Anna Kristina Mykkänen

Background: Streptococcus zooepidemicus subsp. zooepidemicus ( S. zooepidemicus ), an opportunistic pathogen often found in the stable environment and upper respiratory tract of young horses, can cause severe pneumonias in Equidae. In this study we investigated the occurrence, genetic variation and antimicrobial susceptibility of S. zooepidemicus isolates from 63 weanling horses kept in loose housing or conventional stables. The bacterial isolates were typed by using pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). The possible associating factors (stable type, age, breed and clinical signs) for positive S. zooepidemicus finding were analysed using logistic regression analysis. In addition, we describe antimicrobial susceptibility of 535 equine S . zooepidemicus isolates in Finland derived from clinical samples sent to the Clinical Microbiology Laboratory of the Faculty of Veterinary Medicine, University of Helsinki from 2011 to 2024. Results: Out of the 63 weanling foalssampled, S. zooepidemicus was isolated in 26 (41%). There was a positive correlation between signs of respiratory infection and positive S. zooepidemicus finding (OR = 5.15, 95% CI: 1.169–22.694). Age was also a significant factor (OR = 0.972, 95% CI: 0.952–0.992), as younger foals were more likely to be S. zooepidemicus positive. Bacterial isolates were distributed into eleven PFGE clusters. The largest cluster contained six isolates, followed by clusters with five and three isolates, respectively. The cluster with three isolates appeared to have a new pro S allele in MLST analysis. In addition, two more new sequence types were observed. Sequence types observed in our study differed from those previously identified in two earlier equine studies conducted in Sweden and Iceland. All isolates from weanling foals in our study were susceptible to penicillin and trimethoprim-sulfamethoxazole. There was no resistance to penicillin in the patient samples ( n = 535) from 2011 to 2024. Of the 522 isolates tested, 28 (5.4%) were classified as either resistant or intermediate to trimethoprim-sulfamethoxazole. Only 24% of the isolates tested ( n = 403) were susceptible to tetracycline. Conclusions: Younger weanlings are more likely to have a positive S. zooepidemicus finding and their clinical signs, including high temperature, are associated with this common opportunistic pathogen. A high level of genetic variation of S. zooepidemicus is evident in weanling horses. Based on our findings, there is no evidence to suggest that S. zooepidemicus exhibits reduced susceptibility to penicillin. Additionally, the susceptibility to trimethoprim-sulfamethoxazole in the horses under study remains high.

Background: Both invasive and non-invasive blood pressure measuring methods are used in clinical and experimental work in veterinary medicine and several studies validating these methods are published. The aim of this study was to assess the level of agreement between non-invasive and invasive arterial blood pressure measurements within a wide range of blood pressures in sheep. Six adult Texel-cross female sheep were included. Anaesthesia was induced with IV propofol (4–8 mg/kg) and maintained with sevoflurane in 50% oxygen and air. Blood pressure measurements were simultaneously obtained using both invasive methods (electronic pressure transducer (EPT) connected to the auricular and carotid arteries, and aneroid manometer connected to the auricular artery) and non-invasive methods (the oscillometric device (OD) and Doppler). Carotid artery EPT was considered the ‘gold standard’ to which other methods were compared. The agreement between the two methods was evaluated with the Bland-Altman method, in conditions of normotension, hypertension (MAP > 160 mmHg, induced with phenylephrine), and hypotension (MAP < 50 mmHg, induced with acepromazine). The devices were evaluated using the American College of Veterinary Internal Medicine guidelines. Results: Carotid MAP values ranged from 37 to 192 mmHg. Mean bias and limits of agreement were − 2.8 mmHg and − 11–5.4 mmHg for the auricular EPT MAP; 5.1 mmHg and − 12.2–22.3 mmHg for the aneroid manometer MAP; − 2.7 mmHg and − 23.9–18.6 mmHg for the OD MAP; − 1.5 mmHg and − 20.1–23.2 mmHg for the Doppler SAP; respectively. Correlation coefficients for all methods were > 0.95. Conclusions: Doppler SAP and OD MAP demonstrated acceptable accuracy over a broad blood pressure range, supporting their utility for sheep as surrogate of invasive methods of measuring blood pressure. Auricular EPT was the best surrogate of central arterial pressure to be used in clinical conditions.

Background: Very little is known about sleep disturbances in horses, although several management or animal‐based factors may contribute to an increased risk of disturbances. Objectives: To investigate factors related to rest and sleep behaviour of horses kept in stalls as perceived by Nordic horse owners or caretakers and their association with suspected sleep disturbances (SSD). Study Design: Cross‐sectional survey. Methods: The 40 question online international survey included a convenience sample of horse owners or caretakers with horses over 4 years old kept in the same individual stalls for at least the last three previous months. Multivariate binary logistic regression was used to generate models of the factors associated with the SSD and their possible causes and consequences for the horses. Results: Overall, 5.0% of respondents (88/1749) suspected that their horse had sleep disturbances. The horse‐specific factors which were associated with SSD (adjusted OR; 95% CL) were age in years (1.12; 1.07–1.16), withers height (1.05; 1.03–1.08), current illness/injury (3.14; 1.92–5.15), if the horse was not seen laying down (27.82; 8.72–88.75), nightly injuries (9.16; 3.36–25.00), loss of balance/unexpected fall (40.30; 16.77–96.87), daytime drowsiness (3.85; 1.68–8.82) and difficulties lying down/getting up (16.33; 6.02–44.30). The environment‐specific factors associated with SSD were hard and dry (3.50; 1.56–7.84) and hard and wet (8.63; 2.41–30.94) lying surface. Main Limitations: Self‐selection enrolment of participants may limit the generalisability of the findings. Conclusions: Several environmental and horse‐related factors were found to be associated with SSD in horses, including hard and dry/wet lying surfaces.

Mild–moderate and severe equine asthma (MEA and SEA) are prevalent inflammatory airway conditions affecting horses of numerous breeds and disciplines. Despite extensive research, detailed disease pathophysiology and the differences between MEA and SEA are still not completely understood. Bronchoalveolar lavage fluid cytology, broadly used in clinical practice and in equine asthma research, has limited means to represent the inflammatory status in the lower airways. Lipidomics is a field of science that can be utilized in investigating cellular mechanisms and cell-to-cell interactions. Studies in lipidomics have a broad variety of foci, of which fatty acid and lipid mediator profile analyses and global lipidomics have been implemented in veterinary medicine. As many crucial proinflammatory and proresolving mediators are lipids, lipidomic studies offer an interesting yet largely unexplored means to investigate inflammatory reactions in equine airways. The aim of this review article is to collect and summarize the findings of recent lipidomic studies on equine airway inflammation.

Background: The oral sugar test (OST) is commonly used to diagnose insulin dysregulation (ID) and equine metabolic syndrome; however, possible seasonal changes in OST results have not been evaluated. Objective: To determine the possible variation in insulin response to OST throughout the year and risk factors associated with maximum insulin concentration (InsMax) and ID. Study design: Prospective, longitudinal cohort study. Methods: The OST was performed on 29 Finnhorses every other month six times. Serum total adiponectin concentration and phenotypic variables related to obesity were also measured. Changes in InsMax, adiponectin, scale weight, body condition score, cresty neck score (CNS), and fasting glucose concentration were assessed. Risk factor analyses were performed on InsMax and ID status, and ID groups were compared with each other. Results: Fourteen horses were categorised with non‐ID each time and 15 as having ID at least once during the follow‐up period. The ID status of 12 horses varied throughout the year, but neither the insulin variables measured during the OST nor adiponectin expressed significant seasonal variation. Increasing age and CNS, and decreasing adiponectin were observed as risk factors for a high InsMax after OST. The risk of ID was higher in horses with no exercise compared to horses with exercise (OR 7.6, 95% CI 1.2‐49.3, P = .03). Horses with ID had lower serum adiponectin concentrations, longer neck circumference and larger height than horses in the non‐ID group. Main limitations: The environmental conditions (feeding, exercise) were not constant for all horses throughout the study and only one breed was used. Conclusions: Neither OST results nor adiponectin varies with season; however, there were a substantial number of horses with variable ID status throughout the year, in which repeated OSTs may be beneficial. Lack of exercise was a risk factor for ID.

Background: Bit‐related lesions in competition horses have been documented, but little evidence exists concerning their potential risk factors.Objectives: To explore potential risk factors for oral lesions in Finnish trotters.Study design: Cross‐sectional study.Methods: The rostral part of the mouth of 261 horses (151 Standardbreds, 78 Finnhorses and 32 ponies) was examined after a harness race. Information on bit type, equipment and race performance was collected.Results: A multivariable logistic regression model of Standardbreds and Finnhorses showed a higher risk of moderate or severe oral lesion status associated with horses wearing a Crescendo bit (n = 38, OR 3.6, CI 1.4–8.9), a mullen mouth regulator bit (n = 25, OR 9.9, CI 2.2‐45) or a straight plastic bit (n = 14, OR 13.7, CI 1.75‐110) compared with horses wearing a snaffle trotting bit (n = 98, P = .002). Bar lesions (67 horses) were more common in horses wearing unjointed bits than in horses wearing jointed bits (Fisher's exact test P < .001). Lesions in the buccal area and the inner lip commissures were not associated with bit type. Using a tongue‐tie or an overcheck, galloping, placement in the top three or money earned in the race were not associated with lesion risk.Main limitations: The sample size for certain bit types was insufficient for statistical analysis.Conclusions: Moderate and severe oral lesion status was more common in horses wearing a Crescendo bit, a mullen mouth regulator bit or a straight plastic bit than in horses wearing a single‐jointed snaffle trotting bit. However, lesions were observed regardless of bit type. Further studies on rein tension, the interaction between bit type and rein tension and prevention of mouth lesions in trotters are warranted.