Rebecca KeeleyDr. Vina Faulkner, Dr. Charles Faulkner, and Dr. Beth Kitts-Morgan

Lincoln Memorial University-College of Veterinary Medicine

Results

Acknowledgements: Funding for this research was provided through the Masters of Veterinary Biomedical Science program at Lincoln Memorial University and Lincoln Memorial University-College of Veterinary Medicine

Introduction/Background

Methods

Discussion

Figure 2. Number of endoparasite-positive and –negative cotton rats, house mice, and North American deer mice trapped in the Tri-State area of Tennessee, Kentucky, and Virginia

StateAnimal Species

Parasites Found

TennesseeHispid

Cotton Rat

Trichostrongylus, Strongyloide, small and large coccidia,

Capillaria, Trichuris, Nippostrongylus,

Hymenolepis

North American

Deer Mouse

Small and large coccidia, Trichuris,

Hymenolepis, Strongylate-type egg

Kentucky

North American

Deer Mouse

Small and large coccidia

House Mouse

Small coccidia

Table 1. Endoparasites identified in fecal samples of cotton rats, house mice, and North American deer mice trapped in Tennessee and Kentucky

0

5

10

15

20

25

30

35

HCR HM NAD

Nu

mb

er

of

Feca

l Sam

ple

s C

olle

cte

d

Rodent Species

Negative

Positive

Figure 3. Endoparasite eggs and oocysts in fecal samples of wild small mammals trapped in TN and KY

References

Guimaraes, A. O., F. M. Valenca, J. B. Sousa, S. A. Souza, R. R. Madi, and C. M. Melo. 2014. Parasitic and fungal infections in synanthropic rodents in an area of urban expansion, Aracaju, Sergipe State, Brazil. Acta Scientiarum, 36(1), 113-120.

Samuel, W. M., A. A. Kocan, M. J. Pybus, and J. W. Davis. 2001. Parasitic diseases of wild mammals. Ames, Iowa: Iowa State University Press. 30(2).

Thompson, R.C.A., A. J. Lymbery, and A. Smith. 2010. Parasites, emerging disease and wildlife conservation. International Journal for Parasitology, 40 (10): 1163-1170.

Figure 1. Small mammal trap locations in the Tri-State area of Tennessee, Kentucky, and Virginia

P=0.00001

• The common small mammal species trapped in the Tri-State area were Sigmodon hispidus (Hispid cotton rat), Peromyscus maniculatus (North American deer mouse), and Mus musculus (house mouse).

• The prevalence rate of Hispid cotton rats positive for endoparasites based on fecal analysis was 76%, 28% of North American deer mice, and 4% of house mice, based on a Chi-Square 2x3 contingency table (Figure 1; P = 0.00001).

• Based on fecal analysis, the main parasites shared among the three species of rodents were small and large coccidia (Table 1), tentatively identified as Eimeria (Samuel et al, 2001).

• The prevalence rate of mammal species positive for helminths based on GI analysis was 60% of Hispid cotton rats, 50% of Northern short-tail shrews, and 100% Eastern gray squirrel (only 1 squirrel euthanized).

• Helminth findings for Hispid cotton rats:• Longistriata sp. identified based on chitinous ring, ray conformation,

and long spicules (Chandler, 1932) .• Physaloptera sp. and Protospirura sp. identified based on buccal and

bursa formation (Kinsella, 1974).• Helminth finding for Northern short-tail shrews:

• Panopistus sp. identified based on body dimensions, eggs, and similar reportings.

• Helminth findings for Eastern gray squirrel:• Strongyloides robustus, only species found in this genus.• Heligmodendrium hassali , only species found in this genus.

• Most of the helminths identified correlated with fecal findings• Physaloptera sp. is the only known parasite to infect domestic species • There was no correlation between infection status and the rodents’ habitat

• There is limited research describing endoparasites that infect wild rodents in the Tri-state area

• Since the 1900’s, researchers have shifted focus from wildlife endoparasites to parasites that affect humans and domestic animals (Thompson et al., 2010)

• Identifying and describing endoparasites prevalent in small mammals could help bridge the ecological gap between transmission from wildlife to domestic animals

• Goals of the current study:• Increase our knowledge regarding rodent species populations• Provide an understanding and description of endoparasites in

neighboring habitats that could potentially lead to infection in domestic species

• Hypothesis: There is a correlation between the rodent colony location and endoparasite infection status.

• Rodents collected under approval of IACUC protocol number: 1602-CVM-05• Scientific Collecting Permits were obtained from Kentucky, Tennessee, and

Virginia• KY-82087, TN-3954, VA-058453• Animals on the endangered/threatened species list for a respective state

were immediately released• Trapping occurred from March 6 to July 7 using Sherman live traps• Standard Protocol: Animals were euthanized in a plastic box with a CO2 rate of

4.4 L/min until breathing cessation• Humane euthanasia was performed under the AVMA guidelines using CO2

inhalation • Animals identified using body length, tail length, hind foot length, picture

ID, and dentition • A bilateral thoracotomy was performed to ensure death• All organs were harvested for future studies

• Fecal pellets were collected and stored in a 4°C refrigerator until further analysis for endoparasites

• Centrifugal fecal flotation was performed• Two step process with a water wash step:

• Eggs were identified by size and morphology using microscopic examination

• GI tracts were dissected from stomach to anus• Helminths were collected and identified by buccal, bursa, and body

characteristics

Table 2. Helminths identified in Hispid cotton rats, Northern short-tail shrew, and an Eastern gray squirrel trapped in the Tri-State area of Tennessee, Kentucky, and Virginia

Figure 4. Helminths identified in small mammals of the Tri-State area. A- Longistriata sp. from Hispid cotton rats, B- Physaloptera sp. from Hispid cotton rats, C- Panopistus sp. from Northern short-tail shrew, and D- Strongyloides robustus from Eastern gray squirrel

A

C

B

D