The Veterinary clinics of North America. Equine practice.
Publisher:
W.B. Saunders,
Frequency: Three no. a year
Country: United States
Language: English
Start Year:1985 -
ISSN:
0749-0739 (Print)
1558-4224 (Electronic)
0749-0739 (Linking)
1558-4224 (Electronic)
0749-0739 (Linking)
Impact Factor
1.1
2022
| NLM ID: | 8511904 |
| (DNLM): | SR0053812(s) |
| (OCoLC): | 11078671 |
| LCCN: | sn 84006968 |
| Classification: | W1 VE929F |
Viral respiratory disease of the horse. The diagnosis of any viral respiratory disease relies on laboratory procedures to isolate the virus and demonstrate a significant rise in serum antibody titers. To isolate viruses from the upper respiratory tract, it is imperative that nasopharyngeal swabs are obtained from animals in the early acute stage of illness, i.e., during the pyrexic phase when the virus is replicating. Nasopharyngeal swabs must be placed in a virus transport medium and forwarded immediately to the laboratory at refrigerated temperature. Equine influenza, rhinopneumonitis, and equine viral arteritis are the three vira...
Pleuropneumonia. The historical, clinical, diagnostic, and therapeutic aspects of pleuropneumonia are reviewed with emphasis placed on aggressive treatment and ultrasound diagnosis. The common sequelae are described, and appropriate treatment recommendations are included. A favorable prognosis may be expected for horses receiving long-term treatment.
Clinical examination of the respiratory system. Aspects of a detailed examination of the respiratory system of the horse with suspected respiratory system disease are described. This review includes discussions of the terminology of signs associated with respiratory system disease; radiographic examination of the upper and lower airways and thorax; nuclear scintigraphy; percutaneous and endoscopic tracheal aspiration; bronchoalveolar lavage; electromyography; blood gas analysis; and pleuroscopy and pleural fluid examination.
Upper airway obstruction in performance horses. Differential diagnoses and treatment. Abnormalities of the nasal cavity, pharynx, larynx, and trachea result in respiratory noise and exercise intolerance. Clinical features of common upper respiratory conditions of performance horses are reviewed with emphasis on diagnosis, treatment, and risk factors that affect the outcome of surgical treatment.
Chronic obstructive pulmonary disease. COPD continues to be a severe condition in horses. Despite increased understanding of its pathogenesis, there is relatively little information on effective treatment regimens. Management and prevention are critical, and more emphasis should be placed on improved housing, bedding, and feeding. More sophisticated accurate methods also are required for identifying specific causative allergens.
Upper airway conditions in older horses, broodmares, and stallions. Upper respiratory tract conditions of the older horse that are not necessarily associated with athletic exercise intolerance are discussed. Some of the diseases described include ethmoid hematoma, sinus disease, guttural pouch empyema and mycosis, retropharyngeal abscess, nasopharyngeal cicatrix, arytenoid chondropathy, and neoplasia.
Additional diagnostic procedures. This article reviews recent diagnostic procedures that have arisen over the last 10 years. Videoendoscopy of horses on a high-speed treadmill allows observation of some of the changes that take place in a horse's airway during exercise. Measurements of upper airway airflows and transupper airway pressure, the use of an esophageal balloon and a Ventigraph to measure changes in pleural pressure, and pulmonary function testing are new techniques that aid the researcher in understanding the mechanics and pathologic characteristics of airway diseases and help the practitioner in assessing the sever...
Bacterial pneumonia. Bacterial pneumonia in the horse often occurs secondary to viral respiratory infection; however, primary infections can occur. A diagnosis of bacterial pneumonia is made on the basis of history, physical examination, and laboratory and radiographic findings. Treatment consists of appropriate antimicrobial therapy for at least 7 to 10 days; further therapy may be needed in more severe cases. Prevention of bacterial pneumonia includes attempting to prevent viral respiratory infections and appropriate management to prevent stress to the respiratory tract.
Upper respiratory obstruction in foals, weanlings, and yearlings. Upper airway obstruction may result from nasal, pharyngeal, or tracheal diseases. In the young horse, a relatively severe obstruction usually is present before clinical signs are evident. This article reviews the clinical manifestations, diagnostic features, treatment, and outcome of commonly encountered conditions of the nasal passages, pharynx, larynx, and trachea in young horses.
Exercise-induced pulmonary hemorrhage. This article addresses many aspects of exercise-induced pulmonary hemorrhage (EIPH). Reports of the prevalence, effect on performance, and the clinical signs and means of diagnosis of EIPH are included. Radiologic and scintigraphic findings in horses with EIPH are reported. Pathogenesis and treatment are discussed.
Application of lasers in equine upper respiratory surgery. The advantages and disadvantages of various surgical lasers are discussed. Included are aspects of laser safety, anesthesia and analgesia considerations for laser surgery, and diagnostic considerations. Horses with lesions such as ethmoid hematomas, nasal polyps, and lymphoid masses are ideal candidates for laser treatment. Other conditions that are suitably treated with lasers, such as dorsal displacement of the soft palate and entrapment of the epiglottis, are described.
Anesthetic complications in the horse. The basis for management of all complications is early recognition, preparation, and a problem-solving approach. Some anesthetic complications, such as equipment malfunction and injuries from endotracheal intubation or misplaced drug injections, are common to all animals and can be prevented almost entirely by careful management. Other problems, such as pulmonary dysfunction and cardiovascular depression, seem to occur more often in healthy horses than in healthy members of other domestic species. Postoperative myopathy-neuropathy, sometimes a devastating complication, seems to be peculiar to ...
Clinical use of positive-pressure ventilation in the horse. Positive-pressure ventilation is used to provide improved ventilatory support during anesthesia in the horse. Because of the horse's size and the physiologic changes it undergoes during anesthesia, however, the use of positive-pressure ventilation does not always provide the improvement seen in smaller species. Careful attention to respiratory rate, inspiratory pressure, and I:E ratio minimizes the negative aspect of IPPV on the cardiovascular system. The goal of future ventilatory techniques will be to improve oxygenation without cardiovascular compromise and to do so at a reasonable cost to ...
Chemical restraint and analgesia in the horse. Chemical restraint in the standing horse is used for a variety of procedures in veterinary medicine. The choice of agent depends on the physical status, temperament, and size of the patient; the procedure to be performed; and safety for the patient, veterinarian, and owner. The combination of certain agents may provide more desirable restraint and analgesia than does the use of individual agents. The use of analgesics in the horse is not without side effects, some of which may be detrimental to the patient's condition. Analgesics should be chosen with these untoward effects in mind. Draft bree...
Regional anesthesia. Organ toxicity from local anesthetic agents is rare. This makes these agents an attractive option in the high-risk patient. Complications associated with local anesthetics are related to overdosage. Overdosage with local anesthetic agents administered epidurally may cause motor paralysis and hind-limb weakness. Systemic signs of local anesthetic overdosage include changes in central nervous system activity (excitement or depression), muscle tremors, and hypotension. Because the dose required to produce these effects in the horse is high (12 mg/kg), this complication is uncommon. Few side effec...
Local anesthetic techniques for diagnosis of lameness. Successful diagnostic local anesthesia is dependent upon a thorough knowledge of appendicular anatomy, application of correct technique, and accurate interpretation. Use of cadaver specimens to review anatomy and practice needle placement is strongly recommended. A marker solution, such as new methylene blue, can be injected into cadaver limbs, which can be subsequently dissected to verify accuracy. Detailed interpretation of local anesthetic blocks in the lame horse reaches beyond the scope of this article. Interpretive difficulties, however, can be responsible for the failure of a block to p...
Intravenous anesthesia. Anticholinergics, tranquilizers, and sedative-hypnotics are the usual agents used for preanesthetic sedation of the horse. Of these drugs, the anticholinergics are of little importance in the horse. Acepromazine is the most useful and widely used tranquilizer, whereas xylazine is a safe and popular sedative. A newer sedative recently made available to the veterinarian for clinical use in horses is detomidine. Thiobarbiturates are seldom used alone any longer but are still useful when combined with guaifenesin for induction and maintenance of anesthesia. Other, more contemporary drug combinatio...
Management of anesthesia in the foal. Several unique pharmacologic and physiologic factors must be considered when attempting to anesthetize premature or neonatal foals. Juvenile foals are similar to adults in their physiology and metabolism. Anesthetic drug and protocol selection should reflect the differences between these two age groups. Neonates are best anesthetized using an inhalation technique, whereas older foals can be safely anesthetized with either parenteral or inhalation anesthetic agents. Careful monitoring is absolutely essential when anesthetizing foals. The clinician should plan to routinely administer fluids and ...
Use of halothane and isoflurane in the horse. When compared with halothane, isoflurane has several distinct characteristics. Vaporizer settings are higher because of its lower potency. Respiratory rates will be slower, and intraoperative changes in depth and recovery from surgical depth of anesthesia will be more rapid, although total recovery times frequently will not be different. Halothane and isoflurane appear similar in their effects on ocular reflexes and mean arterial blood pressure. Recovery from isoflurane should be managed to provide added sedation or physical support if the horse attempts to stand prematurely.
General clinical considerations for anesthesia of the horse. The peculiarities of the equine species present a number of unique situations that must be addressed when horses are anesthetized. Perhaps the most troublesome situation is related to the horse's size. Though the horse's large lungs are responsible in part for its sustainable athletic ability, they are detrimental to effective ventilation when the horse is anesthetized and placed in a recumbent position. Of major concern is depression of ventilation and cardiovascular function. Hypercapnia and hypoxemia usually result from hypoventilation, and with time all anesthetized horses suffer from some...
Neuromuscular blocking agents in equine anesthesia. In summary, neuromuscular blocking agents can be used safely and to advantage in equine anesthesia. Muscle-relaxant use in equine anesthesia has been helped by the development of new relaxants such as atracurium, which has a reliable and reproducible duration of action. There are certain cases that benefit particularly by the use of relaxants but their use is not limited to these cases. These cases involve horses that experience persistent movement and hypotension during anesthesia, are undergoing ophthalmic or abdominal surgery or fracture repair, or are severely ill. Horses receiving muscle ...
Equipment for inhalation anesthesia. Inhalation anesthesia has three requirements: delivery of oxygen, delivery of an appropriate concentration of a volatile anesthetic agent, and removal of carbon dioxide. Halothane and isoflurane are the most commonly used anesthetic agents. They are usually delivered with a semiclosed circle system using an out-of-the-circuit vaporizer. Carbon dioxide is eliminated by chemical absorption and by flow of excess oxygen and waste anesthetic agent through the pop-off valve. These gases should be scavenged to prevent room contamination. A variety of ancillary equipment is available to assist the ane...
Monitoring equine anesthesia. In conclusion, monitoring the depth of anesthesia plays an integral role in the anesthetic regimen. Although the use of sophisticated monitoring equipment has replaced some of the art of anesthesia and made assessment of depth of anesthesia more precise, a vigilant clinician still needs to serve as the animal's advocate. He or she must gather the data that are generated by machines, acquire data that monitoring equipment cannot obtain, assimilate all the facts, and make appropriate changes in anesthetic management.
General anesthesia for horses with specific problems. We have discussed anesthetic techniques, special considerations, and expected complications involved in anesthetizing horses for abdominal, orthopedic, and head and neck surgery, and myelography and have described expected physiologic dysfunction that may require changes in anesthetic technique or supportive measures. The objective is high-quality patient care and reduction in anesthesia-related morbidity and death.
Supportive therapy in the anesthetized horse. In conclusion, vigilant supportive care is necessary to prevent morbidity and death in the anesthetized horse. Because some of the equipment and drugs are specialized and the consequences of some postanesthetic complications are severe, availability of those items must be confirmed prior to anesthesia. Proper positioning and padding will help to reduce the incidence of postanesthetic myopathy-neuropathy syndrome in these large patients. Adequate tissue perfusion is important and can be achieved by controlling anesthetic depth, increasing intravascular volume with fluid administration, and by a...
Molds, mycotoxins, and mycotoxicosis. Interest in mycotoxins and mycotoxicosis in humans and animals has greatly increased in recent years. Horses have long been considered very susceptible to molds. The signs, treatment, and prevention of several conditions, such as leukoencephalomalacia, aflatoxicosis, ergotism, fescue toxicity, slobbering disease, ryegrass staggers, and moldy sweet clover disease, are discussed.
Dietary aspects of developmental orthopedic disease in young horses. The clinician may choose between two approaches to nutritional intervention. One is to evaluate the ration and make a painstaking effort to identify those specific factors operating in a particular case, then correct them. The second is to evaluate the ration, inspect for obvious aberrations, and, if finding none, proceed with no further delay to formulate an optimal diet, or a series, for the animals, and design a feeding program to suit farm management. Veterinarians should counsel clients on the possible or probable consequences of level of feeding on growth rate and clinical expression of ...