1. PARAFILARIA & DIROFILARIA IMMITIS HEARTWORM

5. Morphology of D. immitis :

6. Dirofilaria immitis microfilaria. (From Soulsby, E.J.L. 1969). Dirofilaria immitis microfilaria morphology

7. Dirofilaria immitis - microfilaria Note the tapered anterior end. In most specimens you will see a straight body and straight or slightly curved) tail. The width is > 6 um.

8. Microfilaria Microfilarial stage as seen @ 400X magnification [wiki-image] 1 st stage microfilaria in blood smear.

9. Scanning electron micrograph of tail of D. immitis showing alae. Under electron microscope

10. Kingdom Animalia (animals) Eumetazoa (metazoans) Bilateria (bilaterally symmetrical animals) Protostomia (protostomes) Ecdysozoa Phylum Nematoda (nematodes) Class Secernentea Order Spirurida Superfamily Filarioidea Family Filariidae Genus Dirofilaria Species Dirofilaria immitis Systemic classification of D. immitis Kingdom: Animalia Phylum: Nematoda Class: Secernentea Order: Spirurida Family: Filariidae Genus: Dirofilaria Species: Dirofilaria immitis

11. Different species of Dirofilaria: Black bears Yamaguti [1941] D.Urci Subcut recoons Chandler[1942] D.Tenuis Subcut, IM CT, Pelvic region of wallabies & kangroo Linstow[1605] D. romeri Human Addario[1885] D. Conjuctivae Monkey Linstow[1899] D.Corynods Subcut tissues of dogs Railliet & Henry [1911] D. repens

15. Life Cycle of D. immitis

16. The male mosquito does not bite The female mosquito bites Male & female mosquito responsible for Heartworm Entomological sketches

17. A female mosquito blood feeding. Mosquitoes serve as intermediate hosts of other parasites such as Dirofilaria immitis the dog and cat heartworm and Plasmodium species causing malaria in humans and birds. They are also vectors of viruses causing yellow fever and encephalitis. Mosquito responsible for Dirofilariosis feeding on skin …..

21. A, Thoracic radiograph from a cat with mild radiographic signs of heartworm disease. Note the right caudal pulmonary artery (arrow). The arrow is located in the ninth intercostal space, the site for comparison of the ninth rib with the pulmonary artery (right or left side). If the pulmonary artery is greater than 1.6 times the size of the rib, it is suggestive of heartworm disease (Schafer and Berry, 1995). B, Thoracic radiograph obtained from a more severely affected cat. Note the alveolar infiltrate in the caudal lung lobes. (From Schafer M, Berry CR: Cardiac and pulmonary artery mensuration in feline heartworm disease. Vet Radio Ultrasound 36:499, 1995.) Diagnosis from X-ray….[feline]

22. Ascites is a fluid build up in the abdomen seen in late stages of Heartworm Disease. Ascites Diagnosing the Canine Heartworm……

23. Worm load in the canine heart See the worms protruding out from ventricular walls to be more specific from Interventricular septum & from the bas of the heart. This is level 5 of worm load – the higher level.

24. Canine heart ….cut open See the length of worms. These are oriented from apex to the base. It gives idea about the morphology of worm. University of Kansas

25. ECG of Normal & Inverted T-wave Inverted T wave Normal T wave

29. Zoonotic aspects of D.immitis D.immitis is not important from zoonotic point of view. However in some cases signs of respiratory infections are seen. But in most of such cases the parasite dies shortly as it enters the lung of the human being. The granuloma is formed around dead worms as it is being killed & absobed. Many times this granuloma resembles with lung cancer on X-ray & biopsy is done for confirmation. D. Tenuis ---- raccoons ---- eye infections D. Repens ---- dogs [Italy] ---- subcutaneous infections