Infection with the intravascular parasite Dirofilaria immitis is an increasingly recognized problem in domestic dogs and cats. Heartworm infection is preventable; however, once an animal is infected, heartworm disease and potentially life-threatening complications can develop. An understanding of the heartworm life cycle and transmission season, the limitations of testing methods, and the clini...

OBJECTIVE To determine the prevalence and severity of pulmonary arterial lesions in cats seropositive for heartworms (Dirofilaria immitis) but lacking adult heartworms in the heart and lungs during necropsy. ANIMALS 630 adult cats from an animal control shelter in Florida. PROCEDURE Cats were tested for adult heartworms in the heart and pulmonary arteries and antibody against heartworms in ...

OBJECTIVE To compare heartworm serum antibody (Ab) and antigen (Ag) test results, using commercial laboratories and in-house heartworm test kits, with necropsy findings in a population of shelter cats. DESIGN Prospective study. ANIMALS 330 cats at an animal shelter. PROCEDURE Between March and June 1998, 30 ml of blood was collected from the cranial and caudal venae cavae of 330 cats that...

Mass testing of dogs in Canada for the presence of Dirofilaria immitis has been ongoing since 1977. Since that time, there have also been changes in the diagnostic tests available to detect the presence of heartworm and changes in the therapy for heartworm, which necessitate a reevaluation of heartworm screening as currently practiced in Canada. The principles of evidence-based medicine were us...

Serological tests were performed on 380 cats with necropsy-confirmed heartworm disease to compare the performance of currently available commercial laboratory and point-of-care heart-worm serological tests in a heartworm-endemic area. Overall, antigen tests detected 79.3% to 86.2% of heartworm infections and were highly specific. Most cats with false-negative antigen tests had a single male wor...

OBJECTIVE To determine prevalences of heartworm exposure (ie, positive heartworm antibody test results) and heartworm infection (ie, positive heartworm antigen test results or identification of mature heartworms at necropsy) among nondomestic cats housed in an area in rural North Carolina where Dirofilaria immitis is known to be endemic and among nondomestic cats housed in areas with a low prev...

OBJECTIVE To determine prevalence of heartworm infection among healthy, client-owned cats in the lower peninsula of Michigan. DESIGN Cross-sectional prevalence study. ANIMALS 1,348 healthy cats examined at private veterinary practices throughout the lower peninsula of Michigan. PROCEDURE Sera were tested by use of an ELISA-based antigen test kit to determine infection and 2 commercially a...

BACKGROUND The North Eastern Region in India is endemic for canine heartworm disease but in clinics accurate diagnosis is some times difficult. The aim of the present study was to determine the prevalence of occult infections for heartworm disease in canine in two geographical regions of North Eastern India. METHODS A total of 782 numbers of three categories of dogs namely, working dogs of mi...

Resistance Resistance to current preventive medications is considered a very prominent topic. All major heartworm preventives are in the macrocyclic lactone class of antiparasiticides. Those approved for use in dogs and cats include ivermectin, moxidectin, milbemycin, selamectin, and milbemycin. They demonstrate excellent lethality to the L3 and L4 stages of Dirofilaria immitis. Based upon incr...