Liphook Equine Hospital Research Articles

Osteochondral fragmentation of the cervical articular process joints; prevalence in horses undergoing CT for investigation of cervical dysfunction.

Computed tomography (CT) imaging of the cervical spine of mature horses under general anaesthesia is becoming increasingly accessible. Osteochondral fragmentation (OF) of the cervical articular process joints (APJs) has been identified on CT imaging; the prevalence, clinical features and significance of this finding are currently unknown. To describe the prevalence and clinical features of a population of horses with CT evidence of OF within the cervical APJs. Retrospective, descriptive case series. The study population consisted of all horses undergoing CT imaging of the entire cervical spine between April 2016 and December 2019 at Liphook Equine Hospital for investigation of clinical signs localised to this region. CT scans were examined for evidence of OF within the APJs and additional case features were recorded. A total of 55 horses underwent CT imaging during the study period. OF was identified in 13 horses, giving a CT prevalence of 24% in the study population. OF occurred in a range of ages, breeds and uses of equine, presenting with varied clinical signs. It was identified at every level of the neck. Additional cervical pathology was identified in 11/13 OF cases. Retrospective analysis of a clinical caseload with a lack of clinically normal controls or post mortem confirmation of imaging findings. Low case numbers. OF within the cervical APJs is recognised on CT imaging in horses with cervical dysfunction. Fragments are commonly identified in combination with additional cervical pathology. Further investigation is required to confirm their clinical significance and develop potential treatment options where necessary.

Diagnostic imaging: its role in remedial shoeing

Dr. Matthew Sinovich BVSc BVSc(Hons) CertAVP(ESST) MSc MRCVS, Liphook Equine Hospital, discusses how diagnostic imaging can help vets guide farriers in treatment

The decision path for the referral of equine patients

Jamie Prutton BSc (Hons) BVSc DipACVIM DipECEIM MRCVS RCVS, ACVIM, ECEIM Specialist in Equine Internal Medicine Liphook Equine Hospital looks at the options

Equine distal interphalangeal joint lameness

Russell A Parker BVSc MSc DECVS MRCVS, Liphook Equine Hospital, discusses the options for managing and treating this common, but diagnostically challenging cause of lameness

Acute abdominal crisis due to gastrointestinal rupture

Jamie SW Prutton BSc (Hons) BVSc DipACVIM DipECEIM MRCVS Liphook Equine Hospital assesses the facts when faced with this frequently fatal condition

The use of casts in equine wound management

Russell Parker BVSc MSc DECVS MRCVS, Liphook Equine Hospital, explains their role in supporting healing and their application

Management of joint disease in horses

Russell Parker BVSc. MSc. DECVS. MRCVS, Liphook Equine Hospital, discusses the options

Laboratory advances for equine practices

Jamie Prutton from Liphook Equine Hospital outlines some of the recent diagnostic advances and new tests that will be available at their Liphook laboratory

Ethylenediaminetetraacetic acid (EDTA) anticoagulant affects the refractometric measurement of total protein concentration in equine synovial fluid

SummaryThe objectives of this study were to (i) determine the effect of ethylenediaminetetraacetic acid (EDTA) concentration on the refractometric measurement of the total protein (TP) concentration of equine synovial fluid and (ii) assess the effect of time and temperature on the refractometric measurement of TP concentration. Synovial fluid was retrieved aseptically from horses presenting to Liphook Equine Hospital either (a) immediately after euthanasia or (b) from those requiring arthrocentesis as part of their clinical investigation. Samples were aliquoted into commercially available (i) plain tubes (0.5 mL; control) and (ii) EDTA tubes (at different volumes to obtain serial dilutions of EDTA:synovial fluid). TP concentration was measured by two independent observers using a calibrated hand‐held refractometer. Samples from a separate group of horses were stored for 24 h at 4°C and 20°C before analysis to assess the effects of time and temperature. Results were compared using repeated measures ANOVA. TP concentration was significantly higher at all EDTA concentrations compared to control samples, with the greatest effect seen with higher concentrations (P<0.0001 for samples with ≥3.17 mg EDTA/mL). Storage time or temperature did not significantly affect TP concentration. Refractometric measurement of small volumes of synovial fluid in commercially available EDTA tubes leads to artificially elevated TP concentrations. Delays in sample analysis and alterations in storage conditions did not significantly affect TP concentration within the parameters studied. The magnitude of overestimation of synovial total protein concentration could result in misclassification of suspect synovial sepsis cases where EDTA tubes are used.

Exercise intolerance: a medical perspective

Jamie Prutton BSc (Hons) BVSc DipACVIM DipECEIM MRCVS Liphook Equine Hospital looks at some of the possible causes of exercise intolerance, their diagnosis and treatment

Distal phalangeal fractures in the horse

Russell Parker BVSc. MSc. DECVS. MRCVS Liphook Equine Hospital, discusses the diagnosis and treatment of this common, but often tricky to identify condition

Emergency care of the equine neonate in the field

James SW Prutton BSc (Hons) BVSc DipACVIM DipECEIM MRCVS, Equine Medicine Specialist, Liphook Equine Hospital, outlines the assessment process

Equine liver disease: think outside the ragwort box

Andy E Durham, from the Liphook Equine Hospital explains why it is important not to assume liver disease is only a result of ragwort poisoning

Does oral prednisolone treatment increase the incidence of acute laminitis?

It is accepted among equine practitioners that glucocorticoid treatment is a risk factor for the development of laminitis. However, there is little published evidence of a link between glucocorticoids and laminitis. To determine whether horses receiving oral prednisolone are at increased risk of laminitis. Retrospective case-control study. Clinical records of horses registered with the ambulatory service at Liphook Equine Hospital between January 2001 and November 2014 were reviewed retrospectively to identify horses that had received treatment with oral prednisolone. For each treated horse, 2 time-matched controls that received veterinary attention but were not treated with prednisolone were selected. Incidence of laminitis was compared between the 2 groups and factors associated with laminitis were assessed using Cox regression analysis. Of the 416 horses treated with prednisolone, 16 (3.8%) were diagnosed with laminitis subsequent to the initiation of prednisolone treatment with an overall incidence of 2.60 (95% CI 1.49-4.22) cases per 100 horse-years at risk. A total of 7 horses (1.7%) developed laminitis during the course of their treatment and 3 (0.7%) of the horses treated with prednisolone were ultimately subjected to euthanasia as a result of laminitis. A total of 46 (5.7%), of the 814 time-matched control horses were diagnosed with laminitis during the study period with an overall incidence of 3.46 (95% CI 2.54-4.62) cases per 100 horse-years at risk. Of these, 12 (1.5%) were subjected to euthanasia as a result of laminitis. There were no significant differences in the overall laminitis incidence rate (P = 0.8), incidence rate during prednisolone treatment (P = 0.09), or probability of laminitis (P = 0.3) between the 2 groups. Mean survival time was greater in the prednisolone than the control group. Equine metabolic syndrome and increasing age were associated with increased risk of laminitis. Administration of oral prednisolone did not increase the risk of laminitis.

Case study: Keratoma - A cause of recurrent lameness

Suzy Hall resident in lameness and diagnostic imaging, Liphook Equine Hospital

Dietary control of gastric ulcers in horses

Andy E Durham European Specialist in Equine Medicine, Liphook Equine Hospital, discusses potential strategies for long-term control

Effects of Pergolide Mesylate on Plasma Adrenocorticotropic Hormone Concentration in Horses with Pituitary Pars Intermedia Dysfunction

AimsPituitary pars intermedia dysfunction (PPID) is a common degenerative neuropathy of horses associated with ageing. Pergolide mesylate (pergolide) is the only licensed treatment for PPID in the UK; however, published evidence of its efficacy is limited to small case series and anecdotal reports. This study evaluated adrenocorticotropic hormone (ACTH) responses in horses treated with pergolide and investigated factors that may influence response to treatment.MethodsA retrospective review of submissions to The Liphook Equine Hospital Laboratory was performed from January 2007 to December 2012 and cases in which ACTH concentration was measured before and after instigation of pergolide treatment were identified. Data were analysed using Rv.2.15 software (R Development Core Team). Improvement was defined as a reduction of ACTH concentration of ≥75%, or a return of ACTH concentration to within seasonally adjusted reference intervals.ResultsA total of 2122 cases satisfied the inclusion criteria. Improvement was identified in 54.8% of horses at the first follow‐up assessment; however, ACTH concentration returned to within reference intervals in only 28%. Equids with a higher ACTH concentration pretreatment were more likely to improve (odds ratio [OR] 1.01, 95% confidence intervals [CI] 1.00–1.02; P = 0.027), but less likely to return to within the reference interval (OR 0.97; 95% CI 0.96–0.98; P<0.001). Older equids were significantly less likely to improve (OR 0.56, 95% CI 0.46–0.67; P<0.001). Improvement was more likely after a cumulative dose of 50 mg (OR 1.59, 95% CI 1.10–2.29; P = 0.013) and duration of treatment was positively associated with treatment response (P = 0.039). A daily dose >0.5 μg/kg bwt was less likely to be associated with a reduction in ACTH concentration (OR 0.86, 95% CI 0.77–0.96; P = 0.009). Native breeds, mini and draught horses were more likely to return to the reference range than other breeds (OR 1.6, 95% CI 1.24–2.07; P<0.001). Neither gender nor season were associated with response to treatment.Conclusions and practical significancePergolide is an effective means of reducing ACTH concentration in equids with PPID.Ethical animal researchNot required by this Congress: retrospective clinical study. Sources of funding: None. Competing interests: Rendle and Durham have acted as paid speakers and consultants for Boehringer Ingelheim, manufacturers of Prascend, the licensed equine pergolide product.

A sore point

Tom Hughes RCVS and European specialist equine surgery, of the Liphook Equine Hospital discusses field castration and its complications

Equine metabolic syndrome: the issues

Andy E Durham BSc, BVSc, CertEP, DEIM, DipECEIM, MRCVS RCVS & European Specialist in Equine Internal Medicine of the Liphook Equine Hospital, discusses the management of ‘good-doers’

Circannual variation in plasma adrenocorticotropic hormone concentrations in the UK in normal horses and ponies, and those with pituitarypars intermediadysfunction

Pituitary pars intermedia dysfunction (PPID) is a common endocrinopathy, frequently diagnosed via plasma adrenocorticotropic hormone (ACTH) concentrations. Seasonal variation in plasma ACTH concentrations has been described in normal horses prompting caution in diagnosing PPID at certain times of the year. The aims of this study were to determine appropriate reference intervals for equine plasma ACTH throughout the year; and to examine the circannual variation of plasma ACTH concentrations in PPID cases. Plasma ACTH can be used as a test for PPID throughout the year with the use of appropriate reference intervals. Data for reference interval calculations were obtained from samples collected from inpatients of Liphook Equine Hospital (non-PPID group, n=156). Data from PPID cases (n=941) were obtained from samples submitted to the Liphook Equine Hospital Laboratory from horses with a clinical suspicion of PPID found to have plasma ACTH concentrations greater than our upper reference interval for that time of year. Upper limits for reference interval of plasma ACTH were 29 pg/ml between November and July and 47 pg/ml between August and October. Circannual variation in plasma ACTH occurred in both non-PPID and PPID horses with the highest ACTH concentrations found between August and October in both groups (P<0.0001). The greatest difference between the 2 populations also occurred between August and October. Plasma ACTH can be used for the diagnosis and monitoring of PPID throughout the year with the use of appropriate reference intervals. These findings demonstrate an increase in pituitary gland secretory activity during the late summer and autumn in both normal and PPID cases.