Equine laryngeal dysplasia as a cause of acute respiratory distress in a neonatal foal

Equine laryngeal dysplasia (ELD) is a congenital disorder caused by hypoplasia or aplasia of the structures derived from the fourth and possibly sixth branchial arches. The severity of the clinical signs varies widely, and depends on which structures are involved and the extent of the defect. In most cases, affected horses present with abnormal respiratory noise during exercise and poor performance. Manifestation of the disease in foals is very rare. This case report describes an unusual presentation of ELD in a neonatal foal. The foal presented with severe respiratory distress and weakness. Equine laryngeal dysplasia was suspected on endoscopy and later confirmed on post mortem examination of the larynx. To the best of our knowledge, this is the first report describing ELD as a cause of respiratory distress in a neonatal foal.     

Colic and diaphragmatic hernias in neonatal foals

Colic in neonatal foals is common and unusual causes of colic are not rare. The case reported in this issue by Tapio et al. (2012 ) is a good example of an unusual cause of neonatal colic which presents both a diagnostic challenge and unusual consequences. Gastrointestinal disease, especially colic, ranks as one of the most common reasons why foals require veterinary attention during their first week of life, beyond the initial post natal examination. Foals with colic present a special diagnostic challenge, especially to the practitioner who might not have extensive experience in neonatal medicine. With the often rapid progression of neonatal diseases it is important to make a rapid and accurate assessment.     

Evaluation of respiratory parameters at presentation as clinical indicators of the respiratory localization in dogs and cats with respiratory distress

Objective ? To describe clinical respiratory parameters in cats and dogs with respiratory distress and identify associations between respiratory signs at presentation and localization of the disease with particular evaluation between the synchrony of abdominal and chest wall movements as a clinical indicators for pleural space disease. Design ? Prospective observational clinical study. Setting ? Emergency service in a university veterinary teaching hospital. Animals ? Cats and dogs with respiratory distress presented to the emergency service between April 2008 and July 2009. Interventions ? None. Measurements and Main Results ? The following parameters were systematically determined at time of admission: respiratory rate, heart rate, temperature, type of breathing, movement of the thoracic and abdominal wall during inspiration, presence of stridor, presence and type of dyspnea, and results of thoracic auscultation. Abdominal and chest wall movement was categorized as synchronous, asynchronous, or inverse. Diagnostic test results, diagnosis, and outcome were subsequently recorded. Based on the final diagnoses, animals were assigned to 1 or more of the following groups regarding the anatomical localization of the respiratory distress: upper airways, lower airways, lung parenchyma, pleural space, thoracic wall, nonrespiratory causes, and normal animals. One hundred and seventy‐six animals (103 cats and 73 dogs) were evaluated. Inspiratory dyspnea was associated with upper airway disease in dogs and expiratory dyspnea with lower airway disease in cats. Respiratory noises were significantly associated and highly sensitive and specific for upper airway disease. An asynchronous or inverse breathing pattern and decreased lung auscultation results were significantly associated with pleural space disease in both dogs and cats (P<0.001). The combination is highly sensitive (99%) but not very specific (45%). Fast and shallow breathing was not associated with pleural space disease. Increased or moist pulmonary auscultation findings were associated with parenchymal lung disease. Conclusions ? Cats and dogs with pleural space disease can be identified by an asynchronous or inverse breathing pattern in combination with decreased lung sounds on auscultation.     

Developments in management of the newborn foal in respiratory distress 2: Treatment

New developments in therapy for foals in respiratory distress are discussed. Therapy is based on preservation of the foal's life by maintenance of a patent airway, resuscitation with fluids and warmth, provision of humidified oxygen to raise the fractional concentration of inspired oxygen sufficient to avoid hypoxia and provision of ventilatory support when hypercapnia becomes critical. Ventilatory support described includes assisted and controlled ventilation, positive end expiratory pressure, continuous positive airway pressure and intermittent mandatory ventilation. The aims of these techniques are discussed together with their associated indications, disadvantages and complications. Secondary therapy includes coupage, airway hygiene, drug therapy and stress management. Knowledge of equine neonatology is limited in comparison with human neonatology. More information in basic physiology and pharmacology relating to equine neonatology is needed and the efficacy of various modes of therapy must be evaluated.     

Developments in management of the newborn foal in respiratory distress 1: Evaluation

Developments in evaluation of newborn foals with respiratory distress are discussed. Major causes of respiratory distress are outlined and discussed in terms of the similar respiratory signs exhibited by foals with this clinical syndrome. History, physical examination, clinical pathology, chest radiography and blood gas analyses are discussed as important elements of the evaluation of the condition of these foals. Foals with respiratory disease are grouped into three major categories on the basis of clinical signs and arterial blood gas profiles. The evaluation of foals with respiratory distress is designed not only to reach an accurate diagnosis of the aetiology but also to define the foal's need for respiratory support.     

Bullous emphysema with haemorrhage in a premature foal

A Warmblood foal was admitted at one day of age because of prematurity and seizures. Clinical and clinical pathology abnormalities were consistent with prematurity and suspected hypoxic seizures that responded to anti‐convulsive therapy. The foal stabilised after several days of intensive care but then developed an airway infection. Thoracic radiographs showed multiple cavitary lesions and ultrasound examination suggested intra‐cavital haemorrhage. The foal went on to develop septicaemia and was subjected to euthanasia. Post mortem examination revealed multiple bullous emphysema with haemorrhage. This disorder should be considered in the differential diagnosis of foals having air‐fluid filled cavities on thoracic radiographs.     

Nutritional management of the foal with diarrhoea

Diarrhoea is a common problem in the neonatal and suckling foal. In certain circumstances supplemental nutrition is necessary depending on the age of foal, severity of diarrhoea and presence of other systemic manifestations. Nutritional supplementation can be provided either enterally or parenterally. Enteral nutrition is superior to parenteral nutrition because it is the most natural and physiologically sound means to provide nutritional support. Parenteral nutrition may be warranted if the foal is unable to receive or tolerate enteral nutrition. Dextrose alone or with amino acids and lipids can provide appropriate nutrition when enteral feeding is not tolerated. As soon as the foal stabilises enteral feeding can be reintroduced.     

Acute respiratory distress syndrome in dogs and cats: a review of clinical findings and pathophysiology

Objective: To review the clinical and pathophysiologic aspects of acute respiratory distress syndrome (ARDS) in dogs and cats. Data sources: Data from human and veterinary literature were reviewed through Medline and CAB as well as manual search of references listed in articles pertaining to acute lung injury (ALI)/ARDS. Human data synthesis: Since the term ARDS was first coined in 1967, there has been a abundance of literature pertaining to this devastating syndrome in human medicine. More complete understanding of the complex interactions between inflammatory cells, soluble mediators (e.g., tumor necrosis factor, interleukin (IL)‐6, IL‐8, platelet activating factor) and the clinical patient has provided for timely recognition and mechanistically based protective strategies decreasing morbidity and mortality in human patients with ARDS. Veterinary data synthesis: Although little is known, ARDS is becoming a more commonly recognized sequela in small animals. Initial case reports and retrospective studies have provided basic clinical characterization of ARDS in dogs and cats. Additionally, information from experimental models has expanded our understanding of the inflammatory mechanisms involved. It appears that the inflammatory processes and pathologic changes associated with ARDS are similar in dogs, cats, and humans. Conclusions: Unfortunately, current mortality rates for ARDS in small animals are close to 100%. As our capability to treat patients with advanced life‐threatening disease increases, it is vital that we develop a familiarity with the pathogenesis of ARDS. Understanding the complex inflammatory interactions is essential for determining effective preventative and management strategies as well as designing novel therapies for veterinary patients.     

THORACIC RADIOGRAPHY IN THE NEONATAL FOAL: A PRELIMINARY REPORT

Thoracic radiographs from 22 neonatal foals were reviewed to investigate the radiographic appearance of the thorax in normal, immature, and septicemic foals, and in foals with neonatal respiratory distress syndrome. The size and radiographic appearance of intrathoracic structures and abnormal lung opacities were evaluated. The craniocaudal and apicobasilar dimensions of the heart were 5.6–6.3 and 6.7–7.8 times the length of a midthoracic vetebral body, respectively, in normal, immature and septicemic foals. Apicobasilar measurements were greater (8.0–8.7) in the foals with respiratory distress syndrome. Normal foals had clear lung fields within 12 hours of birth. A more marked interstitial pattern was observed in immature and septicemic foals compared to normals. Diffuse air–space (alveolar) pattern with air bronchograms was seen in foals with respiratory distress syndrome. It was concluded from this series that thoracic radiographs taken 24–48 hours after birth may aid differentiation of normal foals, septicemic or immature foals, and foals with respiratory distress syndrome.     

Thoracic trauma and post operative lung injury in a neonatal foal

A 24‐hour‐old Standardbred filly was referred with an acute history of weakness, respiratory distress and subcutaneous emphysema. Radiographic evaluation revealed left sided rib fractures, unilateral pneumothorax and pneumomediastinum. Serial arterial blood gas measurements pre‐ and post rib repair showed pulmonary dysfunction. Post operative radiographs revealed the presence of air bronchograms and a bronchointerstitial pattern, suggestive of alveolar parenchymal pathology consistent with pulmonary contusion, pulmonary oedema or ALI/ARDS. The filly was treated with intranasal oxygen and an active chest draining unit and recovered uneventfully.     

Nutritional management and practical feeding of the orphan foal

Foals are dependent on a milk‐based diet for the first 3–4 months of life. If they are orphaned during this period they require appropriate nutritional and behavioural management to allow them to develop into sound, well‐grown horses and ponies with well established normal behavioural patterns. In order to meet these needs it is necessary to understand the metabolic requirements of the foal and the composition of mares' milk. Usually managing these foals requires short‐term, emergency feeding of the foal while a long‐term option is sought. Long‐term options include use of a foster mare, induction of lactation in a parous, barren mare or hand rearing with suitable equine company. It is important to monitor growth and development of these foals to ensure that over the long term their nutritional needs are being met to allow normal growth and development.     

Multiple rib fracture in a neonatal foal using a nylon strand suture repair technique

OBJECTIVES: To report rib fracture repair using the Securos Cranial Cruciate Ligament Repair System (SCCLRS; Securos Veterinary Orthopedics, Charlton, MA) in a neonatal foal. STUDY DESIGN: Case report. ANIMALS: A 1-day-old Standardbred foal with fracture of left ribs 2-9. METHODS: Four days after admission the foal was anesthetized and rib fractures were repaired using open reduction and the SCCLRS. RESULTS: Rib fractures were successfully stabilized and the foal was discharged 7 days postoperatively without further complications. CONCLUSIONS: The SCCLRS provided a straightforward, effective method of rib fracture repair in neonatal foals. CLINICAL RELEVANCE: Effective rib fracture repair in neonatal foals can be achieved with the SCCLRS.     

Osteochondral dysplasia of the coxofemoral joints in a Friesian foal: Clinical findings and methods of diagnosis

Diseases of the coxofemoral (hip) joint are infrequently diagnosed in horses. Most cases are presented as an unilateral condition and usually are of traumatic origin. This case report describes a Friesian foal with a clinically obvious thoracolumbar kyphosis, combined with a weight‐shifting stance and a shortened stride of both hindlimbs. General clinical and lameness examinations, computed tomographic examination of the pelvis, and macroscopic and histopathological examinations of the coxofemoral joints were performed. This revealed a final, phenotypical diagnosis of a primary osteochondral dysplasia of both coxofemoral joints with secondary osteoarthritis. Similar to the occurrence of this condition in other species and considering the small genetic basis of the Friesian horse breed, a genetic predisposing factor is suspected to play a key role in the developing mechanism of dysplastic coxofemoral joint disease in horses as illustrated with this case. Computed tomography scanning appears to be a useful imaging technique in the detection of coxofemoral joint disease in small horses and foals.     

Polymerized Hemoglobin Therapy in a Foal with Neonatal Isoerythrolysis

Objective: To present the successful management of a foal with severe neonatal isoerythrolysis (NI) given polymerized (bovine) hemoglobin while awaiting appropriate red blood cells for transfusion.
Case Summary: A foal with peracute neonatal isoerythrolysis, anemia and low venous oxygen tension was stabilized with intravenous polymerized hemoglobin. Polymerized hemoglobin treatment maintained the foal's oxygen requirement for up to 18 hours permitting adequate time for preparation of the donor's washed red blood cells for transfusion. The clinical findings and venous oxygen tension improved following the hemoglobin administration. No adverse effects were noted from the polymerized hemoglobin administration.
Unique information provided: This paper presents a foal with an uncommon cause of NI due to anti-Pa antibodies and the short term management of NI using polymerized hemoglobin while awaiting a washed and packed RBC transfusion. Clinical and laboratory findings (trigger factors), which can be used to determine the need for a blood transfusion, are discussed. These "trigger factors" include weakness, tachypnea and tachycardia, increased anion gap and decrease in hematocrit, hemoglobin concentration and mixed venous (pulmonary artery) oxygen tension (approximated using jugular venous samples). ( J Vet Emerg Crit Care 2001; 11(2): 141–146 )     

Surgical management of an extrahepatic portosystemic shunt in a foal: A multidisciplinary problem

A 5‐week‐old American Miniature filly was referred due to intermittent neurological signs of 4 weeks' duration. Clinicopathological findings showed increased ammonia and bile acids in venous blood samples. Abdominal ultrasonography detailed a portosystemic shunt (PSS). The foal underwent laparotomy and operative mesenteric portovenography, which further defined the PSS as extrahepatic portocaval in configuration. The PSS was occluded and intraoperative portovenography confirmed successful shunt occlusion. The foal made a good recovery from surgery and had a successful showing career until she succumbed to colic just over 3 years after surgery.     

High prevalence of Mycoplasma equirhinis in Thoroughbred horses with respiratory symptoms in autumn 2018

Mycoplasma species are often isolated from horses with respiratory symptoms; however, the pathogenicity of Mycoplasma is still unclear. In autumn of 2018, we encountered an increase in cases with respiratory symptoms, mainly coughing, in a group of Thoroughbred racehorses in Japan. We examined tracheal wash samples obtained from 40 of those cases. Bacteria and viruses that commonly cause respiratory symptoms were investigated, and anaerobes were detected in only 5 cases and Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) was detected in only 1 case of 40 cases with loop-mediated isothermal amplification assay. S. zooepidemicus and Streptococcus pneumoniae were isolated at a bacterial count of higher than 1.0 × 10⁴ CFU/ml from 5 and 2 cases of 28 cases cultured, respectively. None of the viruses investigated was detected in 40 cases. Mycoplasma equirhinis (M. equirhinis) was isolated from 40.0% (16/40) of the cases, which was higher than previously reported isolation rates. The rate of M. equirhinis isolation in the cases from 2018 was significantly higher than the isolation rates in the other horses: clinical cases with respiratory symptoms in 2019–2020 (13.6%, 3/22) and healthy horses (13.5%, 5/37) in Japan. In this study, the isolation rate of M. equirhinis from horse group with cough symptoms in 2018 was high and no other common etiological agents were detected. The pathogenesis of M. equirhinis is still unclear, however, M. equirhinis might have been associated with respiratory symptoms in the Thoroughbred horse cases in 2018.