DIAGNOSIS AND MEDICAL AND SURGICAL MANAGEMENT OF CHRONIC INFECTIOUS FIBRINOUS PLEURITIS IN AN OKAPI (OKAPIA JOHNSTONI) Author(s): Dana Franzen, D.V.M., Nadine Lamberski, D.V.M., Dipl. A.C.Z.M., Jeffery Zuba, D.V.M., G. Lynn Richardson, M.S., D.V.M., Dipl. A.C.V.S., A. T. Fischer, Jr., D.V.M., Dipl. A.C.V.S., and Norman W. Rantanen, D.V.M., Dipl. A.C.V.R. Source: Journal of Zoo and Wildlife Medicine, 46(2):427-430. Published By: American Association of Zoo Veterinarians DOI: http://dx.doi.org/10.1638/2014-0232R.1 URL: http://www.bioone.org/doi/full/10.1638/2014-0232R.1
BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the biological, ecological, and environmental sciences. BioOne provides a sustainable online platform for over 170 journals and books published by nonprofit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/ terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder.
BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research.
Journal of Zoo and Wildlife Medicine 46(2): 427–430, 2015 Copyright 2015 by American Association of Zoo Veterinarians
DIAGNOSIS AND MEDICAL AND SURGICAL MANAGEMENT OF CHRONIC INFECTIOUS FIBRINOUS PLEURITIS IN AN OKAPI (OKAPIA JOHNSTONI) Dana Franzen, D.V.M., Nadine Lamberski, D.V.M., Dipl. A.C.Z.M., Jeffery Zuba, D.V.M., G. Lynn Richardson, M.S., D.V.M., Dipl. A.C.V.S., A. T. Fischer, Jr., D.V.M., Dipl. A.C.V.S., and Norman W. Rantanen, D.V.M., Dipl. A.C.V.R.
Abstract: A 10-yr-old female okapi (Okapia johnstoni) at the San Diego Zoo Safari Park was evaluated for intermittent malaise, inappetence, occasional cough, abdominal splinting, and licking at both flanks. Physical examination revealed tachypnea, tachycardia, and fluid sounds on thoracic auscultation. Transthoracic ultrasound showed multiple uniform, anechoic filled structures in the right and left pleural space. Surgical exploration of the thoracic cavity revealed bilateral, mature, fibrous, compartmentalizing adhesions between the visceral and parietal pleura, confirming a diagnosis of chronic, infectious, fibrinous pleuritis. The suspected etiology was occult aspiration pneumonia secondary to historical episodes of regurgitation associated with general anesthesia. Culture of the pleural fluid and fibrous adhesions grew Trueperella (Arcanobacterium) pyogenes, Arcanobacterium haemolyticum, and few Fusobacterium species. Treatment consisted of chest-tube placement to establish drainage, thoracic lavage, unilateral surgical debridement, and long-term antibiotics. The animal made a complete clinical recovery over 7 mo. Key words: Aspiration pneumonia, okapi, Okapia johnstoni, pleuritis, thoracotomy, Trueperella pyogenes.
BRIEF COMMUNICATION Okapi (Okapia johnstoni) are members of the Giraffidae family native to the Democratic Republic of the Congo.7 Okapi are classified as endangered on the International Union for Conservation of Nature Red List of threatened species with a declining population.7 Anesthetic complications are a significant cause of captive adult morbidity and mortality.4 Okapi are highrisk anesthetic candidates because of their tendency to regurgitate, the associated risk of aspiration, and potential postanesthetic ileus.1,4 Pleuritis is inflammation of the potential space between the visceral and parietal pleura.2,3,8,11 Pleuritis is rarely a primary disease process in horses and cattle, and is usually secondary to bronchopneumonia or a penetrating foreign body.2,3,8,11 Patients may present with anorexia, lethargy, tachypnea, and dyspnea.2,3,8 Ultrasound is the most sensitive and specific diagnostic test to
From the San Diego Zoo Safari Park, 15500 San Pasqual Valley Road, Escondido, California 92027, USA (Franzen, Lamberski, Zuba); P.O. Box 9083, Rancho Santa Fe, California 92067, USA (Richardson); Chino Valley Equine Hospital, 2945 English Place, Chino Hills, California 91709, USA (Fischer); 4551 La Canada Road, Fallbrook, California 92028, USA (Rantanen). Present address (Franzen): 18040 Elgin Avenue, Farmington, Minnesota 55024, USA. Correspondence should be directed to Dr. Lamberski ([email protected]).
identify pleuritis when compared with physical examination and radiographs.2,3,9,10,12 Therapeutics include long-term antimicrobials, chest-tube placement and thoracic lavage, and thoracotomy with debridement of infected tissue.2,3,5,6,8,11,14 Following is the first known report of the diagnosis and medical and surgical management of infectious fibrinous pleuritis in an okapi. A 10-yr-old 338-kg gravid female okapi at the San Diego Zoo Safari Park was evaluated on 23 February 2013 for intermittent malaise, inappetence, occasional cough, abdominal splinting, and licking at both flanks. Similar clinical signs were first noted on 24 May 2011, intermittently throughout the remainder of 2011, and in November 2012. This animal had a history of regurgitation associated with anesthesia, including episodes on 15 July 2010 and 27 May 2011. Physical exam revealed abdominal discomfort, tachycardia (70 beats per minute), and tachypnea (46 breaths per minute). A healthy conspecific had a heart rate of 55–60 beats per minute and a respiratory rate of 12–15 breaths per minute. Because of pregnancy and nontractable demeanor, empirical treatment with an oral nonsteroidal anti-inflammatory drug was initiated (Banaminet, flunixin meglumine, 1.5 mg/kg orally q. 24 hr for 7 days, Merck Animal Health, Summit, New Jersey 07901, USA). The animal was re-examined a month later after aborting a mid-gestational fetus, and was tachy-
427
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Table 1. Complete blood count, chemistry values, and body weight recorded before documented illness, during the course of treatment, and after recovery; International Species Inventory System (ISIS) reference ranges for okapi are included.13
Date
PCV (%a, 20.9–49.3)
WBC 3 103b (2.76–13.88)
TP (g/dlc, 5.0–9.1)
Albumin (g/dl, 1.6–4.2)
Globulin (g/dl, 2.0–6.8)
Fibrinogen (mg/dl, 0–768)
Body weight (kg)
24 May 2011 27 May 2011 11 Aug 2011 4 Apr 2013 16 Apr 2013 17 Apr 2013 18 Apr 2013 01 May 2013 02 May 2013 10 May 2013 9 July 2013 25 Jan 2014 11 Mar 2014
38 40 36 15 16 14 11 17 11 15 24 30 37
10.2 2.8 6.2 21.3 14.3 11.8 16.9 12.4 5.4 7.3 9.1 12.0 13.6
6.1 6.3 6.2 11.1 11.3 10.8 10.9 10.7 7.4 9.5 9.1 8.0 9.1
3.4 3.2 2.7 1.5 1.5 1.4 1.5 2.0 1.4 2.0 2.7 3.2 3.3
2.7 2.8 2.6 8.5 9.0 8.4 8.5 8.0 5.4 6.6 6.0 4.8 4.8
200 600 500 700 600 600 600 700 500 600 500 400 700
324 324 309 302 303 NMd NM NM NM 279 300 300 300
Packed cell volume. White blood cell count. c Total protein measured by refractometer. d NM, not measured. a
b
cardic and tachypneic with an increased respiratory effort and abdominal splinting. Borborygmi and fluid-like sounds were heard on thoracic auscultation. Blood work was consistent with chronic inflammation and anemia; chronological blood work and body weights are outlined in Table 1. The animal was sedated for transthoracic ultrasound with butorphanol (0.05 mg/kg i.m., Wildlife Pharmaceuticals, Windsor, Colorado 80550, USA), azaperone (0.17 mg/kg i.m., Wildlife Pharmaceuticals), and xylazine (0.2 mg/kg i.m., AnaSedt, Lloyd Laboratories, Shenandoah, Iowa 51601, USA). The animal became recumbent and was reversed with atipamezole (0.1 mg/ kg i.m., Antisedant, Orion Corporation, Espoo, Finland) and naltrexone (0.33 mg/kg i.m., Komoto Custom Care Pharmacy, Bakersfield, California 93301, USA). The remaining sedation was adequate. Regurgitation was noted during recovery. Ultrasound showed multiple uniform, anechoic filled structures in both pleural spaces (Fig. 1). The heart and mediastinum were displaced to the left of midline. Standing lateral thoracic radiographs revealed a diffuse soft tissue opacity in the ventral thorax border effacing the cardiac silhouette. Differential diagnoses included a diaphragmatic hernia, infectious or neoplastic pleural effusion/disease, traumatic reticulopleuritis/pericarditis, and bacterial, viral, or fungal pneumonia. Surgical exploration of the thorax was planned as the next diagnostic and therapeutic intervention. The animal was hospitalized 48 hr before
surgery for supportive care and treatment of possible aspiration, which included amikacin (21 mg/kg i.v. q. 24 hr, Amiglyde-Vt, Fort Dodge Animal Health, Fort Dodge, Iowa 50501, USA) and potassium penicillin G (130,000 international units [IU]/kg per day i.v., WG Critical Care LLC, Paramus, New Jersey 07652, USA). The patient also received ceftiofur crystalline free acid (8 mg/ kg s.q. q. 72 hr, Excedet Zoetis, Florham Park, New Jersey 07932, USA) intermittently throughout diagnosis and treatment. The animal was anesthetized on 18 April 2013, 61 days after presentation, with carfentanil (0.0025 mg/kg i.v., Wildlife Pharmaceuticals), xylazine (0.08 mg/kg i.v.), and ketamine (0.5 mg/kg i.v., KetaVedTM, VetOne, Boise, Idaho 83705, USA), followed by propofol (0.3 mg/kg i.v., PropoFloTM, Abbott Laboratories, Chicago, Illinois 66064, USA) for intubation and maintenance with isoflurane (FlurisoTM, VetOne). Induction was rapid without regurgitation. The animal was thin and had lost 21 kg. Rigid thoracoscopy was performed with the assistance of transthoracic ultrasound. There were mature, fibrous, compartmentalizing adhesions between the visceral and parietal pleura in the right caudoventral hemithorax. Approximately 700 ml of fetid, yellow, flocculent fluid was removed from the pleural space. Culture of the effusion grew Trueperella (Arcanobacterium) pyogenes and few Fusobacterium species. Recommended antibiotics included penicillin, ampicillin, erythromycin, and chloramphenicol. The right
FRANZEN ET AL.—MANAGEMENT OF PLEURITIS IN AN OKAPI
Figure 1. Ultrasound image of the right hemithorax obtained before medical and surgical therapy. Letter ‘‘a’’ indicates the body wall; ‘‘b’’ indicates the lung margin. The pleural space is occupied by hyperechoic fibrin with multifocal areas of hypoechoic to anechoic fluid. Images obtained from the left hemithorax appeared similar but were less extensive.
hemithorax was flushed with 2.5 L of plasmalyte A (Abbot Laboratories, North Chicago, Illinois 60064, USA) containing 6 g of ampicillin (Sagent Pharmaceuticals Inc., Schaumburg, Illinois 60195, USA). A 32 French argyle trocar thoracic catheter (TYCO Healthcare Group LP, Mansfield, Massachusetts 02048, USA) was placed in the right midventral thoracic wall with a Heimlich valve (BD, Franklin Lakes, New Jersey 07417, USA) to prevent iatrogenic pneumothorax. Thoracoscopy of the left hemithorax showed mature pleural adhesions, hepatized lung, no free fluid, and a 5– 6-cm-diameter mass-like lesion in the mid-ventral thorax. Anesthetic drugs were antagonized with naltrexone (0.25 mg/kg i.m.), and recovery was uncomplicated. The animal was diagnosed with bilateral, chronic, severe infectious fibrinous pleuritis. Postoperative management included daily thoracic lavage using warm sterile saline (0.9% sodium chloride, Hospira, Inc., Lake Forest, Illinois 60045, USA) for 12 days. Initially the animal was distracted with browse while lavage was performed free standing in the stall. Over time the animal became less tolerant, and lavage was performed through the stall door with a partial barrier. Therapy also included potassium penicillin G (130,000 IU/kg per day i.v.), ceftiofur sodium (3.3 mg/kg i.v. q. 12 hr; Naxcelt Zoetis), amikacin (21 mg/kg i.v. q. 24 hr for 7 total days of therapy), and supportive care including i.v. fluids and nutritional support. The patient’s respiratory
429
rate and effort, attitude, and appetite gradually improved. Recheck transthoracic ultrasound was performed 7 days postoperatively free standing in the stall while the animal was distracted with browse. The adhesions in the right pleural space had decreased by one-third. The left hemithorax was unchanged. Culture of the drainage fluid from thoracic lavage produced no growth. The animal became noncompliant with medical therapy before clinical resolution. Therefore, a second surgery was performed 14 days after the first to debride the right hemithorax. A standing lateral abdominal radiograph ruled out a metal foreign body causing reticulopleuritis. The animal was anesthetized with carfentanil (0.0025 mg/kg i.v.), xylazine (0.08 mg/kg i.v.), and ketamine (0.66 mg/kg i.v.), was intubated, and maintained on isoflurane. Induction was rapid with no regurgitation. Rigid endoscopy of the left hemithorax showed white, gelatinous tissue but no drainable abscess. A 20-cm section of rib was resected from the right ventral thorax. A large amount of fibrous material (1.18 kg) was manually removed from the right pleural space. The thoracic window was left open to heal by second intention. The animal was reversed with naltrexone (0.25 mg/kg i.v.). A small amount of regurgitation was noted during recovery. The procedure did not produce a pneumothorax, most likely due to the extensive scarring of the pleural space. Cytology from the right chest tube showed suppurative inflammation with intracellular Gram-positive bacteria. Aerobic and anaerobic culture of the chest tube and right and left thoracic cavity samples produced no growth. The fibrous material cultured Arcanobacterium haemolyticum. Blood culture showed methicillin-resistant Staphylococcus epidermidis, most likely secondary to longterm intravenous jugular catheters. Potassium penicillin and ceftiofur were continued as previous for 5 days postoperatively, for a total of 20 days of intravenous therapy. The patient clinically improved and was discharged from the hospital after 25 days with no further medications. The animal cleaned the thoracic window with its tongue; no further medical management was performed and it healed within 5 mo. Recheck transthoracic ultrasound was performed on 18 November 2013. The left pleural space had a marked decrease in fibrous material with no signs of cardiac compromise (Fig. 2). The right hemithorax was not imaged because of lack of animal compliance without chemical restraint. Because of the ultrasonographic improvement
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JOURNAL OF ZOO AND WILDLIFE MEDICINE
LITERATURE CITED
Figure 2. Ultrasound image of the left hemithorax obtained 7 months after medical and surgical therapy. Letter ‘‘a’’ indicates the body wall; ‘‘b’’ indicates the lung margin. The two cursors outline the remaining hyperechoic fibrin and scar tissue in the pleural space, measuring 4.68 cm. There was no free fluid.
and the animal’s clinically normal status, no further treatment was pursued. The most likely disease etiology in this case was occult aspiration pneumonia secondary to regurgitation during anesthesia. The animal’s clinical signs and gradual weight loss were noninvasive indications of an underlying respiratory disease. This individual was not amenable to medical procedures without anesthesia unless systemically ill, which caused the delay in diagnostic testing. Radiographs identified intrathoracic disease, but were unable to differentiate between disease of the pulmonary parenchyma and the pleural space. Transthoracic ultrasound localized the disease to the pleural space. A definitive diagnosis was made after surgical exploration. Improvement was noted after medical management with thoracic lavage and intravenous antibiotics. A complete recovery may have been achieved with medical therapy; however, this individual became noncompliant before significant resolution was achieved. Therefore, unilateral surgical management was pursued. The animal made a complete clinical recovery and was reinstated in the institution’s breeding program. Acknowledgments: Special thanks to Dr. Stan Perkins, M.D., for assisting with anesthesia, and to the mammal keepers, hospital keepers, and veterinary technicians that helped manage this case.
1. Bertelsen, MF. Giraffidae. In: Miller RE, Fowler ME (eds.). Fowler’s zoo and wild animal medicine, Volume 8. St. Louis (MO): Elsevier; 2015. p. 602–610. 2. Braun U, Pusterla N, Fluckiger M. Ultrasonographic findings in cattle with pleuropneumonia. Vet Rec. 1997;141:12–17. 3. Byars TD, Becht JL. Pleuropneumonia. Vet Clin North Am Equine Pract. 1991;7(1):63–78. 4. Citino SB, Bush M. Giraffidae. In: West G, Heard D, Caulkett N (eds.). Zoo animal and wildlife immobilization and anesthesia. 2nd ed. Ames (IA): Wiley Blackwell; 2014. p. 818–821. 5. Ducharme NG, Fubini SL, Rebhun WC, Beck KA. Thoracotomy in adult dairy cattle: 14 cases (1979– 1991). J Am Vet Med Assoc. 1992;200:86–90. 6. Hilton H, Aleman M, Madigan J, Nieto J. Standing lateral thoracotomy in horses: indications, complications, and outcomes. Las Vegas (NV): American Association of Equine Practioners Convention, 2009. 7. Mallon D., Ku¨mpel N., Quinn A., Shurter S., Lukas J., Hart J, Mapilanga, J. Okapia johnstoni. The IUCN Red List of Threatened Species [Internet]. Version 2014.3. 2013. [cited 2014 November 15] Available from www.iucnredlist.org 8. Raidal SL. Review: equine pleuropneumonia. Br Vet J. 1995;151:233–262. 9. Rantanen NW. Diagnosis of pleural effusion in the horse using diagnostic ultrasound. J Equine Vet Sci. 1994;14(1):15–16. 10. Reimer J, Reef VB, Spencer PA. Ultrasonography as a diagnostic aid in horses with anaerobic bacterial pleuropneumonia and/or pulmonary abscessation: 27 cases (1984–1986). J Am Vet Med Assoc. 1989;194:278–282. 11. Rendle DI, Armstrong SK, Hughes KJ. Combination fibrinolytic therapy in the treatment of chronic septic pleuropneumonia in a Thoroughbred gelding. Aust Vet J. 2012;90(9):358–362. 12. Scott P, Collie D, McGorum B, Sargison N. Relationship between thoracic auscultation and lung pathology detected by ultrasonography in sheep. Vet J. 2010;186:53–57. 13. Teare, JA. ISIS physiological reference intervals for captive wildlife: a CD-ROM resource. Bloomington (MN): International Species Information System; c2013. 14. Vachon AM, Fischer AT. Thoracoscopy in the horse: diagnostic and therapeutic indications in 28 cases. Equine Vet J. 1998;30(6):467–475. Received for publication 21 November 2014
BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the biological, ecological, and environmental sciences. BioOne provides a sustainable online platform for over 170 journals and books published by nonprofit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/ terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder.
BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research.
Journal of Zoo and Wildlife Medicine 46(2): 427–430, 2015 Copyright 2015 by American Association of Zoo Veterinarians
DIAGNOSIS AND MEDICAL AND SURGICAL MANAGEMENT OF CHRONIC INFECTIOUS FIBRINOUS PLEURITIS IN AN OKAPI (OKAPIA JOHNSTONI) Dana Franzen, D.V.M., Nadine Lamberski, D.V.M., Dipl. A.C.Z.M., Jeffery Zuba, D.V.M., G. Lynn Richardson, M.S., D.V.M., Dipl. A.C.V.S., A. T. Fischer, Jr., D.V.M., Dipl. A.C.V.S., and Norman W. Rantanen, D.V.M., Dipl. A.C.V.R.
Abstract: A 10-yr-old female okapi (Okapia johnstoni) at the San Diego Zoo Safari Park was evaluated for intermittent malaise, inappetence, occasional cough, abdominal splinting, and licking at both flanks. Physical examination revealed tachypnea, tachycardia, and fluid sounds on thoracic auscultation. Transthoracic ultrasound showed multiple uniform, anechoic filled structures in the right and left pleural space. Surgical exploration of the thoracic cavity revealed bilateral, mature, fibrous, compartmentalizing adhesions between the visceral and parietal pleura, confirming a diagnosis of chronic, infectious, fibrinous pleuritis. The suspected etiology was occult aspiration pneumonia secondary to historical episodes of regurgitation associated with general anesthesia. Culture of the pleural fluid and fibrous adhesions grew Trueperella (Arcanobacterium) pyogenes, Arcanobacterium haemolyticum, and few Fusobacterium species. Treatment consisted of chest-tube placement to establish drainage, thoracic lavage, unilateral surgical debridement, and long-term antibiotics. The animal made a complete clinical recovery over 7 mo. Key words: Aspiration pneumonia, okapi, Okapia johnstoni, pleuritis, thoracotomy, Trueperella pyogenes.
BRIEF COMMUNICATION Okapi (Okapia johnstoni) are members of the Giraffidae family native to the Democratic Republic of the Congo.7 Okapi are classified as endangered on the International Union for Conservation of Nature Red List of threatened species with a declining population.7 Anesthetic complications are a significant cause of captive adult morbidity and mortality.4 Okapi are highrisk anesthetic candidates because of their tendency to regurgitate, the associated risk of aspiration, and potential postanesthetic ileus.1,4 Pleuritis is inflammation of the potential space between the visceral and parietal pleura.2,3,8,11 Pleuritis is rarely a primary disease process in horses and cattle, and is usually secondary to bronchopneumonia or a penetrating foreign body.2,3,8,11 Patients may present with anorexia, lethargy, tachypnea, and dyspnea.2,3,8 Ultrasound is the most sensitive and specific diagnostic test to
From the San Diego Zoo Safari Park, 15500 San Pasqual Valley Road, Escondido, California 92027, USA (Franzen, Lamberski, Zuba); P.O. Box 9083, Rancho Santa Fe, California 92067, USA (Richardson); Chino Valley Equine Hospital, 2945 English Place, Chino Hills, California 91709, USA (Fischer); 4551 La Canada Road, Fallbrook, California 92028, USA (Rantanen). Present address (Franzen): 18040 Elgin Avenue, Farmington, Minnesota 55024, USA. Correspondence should be directed to Dr. Lamberski ([email protected]).
identify pleuritis when compared with physical examination and radiographs.2,3,9,10,12 Therapeutics include long-term antimicrobials, chest-tube placement and thoracic lavage, and thoracotomy with debridement of infected tissue.2,3,5,6,8,11,14 Following is the first known report of the diagnosis and medical and surgical management of infectious fibrinous pleuritis in an okapi. A 10-yr-old 338-kg gravid female okapi at the San Diego Zoo Safari Park was evaluated on 23 February 2013 for intermittent malaise, inappetence, occasional cough, abdominal splinting, and licking at both flanks. Similar clinical signs were first noted on 24 May 2011, intermittently throughout the remainder of 2011, and in November 2012. This animal had a history of regurgitation associated with anesthesia, including episodes on 15 July 2010 and 27 May 2011. Physical exam revealed abdominal discomfort, tachycardia (70 beats per minute), and tachypnea (46 breaths per minute). A healthy conspecific had a heart rate of 55–60 beats per minute and a respiratory rate of 12–15 breaths per minute. Because of pregnancy and nontractable demeanor, empirical treatment with an oral nonsteroidal anti-inflammatory drug was initiated (Banaminet, flunixin meglumine, 1.5 mg/kg orally q. 24 hr for 7 days, Merck Animal Health, Summit, New Jersey 07901, USA). The animal was re-examined a month later after aborting a mid-gestational fetus, and was tachy-
427
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JOURNAL OF ZOO AND WILDLIFE MEDICINE
Table 1. Complete blood count, chemistry values, and body weight recorded before documented illness, during the course of treatment, and after recovery; International Species Inventory System (ISIS) reference ranges for okapi are included.13
Date
PCV (%a, 20.9–49.3)
WBC 3 103b (2.76–13.88)
TP (g/dlc, 5.0–9.1)
Albumin (g/dl, 1.6–4.2)
Globulin (g/dl, 2.0–6.8)
Fibrinogen (mg/dl, 0–768)
Body weight (kg)
24 May 2011 27 May 2011 11 Aug 2011 4 Apr 2013 16 Apr 2013 17 Apr 2013 18 Apr 2013 01 May 2013 02 May 2013 10 May 2013 9 July 2013 25 Jan 2014 11 Mar 2014
38 40 36 15 16 14 11 17 11 15 24 30 37
10.2 2.8 6.2 21.3 14.3 11.8 16.9 12.4 5.4 7.3 9.1 12.0 13.6
6.1 6.3 6.2 11.1 11.3 10.8 10.9 10.7 7.4 9.5 9.1 8.0 9.1
3.4 3.2 2.7 1.5 1.5 1.4 1.5 2.0 1.4 2.0 2.7 3.2 3.3
2.7 2.8 2.6 8.5 9.0 8.4 8.5 8.0 5.4 6.6 6.0 4.8 4.8
200 600 500 700 600 600 600 700 500 600 500 400 700
324 324 309 302 303 NMd NM NM NM 279 300 300 300
Packed cell volume. White blood cell count. c Total protein measured by refractometer. d NM, not measured. a
b
cardic and tachypneic with an increased respiratory effort and abdominal splinting. Borborygmi and fluid-like sounds were heard on thoracic auscultation. Blood work was consistent with chronic inflammation and anemia; chronological blood work and body weights are outlined in Table 1. The animal was sedated for transthoracic ultrasound with butorphanol (0.05 mg/kg i.m., Wildlife Pharmaceuticals, Windsor, Colorado 80550, USA), azaperone (0.17 mg/kg i.m., Wildlife Pharmaceuticals), and xylazine (0.2 mg/kg i.m., AnaSedt, Lloyd Laboratories, Shenandoah, Iowa 51601, USA). The animal became recumbent and was reversed with atipamezole (0.1 mg/ kg i.m., Antisedant, Orion Corporation, Espoo, Finland) and naltrexone (0.33 mg/kg i.m., Komoto Custom Care Pharmacy, Bakersfield, California 93301, USA). The remaining sedation was adequate. Regurgitation was noted during recovery. Ultrasound showed multiple uniform, anechoic filled structures in both pleural spaces (Fig. 1). The heart and mediastinum were displaced to the left of midline. Standing lateral thoracic radiographs revealed a diffuse soft tissue opacity in the ventral thorax border effacing the cardiac silhouette. Differential diagnoses included a diaphragmatic hernia, infectious or neoplastic pleural effusion/disease, traumatic reticulopleuritis/pericarditis, and bacterial, viral, or fungal pneumonia. Surgical exploration of the thorax was planned as the next diagnostic and therapeutic intervention. The animal was hospitalized 48 hr before
surgery for supportive care and treatment of possible aspiration, which included amikacin (21 mg/kg i.v. q. 24 hr, Amiglyde-Vt, Fort Dodge Animal Health, Fort Dodge, Iowa 50501, USA) and potassium penicillin G (130,000 international units [IU]/kg per day i.v., WG Critical Care LLC, Paramus, New Jersey 07652, USA). The patient also received ceftiofur crystalline free acid (8 mg/ kg s.q. q. 72 hr, Excedet Zoetis, Florham Park, New Jersey 07932, USA) intermittently throughout diagnosis and treatment. The animal was anesthetized on 18 April 2013, 61 days after presentation, with carfentanil (0.0025 mg/kg i.v., Wildlife Pharmaceuticals), xylazine (0.08 mg/kg i.v.), and ketamine (0.5 mg/kg i.v., KetaVedTM, VetOne, Boise, Idaho 83705, USA), followed by propofol (0.3 mg/kg i.v., PropoFloTM, Abbott Laboratories, Chicago, Illinois 66064, USA) for intubation and maintenance with isoflurane (FlurisoTM, VetOne). Induction was rapid without regurgitation. The animal was thin and had lost 21 kg. Rigid thoracoscopy was performed with the assistance of transthoracic ultrasound. There were mature, fibrous, compartmentalizing adhesions between the visceral and parietal pleura in the right caudoventral hemithorax. Approximately 700 ml of fetid, yellow, flocculent fluid was removed from the pleural space. Culture of the effusion grew Trueperella (Arcanobacterium) pyogenes and few Fusobacterium species. Recommended antibiotics included penicillin, ampicillin, erythromycin, and chloramphenicol. The right
FRANZEN ET AL.—MANAGEMENT OF PLEURITIS IN AN OKAPI
Figure 1. Ultrasound image of the right hemithorax obtained before medical and surgical therapy. Letter ‘‘a’’ indicates the body wall; ‘‘b’’ indicates the lung margin. The pleural space is occupied by hyperechoic fibrin with multifocal areas of hypoechoic to anechoic fluid. Images obtained from the left hemithorax appeared similar but were less extensive.
hemithorax was flushed with 2.5 L of plasmalyte A (Abbot Laboratories, North Chicago, Illinois 60064, USA) containing 6 g of ampicillin (Sagent Pharmaceuticals Inc., Schaumburg, Illinois 60195, USA). A 32 French argyle trocar thoracic catheter (TYCO Healthcare Group LP, Mansfield, Massachusetts 02048, USA) was placed in the right midventral thoracic wall with a Heimlich valve (BD, Franklin Lakes, New Jersey 07417, USA) to prevent iatrogenic pneumothorax. Thoracoscopy of the left hemithorax showed mature pleural adhesions, hepatized lung, no free fluid, and a 5– 6-cm-diameter mass-like lesion in the mid-ventral thorax. Anesthetic drugs were antagonized with naltrexone (0.25 mg/kg i.m.), and recovery was uncomplicated. The animal was diagnosed with bilateral, chronic, severe infectious fibrinous pleuritis. Postoperative management included daily thoracic lavage using warm sterile saline (0.9% sodium chloride, Hospira, Inc., Lake Forest, Illinois 60045, USA) for 12 days. Initially the animal was distracted with browse while lavage was performed free standing in the stall. Over time the animal became less tolerant, and lavage was performed through the stall door with a partial barrier. Therapy also included potassium penicillin G (130,000 IU/kg per day i.v.), ceftiofur sodium (3.3 mg/kg i.v. q. 12 hr; Naxcelt Zoetis), amikacin (21 mg/kg i.v. q. 24 hr for 7 total days of therapy), and supportive care including i.v. fluids and nutritional support. The patient’s respiratory
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rate and effort, attitude, and appetite gradually improved. Recheck transthoracic ultrasound was performed 7 days postoperatively free standing in the stall while the animal was distracted with browse. The adhesions in the right pleural space had decreased by one-third. The left hemithorax was unchanged. Culture of the drainage fluid from thoracic lavage produced no growth. The animal became noncompliant with medical therapy before clinical resolution. Therefore, a second surgery was performed 14 days after the first to debride the right hemithorax. A standing lateral abdominal radiograph ruled out a metal foreign body causing reticulopleuritis. The animal was anesthetized with carfentanil (0.0025 mg/kg i.v.), xylazine (0.08 mg/kg i.v.), and ketamine (0.66 mg/kg i.v.), was intubated, and maintained on isoflurane. Induction was rapid with no regurgitation. Rigid endoscopy of the left hemithorax showed white, gelatinous tissue but no drainable abscess. A 20-cm section of rib was resected from the right ventral thorax. A large amount of fibrous material (1.18 kg) was manually removed from the right pleural space. The thoracic window was left open to heal by second intention. The animal was reversed with naltrexone (0.25 mg/kg i.v.). A small amount of regurgitation was noted during recovery. The procedure did not produce a pneumothorax, most likely due to the extensive scarring of the pleural space. Cytology from the right chest tube showed suppurative inflammation with intracellular Gram-positive bacteria. Aerobic and anaerobic culture of the chest tube and right and left thoracic cavity samples produced no growth. The fibrous material cultured Arcanobacterium haemolyticum. Blood culture showed methicillin-resistant Staphylococcus epidermidis, most likely secondary to longterm intravenous jugular catheters. Potassium penicillin and ceftiofur were continued as previous for 5 days postoperatively, for a total of 20 days of intravenous therapy. The patient clinically improved and was discharged from the hospital after 25 days with no further medications. The animal cleaned the thoracic window with its tongue; no further medical management was performed and it healed within 5 mo. Recheck transthoracic ultrasound was performed on 18 November 2013. The left pleural space had a marked decrease in fibrous material with no signs of cardiac compromise (Fig. 2). The right hemithorax was not imaged because of lack of animal compliance without chemical restraint. Because of the ultrasonographic improvement
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Figure 2. Ultrasound image of the left hemithorax obtained 7 months after medical and surgical therapy. Letter ‘‘a’’ indicates the body wall; ‘‘b’’ indicates the lung margin. The two cursors outline the remaining hyperechoic fibrin and scar tissue in the pleural space, measuring 4.68 cm. There was no free fluid.
and the animal’s clinically normal status, no further treatment was pursued. The most likely disease etiology in this case was occult aspiration pneumonia secondary to regurgitation during anesthesia. The animal’s clinical signs and gradual weight loss were noninvasive indications of an underlying respiratory disease. This individual was not amenable to medical procedures without anesthesia unless systemically ill, which caused the delay in diagnostic testing. Radiographs identified intrathoracic disease, but were unable to differentiate between disease of the pulmonary parenchyma and the pleural space. Transthoracic ultrasound localized the disease to the pleural space. A definitive diagnosis was made after surgical exploration. Improvement was noted after medical management with thoracic lavage and intravenous antibiotics. A complete recovery may have been achieved with medical therapy; however, this individual became noncompliant before significant resolution was achieved. Therefore, unilateral surgical management was pursued. The animal made a complete clinical recovery and was reinstated in the institution’s breeding program. Acknowledgments: Special thanks to Dr. Stan Perkins, M.D., for assisting with anesthesia, and to the mammal keepers, hospital keepers, and veterinary technicians that helped manage this case.
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