Understanding Feline Heartworm Infection: Disease, Diagnosis, and Treatment
Abstract
Feline heartworm disease is a very different clinical entity from canine heartworm disease. In cats, the arrival and death of immature heartworms in the pulmonary arteries can cause coughing and dyspnea as early as 3 months postinfection. Adult heartworms suppress the function of pulmonary intravascular macrophages and thus reduce clinical disease in chronic feline heartworm infection. Approximately 80% of asymptomatic cats self-cure. Median survival time for symptomatic cats is 1.5 years, or 4 years if only cats living beyond the day of presentation are considered. Aberrant worm migration is more frequent than it is in dogs, and sudden death can occur with no prior clinical signs. The bacterial endosymbiont Wolbachia likely contributes to the inflammatory pathology of heartworm disease, but its role is not yet fully clear. Unfortunately, the diagnosis, treatment, and management of feline heartworm disease are far from simple. Antemortem diagnosis is hampered by low worm burdens, the frequency of all-male infections, and nonspecific radiographic lesions. It is up to the veterinarian to determine the correct index of suspicion and choose the right combination of diagnostic tests to achieve an answer. Treatment is symptomatic because adulticide therapy is risky and does not increase survival time. Despite the dangers of feline heartworm disease, less than 5% of cats in the United States are on chemoprophylaxis. It is important for veterinarians to take a proactive preventive stance because heartworm infection in cats is a multisystemic disease that has no easy cure.
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Cats are assumed not to play an important role for Dirofilaria transmission.
“Besides dogs and humans, there were also several reports of infections in cats, although it is assumed that cats do not play an important role for Dirofilaria transmission [46].”
From Vectors, host range, and spatial distribution of Dirofilaria immitis and D. repens in Europe: a systematic review (2025) · cites this paper as [46]
Many heartworm-infected cats are misdiagnosed with asthma or allergic bronchitis.
“It is estimated that many heartworm-infected cats are misdiagnosed with asthma or allergic bronchitis (4, 5).”
From Seroprevalence of Feline Heartworm in Spain: Completing the Epidemiological Puzzle of a Neglected Disease in the Cat (2022) · cites this paper as [4]
Cats are less suitable hosts than dogs, so fewer larvae develop into adults and adult worms have a shorter lifespan.
“Although cats can be infected, they are less suitable hosts than dogs, so less larvae develop into adults and adult worms have a shorter lifespan.”
From Seroprevalence of Feline Heartworm in Spain: Completing the Epidemiological Puzzle of a Neglected Disease in the Cat (2022) · cites this paper as [4]
Infections with even a single worm can have fatal consequences and present high mortality rates in cats.
“However, infections with even a single worm can have fatal consequences and present high mortality rates in the cat (3, 4).”
From Seroprevalence of Feline Heartworm in Spain: Completing the Epidemiological Puzzle of a Neglected Disease in the Cat (2022) · cites this paper as [4]
Feline heartworm disease should be added to the differential diagnosis of cats presenting with respiratory and gastrointestinal signs, especially in endemic areas.
“It has been reported that feline heartworm disease should be added to the differential diagnosis of cats presenting at the veterinary clinic with respiratory and gastrointestinal signs, especially in endemic areas (4).”
From Seroprevalence of Feline Heartworm in Spain: Completing the Epidemiological Puzzle of a Neglected Disease in the Cat (2022) · cites this paper as [4]
The sensitivity of antigen testing is relatively low in cats, and these tests only detect adult and female worms.
“This may be due to the fact that the sensitivity of antigen testing is relatively low in cats, and because these only detect adult and female worms.”
From Prevalence of heartworm in dogs and cats of Madrid, Spain (2017) · cites this paper as [24]
No apparent correlation with FeLV and FIV infection was noted in a study of 2011.
“Contrary to this study, no apparent correlation with FeLV and FIV infection was noted in a study of 2011 [8,20,34].”
From First Autochthonous Infection of a Cat with Dirofilaria immitis in Austria (2021) · cites this paper as [34]
In cats, the benefit of doxycycline pre-treatment has not yet been evaluated.
“In cats, this benefit has not yet been evaluated.”
From First Autochthonous Infection of a Cat with Dirofilaria immitis in Austria (2021) · cites this paper as [34]
Running antigen and antibody tests can improve sensitivity compared to running one test alone.
“Running antigen and antibody tests can improve the sensitivity compared to running one test alone [15,34].”
From First Autochthonous Infection of a Cat with Dirofilaria immitis in Austria (2021) · cites this paper as [34]
When microfilariae are present, it is considered a definitive diagnosis for FHWD.
“When microfilariae are present, it is considered a definitive diagnosis for FHWD [34].”
From First Autochthonous Infection of a Cat with Dirofilaria immitis in Austria (2021) · cites this paper as [34]
Antibody tests detect antibodies produced by the host in response to infection, can remain positive for a long time after the death of the parasite, and do not differentiate a current from a past infection.
“On the other hand, antibody tests detect antibodies produced by the host in response to infection, which therefore can remain positive for a long time after the death of the parasite and do not differentiate a current or a past infection [24, 26].”
From Prevalence of heartworm in dogs and cats of Madrid, Spain (2017) · cites this paper as [24]
Diagnosis of feline heartworm is complicated by low adult worm burden, lack of microfilaremia, short life span, non-specific clinical signs, and frequent asymptomatic course.
“This is reflected by relatively low adult worm burden, the lack of microfilaremia and their short life span, which complicates the diagnosis of this disease in the feline patient.”
From First epidemiological report of feline heartworm infection in the Barcelona metropolitan area (Spain) (2014) · cites this paper as [4]
Cats are inherently resistant to heartworm infection.
“Cats are inherently resistant to heartworm infection.”
From First epidemiological report of feline heartworm infection in the Barcelona metropolitan area (Spain) (2014) · cites this paper as [4]
Antibody tests detect antibodies produced by the host in response to infection, become positive after 2-3 months from infection in the prepatent phase, can remain positive long after the death of the parasite, and do not differentiate a current or a past infection.
“these detect antibodies produced by the host in response to infection and become positive after 2-3 months from infection, in the prepatent phase; however, they can remain positive for a long time after the death of the parasite and therefore do not differentiate a current or a past infection [4,18].”
From First epidemiological report of feline heartworm infection in the Barcelona metropolitan area (Spain) (2014) · cites this paper as [4]
The sensitivity of antigen testing is relatively low in cats.
“The sensibility of antigen testing is relatively low in cats”
From First epidemiological report of feline heartworm infection in the Barcelona metropolitan area (Spain) (2014) · cites this paper as [4]
Antigen tests only detect adult and female worms, so a negative result does not rule out an infection from male worms or pre-adult worms.
“because these tests only detect adult and female worms a negative result does not rule out an infection from male worms or pre-adult worms, most of which are common in cats [4].”
From First epidemiological report of feline heartworm infection in the Barcelona metropolitan area (Spain) (2014) · cites this paper as [4]
Of seropositive cats, 24.1% showed respiratory signs, which may be a vascular and parenchymal inflammatory response associated with the arrival and death of D. immitis in the distal pulmonary arteries in cats.
“Of the seropositive cats 24.1% showed respiratory signs, which may be a vascular and parenchymal inflammatory response associated with the arrival and death of D. immitis in the distal pulmonary arteries in cats, this has been previously reported in seropositive cats from Barcelona [4,19,20].”
From First epidemiological report of feline heartworm infection in the Barcelona metropolitan area (Spain) (2014) · cites this paper as [4]
Cites
Heartworm Biology, Treatment, and Control
Bowman, D. D., & Atkins, C. E. (2009) · Veterinary Clinics of North America: Small Animal Practice · doi:10.1016/j.cvsm.2009.06.003 · Cited by 298 · see citing works
Self-citationPublic health issues concerning the widespread distribution of canine heartworm disease
Lee, A. C. Y., Montgomery, S. P., Theis, J. H., Blagburn, B. L., & Eberhard, M. L. (2010) · Trends in Parasitology · doi:10.1016/j.pt.2010.01.003 · Cited by 106 · see citing works
Self-citationWolbachia and its influence on the pathology and immunology of Dirofilaria immitis infection
Kramer, L., Grandi, G., Leoni, M., Passeri, B., McCall, J., Genchi, C., Mortarino, M., & Bazzocchi, C. (2008) · Veterinary Parasitology · doi:10.1016/j.vetpar.2008.09.014 · Cited by 94 · see citing works
Feline heartworm disease: A clinical review
Litster, A. L., & Atwell, R. B. (2008) · Journal of Feline Medicine and Surgery · doi:10.1016/j.jfms.2007.09.007 · Cited by 90 · see citing works
Heartworm infection in cats: 50 cases (1985–1997)
Atkins, C. E., DeFrancesco, T. C., Coats, J. R., Sidley, J. A., & Keene, B. W. (2000) · Journal of the American Veterinary Medical Association · doi:10.2460/javma.2000.217.355 · Cited by 89 · see citing works
Self-citationComparison of Serological Tests for the Detection of Natural Heartworm Infection in Cats
Berdoulay, P., Levy, J. K., Snyder, P. S., Pegelow, M. J., Hooks, J. L., Tavares, L. M., Gibson, N. M., & Salute, M. E. (2004) · Journal of the American Animal Hospital Association · doi:10.5326/0400376 · Cited by 74 · see citing works
Immunopathology of Dirofilaria immitis infection
Simón, F., Kramer, L. H., Román, A., Blasini, W., Morchón, R., Marcos-Atxutegi, C., Grandi, G., & Genchi, C. (2007) · Veterinary Research Communications · doi:10.1007/s11259-006-3387-0 · Cited by 66 · see citing works
Morchón, R., Ferreira, A. C., Martín-Pacho, J. R., Montoya, A., Mortarino, M., Genchi, C., & Simón, F. (2004) · Veterinary Parasitology · doi:10.1016/j.vetpar.2004.08.003 · Cited by 62 · see citing works
Prevalence of feline heartworm disease - a global review.
Ryan, W. G., Newcomb, K. M., Soll, M. D., & KNIGHT, D. H. (1995) · Cited by 57 · see citing works
Browne, L. E., Carter, T. D., Levy, J. K., Snyder, P. S., & Johnson, C. M. (2005) · American Journal of Veterinary Research · doi:10.2460/ajvr.2005.66.1544 · Cited by 55 · see citing works
Clinical evolution and radiographic findings of feline heartworm infection in asymptomatic cats
Venco, L., Genchi, C., Genchi, M., Grandi, G., & Kramer, L. H. (2008) · Veterinary Parasitology · doi:10.1016/j.vetpar.2008.09.011 · Cited by 52 · see citing works
Gates, M. C., & Nolan, T. J. (2009) · Preventive Veterinary Medicine · doi:10.1016/j.prevetmed.2009.10.012 · Cited by 50 · see citing works
Prevalence and Risk Factors for Heartworm Infection in Cats From Northern Florida
Levy, J. K., Snyder, P. S., Taveres, L. M., Hooks, J. L., Pegelow, M. J., Slater, M. R., Hughes, K. L., & Salute, M. E. (2003) · Journal of the American Animal Hospital Association · doi:10.5326/0390533 · Cited by 50 · see citing works
Labarthe, N., Serrão, M. L., Melo, Y. F., de Oliveira, S. J., & Lourenço‐de‐Oliveira, R. (1998) · Memórias do Instituto Oswaldo Cruz · doi:10.1590/s0074-02761998000200002 · Cited by 49 · see citing works
Genchi, C., Venco, L., Ferrari, N., Mortarino, M., & Genchi, M. (2008) · Veterinary Parasitology · doi:10.1016/j.vetpar.2008.09.005 · Cited by 48 · see citing works
Dillon, A. R., Warner, A. E., Brawner, W., Hudson, J., & Tillson, M. (2008) · Veterinary Parasitology · doi:10.1016/j.vetpar.2008.09.004 · Cited by 46 · see citing works
Biology of experimental heartworm infections in cats
McCall, J. W., Dzimianski, M. T., McTier, T. L., Jernigan, A. D., Jun, J. J., Mansour, A. E., Supakorndej, P., Plue, R. E., Clark, J., & Wallace, D. H. (1992) · Cited by 45 · see citing works
Dillon, R. A. (1984) · Veterinary Clinics of North America Small Animal Practice · doi:10.1016/s0195-5616(84)50153-3 · Cited by 44 · see citing works
Seasonality of heartworm infection and implications for chemoprophylaxis
KNIGHT, D. H., & Lok, J. B. (1998) · Clinical Techniques in Small Animal Practice · doi:10.1016/s1096-2867(98)80010-8 · Cited by 40 · see citing works
Use of echocardiography for the diagnosis of heartworm disease in cats: 43 cases (1985–1997)
DeFrancesco, T. C., Atkins, C. E., Miller, M. W., Meurs, K. M., & Keene, B. W. (2001) · Journal of the American Veterinary Medical Association · doi:10.2460/javma.2001.218.66 · Cited by 40 · see citing works
Self-citationDillon, R. A. (2018) · CRC Press eBooks · doi:10.1201/9781351071420-12 · Cited by 39 · see citing works
Carleton, R. E. (2004) · Veterinary Parasitology · doi:10.1016/j.vetpar.2003.10.019 · Cited by 33 · see citing works
Association of Wolbachia with heartworm disease in cats and dogs
Dingman, P. A., Levy, J. K., Kramer, L. H., Johnson, C. M., Lappin, M. R., Greiner, E. C., Courtney, C. H., Tucker, S. J., & Morchón, R. (2010) · Veterinary Parasitology · doi:10.1016/j.vetpar.2010.01.037 · Cited by 30 · see citing works
CARDIAC AND PULMONARY ARTERY MENSURATION IN FELINE HEARTWORM DISEASE
Schafer, M., & Berry, C. R. (1995) · Veterinary Radiology & Ultrasound · doi:10.1111/j.1740-8261.1995.tb00302.x · Cited by 29 · see citing works
Use of a nitinol gooseneck snare catheter for removal of adult Dirofilaria immitis in two cats
Small, M. T., Atkins, C. E., Gordon, S. G., Birkenheuer, A. J., Booth-Sayer, M. A., Keene, B. W., Fujii, Y., & Miller, M. W. (2008) · Journal of the American Veterinary Medical Association · doi:10.2460/javma.233.9.1441 · Cited by 27 · see citing works
Self-citationBowman, D. D., Torre, C. J., & Mannella, C. (2007) · PubMed · Cited by 16 · see citing works
Dirofilaria immitis in cats: anatomy of a disease.
Nelson, C. (2008) · PubMed · Cited by 11 · see citing works
Right Atriotomy Using Total Venous Inflow Occlusion for Removal of Heartworms in a Cat
IIZUKA, T., HOSHI, K., ISHIDA, Y., & SAKATA, I. (2009) · Journal of Veterinary Medical Science · doi:10.1292/jvms.71.489 · Cited by 11 · see citing works
Flagged first, then by citations
Cited by
Sorted by citations
Human and animal dirofilariasis: The emergence of a zoonotic mosaic
Simón, F., Siles-Lucas, M., Morchón, R., González-Miguel, J., Mellado, I., Carretón, E., & Montoya-Alonso, J. A. (2012) · Clinical Microbiology Reviews · doi:10.1128/cmr.00012-12 · Cited by 834 · see citing works
Heat treatment prior to testing allows detection of antigen of Dirofilaria immitis in feline serum
Little, S. E., Raymond, M. R., Thomas, J. E., Gruntmeir, J., Hostetler, J. A., Meinkoth, J. H., & Blagburn, B. L. (2014) · Parasites & Vectors · doi:10.1186/1756-3305-7-1 · Cited by 286 · see citing works
Feline heartworm disease: A'Rubik's-cube-like' diagnostic and therapeutic challenge
Venco, L., Marchesotti, F., & Manzocchi, S. (2015) · Journal of Veterinary Cardiology · doi:10.1016/j.jvc.2015.08.004 · Cited by 71 · see citing works
Ray Dillon, A., Tillson, D. M., Wooldridge, A., Cattley, R., Hathcock, J., Brawner, W. R., Cole, R., Welles, B., Christopherson, P. W., Lee-Fowler, T., et al. (2014) · Veterinary Parasitology · doi:10.1016/j.vetpar.2014.09.007 · Cited by 51 · see citing works
Diakou, A., Soubasis, N., Chochlios, T., Oikonomidis, I. L., Tselekis, D., Koutinas, C., Karaiosif, R., Psaralexi, E., Tsouloufi, T. K., Brellou, G., et al. (2019) · Parasitology Research · doi:10.1007/s00436-018-6135-9 · Cited by 38 · see citing works
Vieira, L., Silvestre-Ferreira, A. C., Fontes-Sousa, A. P., Balreira, A. C., Morchón, R., Carretón, E., Vilhena, H., Simón, F., & Montoya-Alonso, J. A. (2015) · Journal of Helminthology · doi:10.1017/s0022149x14000352 · Cited by 37 · see citing works
Prevalence of heartworm in dogs and cats of Madrid, Spain
Montoya-Alonso, J. A., Morchón, R., Falcón-Cordón, Y., Falcón-Cordón, S., Simón, F., & Carretón, E. (2017) · Parasites & Vectors · doi:10.1186/s13071-017-2299-x · Cited by 34 · see citing works
Feline asthma and heartworm disease: Clinical features, diagnostics and therapeutics
Garrity, S., Lee-Fowler, T., & Reinero, C. (2019) · Journal of Feline Medicine and Surgery · doi:10.1177/1098612x18823348 · Cited by 33 · see citing works
Dillon, A. R., Blagburn, B. L., Tillson, M., Brawner, W., Welles, B., Johnson, C., Cattley, R., Rynders, P., & Barney, S. (2017) · Parasites & Vectors · doi:10.1186/s13071-017-2425-9 · Cited by 26 · see citing works
García-Guasch, L., Caro-Vadillo, A., Manubens-Grau, J., Carretón, E., Morchón, R., Simón, F., Kramer, L. H., & Montoya-Alonso, J. A. (2013) · Veterinary Parasitology · doi:10.1016/j.vetpar.2013.01.060 · Cited by 24 · see citing works
Montoya-Alonso, J. A., Carretón, E., García-Guasch, L., Expósito, J., Armario, B., Morchón, R., & Simón, F. (2014) · Parasites & Vectors · doi:10.1186/s13071-014-0506-6 · Cited by 24 · see citing works
Hattendorf, C., & Lühken, R. (2025) · Infectious Diseases of Poverty · doi:10.1186/s40249-025-01328-2 · Cited by 22 · see citing works
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Kulmer, L.-M., Unterköfler, M. S., Fuehrer, H.-P., Janovska, V., Pagac, M., Svoboda, M., Venco, L., & Leschnik, M. (2021) · Pathogens · doi:10.3390/pathogens10091104 · Cited by 21 · see citing works
Retrospective evaluation of vector-borne pathogens in cats living in Germany (2012–2020)
Schäfer, I., Kohn, B., Volkmann, M., & Müller, E. (2021) · Parasites & Vectors · doi:10.1186/s13071-021-04628-2 · Cited by 20 · see citing works
Biasato, I., Tursi, M., Zanet, S., Longato, E., & Capucchio, M. T. (2017) · Journal of Veterinary Cardiology · doi:10.1016/j.jvc.2016.08.004 · Cited by 16 · see citing works
Montoya-Alonso, J. A., García Rodríguez, S. N., Carretón, E., Rodríguez Escolar, I., Costa-Rodríguez, N., Matos, J. I., & Morchón, R. (2022) · Frontiers in Veterinary Science · doi:10.3389/fvets.2022.900371 · Cited by 15 · see citing works
First report on clinical feline heartworm ( <i>Dirofilaria immitis</i> ) infection in Romania
Pană, D., Rădulescu, A., Mitrea, I. L., & Ionita, M. (2020) · Helminthologia · doi:10.2478/helm-2020-0009 · Cited by 14 · see citing works
Dirofilaria spp. infection in cats from the Mediterranean basin: diagnosis and epidemiology
Carbonara, M., Perles, L., Venco, L., Gabrielli, S., Barrs, V. R., Miró, G., Papadopoulos, E., Lima, C., Bouhsira, E., Baneth, G., et al. (2025) · International Journal for Parasitology · doi:10.1016/j.ijpara.2025.01.011 · Cited by 12 · see citing works
Tonev, A. S., Kirkova, Z., Iliev, P. T., Roussenov, A., Chaprazov, T., Roydev, R., & Pirovski, N. (2021) · Helminthologia · doi:10.2478/helm-2021-0005 · Cited by 6 · see citing works
Multidetector computed tomographic pulmonary angiography in a cat with fatal heartworm disease
Panopoulos, I., Specchi, S., Soubasis, N., Papastefanou, A., Brellou, G., & Auriemma, E. (2018) · Veterinary Radiology & Ultrasound · doi:10.1111/vru.12508 · Cited by 6 · see citing works
- Authors
- Lee, A. C. Y., & Atkins, C. E.
- Affiliations
- Cornell University (US)
- North Carolina State University (US)
- Corresponding author
- Lee, Alice C.Y.
- Venue
- Topics in Companion Animal Medicine
- Publisher
- Elsevier BV
- Published
- 2010-11
- Volume
- 25
- Issue
- 4
- Pages
- 224-230
- ISSN
- 0882-0511 (ISSN-L)
- 1938-9736
- OpenAlex
- W2125741549
- Cited by
- 93
- References
- 28
- Citations by year
- 2026: 4 · 2025: 5 · 2024: 6 · 2023: 3 · 2022: 18 · 2021: 9 · 2020: 7 · 2019: 4 · 2018: 5 · 2017: 9 · 2016: 3 · 2015: 5 · 2014: 8 · 2013: 4 · 2012: 1
- FWCI
- 0.26
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Topics in companion animal medicine (publishedVersion)
- PubMed (publishedVersion)
- Topics
- Health Sciences › Medicine › Infectious Diseases › Parasitic Diseases Research and Treatment
- Health Sciences › Veterinary › Small Animals › Helminth infection and control
- Health Sciences › Veterinary › Small Animals › Veterinary Medicine and Surgery
- Keywords
- feline heartworm disease, Dirofilaria immitis, cats, pulmonary artery, pulmonary intravascular macrophages, self-cure, sudden death, Wolbachia, chemoprophylaxis, survival time
- MeSH terms
- Animals, Cat Diseases, Cats, Dirofilaria immitis, Dirofilariasis, Echocardiography, Female, Life Cycle Stages, Male, Prognosis, Pulmonary Artery, Remission, Spontaneous, Risk Factors, Radiography, Thoracic
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