The management of wildlife in the United States and Canada, including the monitoring and maintenance of the health of wildlife populations and the ecosystems on which they depend, are conducted under a set of principles that aim for sustainable use. This set of principles is known as the North American Model of Wildlife Conservation (the Model), and it guides wildlife management and conservation decisions in both countries. The purpose of this perspective is to highlight how wildlife health is an important part of the Model and is vital to its future. It is proposed that wildlife health and the Model support one another. First, the history and fundamental ideas of a public trust that shaped the Model are reviewed. Next, wildlife health is defined and examples are offered that highlight how the Model supports wildlife health and how health affects the Model, as well as the limitations or threats if one moves away from the Model's defining principles. Finally, controversies surrounding the Model are reviewed and a perspective on the future is offered, based in large part on the work of Aldo Leopold. Leopold's thinking about health of the land and its organisms was well ahead of its time, and the scientific underpinnings of his writings in making the case for wildlife health and the Model are recounted. As a simple addendum to Leopold's land ethic, a plea for a health ethic is called for, whereby healthy wildlife and healthy landscapes are an obligation of the Model and modern society because health “tends to preserve the integrity, stability and beauty of the biotic community.”⁴¹

Despite the paucity of published literature on elasmobranch hematology and biochemistry, great interspecific diversity has been observed. Blood samples from 43 undulate rays (Raja undulata) (23 males, 20 females) hatched and raised at Oceanogràfic Aquarium, were analyzed for hematology and plasma biochemistry. Animals were divided into two age groups: 1 yr old (28 skates) and 2 yr old (15 skates). All individuals were clinically healthy on physical examination. Weight, total length, standard length, and disc width were recorded. No statistically significant differences were observed between male and female juvenile skates for the evaluated morphometric, hematologic, and plasma biochemical values. Once reference intervals (RI) were determined, blood samples from seven healthy adult skates housed at the same aquarium were collected for comparison. Statistically significant differences were observed in cholesterol, triglycerides, alkaline phosphatase, blood urea nitrogen, chloride, and sodium between juvenile and adult skates. This is the first article describing hematological and plasma biochemical RI for this species, increasing the clinical knowledge on elasmobranch blood analytics. These data will serve as a valuable diagnostic and research tool for professionals working with undulate rays and closer relatives in aquariums and in the field. Further studies using larger elasmobranch sample sizes are needed to determine reliable species-specific baseline health values and to evaluate the effect of intrinsic and extrinsic parameters on blood analytics more accurately.

This study assesses parasitism and pathologic manifestations in free-ranging Crotalus durissus terrificus. A total of 96 rattlesnakes from the State of Minas Gerais (southeast Brazil) were necropsied between September 2019 and February 2020. Granulomatous gastritis affected 48% (46 of 96) of the snakes evaluated, which were associated with the ascaridid nematodes Ophidascaris sp. and Hexametra sp. Other nematodes found included Kalicephalus costatus costatus and Kalicephalus inermis inermis (Diaphanocephalidae; 7%, 7 of 96) in the intestines, Serpentirhabdias sp. (Rhabdiasidae; 18%, 17 of 96) in the lungs, and Hastospiculum sp. (Diplotriaenidae; 2%, 2 of 96) encapsulated in the serosa of the mesentery. Larval cestodes, probably spargana of Spirometra sp. (Diphyllobothriidae; 2%, 2 of 96), were found in the skeletal muscle and unidentified acanthocephalan cystacanths (Oligacanthorhynchidae; 5%, 5 of 96) in the subcutis and coelomic cavity. The pentastome Porocephalus crotali (Porocephalidae; 2%, 2 of 96) was also found in the lungs. Microscopically, intestinal disease was caused by Sarcocystis sp. (7%, 7 of 96), Cryptosporidium sp. (1%, 1 of 96), and Entamoeba sp. (1%, 1 of 96) and fungi (7%, 7 of 96). In addition, hemoparasites such as Hepatozoon spp. (23%, 22 of 96) and Trypanosoma sp. (1%, 1 of 96) were observed in blood smears. This study expands the knowledge of diseases, parasites, and other infectious agents affecting free-ranging C. durissus terrificus in Brazil.

Egyptian fruit bats (Rousettus aegyptiacus) are commonly held within zoos and research facilities. Despite this popularity, there have been no publications regarding normal bone density or bone mineral concentration and few publications regarding the normal dietary requirements of calcium, phosphorus, and vitamin D (25-hydrox-vitamin D₃ [25(OH)D₃]) for the species. A clinical investigation into frequent fractures in a zoo population of 23 adult male Egyptian fruit bats used dual-energy X-ray absorptiometry (DXA) to evaluate bone mineral density (BMD) and bone mineral content (BMC) prior to and after dietary adjustment of calcium and phosphorus. This study documents BMD, BMC, serum trace minerals, and serum levels of 25(OH)D₃ within this population and includes postmortem bone density and bone ash from a subset of bats that died during the study period. A handheld point-of-care analyzer was utilized to assess ionized calcium and electrolytes (sodium, potassium, chloride, total CO₂), glucose, blood urea nitrogen, and creatinine at each DXA time point to contribute to published reference ranges for this species. This study identified a significant (P < 0.001) increase in BMC over 15 mon (4.71–8.26 g) following additional calcium and phosphorus supplementation in the diet. The BMD also trended toward a significant increase (0.124–0.274 g/cm², P < 0.053). Additional studies documenting normal bone density that include both sexes and possibly free-ranging bats consuming a natural diet are recommended to determine normal values for R. aegyptiacus.

Chemical immobilization of wildlife, required for many biological studies and management events, often induces hypoxemia and respiratory depression. Laryngeal mask airways (LMAs) have shown promise as an efficient method of airway protection during anesthesia. Nineteen wild bighorn sheep (Ovis canadensis) lambs were immobilized using an IM combination of medetomidine (0.16 ± 0.062 mg/kg), azaperone (0.20 ± 0.058 mg/kg), and alfaxalone (0.54 ± 0.21 mg/kg) via remote injection. Upon recumbency, arterial blood gas parameters, minute ventilation (V_E), tidal volume (V_T), and respiratory rate were measured before and after LMA placement. The V_E and V_T were measured via respirometer. Time to LMA placement, cuff pressure, cuff volume, and ease of placement were measured. Medetomidine was reversed with IM atipamezole at five times the medetomidine dose upon completion of procedures. Pre- and post-LMA measurements were compared using a t test or a Wilcoxon signed-rank test based on normality of the data. The LMA provided a patent airway in all lambs with a significant (P < 0.0001) increase in VE (mean [95% CI]; pre-LMA: V_E = 17.3 [16.2–18.5] L/min, post-LMA: V_E = 19.8 [18.6–21.0] L/min) but did not have a significant impact on partial pressure of oxygen (PaO₂; pre-LMA: corrected PaO₂ = 45.2 [41.2–49.2] mm Hg, post-LMA: corrected PaO₂ = 47.5 [43.3–51.7] mm Hg; P = 0.19) or partial pressure of carbon dioxide (PaCO₂; pre-LMA: PaCO₂ = 50.4 [46.6–53.2] mm Hg, post-LMA: PaCO₂ = 51.6 [48.8–55.7] mm Hg; P = 0.035) following placement. This study demonstrated that the LMA is a viable option for airway protection in wild bighorn sheep.

The blue-crowned laughingthrush (BCLT) (Pterorhinus courtoisi) is a species of critically endangered passerine that is part of a Global Species Management Plan and experiences high mortality rates in some collections. Complete necropsy and medical records from 15 European institutions that housed BCLT between 1998 and 2018 were assessed to evaluate morbidity and mortality in the captive population. Medical records for 407 BCLT were received; a total of 191 morbidity events were recorded from 111 individual BCLT. The most common cause of morbidity was coccidial disease, including systemic isosporosis (30.4%, n = 58). Age was a significant factor contributing to mortality, with 53% of deaths occurring between 0 and 14 d old and 78% by 1 yr of age. The most common cause of death was trauma (22.8%, n = 31), followed by systemic isosporosis (22%, n = 30). Of the 343 deceased birds for which records were provided, 50.4% had a necropsy performed and 40.5% had histopathology carried out postmortem. Based on these findings, BCLT should be managed carefully to mitigate risk of trauma, and screening for isosporosis should be performed. Institutions should carry out standardized necropsies and histopathology on every BCLT that dies in their collection to elucidate the etiology of disease in this critically endangered species.

Death due to illegal trade and trafficking serves as the largest threat to pangolins in their geographic range countries. Appropriate veterinary care is essential to the welfare of sick or debilitated pangolins. Given the challenge of comprehensive physical examination of this species due to its unique anatomic features and poorly studied physiology, laboratory diagnostics can provide essential information to guide appropriate medical care. This retrospective study included previously analyzed blood and urine samples collected from adult (n = 17) African white-bellied pangolins (Phataginus tricuspis) under managed care that were sampled over a 4-yr period as part of routine veterinary examinations. Samples from clinically normal animals were used to summarize results for this species. Pangolins had a lymphocyte-predominant leukogram with a mean neutrophil to lymphocyte ratio of 0.83 (min–max: 0.13–4.81). Seasonal, sex, and age differences were present for several hematologic and serum biochemical analytes. Urine samples had a median urine specific gravity (USG) of 1.040 (min–max: 1.006–1.060), a neutral-to-basic urine pH (6.0–8.6), and contained mainly struvite crystals or infrequently calcium oxalate dihydrate crystals. Winter samples had higher USG than summer samples. The clinicopathologic data provided herein offers applicable information useful for the clinical management of pangolins.

The greater flamingo (Phoenicopterus roseus) is often maintained in managed care. Although values for plasma concentrations of minerals and vitamins have been published for this species, limited studies investigate the effects of diet changes on these values. Plasma concentrations of selected vitamins (A [and the provitamin A carotenoid β-carotene] and E), minerals (Ca, Cu, Fe, K, Mg, Mn, Na, inorganic P, Se, and Zn), and total protein (TP) were measured in a zoo collection of greater flamingos in November 2018 (n = 48) and in November 2019 (n = 52), 30 d after a change from the summer diet, which was the same in both years, to different winter diets. Chloride, cholesterol, and triglycerides were only measured once in 2019. The nutrient profiles of the two complete diets (labeled and analyzed) differed considerably, especially for the canthaxanthin concentration. The plasma concentrations of β-carotene (P < 0.0001), Cu (P < 0.0001), Fe (P < 0.0001), Mg (P < 0.0001), and Se (P < 0.0001) were significantly higher and vitamin E (P < 0.0001), Ca (P = 0.0014), Mn (P < 0.0001), Na (P = 0.0005), and TP (P < 0.0001) were significantly lower in 2018 than in 2019. Four minerals (Cu, Fe, Mg, and Zn) were measured using both spectrophotometry and inductively coupled plasma mass spectrometry, and all of these minerals showed significant (P < 0.05) differences between the two methods. Based on the results of the study, both the influence of diet and the detection method used for circulating nutrients must be considered when interpreting the plasma vitamin and mineral concentrations in greater flamingos.

With captive invertebrates increasing in popularity, a safe and effective anesthesia protocol is required for their veterinary care. This study investigated the safety and efficacy of 5% isoflurane anesthesia and 0.26 ml hemolymph collection in subadult to adult emperor scorpions (Pandinus imperator; n = 14). Each scorpion was placed in a 2-L anesthetic chamber and induced with 5% isoflurane at a flow rate of 2 L/min oxygen. Anesthetic depth was assessed by rolling the animal into dorsal recumbency and rating the response from one to four: 1 = successful coordinated righting movement, 2 = successful uncoordinated righting movement, 3 = unsuccessful righting movement, 4 = no movement. Ratings 3 and 4 were both adequate for the hemolymph collection. The mean induction time was 4.2 min to reach a level 3 depth and 10.5 min to reach a level 4 depth. All animals were clinically normal for at least 1 yr post experiment. A mean hemolymph volume drawn of 1.92% of body weight, and an anesthetic induction with 5% isoflurane, appear safe in subadult to adult emperor scorpions.

This article summarizes urinary stone submissions from foxes in human care to the Minnesota Urolith Center over 40 years. A previous report documented the analysis of uroliths from foxes that were submitted between 1981 and 2007.¹³ New data compiled from 2008 to 2021 included an additional 38 stones submitted from foxes, totaling 65 fox urolith submissions from 1981 to 2021. Struvite and cystine uroliths were most common, with the remainder comprised of calcium phosphate, calcium oxalate, compound, mixed, or miscellaneous material. Most stones were submitted from male foxes. Seventy-two percent of the stones were urocystoliths, and from 2010 to 2021, most stones were diagnosed antemortem and removed surgically. More than half of the stones were submitted from red foxes (Vulpes vulpes) and fennec foxes (Vulpes zerda). Urolithiasis in foxes may be an underrecognized condition, and data from this study suggest that clinicians should consider routine urinalysis and diagnostic imaging as part of the preventive medicine program for fox species, especially red foxes and fennec foxes.

Although reports of tumors in chiropteran species are rare, postmortem examinations conducted on aging captive populations suggest that neoplasia may be more prevalent and clinically more significant contributors to morbidity and mortality than previously appreciated in these animals. A retrospective study was conducted to describe cases of neoplasia identified in Jamaican fruit bats (Artibeus jamaicensis) under human care at the Vancouver Aquarium between 01 January 2013 and 31 March 2021. Approximately 13.2% (N = 47/355) of the bat population died within this time span, and gross and histologic postmortem examinations were performed on 28 of 47 individuals. There were eight malignant and three benign neoplasms detected in 10 cases (eight females, two males), including: malignant histiocytoma, esophageal adenocarcinoma, two squamous cell carcinomas, spindle cell sarcoma, periosteal chondrosarcoma, uncharacterized uterine neoplasia with unrelated multicentric pulmonary carcinoma, and cholangiocarcinoma. Benign variants included three suspected uterine leiomyomas. A wide variety of tumor types and tissue predilections were identified, suggesting a complex and perhaps multifactorial pathogenesis in neoplastic transformation in microchiropterans. To the authors' knowledge, these tumor types have not been previously described in Artibeus sp., and some of these neoplasms have not previously been reported in chiropterans.

Two co-housed 17-yr-old male lions (Panthera leo) and one 15-yr-old female lion in an adjacent enclosure developed acute lethargy, depression, anorexia, and ataxia at a zoological park in central North Carolina, United States. One of the male lions and the female lion were found dead 5 and 4 d after the onset of clinical signs, respectively. The other male lion recovered without any clinical treatment. A third male lion housed with the female lion never developed clinical signs. Postmortem examination, microscopic evaluation, and bacterial culture of the liver from both deceased lions confirmed systemic Yersinia pseudotuberculosis infection. Susceptibility testing revealed resistance to amoxicillin–clavulanic acid and cefazolin. To investigate the extent of the outbreak, qualitative real-time polymerase chain reaction (PCR) for Y. pseudotuberculosis was performed on feces and substrate from 15 enclosures housing nondomestic felids and canids, resulting in a positive sample from one enclosure housing four asymptomatic lions. This enclosure was adjacent to housing of the deceased female lion. Enrofloxacin was administered to all animals in the vicinity at doses of 5 mg/kg in nondomestic felids and 10 mg/kg in nondomestic canids, orally q24h for 14 d. Repeated fecal PCR performed 1 wk after completing the antibiotic treatment protocol found no positive samples. The source of the infection was not identified despite PCR testing of environmental samples from all enclosures in the vicinity, the remains of a prey item fed out prior to the outbreak, and a single dead rodent found on grounds. No further clinical cases have occurred within the following year.

Pseudo-odontoma can occur in some species with elodont teeth. Pseudo-odontomas affecting maxillary dentition may result in obstruction of the nasal cavities and lead to dyspnea. Effective treatments for the disease in Richardson's ground squirrels (Urocitellus richardsonii) have not yet been established. Three Richardson's ground squirrels exhibiting dyspnea and with maxillary pseudo-odontomas, based on diagnostic imaging, were surgically treated. The animals were placed under general anesthesia, and following excision of skin and subcutaneous tissue at the midpoint of the line connecting the medial canthus and ipsilateral nasal opening, maxillotomy of the incisive bone was performed. The reserve crown of the maxillary incisor tooth was exposed via the maxillotomy site and was sectioned into labial and palatal fragments, and the diseased tooth was completely extracted. In all three cases, dyspnea improved immediately after surgery. In one case, no recurrence was observed 600 d following surgery. These results suggest that the procedure used provides a practical approach for treating maxillary pseudo-odontomas in Richardson's ground squirrels.

This report documents cases of fatal pulmonary mycosis caused by entomopathogenic fungi in the genera Metarhizium and Beauveria (Order Hypocreales) in a loggerhead sea turtle (Caretta caretta), a Chinese alligator (Alligator sinensis), two gopher tortoises (Gopherus polyphemus), a Cuvier's dwarf caiman (Paleosuchus palpebrosus), a false gharial (Tomistoma schlegelii), a green sea turtle (Chelonia mydas), and a Kemp's ridley sea turtle (Lepidochelys kempii), and a case of granulomatous coelomitis in a hawksbill sea turtle (Eretmochelys imbricata). Fungi identified in these cases included Beauveria bassiana, Beauveria brongniartii, Metarhizium anisopliae, Metarhizium robertsii, and one case of infection by a novel Metarhizium species. The animals were either housed at zoos or brought into rehabilitation from the wild. Although the majority of animals had comorbidities, the fungal infections were believed to be the primary cause of death. Fungal susceptibility testing was performed on two Beauveria spp. isolates, and revealed lower minimum inhibitory concentrations for itraconazole and voriconazole when compared to terbinafine and fluconazole. This case series demonstrates that a variety of reptile species from different orders are vulnerable to infection with Metarhizium, and multiple species of sea turtle are susceptible to infection with Beauveria.

Five unrelated adult Colombian boas (Boa imperator) presented with a 1- to 3-mon history of unilateral rostral swelling of the maxilla associated with a chronic rubbing against the enclosure's walls. Moderate to severe gingival inflammation and ulceration of the labial mucosa were present at the level of the swelling with tenderness to the touch. Radiography revealed osteolytic or proliferative lesions of the maxillary bone. Chronic maxillary osteomyelitis was diagnosed. Unilateral maxillectomy was performed on each animal under general anesthesia. Local anesthesia was also achieved by infiltrating lidocaine along the medial and lateral aspect of the maxillary gingiva and at the level of the maxillo–ectopterygoid joint. Using a lateral gingival approach, the maxillo–prefrontal, maxillary–palatine, and maxillo–ectopterygoid attachments were transected, and the maxillary bone removed. Histologic examination revealed pyogranulomatous stomatitis and osteomyelitis in all snakes, and presence of intralesional bacteria (n = 3 snakes). Gram-negative bacteria (Chryseobacterium indologenes and Proteus mirabilis) were cultured from the resected tissue of two snakes. One snake suffered from wound dehiscence 5 d postoperatively. All snakes were fed 15 d postoperatively and ingested dead mice without apparent difficulties. One snake was examined 2 mon and 1 yr after surgery, with no evidence of soft tissue or osseous infection and only minor facial scaring; all other snakes were lost to follow-up 15 d after surgery. Unilateral maxillectomy was performed in a cohort of five Colombian boas suffering from maxillary osteomyelitis. This surgical technique should be considered as an alternative to medical treatment in boid snakes.

A novel case report of acute abdominal compartment syndrome (ACS) with respiratory and hemodynamic collapse during colonoscopy in a western lowland gorilla (Gorilla gorilla gorilla), notably, without colonic perforation is presented here. ACS is a rapidly progressive and sustained increase in intra-abdominal pressure leading to shock with multisystem organ failure. Surgical intervention was mandatory, and abdominal decompression was immediately life-saving, although the patient died 1 wk later of surgical complications. Colonoscopy is a widely performed procedure that is generally considered safe, and serious complications during colonoscopy are rare. ACS has been previously reported during colonoscopy with perforation in four cases (human)^1,4,6,8. In this instance there was no evidence of perforation, representing not only a rare complication of the procedure, but also a novel cause of ACS. This is the first report of ACS in a nonhuman primate and of nonperforation-associated ACS in human or nonhuman primates.

In a study on iron regulation, liver biopsies were collected at two time points from 34 adult Egyptian fruit bats (Rousettus aegyptiacus). An absorbable gelatin hemostatic sponge (GS) was inserted at biopsy sites for local hemostasis in 16 bats. In the subsequent 10 yr, 12 of these bats died or were euthanized, and 11 were examined histologically; in 2 bats, intravascular GS was identified in the lungs and in 1 bat, unabsorbed GS was also identified at the hepatic biopsy site. The remaining hepatic GS was associated with local abscessation and intralesional bacteria and fungi and remained at the hepatic biopsy site for a prolonged period after placement (1 yr). The findings of local hepatic abscessation and GS embolization in the lungs of these two bats highlights a potential adverse effect related to its use in zoologic species.