Treatment and prevention of natural heartworm (Dirofilaria immitis) infections in red pandas (Ailurus fulgens) with selamectin and ivermectin

Ten of the 48 red pandas in the Chengdu Research Base of Giant Panda Breeding, Sichuan province, China, died in 2006 after prolonged periods of depression, weight loss, and mucocutaneous membrane xanthochromia. During postmortem examination, live heartworms were found in the right cardiac ventricles and pulmonary arteries of all 10 animals. Selamectin and ivermectin were used for clinical prophylaxis in the remaining red pandas between December 2006 and November 2010. We observed a gradual decrease in morbidity and mortality during this period. As a consequence of our prophylaxis program, dirofilariosis did not occur in the remaining red pandas at Chengdu Research Base during 2010.

Blood gas analysis in dogs with heartworm caval syndrome

Blood gases and cardiopulmonary function were analyzed in 67 dogs with heartworm (HW) caval syndrome (CS) and 19 HW-free dogs. Arterial oxygen tension (PaO2) was 91.5 +/- 7.3 mmHg in the HW-free dogs, 74.9 +/- 14.3 mmHg in 46 dogs that subsequently survived surgical HW removal (surviving dogs) and 64.6 +/- 14.7 mmHg in 21 dogs which later died or were euthanatized following surgical treatment (nonsurviving dogs). PaO2 levels less than 60 mmHg were detected in 30.4% and 38.1% dogs in the surviving and nonsurviving groups, respectively. Arterial carbon dioxide tension (PaCO2) was 35.8 +/- 4.9 mmHg in the HW-free dogs, 30.7 +/- 5.6 mmHg in the surviving dogs, and 28.8 +/- 6.2 mmHg in nonsurviving dogs. PaO2 (p < 0.01) and PaCO2 were lower (p < 0.01) and the alveolar-arterial oxygen difference (AaDO2) was higher (p < 0.01) in CS dogs than in HW-free dogs. PaO2 was lower (p < 0.01) and AaDO2 was larger (p < 0.01) in the nonsurviving dogs than in the surviving dogs. Arterial blood pH and bicarbonate concentration were lower (p < 0.01) and the anion gap was larger (p < 0.01) in CS dogs than in the HW-free dogs. Serum lactic acid level in nonsurviving dogs (13.2 +/- 3.9 mmol/l) was higher (p < 0.01) than in the HW-free (1.7 +/- 0.8 mmol/l) and surviving dogs (2.7 +/- 1.8 mmol/l). The PaO2 correlated significantly with mean pulmonary arterial pressure (r = -0.65, p < 0.01), cardiac index (r = 0.44, p < 0.05) and total pulmonary resistance (r = -0.70, p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Susceptibility of Aedes albopictus mosquitoes (Oahu strain) to infection with Dirofilaria immitis

The susceptibility of the Oahu strain of Aedes albopictus mosquitoes to infection with Dirofilaria immitis was examined to study the development of larvae in detail. Most of the developing larvae were found in the Malpighian tubules and infective larvae in the labium, indicating that Aedes albopictus Oahu strain is susceptible to the infection with D. immitis. New different patterns of development from those reported by earlier studies were observed: (i) the second-stage larvae in the thorax muscles of the mosquitoes and (ii) a small projection from the head of the sausage-form first-stage larvae.

Mortality factors in whistling swans at Lake St. Clair, Ontario

Post mortem examinations of 31 whistling swans (Olar columbianus) collected from the Lake St. Clair marshes in the spring of 1972 indicated that lead toxicosis and filariasis (Sarconema eurycerca) were the main causes of mortality.