The response to heartworm infection before preventative programs were started was investigated in 56 dogs. Dogs were infected with third-stage larvae of Dirofilaria immitis and started on preventative programs (monthly treatment) with ivermectin/pyrantel pamoate (IVM/PP) or milbemycin oxime (MO) 3.5, 4.5, 5.5, or 6.5 months after infection. Each time period comprised a group of six dogs treated...

This study was conducted to investigate the low prevalence of Dirofilaria immitis in dogs in Johor Bahru as reported by veterinary practitioners, using wet blood mount, Knott’s Concentration Test and two heartworm antigen test kits (IDEXX Canine SNAP® 4Dx and RapiGEN®). This study also compared the two test kits used and determined the microfilaria species. Blood were collected from 100 owned d...

This study establishes a relationship between positive canine heartworm (Dirofilaria immitis) test results frequently observed in California sea lions (Zalophus californianus) and infection with the filarid nematode Acanthocheilonema odendhali. Four commercially available canine heartworm antigen tests were evaluated for cross-reaction with A. odendhali in California sea lions. Sera were tested...

BACKGROUND The sole published data on feline heartworm infection in the Philippines was reported four decades ago. The study therefore endeavoured to assess and provide an update on the current status of heartworm infection in domesticated feline species using serologic and parasitological examination methods. METHODS A total of 46 males and 54 females cats showing clinical signs of dirofilar...

Heartworm infection in dogs and cats in the western United States is a fairly new phenomenon, and for this reason it is often considered to be of minimal significance. The purpose of this survey was to collect data from 11 western states (Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming) in an effort to assess awareness of heartworm diseas...

Several agents are available for the prevention of heartworm infection. Melarsomine is up to 96% efficacious (after two doses) as a heartworm adulticide in infected dogs. However, treatment of dogs infected with D. immitis can be expensive, and adulticide therapy in patients with moderate to severe heartworm disease can be associated with life-threatening complications. Patients with clinical s...

Heartworm prevention: Major factors of resistance First, heartworm preventives were designed and marketed at doses intended to prevent infection by killing third-stage and young fourth-stage larvae, not microfilariae. Thus, microfilariae may persist despite exposure to a macrocyclic lactone (ML); these drug-selected microfilariae can be transmitted between dogs by mosquitoes. This seems an unwi...

Thirty-seven subadult and adult coyotes (Canis latrans), collected August 1992 through December 1996 from a coastal foothill area in northern California (USA), were examined for adult heartworm (Dirofilaria immitis). During 1992 through 1993, at the end of a 6 yr drought, none of four coyotes examined were infected with heartworms. However, during 1994 through 1996, after the drought had ended,...

Dirofilaria immitis is the causative agent of heartworm disease in canines and felines, and pulmonary dirofilariasis in man. It harbors a symbiotic intracellular bacterium from the genus Wolbachia that plays an important role in its biology and contributes to the inflammatory pathology of the heartworm. This endosymbiont is sensitive to the tetracycline family of antibiotics prompting its use i...

Two-hundred fifteen cats with clinical signs consistent with feline heartworm disease (FHD) were entered into this clinical case study. In addition to physical examination, CBC, and heartworm antibody (Ab) and antigen (Ag) tests, thoracic radiographs were taken of 212 cats at initial examination. For cats that had a positive Ab or Ag test, or radiographic changes that could be associated with F...