Background Responsible use of antimicrobials in equine practice relies on knowledge of common bacterial isolates and their antimicrobial sensitivities. Objectives To assess the frequency of bacterial resistance to a combination of parenteral penicillin and gentamicin and to trimethoprim and sulfamethoxazole for PO use in a selection of clinical isolates, and subsequently to determine the prevalence of resistance to antimicrobials that might then be used as alternatives to first‐line antimicrobials for the same isolates. Methods Retrospective analysis of minimal inhibitory concentrations (MICs) of antimicrobials for 6354 bacterial isolates from 365 ambulatory practices and 519 isolates from a referral hospital. The MICs were used to indicate sensitivity or resistance to commonly used antimicrobials and the prevalences of resistance were compared between origin of the isolates, and among antimicrobial drugs. Results Isolates from the referral hospital were significantly (P < .05) more likely to be resistant to the antimicrobials tested than those derived from ambulatory practice. Overall, 91% of the ambulatory isolates and 64% of the hospital isolates were sensitive to penicillin‐gentamicin. For trimethoprim‐sulfamethoxazole combination, 82% of the ambulatory practice isolates and 56% of the referral hospital isolates were sensitive. Conclusions and Clinical Importance Most isolates were sensitive to penicillin and gentamicin as well as trimethoprim‐sulfamethoxazole. No predictable efficacious second choice antimicrobial was identified for those isolates resistant to the first‐line antimicrobials. The likelihood of isolates being sensitive to second choice antimicrobials was variable but generally higher for ambulatory isolates compared to referral isolates. Bacterial identification and measurement of MIC are essential to make the appropriate antimicrobial choice.

Hippotherapy has been used for decades and its benefits to human patients have largely been proven, whether being applied to those with physical or mental disabilities. There have been a plethora of animal welfare studies recently, pertaining especially to ridden horses. This study aimed to investigate stress markers in horses during hippotherapy sessions to address the ethical considerations raised by using horses for therapy. A ridden stress ethogram was established and validated specifically for this study via subjective observation and video recording of a ridden session involving intermediate-level riders. The experiment entailed eight healthy horses undergoing two ridden sessions on separate days, one with disabled riders and one with beginners. Several parameters associated with physiological responses to stress were evaluated at rest, such as heart rate, plasma adrenocorticotropic hormone [ACTH], serum and salivary cortisol. These parameters as well as the behavioural stress score from the ethogram scale were measured during both sessions. No significant differences were found between heart rate, plasma ACTH, and stress scores. Serum and salivary cortisol were significantly lower during the hippotherapy session than during the session with beginners. The current study found no evidence of compromised welfare when horses were used as a therapeutic aid during hippotherapy sessions compared to their usual ridden activity. Although these results indicate that hippotherapy may be ethically justified as it benefits humans without causing harm to the horses, the present study was small, and the results should be interpreted with caution.

Introduction: Xenon, due to its interesting anesthetic properties, could improve the quality of anesthesia protocols in horses despite its high price. This study aimed to modify and test an anesthesia machine capable of delivering xenon to a horse. Materials and methods: An equine anesthesia machine (Tafonius, Vetronic Services Ltd., UK) was modified by including a T-connector in the valve block to introduce xenon, so that the xenon was pushed into the machine cylinder by the expired gases. A xenon analyzer was connected to the expiratory limb of the patient circuit. The operation of the machine was modeled and experimentally tested for denitrogenation, wash-in, and maintenance phases. The system was considered to consist of two compartments, one being the horse’s lungs, the other being the machine cylinder and circuit. A 15-year-old, 514-kg, healthy gelding horse was anesthetized for 70 min using acepromazine, romifidine, morphine, diazepam, and ketamine. Anesthesia was maintained with xenon and oxygen, co-administered with lidocaine. Ventilation was controlled. Cardiorespiratory variables, expired fraction of xenon (FeXe), blood gases were measured and xenon was detected in plasma. Recovery was unassisted and recorded. Results: FeXe remained around 65%, using a xenon total volume of 250 L. Five additional boli of ketamine were required to maintain anesthesia. PaO₂ was 45 ± 1 mmHg. The recovery was calm. Xenon was detected in blood during the entire administration time. Conclusion: This pilot study describes how to deliver xenon to a horse. Although many technical problems were encountered, their correction could guide future endeavors to study the use of xenon in horses.

Prevalence of endocrine disease in sport horses has been sparsely reported. They often compete well into their teenage years; thus, diagnosis and control of endocrine disease could be important to maintain performance and optimise health and welfare. The aim was to compare the prevalence of pituitary pars intermedia dysfunction (PPID), insulin dysregulation (ID) and metabolic obesity between sport and non-sport type breeds and assess disease progression. Blood samples submitted for plasma adrenocorticotropic hormone (ACTH), serum insulin or adiponectin were included in this study. Horses were grouped according to their breed into sport horses, which are typically used for athletic purposes, and non-sport horses, which are less-athletic breeds typically used for leisure. Cases included 1365 non-sport horse initial samples with 1850 non-sport horse follow-up samples and 1022 sport horse initial samples with 1081 sport horse follow-up samples. PPID and metabolic obesity were found to be as prevalent in the sport horse population, but non-sport horses were more likely to have ID. Upon follow up examination PPID was more prevalent with higher median ACTH in sport horses. This was also true of metabolic obesity in sport horses at follow-up, although median adiponectin was higher, perhaps indicating that the population is less severely affected than non-sport horses. Screening for endocrinopathies should be considered in sport horses presenting with poor performance.

This paper describes the clinical and histopathological features of a 16-year-old Cob mare who sustained a hemorrhagic cerebrovascular accident or stroke. The mare presented with an acute onset of neurological signs, with a neuroanatomical localization to the midbrain and thalamus regions. The mare was reported to have suffered from ataxia on all 4 limbs which started 7 days prior to referral, she was also showing several signs of left-sided cranial nerves deficits. On initial examination, the mare presented with quadrilateral ataxia, left-sided facial paralysis, weak tongue tone and a left-sided nose tilt as well as a hemineglect syndrome characterized by an inability to eat food presented on the right side of her mouth. Complete blood count and biochemistry analyses did not reveal any abnormalities, and a standing head CT revealed the presence of a hyperdense lesion localized in the left ventral cortex and thalamus region, which could be consistent with a vascular lesion, cholesterol granuloma or a mass. The mare was monitored, and as her condition slightly improved, she was discharged from the Hospital. Four weeks later, the clinical signs recurred and as the ataxia presented a danger for the mare and anyone handling her, the decision was made to euthanize her. A post-mortem CT scan of the head revealed an enlargement of the previous lesion, and the histopathological examination confirmed the presence of a hemorrhage within the brain, associated with neoplastic emboli. Hemorrhagic stroke has not previously been well described in horses therefore presents a challenge in diagnosis. Treatment in small animals is mainly conservative.