changes associated with functional adaptation of the navicular bone of horses

Failure of functional adaptation to protect the skeleton from damage is common and is often associated with targeted remodeling of bone microdamage. Horses provide a suitable model for studying loading-related skeletal disease because horses are physically active, their exercise is usually regulated, and adaptive failure of various skeletal sites is common. We performed a histologic study of the navicular bone of three groups of horses: (1) young racing Thoroughbreds (n = 10); (2) young unshod ponies (n = 10); and (3) older horses with navicular syndrome (n = 6). Navicular syndrome is a painful condition that is a common cause of lameness and is associated with extensive remodeling of the navicular bone; a sesamoid bone located within the hoof which articulates with the second and third phalanges dorsally. The following variables were quantified: volumetric bone mineral density; cortical thickness (Ct.Th); bone volume fraction, microcrack surface density; density of osteocytes and empty lacunae; and resorption space density. Birefringence of bone collagen was also determined using circularly polarized light microscopy and disruption of the lacunocanalicular network was examined using confocal microscopy. Remodeling of the navicular bone resulted in formation of transverse secondary osteons orientated in a lateral to medial direction; bone collagen was similarly orientated. In horses with navicular syndrome, remodeling often led to the formation of intracortical cysts and development of multiple tidemarks at the articular surface. These changes were associated with high microcrack surface density, low bone volume fraction, low density of osteocytes, and poor osteocyte connectivity. Empty lacunae were increased in Thoroughbreds. Resorption space density was not increased in horses with navicular syndrome. Taken together, these data suggest that the navicular bone may experience habitual bending across the sagittal plane. Consequences of cumulative cyclic loading in horses with navicular syndrome include arthritic degeneration of adjacent joints and adaptive failure of the navicular bone, with accumulation of microdamage and associated low bone mass, poor osteocyte connectivity, and low osteocyte density, but not formation of greater numbers of resorption spaces.

Induction of laminitis by prolonged hyperinsulinaemia in clinically normal ponies

The purpose of this study was to determine the effects of prolonged administration of insulin, whilst maintaining normal glucose concentrations, on hoof lamellar integrity in vivo on healthy ponies with no known history of laminitis or insulin resistance. Nine clinically healthy, unrelated ponies were randomly allocated to either a treatment group (n =5; 5.9±1.7 years) or control group (n =4; 7.0±2.8 years). The treatment group received insulin via a euglycaemic hyperinsulinaemic clamp technique modified and prolonged for up to 72h. Control ponies were infused with an equivalent volume of 0.9% saline. Ponies were euthanased at the Obel grade 2 stage of clinical laminitis and hoof lamellar tissues were harvested and examined for histopathological evidence of laminitis.Basal serum insulin and blood glucose concentrations were 15.7±1.8μU/mL and 5.2±0.1mmol/L, respectively (mean±SE) and were not significantly different between groups. Mean serum insulin concentration in treatment ponies was 1036±55μU/mL vs. 14.6μU/mL in controls. All ponies in the treatment group developed clinical and histological laminitis (Obel grade 2) in all four feet within 72h (55.4±5.5h), whereas none of the control ponies developed laminitis. There was no clinical evidence of gastrointestinal involvement and the ponies showed no signs of systemic illness throughout the experiment. The data show that laminitis can be induced in healthy young ponies, with no prior history of laminitis, by maintaining prolonged hyperinsulinaemia with euglycaemia. This suggests a role for insulin in the pathogenesis of laminitis, independent of hyperglycaemia, or alterations in hind-gut fermentation. For the clinician, early detection and control of hyperinsulinaemia may facilitate management of endocrinopathic laminitis.

Dental and orofacial trauma in pony and horseback riding children

An epidemiological survey was carried among pony and horseback riding children in nine pony and horseback riding clubs, Istanbul. The purpose of the present study was to evaluate the prevalence of dental trauma in young pony and horse riders. A total of 214 children were interviewed to determine the occurrence of dental trauma during pony and horseback riding. Some 2.3% of participants (n = 5) had already been affected by dental and orofacial trauma. Horse riders experienced dental and/or orofacial trauma significantly more than the pony riders. Results revealed that these children's awareness of dental trauma is limited while all of them (100%) wore helmets.

Application of the Comet Assay for Investigation of Oxidative DNA Damage in Equine Peripheral Blood Mononuclear Cells

Oxidative stress occurs when antioxidant defense mechanisms are overwhelmed by free radicals and may lead to DNA damage, which has been implicated in processes such as aging and diseases such as cancer. The two main techniques presently used to quantify DNA damage are measurement of 8-hydroxydeoxyguanosine and the Comet assay (also known as single-cell gel electrophoresis). The aim of this study was to apply the comet assay to equine peripheral blood mononuclear cells (PBMCs) and identify two conditions in which we hypothesized that oxidative DNA damage would be increased in PBMCs: aging and equine recurrent airway obstruction (RAO, a condition similar to human asthma). The images obtained were similar to those previously published for humans, cats, and dogs. The optimum concentration of H(2)O(2) to estimate susceptibility to exogenous damage was 50 microM. Mean intraassay coefficients of variation were 4.7 and 9.7% for endogenous and exogenous tail-DNA quantities, respectively, and 7.3 and 8.3%, respectively, for interassay coefficients. There was no significant difference in either endogenous or exogenous percentages of tail DNA for samples collected from six ponies on three consecutive days. There was no significant difference in endogenous, exogenous, or exogenous (corrected for endogenous) oxidative DNA damage between mature and aged ponies. However, young pony foals had significantly less endogenous DNA damage than mature or aged ponies (P < 0.05). RAO-affected horses without airway inflammation (i.e., in clinical remission) had significantly greater endogenous damage compared with non-RAO-affected control animals (P = 0.009). There was a significant correlation between endogenous percentage of tail DNA in PBMCs and red blood cell hemolysate glutathione concentration (r = 0.720; P < 0.001). In conclusion, the comet assay appears to be suitable for investigating DNA damage in equine PBMCs.

Efficacy of a 2 per cent moxidectin gel against gastrointestinal parasites of ponies

The efficacy of moxidectin was evaluated in young ponies naturally infected with gastrointestinal parasites. Eight animals were treated orally with moxidectin at 0.4 mg/kg bodyweight and eight received only the...

Efficacy of moxidectin 2% equine gel against natural nematode infections in ponies

The efficacy of moxidectin 2% oral gel (Equest®, Fort-Dodge) against European worm strains was studied through post-mortem worm counts and feacal egg counts (FECs) in 12 young ponies naturally infected. The animals were allocated in two groups of six ponies each: the first one was treated at 0.4 mg/kg b.w. and the second one received a placebo and served as control. All the ponies were necropsied 14 days post-treatment. The efficacy of moxidectin in reducing strongyle FECs ranged from 99.8% to 100% from 3 to 14 days after treatment. Moxidectin efficacy was 100% against Trichostrongylus axei and Triodontophorus spp., > 99.9% against Cyathostomes adults and L5, 92% against S. edentatus L5, 100% against O. equi L5, 99% against O. equi L4, and 92% against G. intestinalis. No animal treated with moxidectin was harbouring P. equorum, Habronema spp., G. pecorum nor G. nasalis, while the control group was slightly infected with these parasites. This experiment confirms the post-mortem worm count results obtained in the United States and the FECs results reported in Europe. Moxidectin showed to be safe in young ponies.

The relationship between intraarticular and juxta‐articular intraosseous pressures in the metatarsophalangeal region of the pony

Eight metatarsophalangeal (fetlock) joints were studied in anaesthetized young ponies. Pressure measurements were made in the joint and at various sites in the marrow cavity of the third metatarsal bone with simultaneous measurement of systemic arterial and venous blood pressures. Fetlock joint flexion was always associated with a statistically significant initial decrease in intra-articular pressure (p < 0.05) followed by a marked increase in pressure (p < 0.05). Subsequent extension was accompanied by a similar pressure pattern, although there appeared to be a hysteretic relationship. Fetlock joint distension induced by incremental injection of saline caused a stepwise increase in the intra-articular pressure. Both joint flexion and effusion were associated with an increased intraosseous pressure within the third metatarsal bone. This effect was most pronounced at the distal end of the bone, probably through partial obstruction of the vessels draining the epiphysis and metaphysis.

Effect of ranitidine on healing of experimentally induced gastric ulcers in ponies

Summary Thirty young ponies were examined endoscopically for evidence of gastric ulceration. Seven ponies had noninduced gastric ulcers present at the initial examination and were eliminated from the study. In an attempt to induce gastric ulcers experimentally, flunixin meglumine (1.1 mg/kg of body weight, im, q 8 h) was administered for 7 days to the 23 ponies with endoscopically normal gastric mucosa. During the 7 days of flunixin administration, 11 ponies developed gastric ulcers that were appropriate for study. The 11 ponies were randomly allotted to 2 groups. Group-A (n = 5) and group-B (n = 6) ponies received ranitidine (4.4 mg/kg, po, q 8 h) and corn syrup, respectively, until ulcers healed or for a maximum of 40 days. General anesthesia was induced every 3 to 5 days for visual evaluation of ulcer healing by use of a video endoscope. The earliest complete healing of gastric lesions observed in a corn syrup-treated pony was at 17 days. At 40 days, 3 of 5 and 3 of 6 ponies of the ranitidine and corn syrup-treated groups, respectively, had healed ulcers. Results of this study indicate that: noninduced gastric ulcers may be common in young ponies, flunixin meglumine may be effective in inducing gastric ulcers for gastric healing studies in young ponies, and ranitidine (4.4 mg/kg, q 8 h) is not significantly effective in accelerating healing of experimentally induced gastric ulcers in ponies under conditions of this study.

An outbreak of strangles in young ponies

A natural outbreak of strangles occurred in a group of 19 young experimental ponies. The disease was diagnosed in 11 of them within two days of their arrival at Glasgow University veterinary school and five others developed clinical signs within a further four days, a morbidity rate of 84 per cent. All of the affected ponies had typical signs of strangles including dullness, anorexia, pyrexia, regional lymphadenitis, occasionally with rupture of the lymph node, conjunctivitis and a mucopurulent nasal discharge. Nine of the affected ponies were destroyed during the clinical phase of the disease for post mortem studies. The clinical disease in the remaining animals lasted approximately 21 days although one pony had to be destroyed 10 days after the onset of clinical signs because of the development of septic arthritis. All 16 affected animals exhibited peripheral blood neutrophilia and high plasma fibrinogen levels. beta haemolytic streptococci were isolated by nasopharyngeal swabbing from 18 of the 19 ponies. Streptococcus equi was confirmed only in three animals within the first four days of the outbreak. The majority of the other isolates identified to species were S zooepidemicus. beta haemolytic streptococci were still present in six ponies 40 days after they had clinically recovered and were isolated regularly from three ponies which did not develop clinical strangles but remained in contract with affected animals throughout the study.

Effect of a histamine H2 type receptor antagonist (WY 45, 727) on the healing of gastric ulcers in ponies.

Using video gastroscopy, the efficacy of a Histamine-H2 type receptor antagonist (WY 45, 727) was investigated in young ponies with spontaneous and experimentally induced gastric ulcers. Oral administration of WY 45, 727 at 2 mg/kg and 10 mg/kg of body weight every 12 hours for 14 days resulted in complete healing of spontaneous gastric ulcers in the non-glandular portion of the stomach in 2/5 (40%) and 3/4 (75%) of the ponies, respectively, compared (P < 0.05) to 0/5 (0%) placebo-treated ponies. After intramuscular administration of flunixin meglumine at 1.5 mg/kg body weight every 8 hours for 6 days, 9/18 ponies had ulcers in the non-glandular portion of the stomach. Oral administration of WY 45, 727 at 10 mg/kg body weight every 12 hours for 14 days resulted in complete healing of the non-glandular gastric ulcers in 3/4 (75%) compared with (P < 0.05) 1/5 (20%) placebo-treated ponies. This study indicates that 1) the occurrence of subclinical ulcers may be common in young ponies; 2) flunixin meglumine at 1.5 mg/kg intramuscularly every 8 hours for 6 days may result in ulcers of the non-glandular stomach in ponies; and 3) WY 45, 727, a histaminergic H2 type receptor antagonist could be of value in the therapeutic management of ulcers in the non-glandular stomach of foals and adult horses.

Seasonally inhibited development of cyathostomine nematodes in shetland ponies in The Netherlands

Two groups of three yearling Shetland ponies were used in 1988 to study the epidemiological significance of inhibited development of the Cyathostomine nematodes. In Group 1, acquisition of infections was prevented throughout the grazing season whereas in Group 2 strongylid infections were acquired from the beginning of July until the end of September. Worm counts showed that the Cyathostomine nematode populations of Group 1 ponies mainly consisted of adult worms and those of Group 2 ponies of inhibited early third stage larvae (L3). These results indicate that a large proportion of Cyathostomine larvae which establish between the beginning of July and the end of September inhibit their development. The results also suggest that the pool of inhibited larvae which has overwintered in young ponies will be depleted in autumn.

Pulsatile release of gonadotropins in young pony stallions

Basal concentrations and pulsatile-release patterns of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were characterized in five pony stallions, aged 2 to 4 yr. Jugular blood was collected from each pony at 20-min intervals for 24 h. Plasma was separated and frozen until quantification of LH and FSH by RIA. Hormonal data were subjected to a computerized cycle-detection program for estimating frequency and amplitude of regular and irregular episodic fluctuations in gonadotropin concentrations in the presence of high levels of random measurement errors. Ponies were castrated, testes were weighed, and parenchymal sections were procured for determination of daily spermatozoal production per gram of testicular parenchyma (DSP/gm) and daily spermatozoal production per pony (DSP). Values (mean ± SD) for basal concentration of LH (basal LH), LH pulse amplitude (amp LH), duration of LH pulse (dur LH), LH pulse frequency (freq LH), basal concentration of FSH (basal FSH), FSH pulse amplitude (amp FSH), duration of FSH pulse (dur FSH), and FSH pulse frequency (freq FSH) were 4.80 ± 2.39 ng/ml, 3.13 ± 1.16 ng/ml, 46.4 ± 3.6 min, 0.869 ± 0.04 pulses/h, 7.34 ± 6.33 ng/ml, 6.50 ± 7.60 ng/ml, 43.9 ± 11.7 min, and 0.868 ± 0.14 pulses/h, respectively. Regression analyses revealed significant (P<0.05) linear relationships between freq LH and DSP/gm (r=0.97), basal LH and DSP/gm (r=0.89), amp LH and DSP (r=0.99), freq LH and DSP (r=0.97), and basal LH and DSP (r=0.92). A significant quadratic relationship existed between amp LH and DSP/gm (r=0.99). Both amp LH and freq LH were more highly correlated with DSP/gm and DSP than was basal LH. Basal concentrations and pulsatile release characteristics of LH were not related to testes weight (TW) (P>0.05). Morever, basal concentrations and pulsatile release characteristics of FSH were not related to TW, DSP/gm or DSP (P>0.05). Cross-correlations between LH and FSH were not observed (P>0.05).

Epidemiology and control of equine strongylosis at Newmarket.

Seasonal rises in mean faecal egg output were observed in grazing ponies in spring (578 eggs per gram) and in summer (930 epg) on 30 April and 2 September, respectively, in untreated ponies. Pasture infectivity reached a peak of 18,486 third stage larvae (L3)/kg on 17 September, two weeks after peak egg counts, coincidental with abundant September rainfall (103.0 mm). Differentiation of infective larvae from pasture showed the cyathostomes (small strongyles) to be predominant, but Trichostrongylus axei assumed major importance from late August to October. The large strongyles were rarely detected: Strongylus vulgaris was found only once and S edentatus only twice. The most effective parasite prophylaxis was achieved by twice weekly removal of faeces. In this group, concentrations of infective L3 on pasture reached a maximum of 1000 L3/kg, compared to 18,486 L3/kg for a control group and 4850 to 10,210 L3/kg for anthelmintic treatment groups. The removal of faeces increased the grazing area by about 50 per cent, by eliminating the characteristic separation of horse pasture into roughs and lawns. Spring and summer anthelmintic treatments of mature ponies with oxibendazole were effective in reducing the late season rise in pasture infectivity to 4850 L3/kg, but treatment of young ponies (mainly yearlings) with ivermectin every eight weeks or oxibendazole every four weeks resulted in pasture infectivity as high as 10,000 L3/kg. There was evidence of cyathostome resistance to benzimidazole drugs.