Familial episodic ataxia in lambs is potentially associated with a mutation in the fibroblast growth factor 14 (FGF14) gene.

Familial episodic ataxia of lambs is a congenital transient autosomal dominant disorder of newborn lambs, with varying expressivity. Affected lambs show episodes of an asymmetric ataxic gait, base-wide extensor hypertonia of the thoracic limbs and flexor hypertonia of the pelvic limbs. The aim of the study was to determine the genetic variant causing familial episodic ataxia in lambs. Using whole genome sequencing of two half-sib affected lambs, their sire, and their two normal dams, a heterozygous C>T transition at OAR10:77593415 (Oar_v3.1) in exon 1 of the fibroblast growth factor 14 (FGF14) gene (c.46C>T) was identified. The c.46C>T transition resulted in a premature stop codon at position 16 of the 247 amino acid FGF14 protein (p.Q16*). PCR and Sanger sequencing was used to genotype an additional 20 clinically affected animals, demonstrating all lambs carried the c.46C>T variant but 1 clinically more severely affected inbred lamb was homozygous (TT). A further 11 unrelated normal ewes were positionally sequenced, none of which had the variant, while in 18 lambs of unknown status born over 2 years of breeding trials six lambs were found to have the c.46C>T variant, likely clinically unidentified heterozygotes due to the variable expressivity, while 12 did not. In conclusion, familial episodic ataxia of lambs is potentially associated with a c.46C>T variant in the FGF14 gene. Further research is required into the mechanism behind the apparent recovery of lambs.

Preliminary study of tissue concentrations of penicillin after local administration into the guttural pouches in four healthy horses.

BACKGROUND: Treatment of subclinical carriers of Streptococcus equi subsp. equi with a gelatine-penicillin formulation deposited in the guttural pouch has been empirically proposed, but data on local tissue penicillin concentrations after treatment are lacking. METHODS: We analysed tissue levels of penicillin after administration into the guttural pouches of four healthy horses. Two horses received local treatment with gelatine-penicillin and two horses received local treatment with an intramammary formulation of penicillin. Tissues were harvested for analysis either 12 or 24 h later. CONCLUSION: Results indicate that local treatment may be effective, but more research on optimal drug formulations in a larger sample size is warranted.

The first reported outbreak of equine herpesvirus myeloencephalopathy in New Zealand.

CASE HISTORY AND CLINICAL FINDINGS: On 9 January 2014 (Day 0) a mare from a stud farm in the Waikato region presented with urinary incontinence without pyrexia. Over the following 33 days 15 mares were clinically affected with neurological signs. All but one mare had a foal at foot. The most commonly observed clinical signs were hind limb paresis and ataxia. In some cases recumbency occurred very early in the course of disease and seven mares were subject to euthanasia for humane reasons. LABORATORY FINDINGS: Equid herpesvirus (EHV) type 1 was detected using PCR in various tissues collected post mortem from two mares with neurological signs. DNA sequencing data from the DNA polymerase gene of the virus showed a nucleotide transition at position 2254, a mutation encoding amino acid D752 that is highly associated with the neuropathogenic genotype of EHV-1. In total 12/15 mares were confirmed positive for EHV-1 on PCR. Results from a virus neutralisation test and ELISA on paired serum samples, and PCR on whole blood and nasal swabs, indicated that of four paddocks in a high-risk area where a cluster of cases had occurred, 20/21 (95%) horses were likely to have been exposed or were confirmed infected with EHV-1. Subsequent to the outbreak two mares aborted, one at 9 months and one at 10 months of gestation. The cause of abortion was confirmed as EHV-1 with the same genotype as that involved in the outbreak. DIAGNOSIS: Equine herpesvirus myeloencephalopathy. CLINICAL RELEVANCE: The outbreak described shows the considerable impact that can occur in outbreaks of equine herpesvirus myeloencephalopathy in New Zealand. Early biosecurity controls not only reduced the effect on the farm but mitigated the potential for the virus to spread to other horse enterprises.

Posture and movement characteristics of forward and backward walking in horses with shivering and acquired bilateral stringhalt.

REASONS FOR PERFORMING STUDY: To investigate and further characterise posture and movement characteristics during forward and backward walking in horses with shivering and acquired, bilateral stringhalt. OBJECTIVES: To characterise the movement of horses with shivering (also known as shivers) in comparison with control horses and horses with acquired bilateral stringhalt. STUDY DESIGN: Qualitative video analysis of gait in horses. METHODS: Owners' and authors' videos of horses with shivering or stringhalt and control horses walking forwards and backwards and manually lifting their limbs were examined subjectively to characterise hyperflexion, hyperextension and postural abnormalities of the hindlimbs. The pattern and timing of vertical displacement of a hindlimb over one stride unit was evaluated among control, shivering and stringhalt cases. RESULTS: Gait patterns of shivering cases were characterised as follows: shivering-hyperextension (-HE, n = 13), in which horses subjectively showed hyperextension when backing and lifting the limb; shivering-hyperflexion (-HF, n = 27), in which horses showed hindlimb hyperflexion and abduction during backward walking; and shivering-forward hyperflexion (-FHF, n = 4), which resembled shivering-HF but included intermittent hyperflexion and abduction with forward walking. Horses with shivering-HF, shivering-FHF and stringhalt (n = 7) had a prolonged swing phase duration compared with control horses and horses with shivering-HE during backward walking. With the swing phase of forward walking, horses with stringhalt had a rapid ascent to adducted hyperflexion of the hindlimb, compared with a rapid descent of the hindlimb after abducted hyperflexion in horses with shivering-FHF. CONCLUSIONS: Shivering affects backward walking, with either HE or HF of hindlimbs, and can gradually progress to involve intermittent abducted hyperflexion during forward walking. Shivering-HF and shivering-FHF can look remarkably similar to acquired bilateral stringhalt during backward walking; however, stringhalt can be distinguished from shivering-HF by hyperflexion during forward walking and from shivering-FHF by an acute onset of a more consistent, rapidly ascending, hyperflexed, adducted hindlimb gait at a walk.

Epidemiology of shivering (shivers) in horses.

REASONS FOR PERFOMING STUDY: Investigating the epidemiology of shivering in horses. OBJECTIVES: The purpose of this study was to characterise the signalment, clinical signs and management factors associated with shivering (also known as shivers), a relatively rare, poorly defined movement disorder in horses. STUDY DESIGN: Web-based case series survey and case-control study. METHODS: A Web-based survey was used to obtain information from owners, worldwide, who suspected that their horse had shivering. Survey respondents were asked to answer standardised questions and to provide a video of the horse. Authors reviewed the surveys and videos, and horses were diagnosed with shivering if they displayed normal forward walking, with difficulty during manual lifting of the hoof and backward walking due to hyperflexion or hyperextension of the pelvic limbs. Cases confirmed by video were designated 'confirmed shivering', while those with compatible clinical signs but lacking video confirmation were designated 'suspected shivering'. Owners of confirmed shivering horses were asked to provide information on 2 horses without signs of shivering (control group). RESULTS: Three hundred and five surveys and 70 videos were received; 27 horses were confirmed shivering (50 controls), 67 were suspected shivering and the rest had a variety of other movement disorders. Suspected shivering horses resembled confirmed shivering cases, except that the suspected shivering group contained fewer draught breeds and fewer horses with exercise intolerance. Confirmed shivering signs often began at <5 years of age and progressed in 74% of cases. Owner-reported additional clinical signs in confirmed cases included muscle twitching (85%), muscle atrophy (44%), reduced strength (33%) and exercise intolerance (33%). Shivering horses were significantly taller (confirmed shivering, mean ∼173 cm; control horses, ∼163 cm) with a higher male:female ratio (confirmed shivering, 3.2:1 vs. control, 1.7:1). No potential triggering factors or effective treatments were reported. CONCLUSIONS: Shivering is a chronic, often gradually progressive movement disorder that usually begins before 7 years of age and has a higher prevalence in tall male horses.

Brainstem auditory evoked potential testing in Dalmatian dogs in Brazil / Potencial evocado auditivo de tronco encefálico em cães da raça Dálmata no Brasil

The brain stem auditory-evoked potential (BAEP) is an electrophysiologic test that detects and records the electrical activity in the auditory system from cochlea to midbrain, generated after an acoustic stimulus applied to the external ear. The aim of this study is to obtain normative data for BAEP in Dalmatian dogs in order to apply this to the evaluation of deafness and other neurologic disorders. BAEP were recorded from 30 Dalmatian dogs for a normative Brazilian study. Mean latencies for waves I, III, and V were 1.14 (±0.09), 2.62 (±0.10), and 3.46 (±0.14) ms, respectively. Mean inter-peak latencies for I-III, III-V, and I-V intervals were 1.48 (±0.17), 0.84 (±0.12), and 2.31 (±0.18) ms, respectively. Unilateral abnormalities were found in 16.7% of animals and bilateral deafness was seen in one dog. The normative data obtained in this paper is compatible with other published data. As far as we know this is the first report of deafness occurrence in Dalmatian dogs in Brazil...

O potencial evocado auditivo de tronco encefálico (BAEP) é um teste eletrodiagnóstico que detecta e registra a atividade elétrica do sistema auditivo desde a cóclea até o tronco encefálico, gerada após a emissão de um estímulo acústico na orelha externa. O objetivo deste estudo é obter dados normativos para o BAEP em cães da raça Dálmata para usá-lo para detecção de surdez e de outras alterações neurológicas. BAEP foi obtido de 30 cães da raça Dálmata para um estudo normativo no Brasil. As latências médias para as ondas I, III e V foram 1,14ms (±0,09); 2,62ms (±0,10) e 3,46ms (±0,14), respectivamente. A média das latências dos intervalos I-III, III-V e I-V foi 1,48ms (±0,17); 0,84ms (±0,12) e 2,31ms (±0,18), respectivamente. Alteração unilateral foi observada em 16,7% dos animais, e surdez bilateral foi observada em um cão. Os dados normativos obtidos neste trabalho são compatíveis com outros dados já publicados. Segundo a revisão realizada, este é o primeiro relato da ocorrência de surdez em cães da raça Dálmata no Brasil...

Traumatic brain injury, axonal injury and shaking in New Zealand sea lion pups.

Trauma is a common cause of death in neonatal New Zealand sea lion pups, and subadult male sea lions have been observed picking up and violently shaking some pups. In humans, axonal injury is a common result of traumatic brain injury, and can be due to direct trauma to axons or to ischaemic damage secondary to trauma. 'Shaken baby syndrome', which has been described in human infants, is characterised by retinal and intracranial subdural haemorrhages, and has been associated with axonal injury to the brain, spinal cord and optic nerve. This study identifies mechanisms of traumatic brain injury in New Zealand sea lion pups, including impact injuries and shaking-type injuries, and identifies gross lesions of head trauma in 22/36 sea lion pups found dead at a breeding site in the Auckland Islands. Despite the high frequency of such gross lesions, only three of the pups had died of traumatic brain injury. Observational studies confirmed that shaking of pups occurred, but none were shown to die as a direct result of these shaking events. Axonal injury was evaluated in all 36 pup brains using ß-amyloid precursor protein immunohistochemistry. Immunoreactive axons were present in the brains of all pups examined including seven with vascular axonal injury and two with diffuse axonal injury, but the severity and pattern of injury was not reliably associated with death due to traumatic brain injury. No dead pups had the typical combination of gross lesions and immunohistochemical findings that would conform to descriptions of 'shaken baby syndrome'. Axonal injury was present in the optic nerves of most pups, irrespective of cause of death, but was associated with ischaemia rather than trauma.

Expression of PGP 9.5 by enteric neurons in horses and donkeys with and without intestinal disease.

Intestinal motility disorders are an important problem in horses and donkeys and this study was carried out in order to evaluate the enteric neurons in animals with and without intestinal disease. Surplus intestinal tissue samples were collected from 28 horses undergoing exploratory laparotomy for colic. In addition, surplus intestinal samples from 17 control horses were collected immediately following humane destruction for clinical conditions not relating to the intestinal tract. Similar samples were also collected during routine post-mortem examinations from 12 aged donkeys; six animals were humanely destroyed for conditions related to the intestinal tract, while the remaining six were humanely destroyed for other reasons including dental and orthopaedic diseases. Tissue samples were fixed in formalin and immunohistochemical labelling was performed targeting the enteric neurons using a polyclonal antibody specific for the neuronal marker PGP 9.5. The distribution and density of neuronal networks were assessed qualitatively and semiquantitatively. There was strong PGP 9.5 expression in both the horse and donkey samples and labelling was detected throughout the tissue sections. In both species, PGP 9.5-immunoreactive nerve fibres were detected in all layers of the intestinal tract, both in large and small intestinal samples. Networks of enteric neurons were present in the donkey with a similar distribution to that seen in the horse. There was no demonstrable difference in enteric neuronal density and distribution in the groups of animals with intestinal disease compared with those without, apart from two (out of 28) horses with intestinal disease that showed a marked reduction in PGP 9.5 immunoreactivity. Apart from these two animals, this total cohort analysis differs from some previously observed findings in horses with intestinal disease and may therefore reflect the different pathophysiological processes occurring in varying intestinal conditions resulting in colic both in the donkey and the horse.

Sub-optimal efficacy of ivermectin against Parascaris equorum in foals on three Thoroughbred stud farms in the Manawatu region of New Zealand.

AIM: To ascertain whether resistance was present in Parascaris equorum to the macrocyclic lactone anthelmintic ivermectin, using faecal egg count reduction tests. METHODS: Thirty-nine foals aged between 11 and 28 weeks on three Thoroughbred stud farms (Farms A; n=20, B; n=5 and C; n=14) were treated with ivermectin (Day 0) and faecal egg counts (FEC) were monitored before and for 21 (Farms A and B) or 14 (Farm C) days after treatment. On Farms A and B, the foals were treated with a macrocyclic lactone/benzimidazole/praziquantel combination on Day 21 and FEC assessed on Day 35. The three farms were all in the Manawatu region in the southern half of New Zealand's North Island. RESULTS: Of the 39 foals, 15 were not shedding P. equorum eggs on the day they were treated with ivermectin, but all 15 did so post-treatment. The FEC on Farms A and B showed no evidence of a reduction at any time between Day 7 and 21; egg output increased steadily over this period. Following combination treatment FEC were reduced by 94% on farm A and 100% on Farm B. On Farm C, there was a 69% reduction in P. equorum FEC on Day 14. Twelve of the 14 foals on Farm C were shedding strongylid eggs on Day 0 and on Day 14 FEC were reduced by 84%. CONCLUSIONS: Without comparison to untreated control animals, these results do not allow a reliable estimation of the exact level of efficacy of ivermectin against P. equorum, but they nevertheless show that, within the farms studied, ivermectin no longer achieved a complete kill of egg-laying adults and that foals treated with this drug may continue to shed considerable numbers of eggs after treatment. The results also indicate that ivermectin had sub-optimal efficacy against strongylid nematodes on one of the farms.

Cytotoxic activity of extracts from Hypochaeris radicata.

Pasture-associated stringhalt is an acquired equine disease characterized by peripheral neuropathy and hyperflexion of the pelvic limbs. The disease occurs most commonly during periods of drought in horses grazing pastures heavily contaminated by Hypochaeris radicata. We hypothesized that stringhalt is caused by neurotoxins elaborated by H. radicata in response to the stress of drought conditions. Supernates were collected from H. radicata that were stressed (or not) by immersion in copper chloride solution, then extracted with ethyl acetate and dried. Dilutions of extracts from stressed (SE) and control, unstressed (UE) plants were incubated with myelinating spinal cord cultures (MSCC) established from fetal Swiss mice, and with spinal ganglion cultures (SGC) and dermal fibroblast cultures derived from neonatal mouse tissues. Cytotoxicity in culture monolayers was evaluated both morphologically by microscopy and by release of lactate dehydrogenase activity into culture supernates. Three different SGC preparations were exposed to a single H. radicata extract and single preparations of fibroblasts and MSCC were exposed to three different extracts. Repin, a plant-derived sesquiterpene lactone neurotoxin, was included as a positive control. Significant dose-dependent cytotoxicity was seen within 24 h in all three culture types when incubated with SE or repin. Complete morphologic destruction of culture monolayers was induced by the highest concentrations tested of SE (100 µg/mL) and repin (30 µg/mL). Cytotoxic effect of SE was significantly greater than that of UE for all three cell types and was not due to copper contamination of the extract. This study has identified a cytotoxic activity in leaf exudates of H. radicata that was upregulated by the model stressor, copper chloride.

Familial episodic ataxia in lambs.

HISTORY: A similar episodic neurological disorder occurred in new born lambs on two unrelated properties involving disparate breeds of sheep. Because of the number of lambs born, cross-breeding and the fact it occurred in some mating groups and not others, a dominant mode of inheritance was, initially and separately, suspected in each case. The sires of affected lambs were apparently normal. Whereas one was New Zealand Romney, the other was a composite breed with East Friesian genetics, but both rams originated from the same source property. To investigate the pathogenesis of the disorder these two rams were acquired and mated with unrelated sheep, under experimental conditions in a more controlled environment. CLINICAL FINDINGS: A proportion of lambs born to both sires exhibited a similar neurological disorder. Some lambs were noted to be abnormal at birth, both on home properties and in the experimental flock. They tended to adopt a head and neck extended posture and were slow to get to their feet and suckle when they then became more or less normal. When forced to move, they and other more robust lambs elicited an asymmetric gait, base-wide extensor hypertonia (hypometria) of thoracic limbs and flexor hypertonia (hypermetria) of pelvic limbs. In some there was nystagmus. After several metres of asymmetric ataxic gait they would fall to one side, sometimes adopting a sitting position. Recovery usually occurred in one to several minutes. As lambs aged, it became more difficult to elicit the episodes of dysfunction and by 6 months of age they appeared normal. DIAGNOSIS: The disorder was diagnosed as a dominant familial episodic cerebellovestibular ataxia inherited as a dominant trait, with incomplete penetration of observed clinical signs and variable expressivity. CLINICAL RELEVANCE: A proportion of affected lambs are likely to die in the neonatal period so the specific nature of the disorder may go unrecognised. Because of incomplete penetrance and varying expressivity, many of the lambs carrying this mutation will survive without showing clinical signs and may enter breeding flocks, where the disorder may be perpetuated and contribute to neonatal deaths.

Permanent monoparesis in a dog after intramedullary injection of iohexol into the lumbar spinal cord.

UNLABELLED: Abstract CASE HISTORY: An 8-year-old, spayed, Doberman Pinscher bitch presented for assessment of acute hindlimb paresis. CLINICAL FINDINGS: During a lumbar myelographic contrast study a small volume of iohexol contrast agent was inadvertently injected into the cord parenchyma. After surgical hemilaminectomy for an intervertebral disc extrusion at L1-2 the dog recovered use of one hindlimb, but had ongoing extensor weakness of the left hindlimb. Left femoral nerve function had not returned after 14 months. DIAGNOSIS: EMG findings 14 months after the incident indicated persistent femoral neuropathy consistent with the intramedullary contrast injection at L3-4. CLINICAL RELEVANCE: Inadvertent deposition of iohexol into spinal cord parenchyma may be rare, but if it occurs it can have long-lasting consequences.

Flow-mediated K(+) secretion in horses intoxicated with lolitrem B (perennial ryegrass staggers).

AIM: To investigate the effects of lolitrem B intoxication on renal K(+) secretion in response to increased tubular flow rates. METHODS: Results are derived from a repeated measure pilot study of seven horses fed non-perennial ryegrass feed for a week prior to exposing them to perennial ryegrass seed and hay that contained an average of 2 ppm lolitrem B. At the end of the control and treatment period frusemide (1 mg/kg I/V) was administered and serial fractional excretion of K(+)(FEK(+)) and fractional excretion of Na(+)(FENa(+)) calculated. Baseline concentration of aldosterone in plasma, serum K(+)concentration and feed K(+) concentration were also compared. RESULTS: Key findings included a reduced change in FEK(+) from 0 to 15 minutes in response to frusemide administration (p=0.022, Wilcoxon signed-rank test) and a reduced baseline concentration of aldosterone in plasma (p=0.022, Wilcoxon signed-rank test) during the treatment period compared with the control. CONCLUSIONS: Results suggest that lolitrem B intoxication reduced flow-mediated K(+) secretion and interfered with aldosterone production or secretion. However, further investigation is required to validate these findings and to further elucidate the underlying pathophysiology. CLINICAL RELEVANCE: Lolitrem B intoxication in horses may cause disruption to electrolyte handling in addition to neurological deficits.

Clinical expression of lolitrem B (perennial ryegrass) intoxication in horses.

REASONS FOR PERFORMING STUDY: Perennial ryegrass staggers is purported to be a common neurological mycotoxicosis of horses but the case description lacks detail and evidence. OBJECTIVE: To describe the clinical syndrome of lolitrem B intoxication in horses, limiting tests to those that are applicable to clinical practice, and to assess the potential value of enzyme-linked immunosorbent assay (ELISA) tests for lolitrem B in horse body fluids. METHODS: Seven horses in 2 separate groups were fed perennial ryegrass seed and hay containing 2 ppm lolitrem B. Paired data were collected prior to and after 2 weeks exposure to lolitrem B, including video-documented neurological examination and clinical examination. RESULTS: All horses developed a variable degree of tremor and ataxia when exposed to lolitrem B. Tremor depended on the level of activity and included a subtle, rapid tremor of the eyeball. Ataxia was exaggerated by blindfolding and primarily involved a truncal sway and irregular, but predictable, limb placements. No change was detected in urine lolitrem B levels and, although plasma lolitrem B increased during the treatment period, levels did not correlate with the severity of clinical signs displayed. Limb swelling, heel lesions and serous nasal discharge were also observed in horses most severely intoxicated. CONCLUSIONS: The clinical effects of lolitrem B intoxication in horses primarily involve action-related tremors and symmetrical vestibular ataxia. Ergovaline may have caused the limb swelling, heel lesions and serous nasal discharge. Plasma ELISA for lolitrem B may be of diagnostic use in the future. POTENTIAL RELEVANCE: This study provides a clearer appreciation of the clinical signs and variability of perennial ryegrass intoxication in horses.

Gestation length and occurrence of daytime foaling of Standardbred mares on two stud farms in New Zealand.

AIMS: To examine the gestation lengths and occurrence of daytime foaling of Standardbred mares foaling outdoors at stud farms in Southland, New Zealand (latitude 45˚S). METHODS: Data were collected prospectively at two commercial Standardbred stud farms (Farms A and B), during the 2008/9 and 2009/10 breeding seasons (October to February). For each foaling, the identity of the mare, date and time of foaling, gender of foal, time the mare passed the fetal membranes, time the foal stood, and foaling problems including dystocias, were recorded. The effect of farm, season, gender of foal, month of artificial insemination (AI) or foaling, age and parity of mare on gestation length, percentage of mares foaling during daylight hours, and percentage of foalings recorded as dystocia, were examined. RESULTS: A total of 614 foaling records were obtained from 507 mares. For 594 foalings with complete records, mean gestation length was 349 (SE 0.5) days. Mean gestation length was shorter for fillies (347.8 (SE 0.6) days) than colts (350.3 (SE 0.6) days) p = 0.021) and decreased with month of AI, from October to February (p = 0.001). The time of foaling was bimodally distributed with the primary peak around 0200 hours and a secondary smaller peak around 1300 hours. The percentage of mares foaling in daylight was lower on Farm A (69/285 (24%)) than Farm B (128/313 (41%)) (p = 0.001). Colt foals were less likely to be born during the day than fillies (OR = 0.63; (95% CI = 0.44-0.88); p = 0.008), but there was no effect of age or parity of mare or month of foaling (p>0.05). CONCLUSIONS AND CLINICAL RELEVANCE: Mean gestation length of mares in this study was longer than that previously reported from other countries. Longer gestation length decreases the time available for these mares to get back into foal in the same season. It is important that managers take this into account and ensure optimum conditions for conception; breeding at the first postpartum oestrus may be essential. There were more mares foaling in daylight hours on one stud than has previously been reported. Under these conditions mares should be monitored for foaling during daytime as well as at night.

In vitro electrical activity of the equine pelvic flexure.

REASONS FOR PERFORMING STUDY: The generation and maintenance of intestinal motility patterns involve the complex interactions of several components including the gastrointestinal pacemaker cells (interstitial cells of Cajal, ICC). Central to ICC function is the generation of rhythmic pacemaker currents, namely slow waves, which represent the rate limiting step for intestinal smooth muscle contractions. Currently, intracellular slow wave activity has not been demonstrated in the equine colon. OBJECTIVES: To characterise the in vitro myoelectrical activity of the equine pelvic flexure using intracellular recording techniques. METHODS: Intestinal samples were collected immediately following euthanasia from 14 normal horses. One millimetre thick tissue sections were pinned and superfused with warmed, oxygenated Krebs solution. Intracellular recordings were made from smooth muscle cells close to the submucosal border of the circular muscle layer. The L-type Ca(2+) channel blocker nifedipine was added to the superfusion fluid in 9 experiments while the Na(+) channel blocker tetrodotoxin was added to the superfusion fluid in 4 experiments. The data were recorded and stored using an acquisition system and a software package used to analyse the recordings. RESULTS: In 10 of the 14 horses, electrical events consistent with slow wave patterns were recorded from individual smooth muscle cells. Surprisingly, adding nifedipine to the superfusion fluid abolished all electrical activity. In contrast, tetrodotoxin had no apparent effect on the electrical activity. CONCLUSIONS: Assuming that the electrical events were slow waves, the blockade by nifedipine suggests significant and potentially important differences in the ionic mechanisms responsible for slow waves in the different regions of the equine intestinal tract, which deserve further evaluation.

Cutaneous fungal granulomas due to Alternaria spp. infection in a horse in New Zealand.

Equine cutaneous fungal granulomas have been previously referred to in New Zealand (Fairley 1998), and are described in the veterinary literature from around the world, including North America and Australia (Pascoe and Summers 1981; Genovese et al. 2001; Valentine et al. 2006), but no peer-reviewed reports appear published in the literature in New Zealand. Described here is a case of multiple cutaneous fungal granulomas caused by Alternaria spp. in a horse in New Zealand.

Retrospective evaluation of episodic collapse in the horse in a referred population: 25 cases (1995-2009).

BACKGROUND: Episodic collapse in horses has equine welfare and human safety implications. There are, however, no published case series describing this syndrome. OBJECTIVES: To characterize the cause and outcomes for horses referred for investigation of episodic collapse. ANIMALS: Twenty-five horses referred for investigation of single or multiple episodes of collapse. METHODS: Retrospective study. Clinical records from the Dick Vet Equine Hospital, University of Edinburgh from November 1995 to July 2009 were searched using the following keywords: collapse, collapsing, fall, syncope. Collapse was defined as an incident in which the horse lost postural tone with or without progression to recumbency and with or without loss of consciousness. Long-term follow-up information was obtained by telephone conversation with the owner. RESULTS: A final diagnosis was reached in 11 cases, namely cardiac arrhythmia (4), right-sided heart failure (1), hypoglycemia (2), generalized seizures (2), and sleep disorder (2). A presumptive diagnosis was reached in 8 cases, namely neurocardiogenic syncope (5), exercise-induced pulmonary hemorrhage (2), and generalized seizures (1). No diagnosis was reached in 6 cases despite comprehensive investigations. Three horses were euthanized at presentation. Treatment was attempted in 9 horses with 6 cases having successful outcome before discharge. Follow-up information was available for 14 of 19 horses discharged from the hospital. Only 1 of these horses was observed to collapse after discharge. CONCLUSIONS AND CLINICAL IMPORTANCE: Definitive diagnosis was more likely to be reached in cases with multiple episodes of collapse. Horses in which 1 episode of collapse occurred did not necessarily collapse again.