Neonatal respiratory distress and sepsis in the premature foal: Challenges with diagnosis and management

The presentation of a premature, neonatal foal affected with respiratory distress and seizures represents a difficult diagnostic and therapeutic challenge often best addressed by the provision of appropriate emergency care followed by prompt referral to a well‐equipped critical care facility. Veterinary management of the premature foal described in the accompanying report was complicated by the development of sepsis and pulmonary failure. The development of pulmonary emphysematous bullae was identified during the course of the foal's treatment and probably contributed to its clinical deterioration. Diagnostic imaging modalities that may be used for the diagnosis of respiratory distress in neonatal foals include thoracic radiography, ultrasonography, computed tomography (CT) and magnetic resonance imaging (MRI). Both CT and MRI require general anaesthesia. The likelihood of a successful outcome for the foal in this report might have been improved by the provision of urgent veterinary care and referral to the critical care facility earlier in the course of its management. Important early indicators of the need for urgent veterinary care in this case included the foal's prematurity, inability to stand, and the need to provide manual support to facilitate nursing from the mare's udder. Foals affected in this manner should warrant treatment with broad‐spectrum antimicrobials, circulating volume maintenance, immunoglobulin support, and the use of a nasogastric tube to facilitate nutritional support.     

Transient diabetes mellitus in a neonatal Thoroughbred foal

Objective – To describe the clinical presentation, treatment, and outcome of a neonatal foal diagnosed with transient Type 1 diabetes mellitus. Case Summary – A 3‐day‐old Thoroughbred foal presented with a 24‐hour history of diarrhea and depression. Coronavirus particles were observed in the feces via electron microscopy. During hospitalization the foal developed hyperglycemia concomitantly with low insulin concentration and an adequate response to exogenous insulin therapy supported a diagnosis of Type 1 diabetes mellitus. The foal required SC insulin for 26 days, but developed complications associated with insulin therapy that resolved with appropriate care. On follow up assessment the foal was found to be a healthy euglycemic animal with normal insulin concentration at 11 months of age. New or Unique Information Provided – To our knowledge this is the first report of Type 1 diabetes in this age group and the first report of transient neonatal diabetes mellitus in horses. Type 1 diabetes mellitus should be considered a differential diagnosis for hyperglycemia in equine neonates and that it can be transient and managed successfully.     

Use of Renal Replacement Therapy in a Neonatal Foal with Postresuscitation Acute Renal Failure

A newborn foal was presented because it was unresponsive and in cardiopulmonary arrest. Aggressive cardiopulmonary cerebral resuscitation was administered to the foal, which revived the foal; however, acute renal failure developed. Fluid retention and azotemia occurred although the foal was alert and able to suckle. A 6‐hour renal replacement therapy session using hemodiafiltration and a continuous renal replacement therapy machine was administered to the foal at 3 days of age which lowered the foal's azotemia and facilitated removal of some of the excess body fluid. Despite therapy, the foal developed pulmonary edema and was euthanized. Although the foal in this case did not survive, this report highlights the possibility of developing postresuscitation complications such as acute renal failure and describes the use of renal replacement therapy using hemodiafiltration as a viable option in neonatal foals with acute kidney injury.     

Full recovery after cardiac arrest secondary to accidental iatrogenic venous air embolism in a cat

Objective – To describe the successful management of cardiac arrest following accidental venous air embolism (VAE) in a cat. Case Summary – A 3‐year‐old spayed female domestic shorthair cat, weighing 4 kg, was presented for continuation of its chemotherapy protocol. The cat was inadvertently administered approximately 5.5 mL of air IV during initiation of fluid therapy. Immediate cardiac arrest resulted and CPR successfully achieved return of spontaneous circulation. The cat was discharged 5 days later and is reportedly clinically normal 7 months post‐discharge. New or Unique Information Provided – VAE has been rarely reported in the veterinary literature. This is the first report of a cat surviving cardiac arrest secondary to VAE.     

Diseases in neonatal foals. Part 2: Potential risk factors for a higher incidence of infectious diseases during the first 30 days post partum

Reason for performing study: The development of clinical illness in foals is usually predetermined by perinatal history, management or stressful environmental conditions. Objectives: To determine potential risk factors for an increased incidence of infectious diseases during the first 30 days post partum. Methods: The population consisted of Thoroughbred foals born on stud farms in the Newmarket (UK) area in 2005 (n = 1031). They were followed for their first 30 days. Factors suspected to influence the incidence of infectious neonatal diseases were examined in a logistic regression approach for each of the 3 outcomes (total infectious diseases, systemic disease with diarrhoea and total infectious diseases excluding diarrhoea). All 28 factors were either foal or mare or stud farm related. Results: Several significant risk factors for a higher disease incidence, such as birth complications, colostrum intake by stomach tube and leucocytosis 12–48 h post partum were identified. The factor ‘boarding stud’ seemed to be protective against disease. Conclusion: Some factors, such as the mare's time at stud before foaling, the mare's rotavirus vaccination schedule and fibrinogen‐values that empirically had been linked to the outcome previously were not confirmed as relevant. This included the reported useful prophylactic treatment with antimicrobial drugs. Potential relevance: Factors to be considered when evaluating newborn foals include: stud management, the birth process, route of colostrum intake, white and red blood cells, and the date of birth. These may help to detect foals at risk to develop an infection so that targeted prophylactic measures can be initiated.     

Helium‐oxygen gas‐carrier mixture (heliox): a review of physics and potential applications in veterinary medicine

Background – To review the physics of helium with regard to airway physiology, as well as known human and potential veterinary applications of administration of inhaled helium‐oxygen gas‐carrier mixture (heliox). Data Sources – Human and veterinary studies. Human Data Synthesis – Helium‐oxygen mixtures have been used in human medicine for over 70 years as an adjunct therapy in various upper and lower respiratory disorders. Helium's low density promotes laminar flow through partially obstructed airways, resulting in a decreased work of breathing. Veterinary Data Synthesis – Little to no evidence‐based medicine exists to support or oppose the use of heliox in veterinary species. However, domestic animal species and humans share several common pathophysiologic aspects of various obstructive airway disorders. Thus, veterinary patients may also ultimately and significantly benefit from this novel therapy. Conclusion – Prospective studies are needed in veterinary medicine to determine the utility of heliox in clinical scenarios.     

The use of intravenous lipid emulsion as an antidote in veterinary toxicology

Objective – To review the use of IV lipid emulsion (ILE) for the treatment of toxicities related to fat‐soluble agents; evaluate current human and veterinary literature; and to provide proposed guidelines for the use of this emerging therapy in veterinary medicine and toxicology. Data Sources – Human and veterinary medical literature. Human Data Synthesis – Human data are composed mostly of case reports describing the response to treatment with ILE as variant from mild improvement to complete resolution of clinical signs, which is suspected to be due to the variability of lipid solubility of the drugs. The use of ILE therapy has been advocated as an antidote in cases of local anesthetic and other lipophilic drug toxicoses, particularly in the face of cardiopulmonary arrest and unsuccessful cardiopulmonary cerebral resuscitation. Veterinary Data Synthesis – The use of ILE therapy in veterinary medicine has recently been advocated by animal poison control centers for toxicoses associated with fat‐soluble agents, but there are only few clinical reports documenting successful use of this therapy. Evidence for the use of ILE in both human and veterinary medicine is composed primarily from experimental animal data. Conclusions – The use of ILE appears to be a safe therapy for the poisoned animal patient, but is warranted only with certain toxicoses. Adverse events associated with ILE in veterinary medicine are rare and anecdotal. Standard resuscitation protocols should be exhausted before considering this therapy and the potential side effects should be evaluated before administration of ILE as a potential antidote in cases of lipophilic drug toxicoses. Further research is waranted.     

Oesophageal ectasia as a cause of dysphagia and milk regurgitation in a neonatal foal

Dysphagia and milk regurgitation are relatively infrequently observed clinical signs in neonatal foals but, when present, can commonly arise from anatomic or functional disorders of the upper airway. Less commonly, milk regurgitation can be caused by anatomic or neuromuscular disorders of the oesophagus. In the report presented here, a neonatal foal was examined for milk regurgitation at 4 days of age and was diagnosed with transient oesophageal ectasia via oesophagoscopy and contrast radiography. Aspiration pneumonia was treated with broad-spectrum antimicrobials and the owner was instructed to intermittently elevate the forelimbs to facilitate passage of milk out of the dilated oesophagus. The milk regurgitation resolved and reassessment of the foal at 6 weeks of age documented the absence of oesophageal ectasia and resolution of aspiration pneumonia. The foal was reported to be healthy and consuming food normally 6 months after initial examination and was in good body condition. This case is unique in that the oesophageal ectasia improved with time; furthermore, other potential causes of dysphagia and milk regurgitation of oesophageal origin in neonatal foals are discussed.     

Gastrointestinal nonrotation in a neonatal foal

A 24‐hour‐old Welsh‐Thoroughbred foal presented for routine surgical repair of an abdominal and body wall hernia. The colt became acutely colicky and emergency celiotomy was performed revealing abnormal anatomical configuration of the gastrointestinal tract (GIT). Incomplete gastrointestinal rotation is a rare congenital anomaly only described in man. This report describes the clinical and diagnostic findings, surgical and medical treatment, and outcome of a neonatal foal with nonrotation of the GIT.     

Treatment of accidental ethanol intoxication with hemodialysis in a dog

Objective – To describe the successful treatment of accidental ethanol intoxication with hemodialysis in a dog. Case Summary – A 1.5‐year‐old female intact mixed breed dog was presented in a comatose state believed to be due to ethanol intoxication. The initial 9 hours of supportive care treatment were complicated by multiple seizures and hypothermia, and resulted in only minimal improvement in the dog's level of consciousness. Hemodialysis was implemented and resulted in rapid clinical recovery, corresponding to a rapid decline in serum ethanol concentration. New or Unique Information Provided – To the authors' knowledge, this is the first reported case of using hemodialysis to treat accidental ethanol intoxication in a dog. The patient's initial serum ethanol concentration was higher than those previously reported for cases of accidental ethanol intoxication in dogs, and the serum ethanol concentration was shown to rapidly decline during hemodialysis. Treatment with hemodialysis for severe ethanol intoxication was effective in this case and may be able to decrease morbidity and mortality in some cases.     

4‐Methylpyrazole as a treatment in naturally occurring ethylene glycol intoxication in cats

Objective – To describe the clinical experience and therapeutic use of fomepizole (4‐methylpyrazole [4‐MP]) in 3 cats with naturally occurring ethylene glycol (EG) toxicity. Case or Series Summary – All cats were documented to be EG positive by an ethylene glycol test kit. This report describes the dose of 4‐MP used, available clinicopathological data, and clinical progression during hospitalization. All patients survived to discharge. New or Unique Information Provided – IV use of 4‐MP at 125 mg/kg as an initial dose and 31.25 mg/kg at 12, 24, and 36 hours is safe and effective for treatment of naturally occurring EG toxicity in cats. Increased HCO₃ concentrations were noted after IV use of 4‐MP. This is the first report documenting the successful treatment of naturally occurring EG intoxication in cats with 4‐MP.     

Transplacental infection of a foal with Anaplasma phagocytophilum

This is the first report to document transplacental transmission of Anaplasma phagocytophillum in the horse. A 4-year-old late-term pregnant mare presented for a recent onset of pyrexia due to equine granulocytic anaplasmosis (EGA). She was hospitalised for treatment with oxytetracycline and monitoring of high-risk foaling due to significant thrombocytopenia. Parturition occurred overnight, and the foal was PCR positive for A. phagocytophilum at birth. The foal was slow to stand and nurse, with signs of neonatal encephalopathy and anaplasmosis (thrombocytopenia). Therapy with oxytetracycline resulted in complete clinical recovery of the mare and foal within 5 days. Congenital anaplasmosis should be considered in any foal delivered to a mare suffering from EGA during late-term pregnancy and guide appropriate antimicrobial therapy.     

Congenital branchial apparatus malformation in a Haflinger colt

Objective— To report the diagnosis and treatment of a branchial apparatus anomaly (BAA) associated with a mandibular malformation in a foal.
Design— Clinical report.
Animal— Haflinger foal.
Methods— A 6-day-old foal had a fluctuating cystic mass in the pharyngeal (throatlatch) region, which changed in appearance after ingestion of milk. Upper airway endoscopy and diagnostic imaging (ultrasonography, radiography, computed tomography) permitted identification of the anatomic location of a communicating tract between the lumen of the cystic mass and the pharynx. The mass was surgically removed and communication with the pharynx ligated. Histologic appearance of this mass was consistent with a branchial cyst or sinus. The mandibular malformation was managed conservatively.
Results— Surgical resection of a third branchial sinus resulted in an excellent functional and cosmetic outcome. There was no evidence of any mandibular deformity 2 years later.
Conclusion— BAA may induce secondary mandibular deformation in utero and may cause respiratory compromise postpartum. Careful surgical dissection and removal of BAA resulted in an excellent outcome.
Clinical Relevance— BAAs should be included in the differential diagnosis of a throatlatch region mass in equine neonates. Complete surgical excision is recommended and full recovery of any associated mandibular deformity may be anticipated without additional treatment in very young patients.     

Episcleral cyclosporine A implants for the management of unilateral keratoconjunctivitis sicca in an 8‐year‐old mare

An 8‐year‐old mare was presented for investigation of a 1‐month history of blepharospasm, eyelid swelling, corneal edema, and ocular discharge of the right eye (OD). Ophthalmic examination confirmed mucopurulent ocular discharge, conjunctival hyperemia, and a dry, dull appearance to the cornea OD. Schirmer tear test results confirmed an absence of tear production OD (0 mm/min) consistent with keratoconjunctivitis sicca. Treatment with topical 0.2% cyclosporine A resulted in an improvement in clinical signs. An episcleral cyclosporine A implant was placed under standing sedation 5 days after initial presentation. Re‐examination 9 days post‐operatively confirmed that the mare's tear production in the right eye had improved and no further clinical signs had been observed. Topical medications were gradually discontinued. Re‐examinations performed up to 12 months postsurgery showed no recurrence of clinical signs and no adverse effects of the implant. To our knowledge, this is the first report of the use of a cyclosporine A implant in the management of KCS in a horse and highlights its potential as an effective, alternative therapy in the management of KCS in horses.     

Semilobar holoprosencephaly in a Morgan horse

A6 1/2‐month‐old Morgan filly was examined because of a history of abnormal behavior, teeth grinding, hypothermia, and electrolyte disturbances when weaned. She was from a breeding farm with several other Morgan horses. The 11‐year‐old dam had been purchased the year before as a proven broodmare, which had several previous foals. Breeding, gestation, and birth of this foal were normal. She was raised with 4 other mares and their offspring on pasture with free access to shelter in an open barn. Supplementary feeding consisted of oats and timothy hay. The owners reported that the foal showed unusual behavior, such as lack of apprehension of people, lack of distress from maternal separation, and a higher activity level than other foals of the same age. The foal extensively chewed the dam's tail and mane, masticated oats slowly with rapid jaw movements without actually swallowing them, and ground her teeth. She frequently nibbled the handler's clothes without biting, ate pebbles, and played with the salt block in the paddock. At 4 1/2 months of age, she was treated for suspected gastroduodenal ulcers and weaned. The referring veterinarian examined her 5 days after weaning because of dull demeanor and excessive teeth grinding. The foal was in thin body condition, hypothermic (37°C, 98.6°F), and tachycardic (60 beats per minute [bpm]) and had decreased borborygmi. Major abnormalities on serum biochemistry were severe hypernatremia (166 mmol/L; reference range 136–144 mmol/L) and hyperchloremia (128 mmol/L; reference range 94–104 mmol/L), azotemia (urea, 11.3 mmol/L; reference range 4.2–8.9 mmol/L), and hyperfibrinogenemia (5.2 g/L, reference range 1.6–2.9 g/L). The only abnormality on the CBC was hemoconcentration (PCV, 0.57 L/L; reference range 0.28–0.44 L/L). The foal was treated with penicillin procaine G^a (20,000 IU/kg [9072 IU/1b] IM q12h) and rifampin^b (5 mg/kg [2.7 mg/1b] PO q8h). The next day the tachycardia worsened (120 bpm) and the foal was estimated to be 5–8% dehydrated. IV fluid therapy with lactated Ringer solution^c (LRS) was initiated, and the antibiotic was changed to ceftiofur^d (2 mg/kg [0.91 mg/1b] IV q12h). The foal and dam were rejoined, and the foal's clinical status improved with resumption of nursing. Serial laboratory testing showed persistent hypernatremia 160 mmol/L) and hyperchloremia (123 mmol/L), azotemia urea 11.3 mmol/L and creatinine 168 umol/L; reference range 80–130 μmol/L), hyperglycemia (8.7 mmol/L; reference range 3.7–6.7 mmol/L), high aspartate aminotranferase activity (662 U/L; reference range 259–595 U/L), and high creatine kinase (CK) activity (1,196 U/L; reference range 108–430 U/L). The foal's condition improved and IV fluids were discontinued. Ceftiofur administration was discontinued and trimethoprim‐sulfamethoxazole^e (25 mg/kg [11.3 mg/1b] PO q12h) was administered for 3 days. During the next month the foal was stable but the abnormal behavior persisted. She was weaned again, and within days marked behavior changes such as circling, throwing the head around compulsively, and severe hind‐end shivering recurred. At examination, the foal was dull, tachycardic (60 bpm), was hypothermic (33.6°C, 92.5°F), had dark red mucous membranes, and was estimated to be 5% dehydrated. Laboratory findings were similar to those of the previous tests except for high fibrinogen (7.1 g/L). The foal was again rejoined with the dam, treated with intramuscular penicillin, and referred     

Cervical Vertebral Osteomyelitis With Secondary Septic Arthritis of the Atlantoaxial Joint in a Foal: A Case Report

A 36-day-old, 100-kg Thoroughbred colt was presented with a sudden onset of abnormal head carriage and pyrexia. Radiography revealed an osteomyelitis of the vertebral body of the second cervical vertebra. Ultrasonography revealed abscessation in the region of the atlantoaxial articulation on the left side, and fluid aspirated from the abscess confirmed suppurative inflammation. Surgical management was not feasible on economic grounds, and therefore this case was managed with aggressive medical therapy based on the most likely pathogens involved. To provide prolonged antibiotic therapy within the client’s budget, the antibiotic flucloxacillin (Staphlex, 500 mg) was used at a dose of 10 mg/kg by mouth, three times daily. Thirty-eight days after first presentation, the foal was euthanized because of chronic pain and deterioration in neurologic signs. A diagnosis of chronic osteomyelitis of the body of the second cervical vertebra (axis) was made with concurrent septic arthritis of the atlantoaxial joint involving the articular surface of the first cervical vertebra (atlas) and cervical myelopathy of the spinal cord within the first two vertebrae. No pathogens were isolated post mortem. This is the first report to describe the use of flucloxacillin in a foal. Although the outcome was fatal, the medical therapy provided could be considered successful at sterilizing the bony lesion.     

Presumed immune‐mediated hemolytic anemia in two foals with Rhodococcus equi infection

Objective – To describe the clinical presentation, case management, and outcome in 2 foals with Rhodococcus equi infection associated with presumptive severe immune‐mediated hemolytic anemia. Series Summary – Two foals diagnosed with R. equi pneumonia on the basis of tracheal wash cultures, thoracic radiographs, and thoracic ultrasonography were concurrently diagnosed with hemolytic anemia. Both foals required whole blood transfusions, and were treated with the antimicrobial combination of rifampin and a macrolide (eg, clarithromycin, erythromycin, or azithromycin). Dexamethasone was used to prevent further hemolysis in both foals, and to treat acute lung injury/acute respiratory distress syndrome in 1 of the foals. Both foals survived, and required prolonged antimicrobial therapy. New or Unique Information Provided – Although extra‐pulmonary disorders are commonly diagnosed in foals infected with R. equi, hemolytic anemia is rarely described. Dexamethasone is considered the treatment of choice for immune‐mediated hemolytic anemia, but may be contra‐indicated in foals with severe bacterial infections. In these foals, a relatively low dose and short duration of dexamethasone was utilized in an attempt to minimize immune suppression, although early discontinuation in 1 foal precipitated a second hemolytic crisis.     

Metastatic Tumor in Pregnancy: Placental Germ Cell Tumor With Metastasis to the Foal

A placental mass was observed in an otherwise-healthy Quarter Horse mare; subsequently, the mare's 52-day-old foal was examined because of hind limb ataxia, urinary incontinence, and raised lesions of the distal limbs. Clinical and biochemical findings were supportive of liver disease and lumbosacral injury. Ultrasonographic evaluation of the abdomen suggested a liver mass, which was confirmed with computed tomography (CT) and determined to be neoplastic via histopathologic evaluation of a liver biopsy sample. Initial histopathology suggested a germ cell tumor. Regions of lysis affecting both femurs and third metacarpal bones and a complete oblique sagittal fracture through the body of the first sacral vertebra were present on CT. Supportive care was provided until CT confirmation of diffuse hepatic neoplasia and vertebral fracture. Necropsy revealed a large multinodular mass within the liver and a pathologic fracture of the first sacral vertebral body. Histopathologic comparison between neoplastic cells examined from the placenta and foal confirmed metastases of a germ cell tumor. Placental tumors are rare in all species; however, when noted in horses, clinicians should be aware of the possibility of metastatic spread to the foal.