Natalie Mylniczenko

Dr. Natalie Mylniczenko

orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 October 2019 in American Journal of Veterinary Research
Verified
Journal Article
Closed access
NMNatalie Mylniczenko
Natalie Mylniczenko
SSShiho Sumigama
Shiho Sumigama
JWJennifer T. Wyffels
Jennifer T. Wyffels
CWCatharine Jean Wheaton
Catharine Jean Wheaton
TGTristan L. Guttridge
Tristan L. Guttridge
LPLinda M. Penfold
Linda M. Penfold
OBJECTIVE: To characterize physical examination, plasma biochemical, and ultrasonographic findings in aquarium-housed, managed semiwild, and wild southern stingrays (Hypanus americanus) with and without reproductive disease. ANIMALS: Southern stingrays from aquarium (n = 48), lagoon (managed semiwild; 34), and wild (12) habitats. PROCEDURES: Limited, opportunistic prosections were performed of presumed anatomically normal wild southern stingrays and compared with findings for aquarium-housed stingrays with reproductive disease. Ultrasonographic video data from both groups were used to assign a score (1 to 5) indicating increasing severity of ovarian and uterine reproductive disease. Plasma total 17β-estradiol, estrone, progesterone, and testosterone concentrations were measured with enzyme immunoassays validated for use in southern stingrays. RESULTS: Ultrasonographic ovarian scores were significantly correlated with uterine scores. No reproductive disease was detected in semiwild or wild stingrays, but 65% (31/48) of aquarium-housed stingrays had developing or advanced reproductive disease (ie, ultrasonographic ovarian or uterine score of 4 or 5). Significant correlations were identified between ovarian and uterine disease status and plasma concentrations of all steroid hormones except testosterone. CONCLUSIONS AND CLINICAL RELEVANCE: Findings suggested that ultrasonography and plasma hormone concentrations may be useful in the identification of reproductive disease and determination of disease severity in southern stingrays.

2 September 2012 in Journal of Zoo and Wildlife Medicine
Verified
Journal Article
Closed access
NMNatalie Mylniczenko
Natalie Mylniczenko
KSKathleen E. Sullivan
Kathleen E. Sullivan
MCMichelle E. Corcoran
Michelle E. Corcoran
GFGregory J. Fleming
Gregory J. Fleming
EVEduardo V. Valdes
Eduardo V. Valdes
During routine health screens for black rhinoceroses (Diceros bicornis minor) in a captive setting, serum iron and ferritin were analyzed as well as total iron binding capacity and total iron saturation. Trends for ferritin and percent iron saturation showed steady increases since 2003 in four of four animals (three males; one female) with two animals (one male; one female) consistently showing higher elevations over conspecifics. The historical diet had been comprised of a commercial or in-house complete pelleted feed; several species of fresh browse, Bermuda grass, alfalfa and timothy hays, as well as enrichment and training items (apples, carrots, sweet potatoes, and a small amount of leafy greens and vegetables). In 2009, one of the three male rhinoceroses showed a threefold increase in ferritin and concurrently exhibited clinical signs of lethargy, decreased appetite, and disinterest in training. The lone female showed a twofold increase; she also became reproductively acyclic in the prior year. The male was immobilized for examination and phlebotomy. During the same time period, a new version of the complete pelleted feed, with a reduced amount of iron, was introduced. Subsequent to the diet change, the male's ferritin levels have consistently declined, and the female started cycling again. Even with these corrective steps to reduce iron levels, levels of iron saturation remained high, and ferritin levels were still above 1,500 ng/ml. Therapeutic phlebotomy was instituted via a rigorous training program that allowed phlebotomies over a 30-min time frame. This was possible because of a long-term training program for the animals, consistent training personnel, routine collection of samples on a monthly basis, and general comfort level of the animals in the restraint chute. The results of this integrated approach showed some significant improvements and an overall positive impact on the animals.

29 October 2020 in Animals
Verified
Journal Article
Open access
PDF file
KSKathleen Sullivan
Kathleen Sullivan
NMNatalie Mylniczenko
Natalie Mylniczenko
SJSteven Nelson, Jr.
Steven Nelson, Jr.
BCBrandy Coffin
Brandy Coffin
SLShana R. Lavin
Shana R. Lavin
Critically endangered black rhinoceros (BR) under human care are predisposed to non-hemochromatosis Iron Overload Disorder (IOD). Over the last 30 years, BR have been documented with diseases that have either been induced by or exacerbated by IOD, prompting significant efforts to investigate and address this disorder. IOD is a multi-factorial chronic disease process requiring an evidence-based and integrative long-term approach. While research continues to elucidate the complexities of iron absorption, metabolism, and dysregulation in this species, preventive treatments are recommended and explained herein. The aim of this report is to highlight the accumulated evidence in nutrition, clinical medicine, and behavioral husbandry supporting the successful management of this disorder to ensure optimal animal health, welfare, and longevity for a sustainable black rhinoceros population.

17 September 2021 in Animals
Verified
Journal Article
Open access
PDF file
JGJames Duncan Gillis
James Duncan Gillis
LPLinda Penfold
Linda Penfold
NMNatalie Mylniczenko
Natalie Mylniczenko
This study investigated the reproductive biology and sperm cryopreservation of ex situ southern stingrays (Hypanus americanus) by semen collection and characterization and the development and validation of an enzyme-linked immunoassay for plasma total testosterone. Semen was collected in March and June using a manual massage technique, and the ejaculates were assessed for volume, pH, osmolarity, motility, status (0–5 scale: 0 = no forward progression, 5 = rapid linear progression) and total sperm count. Semen was extended in Hank’s elasmobranch ringer solution containing 10% DMSO, 10% glycerol or 5% glycerol with 5% N-methylformamide and cryopreserved using a conventional freezing method (~−50 °C/min) or a modified slow freezing method (~−3 °C/min). Body condition was scored from 1–5 and was noted to be low in March (1.93 ± 0.07) due to feeding practices and increased by June (2.93 ± 0.05) after dietary corrections were made. A concomitant increase (p < 0.05) in plasma total testosterone concentration and sperm motility was noted between March (8.0 ± 7.2 ng/mL, 5.71 ± 2.77%) and June (97.3 ± 11.3 ng/mL, 51.4 ± 14.3%). Samples cryopreserved using a modified slow freeze method (~−3 °C/min) had higher post-thaw motility and plasma membrane integrity than conventionally cryopreserved samples. Data indicate that southern stingray sperm morphometrics adheres to those of other elasmobranch species and that a slow cooling rate may be an avenue of research to improve southern stingray sperm survival during cryopreservation.

19 January 2023 in American Journal of Veterinary Research
Verified
Journal Article
Open access
PDF file
WGWhitney Greene
Whitney Greene
CWCatharine J. Wheaton
Catharine J. Wheaton
RDRachel Daneault
Rachel Daneault
HFHani D. Freeman
Hani D. Freeman
CRCarlos Rodriguez
Carlos Rodriguez
NMNatalie Mylniczenko
Natalie Mylniczenko
The anti-GnRH immunotherapeutic product Improvest was administered to intact male large flying foxes (Pteropus vampyrus) under managed care for androgen mitigation, leading to a decrease in agonistic behaviors, falls, and injuries from conspecific attention. 12 males were included in this study. Eleven bats received subcutaneous (SC) Improvest interscapular, and 1 animal received Improvest SC in its leg. Assessments included clinical presentation, treatment, behavior, and urine and fecal glucocorticoid metabolites and testosterone (T5) concentrations. Eleven of the 12 bats developed reactions, which included facial edema, localized irritation, swelling of the head and neck, and pruritus with varying degrees of skin ulceration and subsequent necrosis. Three of the animals required extensive treatments, and the 1 animal who received the injection in its leg was unaffected. Posttreatment, fecal glucocorticoid metabolite and/or T5 values were at or below the nonbreeding season baseline for 3 successive breeding seasons, and there was a reduction in agonistic interactions, falls, and injuries. A behavioral characteristic of this species is to focus on areas of irritation that exacerbated the extent of the skin wounds. Some cases required medical, surgical, and behavioral intervention. Large flying foxes may be particularly sensitive to this immunotherapeutic when given subcutaneously in the interscapular region. Despite this reaction, the positive long-term effects on behavior and multiyear reduction of hormones suggest that the use of this immunotherapeutic warrants further investigation, although the results should be taken into consideration with other factors such as handling, treatments, chronicity of lesions. The anti-GnRH immunotherapeutic product Improvest was administered to intact male large flying foxes (Pteropus vampyrus) under managed care for androgen mitigation, leading to a decrease in agonistic behaviors, falls, and injuries from conspecific attention. 12 males were included in this study. Eleven bats received subcutaneous (SC) Improvest interscapular, and 1 animal received Improvest SC in its leg. Assessments included clinical presentation, treatment, behavior, and urine and fecal glucocorticoid metabolites and testosterone (T5) concentrations. Eleven of the 12 bats developed reactions, which included facial edema, localized irritation, swelling of the head and neck, and pruritus with varying degrees of skin ulceration and subsequent necrosis. Three of the animals required extensive treatments, and the 1 animal who received the injection in its leg was unaffected. Posttreatment, fecal glucocorticoid metabolite and/or T5 values were at or below the nonbreeding season baseline for 3 successive breeding seasons, and there was a reduction in agonistic interactions, falls, and injuries. A behavioral characteristic of this species is to focus on areas of irritation that exacerbated the extent of the skin wounds. Some cases required medical, surgical, and behavioral intervention. Large flying foxes may be particularly sensitive to this immunotherapeutic when given subcutaneously in the interscapular region. Despite this reaction, the positive long-term effects on behavior and multiyear reduction of hormones suggest that the use of this immunotherapeutic warrants further investigation, although the results should be taken into consideration with other factors such as handling, treatments, chronicity of lesions.

10 March 2025 in Frontiers in Veterinary Science
Verified
Journal Article
Open access
PDF file
WGWhitney Greene
Whitney Greene
NPNuno Pereira
Nuno Pereira
BDBethany Doescher
Bethany Doescher
CRCarlos Rojo-Solis
Carlos Rojo-Solis
HDHugo David
Hugo David
NMNatalie Mylniczenko
Natalie Mylniczenko
The inner ear is an often overlooked system in elasmobranchs with few documented reports of disease or other abnormalities in the literature. Similar to terrestrial vertebrates, it is located in the cranium, and there are multiple components to the ear of elasmobranchs including a pair of membranous labyrinths each with three semicircular canals and four chambers or end organs (the saccule, the lagena, the utricle and the macula neglecta) making up the endolymphatic system (ELS). There is species variability among the inner ear anatomy of elasmobranchs, and this may play a role in disease development, progression, and treatment outcomes. Also similar to terrestrial vertebrates, this system plays a key role in hearing, acceleration, and orientation. When affected, clinical signs may include localized areas of swelling or stoma development along the dorsal midline of the head at the endolymphatic pores, atypical swimming behaviors consistent with vestibular disease (spiraling/spinning or barrel rolling, or tilting to one side), and anorexia. Less frequently, the eyes may also be affected and present with exophthalmia, hyphema, and/or panophthalmitis. Herein are case series from five institutions representing a variety of elasmobranch species affected with ELS disease with discussion of anatomy, clinical presentation, diagnostics, etiology, treatment, and outcomes. Endolymphatic disease may be clinically underdiagnosed in elasmobranchs and mistaken for other diseases such as superficial subcutaneous or subdermal abscesses, focal dermatitis, or neuropathies presumed to not be associated with the inner ear system. In addition, disease may be occult for a long period of time prior to overt manifestation of signs or chronic with waxing and waning clinical signs, likely because of anatomy and resultant treatment challenges. Awareness and additional research may help to promote timely identification, improve diagnostic and treatment options, and help to optimize individual animal welfare.