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Veterinary Parasitology 115 (2003) 19–24 Hookworms of feral cats in Florida Tara Creel Anderson , Garry W. Foster, Donald J. Forrester Department of Pathobiology, College of Veterinary Medicine, University of Florida, PO Box 110880, Gainesville, FL 32611, USA Received 30 October 2002; received in revised form 15 April 2003; accepted 15 April 2003 Abstract Thirty feral cats (Felis catus) from Alachua county (northern Florida) and 30 from Palm Beach county (southern Florida) were examined for hookworms. Two species, Ancylostoma tubaeforme and Ancylostoma braziliense, were identified. Forty-five cats (75%) were infected with A. tubae- forme, with a mean intensity of 48 hookworms per cat. Twenty cats (33%) were infected with A. braziliense, with a mean intensity of 28 worms per cat. The prevalence of A. tubaeforme was greater than that of A. braziliense in Alachua (P = 0.002) and Palm Beach (P = 0.004) counties. The intensity of A. tubaeforme infections was higher in Palm Beach county than Alachua county (P = 0.013). The intensities of A. tubaeforme and A. braziliense were positively correlated (in- creased together) in Palm Beach county (P = 0.011). These hookworms have also been identified in bobcats (Felis rufus), gray foxes (Urocyon cinereoargenteus), and red foxes (Vulpes vulpes) in Florida. The prevalence of A. tubaeforme was significantly greater in feral cats than those reported in bobcats (P< 0.001). The prevalence of A. braziliense was significantly greater in feral cats than in those reported in gray foxes (P = 0.008). The hookworm that infects Florida panthers and bobcats, A. pluridentatum, was not found. © 2003 Elsevier Science B.V. All rights reserved. Keywords: Feral cat; Felis catus; Hookworms; Ancylostoma spp.; Florida 1. Introduction Feral cats (Felis catus) are prevalent in Florida, yet there is little information regarding their hookworms. It is possible for wildlife, domestic animals, and humans to come into contact with feral cats and/or their feces. Since feral cats may act as reservoirs of disease, their parasites are of veterinary and public health importance. Corresponding author. E-mail address: [email protected] (T.C. Anderson). 0304-4017/03/$ – see front matter © 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S0304-4017(03)00162-6

Hookworms of feral cats in Florida

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Page 1: Hookworms of feral cats in Florida

Veterinary Parasitology 115 (2003) 19–24

Hookworms of feral cats in Florida

Tara Creel Anderson∗, Garry W. Foster, Donald J. ForresterDepartment of Pathobiology, College of Veterinary Medicine, University of Florida,

PO Box 110880, Gainesville, FL 32611, USA

Received 30 October 2002; received in revised form 15 April 2003; accepted 15 April 2003

Abstract

Thirty feral cats (Felis catus) from Alachua county (northern Florida) and 30 from Palm Beachcounty (southern Florida) were examined for hookworms. Two species,Ancylostoma tubaeformeandAncylostoma braziliense, were identified. Forty-five cats (75%) were infected withA. tubae-forme, with a mean intensity of 48 hookworms per cat. Twenty cats (33%) were infected withA. braziliense, with a mean intensity of 28 worms per cat. The prevalence ofA. tubaeforme wasgreater than that ofA. braziliense in Alachua (P = 0.002) and Palm Beach (P = 0.004) counties.The intensity ofA. tubaeforme infections was higher in Palm Beach county than Alachua county(P = 0.013). The intensities ofA. tubaeforme andA. braziliense were positively correlated (in-creased together) in Palm Beach county (P = 0.011). These hookworms have also been identifiedin bobcats (Felis rufus), gray foxes (Urocyon cinereoargenteus), and red foxes (Vulpes vulpes) inFlorida. The prevalence ofA. tubaeforme was significantly greater in feral cats than those reportedin bobcats (P < 0.001). The prevalence ofA. braziliense was significantly greater in feral catsthan in those reported in gray foxes (P = 0.008). The hookworm that infects Florida panthers andbobcats,A. pluridentatum, was not found.© 2003 Elsevier Science B.V. All rights reserved.

Keywords: Feral cat;Felis catus; Hookworms;Ancylostoma spp.; Florida

1. Introduction

Feral cats (Felis catus) are prevalent in Florida, yet there is little information regardingtheir hookworms. It is possible for wildlife, domestic animals, and humans to come intocontact with feral cats and/or their feces. Since feral cats may act as reservoirs of disease,their parasites are of veterinary and public health importance.

∗ Corresponding author.E-mail address: [email protected] (T.C. Anderson).

0304-4017/03/$ – see front matter © 2003 Elsevier Science B.V. All rights reserved.doi:10.1016/S0304-4017(03)00162-6

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In domestic dogs and cats, especially young animals, hookworm infections can causerough hair coat, listlessness, weakness, poor weight gain, emaciation, edema, anemia, andeven death (Miller, 1966; Kalkofen, 1987).

Several species ofAncylostoma have been identified from wild canids and felids inFlorida. Conti (1984)reportedA. tubaeforme, A. caninum, and A. braziliense in grayfoxes (Urocyon cinereoargenteus); A. tubaeforme and A. caninum in red foxes (Vulpesvulpes); and A. caninum in coyotes (Canis latrans). Gray and red foxes are distributedthroughout Florida, while coyotes are distributed in the northern two-thirds of the state(Brown, 1987).

Before 1985 the hookwormAncylostoma pluridentatum had only been reported fromwild felids and domestic cats in Central and South America (Schwartz, 1927; Thatcher,1971; Seesee et al., 1981; Moriena, 1983). This hookworm is now one of the most prevalentand abundant parasites found in the endangered Florida panther (Puma concolor coryi) insouthern Florida (Forrester et al., 1985).O’Brien et al. (1990)presented genetic evidence thatpumas (Puma concolor) from Central and South America had been introduced into southernFlorida between 1956 and 1966. It is hypothesized thatA. pluridentatum was introducedinto the Florida panther population through these animals (McLaughlin et al., 1993). A.pluridentatum has since been reported in bobcats (Felis rufus) in southern (McLaughlinet al., 1993) and northern (Cames and Forrester, 1998) Florida. The same authors alsoreportedA. tubaeforme, A. caninum, andA. braziliense in bobcats. Bobcats are distributedthroughout Florida, while the Florida panther is found only in the southern third of the state(Brown, 1987).

The purposes of this study were to determine the prevalence and intensity of hookwormsin feral cats in Florida, to compare these parasites to those found in native wild canids andfelids in Florida, and to determine the status ofA. pluridentatum in the feral cat population.

2. Materials and methods

Sixty feral cats were examined, 30 from Alachua county in northern Florida and 30from Palm Beach county in southern Florida. The Alachua county sample consisted of thegastrointestinal tracts of euthanized adult feral cats (16 males, 14 females). These animalswere collected from March to June 1998 from Alachua county Animal Services, Gainesville,FL. The Palm Beach county sample of euthanized adult feral cats (14 males, 16 females)was collected from August to September 2000 from the Palm Beach County Public SafetyDepartment, Division of Animal Care and Control.

Gastrointestinal tracts were removed, placed into individual plastic bags, and frozen untilanalyzed. Each gastrointestinal tract was divided into three parts: stomach, small intestine,and large intestine. Each section was screened separately with a 100 mesh sieve and thenexamined for parasites with a dissecting microscope. Hookworms were fixed and stored in70% ethanol containing glycerin. Hookworms were then mounted and cleared in lactophenolfor identification and counting. In some cases it was impossible to identify the hookworms tospecies due to damaged specimens (i.e., no head, no tail, or both). Voucher specimens weredeposited in the United States National Parasite Collection (USNPC), Beltsville, MD, USA(USNPC Accession Nos. 92436–92439). Terminology used followsBush et al. (1997).

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We used SigmaStat® for Windows (Jandel Scientific, 1994) for the statistical analyses.Prevalences of individual parasites between collection sites, and prevalences of parasiteswithin collection sites, were evaluated using chi-square tests. Prevalences of infections inmales and females by parasite and collection site were evaluated with Fisher Exact tests. Dataon individual parasite intensities were evaluated using the Mann–Whitney rank sum testfor comparisons between collection sites. Spearman rank order correlations were utilizedto determine relationships between intensities ofA. tubaeforme andA. braziliense. Resultswere considered significant atP < 0.05.

Data from our sample of feral cats were compared with data from wild canids and felidsin Florida, including bobcats (McLaughlin et al., 1993; Cames and Forrester, 1998) andgray and red foxes (Conti, 1984). Prevalences of individual parasites between species wereevaluated with chi-square tests.

3. Results

At least one species ofAncylostoma was found in 47 (78%) of 60 feral cats (22 fromAlachua county, 25 from Palm Beach county). Forty-five cats (75%) were infected withA. tubaeforme (USNPC Accession Nos. 92436 and 92438) with a mean intensity of 48worms per cat (range= 1–283). Twenty cats (33%) were infected withA. braziliense(USNPC Accession Nos. 92437 and 92439), with a mean intensity of 28 worms per cat(range= 1–150). The prevalence and intensity of each parasite are listed by county inTable 1. Mixed infections withA. tubaeforme andA. braziliense were found in 18 (38%)of the 47 cats (7 from Alachua county, 11 from Palm Beach county). Twenty-three males(13 from Alachua county, 11 from Palm Beach county) and 24 females (9 from Alachuacounty, 14 from Palm Beach county) were infected with hookworms.A. pluridentatum wasnot found in any of the 60 feral cats.

The prevalences ofA. tubaeforme andA. braziliense did not differ significantly betweenAlachua county and Palm Beach county (A. tubaeforme, P = 0.551;A. braziliense, P =0.411). The prevalence ofA. tubaeforme was significantly higher than that ofA. braziliensein both Alachua (P = 0.002) and Palm Beach (P = 0.004) counties. There were no signif-icant differences in the prevalence ofA. tubaeforme between males and females by county(Alachua county,P = 0.417; Palm Beach county,P = 0.642). There were no significant

Table 1Hookworms in 60 feral cats from two counties in Florida, 1998–2000

County Number infected (n) Prevalence (%) Intensity

Mean Range

Alachua (n = 30)A. tubaeforme 21 70 18 1–119A. braziliense 8 27 10 1–21

Palm Beach (n = 30)A. tubaeforme 24 80 69 1–283A. braziliense 12 40 40 3–150

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Table 2Prevalence, intensity, and mean abundance ofA. tubaeforme andA. braziliense infections in feral cats and wildlifein Florida

Parasite Number infected (n) Prevalence (%) Intensity Mean Abundance

Mean Range

A. tubaeformeFeral cat 45 75 48 1–283 36Bobcata 9 11b 1.9 1–3 0.2Bobcatc 6 21b 5 1–12 1.1Gray foxd 20 77e 11 1–48 8.5Red foxd 2 50f 10 5–14 5

A. brazilienseFeral cat 20 33 28 1–150 9Bobcata 16 19e 4.1 1–12 0.8Bobcatc 4 14e 2 1–6 0.3Gray foxd 1 4b 4 4 1.6

a Data fromMcLaughlin et al. (1993).b Significantly different from feral cat data.c Data fromCames and Forrester (1998).d Data fromConti (1984).e Not significantly different from feral cat data.f Not compared to feral cat data.

differences in the prevalence ofA. braziliense between males and females by county(Alachua county,P = 0.226; Palm Beach county,P = 0.457). The intensity ofA. tubae-forme infections was higher in Palm Beach county than Alachua county (P = 0.013). Nodifference was noted in the intensity ofA. braziliense infections between Alachua and PalmBeach counties (P = 0.230). There was no relationship between intensities ofA. tubaeformeandA. braziliense in Alachua county (P = 0.083), however the intensities of these hook-worms were positively correlated (increased together) in Palm Beach county (P = 0.011).

The prevalence, intensity, and mean abundance ofA. tubaeforme andA. braziliense in feralcats, bobcats, gray foxes, and red foxes are listed inTable 2. The prevalence ofA. tubaeformewas significantly greater in feral cats than bobcats (P < 0.001 for bothMcLaughlin et al.,1993andCames and Forrester, 1998). The prevalence ofA. tubaeforme in feral cats andgray foxes was not significantly different (P = 0.934); however, the mean abundance ofA.tubaeforme in feral cats (36) was greater than that in gray foxes (8.5). The prevalence ofA.tubaeforme in feral cats and red foxes was not compared. The prevalence ofA. braziliensewas not significantly different in feral cats and bobcats (P = 0.072 forMcLaughlin et al.,1993; P = 0.091 for Cames and Forrester, 1998). The prevalence ofA. braziliense wassignificantly greater in feral cats than in gray foxes (P = 0.008).

4. Discussion

A. tubaeforme is a common parasite of domestic cats and other felids, whileA. brazilienseinfects both felids and canids (Kalkofen, 1987). The greater prevalence ofA. tubaeforme

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rather thanA. braziliense in feral cats sampled in this study is possibly due to the greaterhost specificity ofA. tubaeforme. It is uncertain why the intensity ofA. tubaeforme wasgreater in Palm Beach county (southern Florida) than Alachua county (northern Florida), orwhy the intensities ofA. tubaeforme and A. braziliense were positively correlated (in-creased together) in Palm Beach county.Bowman (1999)noted that most hookwormcases occur in late spring, summer, and early autumn when there are mild temperaturesand adequate rainfall. It is possible that greater intensities ofA. tubaeforme in south-ern Florida were due to differences in the season of sample collection (late spring inAlachua county versus late summer in Palm Beach county).McLaughlin et al. (1993)noted greater intensity of all hookworms combined in bobcats from southern Florida,however no geographic difference in intensities was noted for individual hookwormspecies.

McLaughlin et al. (1993)andCames and Forrester (1998)reportedA. tubaeforme andA. braziliense from bobcats throughout Florida. Interestingly,Conti (1984)reportedA.tubaeforme in gray foxes and red foxes as well asA. braziliense in gray foxes fromFlorida.Conti (1984)proposed two hypotheses to explain the unusual finding ofA. tubae-forme in foxes: (1) foxes and wild felids may ingest similar paratenic hosts, (2) foxesmay have greater contact with wild felids or feral cats than with wild canids or feraldogs. Our findings of a greater prevalence ofA. tubaeforme in feral cats than bobcatsand a greater prevalence ofA. braziliense in feral cats than gray foxes may indicatethat feral cats act as a reservoir of hookworm infection for wild canids and felids inFlorida.

Forrester et al. (1985)identifiedA. pluridentatum in six of seven (86%) Florida panthersexamined from 1978 to 1983.McLaughlin et al. (1993)reportedA. pluridentatum in 25 of44 (57%) bobcats collected in southern Florida from 1974 to 1991, although this hookwormwas not found in 41 bobcats from northern Florida.Cames and Forrester (1998)examined29 bobcats collected from 1986 to 1996, and foundA. pluridentatum in 1 of 21 (5%) bobcatsfrom north-central Florida, thus extending the range of this parasite.

AssumingA. pluridentatum is present throughout Florida and that feral cats share habitatwith Florida panthers and bobcats, it was hypothesized that this parasite may have spreadinto the feral cat population.A. pluridentatum has been shown to be pathogenic to domes-tic kittens (Forrester, 1992) and Florida panther kittens (Dunbar et al., 1994). The statusof A. pluridentatum in the feral cat population, therefore, was of special concern becausethe feral cat could act as a reservoir of hookworm infection for the endangered Floridapanther.

Two factors may have contributed to the absence ofA. pluridentatum in the feral cats weexamined: small sample size and sample location. Sixty cats (30 from each county) may notsufficiently represent the presumably large feral cat population. Sample location is also aconcern. Florida panthers do not inhabit Alachua county, and are only known to inhabit thevery western edge of Palm Beach county. Therefore, it is uncertain whether or not the feralcats we examined from Palm Beach county actually shared habitat with Florida panthers.Overlap of feral cat and bobcat territory is also of interest. Bobcats throughout Florida havebeen reported to harborA. pluridentatum (McLaughlin et al., 1993; Cames and Forrester,1998); however, the likelihood of the feral cats sampled in this study coming into contactwith bobcats and/or their feces is unknown.

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5. Conclusion

Feral cats may serve as reservoirs of hookworm infection for wild canids and felids inFlorida. At this time there is no evidence thatA. pluridentatum has spread into the feral catpopulations we sampled in Florida, however factors such as small sample size and samplelocation may have confounded these results.

Acknowledgements

The authors would like to thank Dr. Julie Levy for her assistance in obtaining samplesfrom feral cats in Alachua county, Dr. Priscilla Stockner for her assistance in obtainingsamples from Palm Beach county, and Drs. Ellis Greiner and Paul Nicoletti for reviewingthe manuscript. This is Florida Agricultural Experiment Station Journal Series No. R-09056.

References

Bowman, D.D., 1999. Georgis’ Parasitology for Veterinarians, 7th ed. Saunders, Philadelphia, PA.Brown, L.N., 1987. A checklist of Florida’s mammals. Nongame Wildlife Program. Florida Game and Freshwater

Fish Commission, Tallahassee, FL.Bush, A.O., Lafferty, K.D., Lotz, J.M., Shostak, A.W., 1997. Parasitology meets ecology on its own terms: Margolis

et al. revisited. J. Parasitol. 83, 575–583.Cames, T.A., Forrester, D.J., 1998. The geographic distribution ofAncylostoma pluridentatum and other

hookworms in bobcats (Felis rufus) from Florida. Fla. Field Nat. 26, 18–20.Conti, J.A., 1984. Helminths of foxes and coyotes in Florida. Proc. Helminthol. Soc. Wash. 51, 365–367.Dunbar, M.R., McLaughlin, G.S., Murphy, D.M., Cunningham, M.W., 1994. Pathogenicity of the hookworm,

Ancylostoma pluridentatum, in a Florida panther (Felis concolor coryi) kitten. J. Wildl. Dis. 30, 548–551.Forrester, D.J., 1992. Parasites and Diseases of Wild Mammals in Florida. University Press of Florida, Gainesville,

FL.Forrester, D.J., Conti, J.A., Belden, R.C., 1985. Parasites of the Florida panther (Felis concolor coryi). Proc.

Helminthol. Soc. Wash. 52, 95–97.Jandel Scientific, 1994. SigmaStat® for Windows, User’s Manual, Version 2.03. San Rafael, CA.Kalkofen, U.P., 1987. Hookworms of dogs and cats. Vet. Clin. N. Am. Small Anim. Pract. 17, 1341–1354.McLaughlin, G.S., Obstbaum, M., Forrester, D.J., Roelke, M.E., Brady, J.R., 1993. Hookworms of bobcats (Felis

rufus) from Florida. J. Helminthol. Soc. Wash. 60, 10–13.Miller, T.A., 1966. Blood loss during hookworm infection, determined by erythrocyte labeling with radioactive

chromium. II. Pathogenesis ofAncylostoma braziliense infection in dogs and cats. J. Parasitol. 52, 856–865.Moriena, R.A., 1983. A report from Argentina ofAncylostoma pluridentatum in Felis concolor. Rev. Med. Vet.

(B. Aires) 64, 184–188.O’Brien, S.J., Roelke, M.E., Yuhki, N., Richards, K.W., Johnson, W.E., Franklin, W.L., Anderson, A.E., Bass Jr.,

O.L., Belden, R.C., Martenson, J.S., 1990. Genetic intergression within the Florida panther (Felis concolorcoryi). Nat. Geograph. Res. 6, 485–494.

Schwartz, B., 1927. Description ofAncylostoma pluridentatum, hookworm of carnivores, and a review of thegenusAncylostoma. Proc. US Nat. Mus. 72, 1–9.

Seesee, F.M., Worley, D.E., Martin, R.L., 1981. A survey of the nematode parasites from carnivores of the ChacoBoreal, Paraguay. In: Proceedings of the Worldwide Furbearer Conference, August 3–11, 1980, pp. 846–858.

Thatcher, V.E., 1971. Some hookworms of the genusAncylostoma from Colombia and Panama. Proc. Helminthol.Soc. Wash. 38, 109–116.