The genome of Przewalski's horse (Equus ferus przewalskii).

The Przewalski's horse (Equus ferus przewalskii) is an endangered equid native to the steppes of central Asia. After becoming extinct in the wild, multiple conservation efforts convened to preserve the species including captive breeding programs, reintroduction and monitoring systems, protected lands, and cloning. Availability of a highly contiguous reference genome is essential to support these continued efforts. We used Oxford Nanopore sequencing to produce a scaffold-level 2.5 Gb nuclear assembly and 16,002 bp mitogenome from a captive Przewalski's mare. All assembly drafts were generated from 111 Gb of sequence from a single PromethION R10.4.1 flow cell. The mitogenome contained 37 genes in the standard mammalian configuration and was 99.63% identical to the domestic horse (Equus caballus). The nuclear assembly, EquPr2, contained 2,146 scaffolds with an N50 of 85.1 Mb, 43X mean depth, and BUSCO quality score of 98.92%. EquPr2 successfully improves upon the existing Przewalski's horse reference genome (Burgud), with 25-fold fewer scaffolds, a 166-fold larger N50, and phased pseudohaplotypes. Modified basecalls revealed 79.5% DNA methylation and 2.1% hydroxymethylation globally. Allele-specific methylation analysis between pseudohaplotypes revealed 226 differentially methylated regions (DMRs) in known imprinted genes and loci not previously reported as imprinted. The heterozygosity rate of 0.165% matches previous estimates for the species and compares favorably to other endangered animals. This improved Przewalski's horse assembly will serve as a valuable resource for conservation efforts and comparative genomics investigations.

PHARMACOKINETICS AND EFFICACY OF A SINGLE TOPICAL DOSE OF EPRINOMECTIN IN GIRAFFE (GIRAFFA SPP.).

Growing resistance to current antiparasitic medications, both in livestock and in zoological species under human care, makes it imperative to evaluate available drugs on the market, such as eprinomectin. In this prospective study, five males and one female of reticulated (Giraffa reticulata; n = 2), Masai (Giraffa tippelskirchii; n = 1), Nubian (Giraffa camelopardalis; n = 2), and hybrid subspecies (n = 1) of giraffe, received 1.5 mg/kg eprinomectin topically along the dorsum. Using high-performance liquid chromatography, concentrations of eprinomectin in plasma samples collected at 0, 4, 24, and 48 h, and 7, 14, 21, and 28 d were evaluated following drug administration. Complete blood cell counts and biochemistry panels were performed before (n = 6) and after (n = 3) eprinomectin administration. Samples for modified double centrifugal fecal flotation (n = 6) were evaluated prior to eprinomectin administration to evaluate for endoparasites and were repeated after the study (n = 5). Noncompartmental pharmacokinetic analysis was applied to the data. The observed maximum plasma concentration was 11.45 ng/ml and the time of observed maximum concentration was 2.67 d. The mean terminal half-life was 5.16 d. No adverse effects were observed related to eprinomectin administration and no blood work changes were observed. Parasite loads decreased (n = 3) or did not change (n = 2) after eprinomectin administration. The mean peak plasma concentration of eprinomectin in giraffe was similar to that achieved in cattle, despite using three times the dose.

RESPONSE AND PHYSIOLOGIC OUTCOMES AFTER BUTORPHANOL, MIDAZOLAM, AND MEDETOMIDINE IMMOBILIZATION AND REVERSAL IN CAPTIVE REINDEER (RANGIFER TARANDUS).

Sedation, recovery response, and physiologic outcomes were evaluated in five captive reindeer (Rangifer tarandus) in Minnesota using a completely reversible immobilization protocol. Reindeer were immobilized with butorphanol (0.23-0.32 mg/kg), midazolam (0.23-0.32 mg/kg), and medetomidine (0.15 mg/kg) (BMM) via IM dart. Induction time (IT), recumbency time (DT), and recovery time (RT) were recorded. Temperature (T), respiratory rate (RR), pulse rate (PR), pulse oximetry (SpO2), arterial blood gas values including oxygen (PaO2), and carbon dioxide (PaCO2) tensions and lactate (Lac) were recorded preoxygen supplementation and 15 min postoxygen supplementation. Reversal was done using naltrexone (2.3-3.0 mg/kg), flumazenil (0.008-0.01 mg/kg) and atipamezole (0.62-0.78 mg/kg) (NFA) IM, limiting recumbency to 1 h. Median IT, DT, and RT were 5 min, 46 min, and 7 min, respectively. SpO2 (92 to 99%, P = 0.125), PaO2 (45.5 to 97 mmHg, P = 0.25), and PaCO2 (46.5 to 54.6 mmHg, P = 0.25) all increased, whereas Lac (3.02 to 1.93 mmol/L, P = 0.25) decreased between baseline and 15 min postoxygen supplementation, without statistical significance. BMM immobilization, and reversal with NFA provided rapid and effective immobilization and recovery, respectively. Oxygen supplementation mitigated hypoxemia in all reindeer.

Outbreak of epizootic hemorrhagic disease in captive reindeer (Rangifer tarandus).

In September 2020, an outbreak of epizootic hemorrhagic disease occurred in captive reindeer (Rangifer tarandus) and was associated with neurological signs and mortality. Four reindeer died or were euthanized after acute illness over a 12-day period. Affected reindeer displayed abnormal behavior, neurologic signs, lethargy, and/or lameness. The most consistent gross finding was dark red streaks throughout the adrenal gland cortices (4/4). One animal had acute hemorrhage involving the subcutis and skeletal muscles over the ventrolateral body wall and back, and abomasal serosa. Histologically, the most common lesions were adrenal gland cortical hemorrhage (4/4) with necrosis (3/4) and lymphoplasmacytic meningoencephalitis with gliosis, glial nodules, satellitosis, and nonsuppurative perivascular cuffing (4/4). The brain lesions were most frequent in the gray matter of the cerebrum, hippocampus, and thalamus but also involved the cerebellum and brainstem. Epizootic hemorrhagic disease virus serotype 6 was detected through PCR and sequencing of the spleen in all cases.

DIAGNOSIS AND TREATMENT OF A NATURAL INFECTION WITH TRYPANOSOMA CRUZI (CHAGAS DISEASE) IN A SYMPTOMATIC DE BRAZZA'S MONKEY (CERCOPITHECUS NEGLECTUS) IN ALABAMA.

Trypanosoma cruzi, the causative agent of Chagas disease, is a zoonotic, vector-borne, protozoan hemoflagellate with a wide host range. An 11-yr-old, captive-bred male De Brazza's monkey (Cercopithecus neglecus) presented with weight loss despite normal appetite. Examination revealed hypoglycemia, nonregenerative anemia, and many trypanosomes on a blood smear. A whole blood sample was PCR-positive for T. cruzi discrete typing unit TcIV and the monkey seroconverted using two different methods. The monkey was treated with the standard human dose of benznidazole twice daily for 60 d; however, blood obtained over the next 1.5 yr posttreatment remained PCR-positive for T. cruzi. A second course of benznidazole at a higher dose but lower frequency for 26 wk was required for the monkey to convert to sustained PCR-negative status. The monkey recovered with no apparent lasting effects.

EVALUATION OF PASSIVE TRANSFER IN NINE SPECIES OF CERVIDAE.

The reliability of packed cell volumes (PCV), total solids (TS), blood glucose (BG), γ-glutamyl transferase (GGT), and glutaraldehyde test in determining passive transfer of colostral immunoglobulins was investigated in nine species of cervids: axis deer (Axis axis), hog deer (Axis porcinus), sika deer (Cervus nippon), tufted deer (Elaphodus cephalophus), Père David's deer (Elaphurus davidianus), pudu (Pudu puda), sambar deer (Rusa unicolor), barasinga deer (Rucervus duvaucelli), and Eld's deer (Rucervus eldii). Individually the parameters evaluated were significant though imperfect predictors of passive transfer status in cervids. Interpreted collectively as a panel along with neonate condition, these tests were clinically helpful in diagnosing failure of passive transfer (FPT). Collectively interpreting test results as a panel along with clinical assessment of the animal is recommended. Some species-specific variations in TS, GGT, and glutaraldehyde test results were identified.

SARCOCYSTOSIS IN A CAPTIVE FLOCK OF THICK-BILLED PARROTS (RHYNCHOPSITTA PACHYRHYNCHA) FROM 2005 TO 2016: MORBIDITY, MORTALITY, DIAGNOSTICS, AND MANAGEMENT STRATEGIES.

Sarcocystosis was diagnosed in a captive flock of thick-billed parrots (Rhynchopsitta pachyrhyncha) at the Wildlife Conservation Society's Queens Zoo. Since the index case in 2005, 45% of mortalities in birds over 30 days of age were due to sarcocystosis. Sarcocystis falcatula was repeatedly identified as the causative agent. The disease predominantly affected younger adult parrots. Administration of antiparasitic medications prior to development of respiratory signs prolonged life in infected birds, but disease was fatal until utilization of a three-drug combination (pyrimethamine, trimethoprim-sulfamethoxazole, and ponazuril). This protocol may require in excess of 6 mo of therapy to achieve clinical resolution of active disease. Plasma creatine kinase activity was found to be the most useful test in diagnosing infection and monitoring response to therapy. Polymerase chain reaction (PCR) for apicomplexan organisms on antemortem whole blood, blood smears, or dried blood spots helped confirm suspected cases, but due to the poor sensitivity was sometimes misleading when assessing response to therapy or resolution of clinical disease. Preventive measures, focusing on exclusion and removal of Virginia opossums (Didelphis virginiana) from zoo grounds failed to curtail the occurrence of sarcocystosis in the flock. Other preventative steps, such as modification of feeding stations to exclude potential arthropod paratenic hosts and prophylaxis trials with diclazuril, appeared to successfully mitigate new infections. Given the diagnostic and therapeutic challenges, prevention of exposure to S. falcatula is essential to ex-situ conservation efforts for thick-billed parrots.

STANDING COMPUTED TOMOGRAPHY IN NONANESTHETIZED LITTLE PENGUINS (EUDYPTULA MINOR) TO ASSESS RESPIRATORY SYSTEM ANATOMY AND MONITOR DISEASE.

Multidetector computed tomography (MDCT) scans were performed in clinically healthy, nonanesthetized, standing little penguins (Eudyptula minor) to determine reference ranges for air-sac and lung volumes, as well as lung density. Five of 15 clinically healthy birds were diagnosed with pulmonary granulomas on initial MDCT scans. Granulomas were not readily apparent on radiographs, even in cases where the entire normal pulmonary parenchymal architecture was effaced on the MDCT scan. Serial MDCT scans after antifungal and antimycobacterial therapies demonstrated a response to treatment. MDCT scanning in nonanesthetized little penguins proved to be a well-tolerated, non-invasive imaging modality for respiratory diseases that are otherwise difficult to diagnose, including aspergillosis and mycobacteriosis.

DIAGNOSIS AND MANAGEMENT OF MYCOBACTERIOSIS IN A COLONY OF LITTLE PENGUINS (EUDYPTULA MINOR).

A group of zoo-housed little penguins (Eudyptula minor) was diagnosed with mycobacteriosis. While undergoing multidetector computed tomography (MDCT) imaging for an unrelated research project, pulmonary lesions were detected in multiple individuals. In general, birds appeared healthy and free of outward signs of disease. After the loss of three individuals, polyclonal mycobacterial disease due to Mycobacterium avium-intracellulare complex was confirmed. Surviving birds were treated with rifampin (45 mg/kg), ethambutol (30 mg/kg), clarithromycin (10 mg/kg), and enrofloxacin (30 mg/kg) compounded into a single capsule administered once a day in food. After 3 mo of therapy, MDCT imaging documented a decrease in nodule size and number in all remaining birds, with further improvement documented after 13 mo of treatment. MDCT imaging was invaluable for diagnosing disease, documenting disease progression over time, and assessing response to therapy. Early initiation of therapy before the development of outward signs of disease led to resolution of mycobacterial pulmonary lesions in multiple penguins. Mycobacterial disease in this group of little penguins, as well as previously published reports, suggests that the species is at increased risk for developing mycobacteriosis.

TREATMENT OF CRYPTOSPORIDIUM SERPENTIS INFECTION IN A KING COBRA ( OPHIOPHAGUS HANNAH) WITH PAROMOMYCIN.

Feces collected from a wild-caught, young adult king cobra ( Ophiophagus hannah) were repeatedly positive for Cryptosporidium on both direct immunofluorescent antibody (DFA) and polymerase chain reaction (PCR), and sequencing identified the organism as Cryptosporidium serpentis. Infection was subclinical, as the snake was in good body condition and active, and readily consumed dead rats that were scented with snake skin. A course of paromomycin, inserted in feeder rats, was initiated at 360 mg/kg, orally, twice weekly for 6 wk. Feces collected at the end of treatment were negative for Cryptosporidium on PCR, as were feces collected 3 wk, 6 mo, 12 mo, and 18 mo later. At higher dosages, paromomycin may prove useful and may be curative for early gastric and intestinal cryptosporidiosis in squamate reptiles.

ENVIRONMENTAL FUNGAL LOADS IN AN INDOOR-OUTDOOR AFRICAN PENGUIN ( SPHENISCUS DEMERSUS) EXHIBIT.

Aspergillosis continues to be one of the most important causes of disease in captive penguins. As such, designing exhibits and holding areas that minimize the risk of aspergillosis is of great interest; however, very little has been published regarding this topic. The goal of this study was to assess total fungal spore loads as well as the loads of Aspergillus spp. encountered in multiple indoor and outdoor microenvironments around the exhibit for a large colony of African penguins ( Spheniscus demersus). Air samples were collected via impaction at the microenvironments on a monthly basis over a 1-yr period. Results of this study indicated seasonal trends in both total fungal spore loads as well as Aspergillus spp. loads, with the lowest levels encountered during January through April. During the warmer, more humid spring, summer, and fall months when outdoor microenvironments experienced the highest fungal loads, the air-handling system and the pleated filters used indoors are thought to have reduced the fungal loads in the indoor microenvironments compared with the outdoor microenvironments. Additionally, surrounding planting beds were thought to contribute to the higher total fungal loads and Aspergillus spp. loads in the outdoor microenvironments. Results of this study are useful in understanding the factors that contribute to Aspergillus spp. loads in areas that house penguins, and can be used in guiding design, construction, and landscaping of penguin enclosures.

CLINICAL EFFECT OF HEMOPARASITE INFECTIONS IN SNOWY OWLS ( BUBO SCANDIACUS).

Vector-borne hemoparasites are commonly found in avian species. Plasmodium spp., the causative agent of avian malaria, are intraerythrocytic parasites that can cause signs ranging from subclinical infection to severe acute disease. In raptor species, most hemoparasites are associated with subclinical infection and are generally not treated when seen on blood evaluation. This case series reviews five cases of hemoparasite infection in snowy owls ( Bubo scandiacus). These animals were infected with a variety of hemoparasites, including Plasmodium, Haemoproteus, and Leukocytozoon spp. Death of one of these birds due to hemoparasite burden led to a change in the monitoring for and treatment of subclinical hemoparasitic infections in this species. Three subsequently infected snowy owls have been treated with primaquine and chloroquine. The birds that were treated survived infection, and parasite burdens in peripheral blood diminished. Postulated reasons for increased morbidity and mortality associated with hemoparasitic infections in captive snowy owls, as opposed to other raptor species, include stress, concurrent disease, novel pathogen exposure, and elevated environmental temperatures.

PIGMENTED VILLONODULAR SYNOVITIS IN A RETICULATED GIRAFFE (GIRAFFA CAMELOPARDALIS).

: A 17-yr-old, female, captive-born reticulated giraffe ( Giraffa camelopardalis ) presented with acute-onset lameness of the right metacarpophalangeal (fetlock) joint. Despite multiple courses of treatment, the lameness and swelling progressively worsened over a 3.5-yr period, and the giraffe was euthanized. At necropsy, gross and microscopic changes in the right, front fetlock and associated flexor tendon sheath included villous synovial hyperplasia and the formation of discrete pigmented nodules within synovial membranes. Histologically, the nodules were composed of abundant, fibrous connective tissue with heavy macrophage infiltration, hemosiderin deposition, and distinctive, multinucleated cells that resembled osteoclasts. These findings were consistent with pigmented villonodular synovitis (PVNS), a rare condition affecting both humans and animals. Although the pathophysiology of PVNS is poorly understood, lesions exhibit features of both neoplastic and reactive inflammatory processes. This case report represents, to the authors' knowledge, the first description of PVNS in a nondomestic ungulate.

CLINICAL MANAGEMENT OF THIRD PHALANX FRACTURES IN LESSER (TRAGELAPHUS IMBERBIS) AND GREATER KUDU (TRAGELAPHUS STREPSICEROS).

Two greater kudu ( Tragelaphus strepsiceros ) and one lesser kudu ( T. imberbis ) from two zoological institutions presented with overgrown front hooves, and were diagnosed with fractures of the third phalanges in the affected digits. Both greater kudu had milder lamenesses at diagnosis, and were managed conservatively with hoof trims, stall rest, and nonsteroidal anti-inflammatory medications. Ongoing management through regular hoof trims led to improvement and eventual resolution of lameness. The more severely lame lesser kudu received hoof blocks on the front claws not associated with fractured phalanges. This therapy was well tolerated and resulted in resolution of lameness immediately after application. Radiographic evidence of healing was present 8 wk posttherapy. Diagnosis of these fractures was greatly aided by radiographic views obtained at a 45° oblique angle with the claws distracted.

Evaluation of the anesthetic efficacy of alfaxalone in oscar fish (Astronotus ocellatus).

OBJECTIVE: To evaluate effects of alfaxalone on heart rate (HR), opercular rate (OpR), results of blood gas analysis, and responses to noxious stimuli in oscar fish (Astronotus ocellatus). ANIMALS: 6 healthy subadult oscar fish. PROCEDURES: Each fish was immersed in water containing 5 mg of alfaxalone/L. Water temperature was maintained at 25.1°C, and water quality was appropriate for this species. The HR, OpR, response to noxious stimuli, and positioning in the tank were evaluated, and blood samples for blood gas analysis were collected before (baseline), during, and after anesthesia. RESULTS: Immersion anesthesia of oscar fish with alfaxalone (5 mg/L) was sufficient for collection of diagnostic samples in all fish. Mean ± SD induction time was 11 ± 3.8 minutes (minimum, 5 minutes; maximum, 15 minutes), and mean recovery time was 37.5 ± 13.7 minutes (minimum, 20 minutes; maximum, 55 minutes). There was a significant difference in OpR over time, with respiratory rates significantly decreasing between baseline and anesthesia and then significantly increasing between anesthesia and recovery. There was no significant difference in HR over time. Median lactate concentrations were significantly increased in all anesthetized fish. Other physiologic or blood gas variables did not change significantly. CONCLUSIONS AND CLINICAL RELEVANCE: Alfaxalone should be considered as a readily available and easy-to-use anesthetic for oscar fish. Because it is more likely to be found in veterinary hospitals than other traditional anesthetics for fish, its value as an anesthetic for other species of fish should also be considered.

Herpesvirus and calicivirus infection in a black-footed cat (Fels nigripes) family group following vaccination.

Preventive healthcare recommendations for zoo felids include vaccination against primary viral diseases that affect domestic felids. Although associated with a more-substantial immune response in their domestic counterparts, use of modified live virus vaccines (MLV) in nondomestic carnivores can result in vaccine-induced viral disease. This case report details a feline herpesvirus and calicivirus outbreak in two black-footed cat (Felis nigripes) kittens and their dam following use of an MLV in the kittens. Clinical signs included anorexia, nasal discharge, sneezing, and tachypnea. Patient history, clinical signs, real-time polymerase chain reaction results, and histopathologic evaluation of tissues confirmed the diagnosis. Although unable to definitively prove that the disease observed in these cases was caused by the MLV, there is strong temporal and circumstantial evidence that this was the case. This outbreak of feline upper respiratory infection following vaccination with a multivalent MLV resulted in significant morbidity and mortality, serving as an important reminder that recombinant or killed vaccines are the safest choice for use in nondomestic species, particularly in kittens.