Paralysis in horses refers to the loss of voluntary muscle function, which can result from a variety of neurological or musculoskeletal conditions. It can affect different parts of the horse's body and may be partial or complete. Causes of paralysis in horses include traumatic injuries, neurological disorders, infections, and toxicities. Common conditions associated with equine paralysis include equine protozoal myeloencephalitis (EPM), cervical vertebral stenotic myelopathy (CVSM), and botulism. Diagnosis and management of paralysis in horses require comprehensive veterinary evaluation, including neurological examinations and diagnostic imaging. This page compiles peer-reviewed research studies and scholarly articles that explore the causes, diagnostic approaches, and treatment options for paralysis in horses.
Olitsky PK, Kligler IJ.With the methods which have been described we have separated an exotoxin and an endotoxin from cultures of the Shiga dysenteric bacillus. The study of the nature and effect of the poison of this microorganism is thus simplified. The two toxins are physically and biologically distinct. The exotoxin is relatively heat-labile, arises in the early period of growth, and yields an antiexotoxic immune serum. The endotoxin, on the other hand, is heat-stable, is formed in the later period of growth, and is not neutralized by the antiexotoxic serum. The exotoxin exhibits a specific affinity for the cent...
Fitzgerald WE.Four cases of snakebite in horses are presented. Diagnosis was made on clinical signs in all, plus fang punctures in 2 cases. Tiger snake antivenene was used in the treatment of 2 patients and these recovered rapidly. Of the 2 in which antivenene was not used, 1 severely affected horse died. The clinical signs which were observed were those of progressive general paralysis and were entirely referable to the neurotoxic component of the venom.
De Jonge B, Dufourni A, Oosterlinck M, Chiers K.We report a 9-year-old Thoroughbred gelding that had sudden onset lameness of the right forelimb with episodes of lateral decubitus and generalized pain after completion of a normal training session. The clinical signs subsequently became less pronounced with only mild right forelimb lameness. However, after further orthopaedic examination, it developed severe, acute ataxia and paraplegia, the Schiff-Sherrington phenomenon and risus sardonicus. At necropsy, a partial duplication of the cervical spinal cord was identified, consistent with split spinal cord malformation type II or diplomyelia. H...
Hildebrand SV, Hill T, Holland M.To determine whether cholinesterase inhibition by an organophosphate would influence atracurium's neuromuscular blockade, six horses were anesthetized and paralyzed with atracurium (total of five injections per horse) on experimental Day 1, then were given trichlorfon (64 mg/kg per os) 6 days later. On Day 7, horses were anesthetized and paralyzed in the same manner as on experimental Day 1. Blood was taken to measure serum cholinesterase activity prior to anesthesia on Days 1 and 7. No significant difference was noted in atracurium's neuromuscular blocking activity between the 2 experimental ...
Hughes KJ, McGorum BC, Love S, Dixon PM.Six ponies and four horses with a mean (sd) age of 15.9 (6.0) years developed sudden-onset bilateral laryngeal paralysis (BLP) in association with hepatic dysfunction. Nine of them had been referred for the investigation of respiratory distress, and one pony had been referred for weight loss before BLP developed. Nine of the animals had clinicopathological evidence of liver disease, and nine had histological evidence of liver disease. All of the animals had one or more of the following: hepatic encephalopathy (in eight), hyperammonaemia (in six) and endoscopic evidence of BLP (in nine). Three ...
Sloet van Oldruitenborgh-Oosterbaan MM.Hyperkalaemic periodic paralysis(HYPP) is characterized by intermittent episodes of muscular tremor, weakness, and collapse, and is probably caused by abnormal electrolyte transport in the muscle cell membrane. During an episode of HYPP, most animals are severely hyperkalaemic. HYPP is a hereditary disease and occurs only in American Quarter horses or crossbreds. Because these horses are now being imported into the Netherlands, HYPP should be included in the differential diagnosis of horses showing signs of muscle tremor, paresis, or paralysis. The present article reviews the literature on HYP...
Grant RC, Basson PA, Kidd AB.A paralytic condition of farm stock in South West Africa, characterized by prominent neuronal and some mild extraneuronal pigmentation, is described. The distribution of the pigment, which was mainly located in the larger neurones of the brain and spinal cord, is given. Experimental evidence, obtained by feeding the plant, is presented that the condition is caused by Trachyandra laxa var. laxa. The histochemical features of the pigment proved to be compatible with a lipofuscin.
Church S.Three Quarter Horse stallions and 5 of their 11 tested progeny were diagnosed as affected with the inherited autosomal dominant defect hyperkalaemic periodic paralysis in Victoria in 1992. The diagnoses were based on the appearance of clinical signs and associated increased plasma potassium concentrations in response to oral potassium loading. All affected horses were descendants of the American Quarter Horse Impressive. Indirect evidence indicates that at least 3 other affected Quarter Horse stallions have stood or are standing at stud in Australia. The clinical details of the affected horses...
Meyer S, Ptok M.The term 'laryngeal neuropathy' (LN) has first been used in veterinary medicine to describe an idiopathic and typically exercise induced inspiratory noise in horses.Nowadays, the term is often used in relation with intermittent vocal cord pareses in humans. Some authors use the term 'irritable larynx syndrome' (ILS) in a similar context. This article reviews the state of knowledge regarding LN and ILS and discusses the somewhat confusing terminology.For this systematic review a selective literature research in PubMed has been carried out.35 articles were found, which report on LN in animals an...
Hay WP, Tulleners EP, Ducharme NG.An extralaryngeal approach to partial arytenoidectomy in the horse was developed by in vitro experiments on isolated larynges and then on intact equine cadavers. The goals of the approach were to preserve the laryngeal mucosa, eliminate the need for a laryngotomy or tracheotomy, and minimize postoperative complications. The new approach was evaluated in seven horses with normal upper respiratory tracts. Left laryngeal hemiplegia was surgically created, and, after a 30-day convalescence, left partial arytenoidectomy was performed using an extralaryngeal approach. The left-to-right hemilaryngeal...
Manohar M, Goetz TE, Nganwa D.Diaphragmatic O2 and lactate extraction were examined in seven healthy ponies during maximal exercise (ME) carried out without, as well as with, inspiratory resistive breathing. Arterial and diaphragmatic venous blood were sampled simultaneously at rest and at 30-s intervals during the 4 min of ME. Experiments were carried out before and after left laryngeal hemiplegia (LH) was produced. During ME, normal ponies exhibited hypocapnia, hemoconcentration, and a decrease in arterial PO2 (PaO2) with insignificant change in O2 saturation. In LH ponies, PaO2 and O2 saturation decreased well below tha...
Cramp P, Derksen FJ, Stick JA, de Feijter-Rupp H, Elvin NG, Hauptman J, Robinson NE.The nerve-muscle pedicle graft technique is a treatment for recurrent laryngeal neuropathy (RLN), but the optimal placement of the pedicles within the cricoarytenoideus dorsalis (CAD) muscle is unknown. Objective: The magnitude and direction of force placed on the muscular process of the left arytenoid cartilage affects the magnitude of laryngeal abduction. Methods: Five larynges were harvested from cadavers. Using increments of 0.98 N, a dead-weight force generator applied a force of 0-14.7 N for 1 min each to the left muscular process at 0, 10, 20, 30, 40, 50, 60 and 70 degrees angles. The r...
Sloet van Oldruitenborgh-Oosterbaan MM, Schipper FC, Goehring LS, Gremmels JF.In the course of several days most of the 40 riding-school horses turned out in paddocks developed ataxia of variable severity. Five of these horses showed severe ataxia and tremors, became paralyzed and were euthanized. Eleven privately-owned horses which were stabled on the same premises showed no clinical signs. The most likely diagnosis seemed to be the 'neurological form of EHV1', although the signs were not entirely typical. A few weeks later a second outbreak occurred among the riding-school horses and one of the privately-owned horses also showed signs of ataxia. In the meantime it had...
Dunlop CI, Hodgson DS, Watson JW, Gillespie JR, Steffey EP, Jackson AC.High frequency jet ventilation (HFJV) is a recently developed mode of ventilation that delivers small tidal volumes at frequencies greater than 60 cycles per min via an injection catheter to the animal's airway. The construction of a high frequency jet ventilator suitable for use in adult horses is described. The effectiveness of this ventilator in maintaining normal arterial blood-gas tension was evaluated in five healthy adult horses. The horses were anaesthetised with intravenous acetylpromazine, guaifenesin, and thiamylal, positioned in lateral recumbency and baseline measurements were mad...
Martin-Giménez T, Cruz AM, Barragán A, Montero E, Sanchez PG, Caballero G, Corradini I.Occipital condylar fractures (OCFs) causing delayed onset lower cranial nerve paralysis (LCNPs) are rare. We present a 7-year-old Friesian horse with delayed onset dysphagia caused by vagus nerve (CNX) paralysis and suspicion of glossopharyngeal nerve (CNIX) paralysis developed several days after a minor head injury. Endoscopic examination revealed right laryngeal hemiplegia and intermittent dorsal displacement of the soft palate. An area of submucosal hemorrhage and bulging was appreciated over the dorsal aspect of the medial compartment of the right guttural pouch. Radiological examination o...
Pearson EG.Of 41 equids referred to a veterinary teaching hospital in the Pacific northwest because of dyspnea and inspiratory noise, 3 ponies were diagnosed as having liver failure, most likely attributable to pyrrolizidine alkaloid toxicosis. Dyspnea appeared to be caused by laryngeal and/or pharyngeal paralysis. It is proposed that this paralysis was a manifestation of hepatic encephalopathy. Although these clinical signs are not common for pyrrolizidine toxicosis, practitioners should be aware of the possibility so that misdiagnosis of other causes of inspiratory dyspnea may not be made.
Lumsden JM, Derksen FJ, Stick JA, Robinson NE, Nickels FA.The efficacy of partial arytenoidectomy was assessed in 6 Standardbred horses, with surgically induced laryngeal hemiplegia, at rest (Period A) and during exercise at speeds corresponding to maximum heart rate (Period C) and 75% of maximum heart rate (Period B). Peak expiratory and inspiratory airflow rate (PEF and PIF), and expiratory and inspiratory transupper airway pressure (PUE and PUI) were measured and expiratory and inspiratory impedance (ZE and ZI) were calculated. Simultaneously, tidal breathing flow-volume loops (TBFVL) were acquired using a respiratory function computer. Indices de...
Finno CJ, Eaton JS, Aleman M, Hollingsworth SR.A 23-year-old female mule was presented for bilateral ocular abnormalities and an abnormal pelvic limb gait. Results: Anisocoria, unilateral enophthalmos, medial strabismus, ptosis, pupillary light reflex deficits, and bilateral reticulated pigmentary retinopathy were observed on ophthalmic examination. Neurologic abnormalities included right-sided facial nerve paralysis, extensive symmetric muscle atrophy, and asymmetric pelvic limb ataxia with an abnormal pelvic limb gait. A positive titer (1:40) for equine protozoal myeloencephalitis (EPM) associated with Neospora hughesi was obtained from ...
Chiapetta JR, Baker JC, Feeney DA.An Arabian foal, which was recumbent for 4 days, had signs of extensor rigidity of the thoracic limbs and hypotonic paralysis of the pelvic limbs. Survey radiography revealed a lesion at T15, with radiographic impression of a compression fracture or a hemivertebra. Postmortem examination revealed a fracture at T15. Clinical and pathologic findings in this case were compatible with the Schiff-Sherrington syndrome, which is characterized by thoracic limb extensor hypertonia associated with paraplegia from acute thoracolumbar trauma.
Ivancic PC.We reported two cases of jockeys who sustained fracture/dislocation of the mid-thoracic spine due to traumatic falls during horse racing. We examined the injury mechanism based upon the patients' diagnostic images and video footage of races, in which the accidents occurred. Admission imaging of patient 1 (a 42 years old male) revealed T5 burst fracture with bony retropulsion of 7 mm causing complete paralysis below T5/6. There existed 22° focal kyphosis at T5/6, anterolisthesis of T5 relative to T6, T5/6 disc herniation, cord edema and epidural hemorrhage from T4 through T6, and cord injury f...
Thein P, Darai G, Janssen W, Bergle RD, Strube W, Floss G.From spring 1990 to summer 1991 we investigated 21 horses with clinical symptoms of EHV-infection by means of serological and virological methods including DNA-hybridization to identify the causative agents. The results indicated that, as already reported by us, EHV4 may also cause the paralytic form of the infection. The possibility of double infection with EHV4 and EHV1 cannot be excluded. In 3 out of 21 affected horses we could investigate brain tissue and/or spinal fluid by Dotblot hybridization with EHV1 and EHV4-DNA. The investigated samples of all three horses showed hybridization with ...
Barba M, Groover ES, Bailey J, Cole R, Christopherson P, Cattley R.A 4-year-old American Quarter Horse gelding was evaluated for acute non-weight-bearing lameness of the right thoracic limb with swelling in the right shoulder region. Physical examination revealed radial nerve paralysis of unknown etiology. The primary differential diagnosis was musculoskeletal trauma. Ultrasonography of the right shoulder region identified a heterogeneous mass that extended from the point of the shoulder to the thoracic inlet. Cytologic analysis of fluid collected by fine needle aspirate of the mass was consistent with large cell lymphoma. Based on the cytological findings, l...
Speirs VC, Bourke JM, Anderson GA.Four variations of abductor muscle prosthesis for treating laryngeal hemiplegia were evaluated in 153 horses by questionnaire, and in the 100 Thoroughbred racehorses in this group survival analysis was used to compare their racing performances and earnings with those of 400 control horses. The questionnaire indicated that the technique which included a ventriculectomy and 2 prostheses was regarded as being the most successful (P less than 0.01) and resulted in the least residual stertor (P less than 0.001). Survival analysis showed that there was no significant difference between the treated g...
Exner G, Engelmann A, Lange K, Wenck B.A total of 67 patients, both paraplegic and quadriplegic, had participated in a hippotherapy programme over a study period of almost 18 months, with positive effects found relative to spasticity, certain pain syndromes, as well as contraction syndromes associated with impaired joint mobility. Frequently the only effective measure at all, and moreover of astonishingly lasting effect, the spasticity-reducing treatment turned out especially beneficial. Along with these statistically supported findings, a number of associated effects were noted in the physiotherapy and, especially, the nursing sec...
White DA, Hildebrand SV, Jones JH, Fung DL, Gronert GA.On the basis of results in dogs, conditioning exercise may increase sensitivity to nondepolarizing muscle relaxants. Five Thoroughbreds were exercised/conditioned 3 times weekly on a treadmill for 8 months. Increasing maximal rate of O2 consumption verified that the horses were responding to exercise conditioning. Six nonexercised Thoroughbreds served as the control group. Studies were done with horses under general anesthesia by use of halothane during partial paralysis by a brief constant-rate infusion with the muscle relaxant, metocurine iodide. Quantification of degree of paralysis of the ...
Swerczek TW.Unexplained clinical signs of weight loss and emaciation were reported in a herd of Thoroughbred horses grazing spring pastures on a central Kentucky farm, even though supplemental grain and hay were provided. Results: A buttercup plant, Ranunculus bulbosus L, was abundantly present in all pastures and paddocks on the farm. All horses, especially lactating mares and their foals, had mild to severe weight loss as assessed by body condition. Seven mares on the farm had been confirmed pregnant between 30 and 45 days of gestation, but were later found to have aborted. Two 2-year-old fillies develo...
Barnard BJ.The most obvious symptoms of rabies in farm animals and pets in South Africa and South-West Africa are discussed in the light of information obtained during routine examination of specimens for the 10-year-period 1967--1976. More than 55% of the cases encountered were cattle in which the most obvious symptoms were salivation (92%), bellowing (69%), aggressiveness (47%), paresis or paralysis (30%) and straining (12%). Unlike cattle, the most obvious symptom in goats was aggressiveness (83%). Salivation was observed in ony 29% of goats but, like bellowing in cattle, bleating was very obvious in ...
Lean NE, Franklin SH, Ahern BJ.To describe left recurrent laryngeal neurectomy (LRLn) performed under standing sedation and evaluate the effect of LRLn on upper respiratory tract function using a high-speed treadmill test (HST). We hypothesized that (1) unilateral LRLn could be performed in standing horses, resulting in ipsilateral arytenoid cartilage collapse (ACC); and (2) HST after LRLn would be associated with alterations in upper respiratory function consistent with dynamic ACC. Methods: 6 Thoroughbred horses. Methods: The horses were trained and underwent a baseline HST up to 14 m/s at 5% incline until fatigue. Evalua...
Haussler KK.Congenital cervical vertebral anomalies in horses are structural changes in the neck vertebrae that develop during the fetal stage. These anomalies can vary in their severity and effects. Some horses may not show any clinical signs and can live normally, while others may develop serious problems such as spinal cord compression. This compression can lead to issues like ataxia or even paralysis, affecting the horse's mobility and quality of life. Recognizing and diagnosing these anomalies early are very important, as it helps guide decisions about the best treatment options and overall managemen...
Norrlund RR, Caragounis EC, Olsén MF.Equestrian sports have been found to cause high rates of injuries. In clinical practise after such injuries, polytrauma protocol workups usually include whole-body computed tomography (WBCT), CT of the chest, abdomen and pelvis with intravenous iodine contrast medium, and CT of the cervical spine and brain without contrast. The purpose was to investigate the use of WBCT in equestrian-related accidents, to analyse demographics, mechanism of injury (MOI), therapy and severity of equine-related accidents, radiology, and the use of protecting equipment. Methods: This is a retrospective study inclu...
