Is there a relationship between clinical presentation,diagnostic and radiographic findings and outcome in horses with osteoarthritis of the small tarsal joints?

Reasons for performing study: Despite the possibility that sound horses may have radiographic signs consistent with osteoarthritis of the small tarsal joints (OA‐STJ), a diagnosis of ‘bone spavin’ as a cause of lameness is often made based only on radiographic examination. Objectives: To determine whether severity of radiographic change and response to treatment are correlated with the duration and degree of lameness and the response to intra‐articular anaesthesia in horses with OA‐STJ. Methods: A retrospective study of all horses that showed a positive response to intra‐articular anaesthesia of the STJ was performed. Details of history, clinical presentation and diagnostic findings were recorded. Radiographs of affected tarsi were evaluated and scored independently by 2 observers. Follow‐up was via a telephone questionnaire with the owner. Statistical analysis was used to assess the association between the duration and degree of lameness, the response to intra‐articular anaesthesia and radiographic findings. Response to treatment was compared with the findings from the diagnostic work‐up. Results: Ninety‐one horses were included (61 unilateral and 30 bilateral lameness). Fifty‐nine percent of horses had been lame for over 2 months. There was no association between the duration and degree of lameness, or between duration or degree of lameness, intra‐articular anaesthesia and radiographic findings. Response to treatment showed a significant positive association with less severe radiographic changes within the tarsometatarsal (TMT) joint. Follow‐up was available for 48% of cases, with 52% horses returning to the same level of exercise. Conclusions: There is no association between the duration and degree of lameness, the response to intra‐articular anaesthesia and radiographic findings in horses with OA‐STJ. However, horses that improved following treatment tended to have less marked TMT joint pathology. Potential relevance: Response to intra‐articular anaesthesia should remain the gold standard for diagnosis of OA‐STJ. Predicting which cases are likely to improve following treatment remains difficult.     

Cardiovascular changes in horses with atrial fibrillation and high thyroid hormone concentration: a case–control study

IntroductionHyperthyroidism is a predisposing factor for atrial fibrillation (AF) in humans. The relationship between high thyroid hormone (TH) and AF in horses has not been evaluated.ObjectivesThe aim of this study is to identify whether (1) high TH concentrations were present in horses with AF, (2) other cardiovascular effects were observed in horses with high TH and AF, and (3) TH status affected recurrence rate.AnimalsTwenty-three horses presented with naturally occurring AF.MethodsProspective case–control clinical study. Thyroid hormone concentration was measured in horses presenting with AF. Heart rate, electrocardiogram, blood pressure, and an echocardiogram were recorded as part of their clinical workup. Recurrence rate was determined by owner/veterinarian follow-up.ResultsHigh TH concentration was found in 60% of horses with AF. Horses in the high TH group had a higher heart rate (P=0.001), systolic blood pressure (P=0.019), left ventricular free wall thickness (P=0.026), relative wall thickness (P=0.041) and were more likely to have periods of AF with a rapid ventricular response rate (P=0.022). All horses were successfully converted to normal sinus rhythm. The likelihood of recurrence was not different between groups.ConclusionElevated TH concentration can be found in horses with AF. Other cardiovascular effects of high TH concentrations in other species were also present in horses with AF and elevated TH concentrations. This study recommends measuring TH concentrations in horses presenting for AF with a history of thyroid or iodine supplementation. This study also cautions against TH or iodine supplementation in healthy performance horses.     

A preliminary study on the effect of wounding on transforming growth factor-β1 and cartilage oligomeric matrix protein concentrations in the skin of horses

Objective: To evaluate whether wound type or site influence the production of cartilage oligomeric matrix protein (COMP) and transforming growth factor β1 (TGF‐β1), and determine if there is a correlation between TGF‐β1and COMP during healing. Study Design: Experimental. Animals: Standardbred horses (n=6), 4–8 years old. Methods: Six, standardized, full‐thickness skin wounds (open, straight, and elliptical) were surgically created on the neck (n=3) and metacarpus (3) on each horse. Wounds were randomly allocated to site and side. Tissue samples were collected before creating wounds and on days 7, 14, and 42. COMP concentration (μg/g dry weight of tissue) was determined using a standard competitive ELISA and TGF‐β1 (ng/g dry weight of tissue) was determined using a commercially available sandwich ELISA. Results: COMP concentrations were higher in intact skin on the neck compared with the metacarpus (P=.02). There was no difference in COMP and TGF‐β1 concentrations between the different wound types or sites during healing. There was no correlation between TGF‐β1 and COMP during healing. Conclusions: Within the limitations of the study design, production of COMP during healing of skin wounds does not appear to be influenced by wound type or anatomic site, nor does it appear to be correlated with TGF‐β1 concentrations.     

Is metoclopramide an alternative to tramadol in management of post-operative pain? An experimental study

In this study, metoclopramide was compared with other pharmacological agents for preventing post-operative pain. Sixty Sprague-Dawley male rats, weighing 310-345 g were included in the study; 1 cm surgical incision, including skin, facia, and muscle was made to the plantar surface of rear foot of all anaesthetized rats. Rats were randomized into four groups. In group 1 (group S) 2 cm3 saline, in group 2 (group M) 2 cm3 metoclopramide (5 mg/kg) in group 3 (group T) 2 cm3 tramadol (45 mg/kg), in group 4 (group M+T) half doses of group M and group T was given intraperitoneally. Post-operative pain was assessed after 2 h, first and second days of incision. Post-operative pain scores were found to be significantly lower in group M, group T and group M+T when compared with the control group. But there was no significant difference between these groups. We concluded that metoclopramide, with low cost, fewer side-effects and being significantly effective for preventing post-operative pain, can be an alternative to tramadol.     

Neurological trypanosomiasis in quinapyramine sulfate-treated horses—a breach of the blood–brain barrier?

Trypanosoma evansi infection typically produces wasting disease, but it can also develop into a neurological or meningoencephalitis form in equids. Trypanosomiasis in horses was treated with quinapyramine sulfate, and all the 14 infected animals were recovered clinically. After clinical recovery, four animals developed a neurological form of the disease at various intervals. Two of these animals treated with diminazene aceturate recovered temporarily. Repeated attempts failed to find the parasite in the blood or the cerebrospinal fluid (CSF), but all of the animals were positive in enzyme-linked immunosorbent assay. The calculation of the antibody index (AI) in the serum and the CSF and polymerase chain reaction (PCR) analysis of the CSF and brain tissue were carried out to confirm the neuro-infection. We found PCR and AI analyses of the CSF to be useful tools in the diagnosis of the neurological form of trypanosomiasis when the organism cannot be found in the blood or CSF. The increased albumin quotient is indicative of barrier leakage due to neuroinflammation. The biochemical changes in the CSF due to nervous system trypanosomiasis include increases in the albumin quotient, total protein, and urea nitrogen. It seems to be the first report on relapse of the nervous form of trypanosomiasis in equids even after quinapyramine treatment in endemic areas.     

A pilot study of 4CYTE™ Epiitalis® Forte,a novel nutraceutical,in the management of naturally occurring osteoarthritis in dogs

The primary goal of this pilot study was to assess, the efficacy of a new nutraceutical, 4CYTE™ Epiitalis® Forte, containing, as a standalone, a proprietary plant oil extract, Epiitalis, in dogs presenting with signs of osteoarthritis (OA). Fifty dogs aged 9.2 (±3.2) years with signs of naturally occurring OA were included in this report. They were free of other comorbidities and were not on any medications except for those utilised for managing their OA. In these dogs, the current treatments were continued to avoid any sudden changes in their disease management. The effects of the 4CYTE Epiitalis Forte were assessed both at the beginning and at the end of a 1 month-long treatment period. The evaluation consisted of an objective lameness assessment (TPI%[total pressure index]) using a gait analysis (GAITRite® Portable Walkway System) and a subjective quality-of-life questionnaire, the Helsinki Chronic Pain Index (HCPI). Additional exploratory objective measurements included the Symmetry Index (SI) and the fore/hind limb ratio (T/P TPI%). Of dogs, 74% (34/46) registered a numerical improvement in TPI% in their worse limb. In addition, of the 93.5% of the dogs that demonstrated improvement in their HCPI scores by at least 5% on the quality-of-life questionnaire, 79% demonstrated improvements in gait based on TPI%. Finally, there were improvements measured in both exploratory objective endpoints SI and T/P TPI%. These encouraging results will be used to develop a protocol for a follow-up placebo-controlled randomised study to confirm the efficacy of this new nutraceutical for dogs suffering from OA.     

Description of a regional anaesthesia technique for the dorsal cranium in the dog: a cadaveric study

Objective

To identify landmarks and to describe a technique for nerve blockade of the dorsal cranium in dogs.

Evaluation of the clinical efficacy of prokinetic drugs in the management of post-operative ileus: can retrospective data help us?

The objectives of the study were to determine whether retrospective data can be used to answer questions about the efficacy of prokinetic agents when used to treat horses with post-operative ileus (POI). We describe prevalence and mortality of POI with reference to treatment with four prokinetic agents. By combining data from two Hospitals a study population of 55 horses with POI following pedunculated lipoma obstruction (PLO) was established. Univariable and multivariable associations were determined between short term survival and potential explanatory variables. With death as outcome in multivariable models, breed and hospital were significantly associated with outcome but the use of prokinetic agents was not (P=0.15). However, sample size estimates indicate the low power of this study to detect differences in outcome. It was not possible definitively to evaluate the efficacy of prokinetics as treatment for POI following PLO using retrospective data. The data were suggestive of limited efficacy of prokinetics as treatment for POI. It is postulated that the identified association between hospital and survival reflects differences in clinician decision making. The study highlights the need for further prospective studies using randomised clinical trials to evaluate accurately the efficacy of prokinetic agents. This report illustrates difficulties with performing retrospective analysis of clinical data to determine the efficacy of treatment regimes.     

Is there a characteristic distal tarsal subchondral bone plate thickness pattern in horses with no history of hindlimb lameness?

REASONS FOR PERFORMING STUDY: Osteoarthritis (OA) is a common cause of distal tarsal pain, but disease development is poorly understood. Awareness of normal tarsal structure and function is important in order to understand the pathogenesis of OA. Thickening of the subchondral bone (SCB) plate has been related to the development of OA, but SCB plate patterns in the equine tarsus have not been documented. HYPOTHESES: There is a repeatable pattern of SCB thickness across the distal tarsal joints, and specifically that thickness would be greatest dorsally and laterally. METHODS: Twenty cadaver tarsi were collected from mature horses that had undertaken low-level exercise only with no history of hindlimb lameness. Magnetic resonance images were acquired using a high-resolution sagittal 3-dimensional T1-weighted spoiled gradient echo sequence. Subchondral bone thickness was measured on sagittal images at dorsal and plantar locations on the proximal and distal aspects of the central (CT) and third (T3) tarsal bones and proximal aspect of the third metatarsal bone (Mt3). RESULTS: On the proximal aspect of CT, medial and lateral SCB thickness were significantly greater than midline. On the distal aspect of CT and T3 and proximal Mt3, lateral SCB thickness was significantly greater than medial and midline sites. Dorsal SCB thickness was greatest on the proximal and distal aspects of CT and proximal Mt3. Subchondral bone accounted for a greater proportion of CT and T3 on the dorsal aspect than the plantar. CONCLUSIONS: There is a repeatable pattern of SCB thickness in the distal tarsal bones of horses with no history of hindlimb lameness. This reflects the pattern of loading across the joints. POTENTIAL RELEVANCE: This study provides evidence of a consistent osteochondral pattern in the equine tarsus for reference in identification of osteoarticular pathologies.     

Seasonal dynamics of ticks (Acari: Ixodidae) on horses in the state of São Paulo, Brazil

Natural tick infestations were assessed every 14 days on horses over a 2-year period. Amblyomma cajennense adult ticks were counted individually, without detachment from the horses. Larvae and nymphs of A. cajennense were collected using a rubber scraper that scratched engorged immature ticks from the host. Adult females of Anocentor nitens larger than 4mm length were counted on the horses. Blood samples were also obtained from the horses every 14 days and macroclimatic data were obtained for the study period. Infestations of A. cajennense demonstrated distinct peaks of activity for each of the three parasitic stages over each 12-month period, showing a 1-year generation pattern. Larvae predominated from April to July and nymphs from June to October. Adults predominated from October to March with a greater number of adult males than females. Although other studies on seasonal dynamics in the states of Rio de Janeiro and Minas Gerais were performed with the free-living stages of A. cajennense on pastures, the present study in the state of S?o Paulo, performed with the parasitic stages of A. cajennense on horses, showed similar results to those observed in other states. Infestations by A. nitens demonstrated distinct peaks of activity of adult females (>4 mm), suggesting different tick generations during the year. Infestation with A. nitens was much higher in the first year than the second year which may have been related to horse nutritional status and stocking rate. Although several climatic variables showed statistical significant correlation (r) with tick counts, the determination coefficients (R(2)) were always lower than 0.40, suggesting that any single significant variable (i.e. mean temperature) would not explain the tick distribution pattern over the year. The highest peaks of A. nitens females (>4 mm) were significantly associated with decrease in horse packed cell volumes (R(2)=0.603). The ears and the perineum, tail and groin region accounted for around 70% of all A. nitens females counted on the horses.     

Does examination of fecal samples 24 hours after cestocide treatment increase the sensitivity of Anoplocephala spp. detection in naturally infected horses?

Fecal samples were examined immediately before and 24 to 48 h after cestocide treatment for a comparative detection of tapeworm-positive horses. In early winter, 17 weanlings, 20 yearlings, 15 2-year-old horses, 24 breeding mares, and 2 stallions were treated with praziquantel in combination with a macrocyclic lactone. The horses were presumed to be naturally infected with tapeworms after pasture grazing. Fecal samples were collected before treatment (Day 0), at 24 or 48 h after treatment (Day 1-2), and 16 to 21 d after treatment (Day 16-21). A Wisconsin test was done on all fecal samples. Odds of detection of infection for all age groups increased by a factor of 2.04 [95% confidence interval (CI): 1.30 to 3.20] from Day 0 to Day 1-2 (P = 0.002).     

Can jumping capacity of adult show jumping horses be predicted on the basis of submaximal free jumps at foal age? A longitudinal study

The purpose of this study was to quantify performance characteristics of good jumping horses, and to determine whether these were already detectable at foal age. Kinematic data were collected of horses performing free jumps over a 0.60 m high fence at six months of age and of these same horses jumping with a rider over a 1.15 m high fence at five years of age. At five years of age the horses were divided into three groups on the basis of a puissance competition: a group of seven best jumpers that made no errors and in the end cleared a 1.50 m high fence, a group of nine worst jumpers that were unable to clear a 1.40 m high fence, and an intermediate group of 13 horses. Longitudinal kinematic data was available for all seven best jumpers and for six of the nine worst jumpers. Average values of variables for the best jumpers were compared with those of the worst jumpers for the jumps over 1.15 m. In the group of best jumpers, the forelimbs were shorter at forelimb clearance due to increased elbow flexion, and the hind limbs were further retroflexed at hind limb clearance. The same superior technique in clearing fences with the limbs was also found in this group at six months of age. Nevertheless, for individual horses it turned out to be too far-fetched to predict adult jumping capacity on the basis of kinematic variables collected during submaximal jumps at foal age.