Kizmo
New member
I hunt in south Georgia, a half hour or less from the Florida line. A couple of weeks ago, my buddy from Texas was in town and wanted to go coyote hunting, so I took him out to my place. On the third stand, I called up this big male, which he shot in the chest at 95 yards with a .243.
Pretty healthy looking, isn’t he?
Closer inspection of the exit wound, however, reveals a different story.
The white thread-like things are adult heartworms, aka Dirofilaria immitis. The smaller, thinner ones are male and the larger ones are female. What you can’t see are the microscopic “larva” (aka microfilariae) which are present throughout the blood. These are the things you spend $$$ at the veterinarian’s office to prevent your dog from having.
Heartworms are native to the southeastern United States but have spread to nearly everywhere that mosquitos are found. Mosquitos are the vector for heartworms. Vector = an organism that transmits a disease from one creature to another. There have even been reports of them as far north as Alaska and Canada, and they are now found in Central and South America, Europe and Asia. Though they were originally identified in dogs, they have been found in various members of the cat family, foxes, wolves, sea lions, ferrets, some birds, and (occasionally) humans.
As is the case with most parasites, the life cycle of the heartworm is fairly complicated. It begins when a mosquito ingests blood from an infected animal which contains the microfilariae. They end up in the mosquito’s gut, where they undergo 2 stages of maturation. After this, they migrate to the mosquito’s head, “beak” (aka proboscis) and salivary glands. When the mosquito bites a second animal, the immature worms are deposited under the skin, where they undergo a 4th stage of maturation. They then migrate to the nearby muscles, where they undergo a 5th stage of maturation. They then burrow into the blood vessels and are carried by the blood stream to, and through, the heart to lodge in the arteries in the lung (aka the pulmonary arteries). There, they mature and breed (disgusting, I know). The females then give birth to new microfilariae which circulate in the blood for up to two years, just waiting to be sucked up by another mosquito, thus beginning the cycle once again.
The entire process, from initial infection to having adult worms residing in the pulmonary arteries, takes approximately 7 months. The portion of the process occurring in the mosquito takes 2-7 weeks and is dependent upon ambient temperature. A minimum of two weeks of temperatures of 80 degrees or above is required for the the part of the cycle occurring in the mosquito.
Interestingly, heartworm infections are more severe in active dogs than in “couch potato” dogs. Presumably, this is due to the fact that increased heart rate leads to increased circulation of nutrient-rich blood, allowing the worms to mature and proliferate at a greater rate. Since few dogs are as active as coyotes, you can see coyotes really “take it on the chin” when it comes to heartworms. In severe cases (like this one), heartworms spread to the right side of the heart and the great vessels leading into and out of the heart. Left untreated, death is due to congestive heart failure due to all those worms “clogging the plumbing”. The heart essentially wears itself out due to the strain of trying to pump blood through all that matted mass of worms.
Humans represent accidental hosts of heartworms on occasion. The worms are usually found in the lung tissue near the outer surfaces of the lungs. In humans, most worms die before reaching adulthood. The dead worm produces a nodule of reactive inflammatory tissue called a granuloma. The significance of human infection is that these granulomas may be seen on chest X-rays and (initially) mistaken for lung cancer. Only after the portion of the lung is removed (not something you want to have done just for fun) is the truth discovered. I’ve personally seen two cases in which I’ve found remnants of the dead worm.
As far as other such things that coyotes harbor, a 2009 University of Georgia study of 41 coyotes at the Savannah River Site near Augusta, Ga. found that 60% of their coyotes tested positive for West Nile virus, 38% were positive for Eastern Equine Encephalitis virus, and 15% were positive for Canine Distemper virus. Only one adult carried Parvovirus. Various intestinal parasites were also identified. The most significant of these (in terms of prevalence and significance to humans) was hookworm (Ancyclostoma), which was present in over 50%.
Heartworms were first identified in coyotes in 1992, right down the road from where I hunt. Our average annual rainfall is 53" and our average annual high temperature is 79 degrees. Even though mosquitos spend their entire lives only within 70-100 yards of where they hatched, we have mosquitos here everywhere and all the time. Consequently, most of our local coyotes (75%) have heartworms, and most acquire them in their first summer of life. Since coyotes are an invasive species here and are relative newcomers to the area, it remains to be seen how they will adapt. Most authorities believe that heartworms will represent a significant source of natural mortality for them in our area, and I believe they are the main reason we will never have the numbers of coyotes of you guys out west.
All that being said, any of you ever found any creepy crawlies in any of your yotes?
Pretty healthy looking, isn’t he?
Closer inspection of the exit wound, however, reveals a different story.
The white thread-like things are adult heartworms, aka Dirofilaria immitis. The smaller, thinner ones are male and the larger ones are female. What you can’t see are the microscopic “larva” (aka microfilariae) which are present throughout the blood. These are the things you spend $$$ at the veterinarian’s office to prevent your dog from having.
Heartworms are native to the southeastern United States but have spread to nearly everywhere that mosquitos are found. Mosquitos are the vector for heartworms. Vector = an organism that transmits a disease from one creature to another. There have even been reports of them as far north as Alaska and Canada, and they are now found in Central and South America, Europe and Asia. Though they were originally identified in dogs, they have been found in various members of the cat family, foxes, wolves, sea lions, ferrets, some birds, and (occasionally) humans.
As is the case with most parasites, the life cycle of the heartworm is fairly complicated. It begins when a mosquito ingests blood from an infected animal which contains the microfilariae. They end up in the mosquito’s gut, where they undergo 2 stages of maturation. After this, they migrate to the mosquito’s head, “beak” (aka proboscis) and salivary glands. When the mosquito bites a second animal, the immature worms are deposited under the skin, where they undergo a 4th stage of maturation. They then migrate to the nearby muscles, where they undergo a 5th stage of maturation. They then burrow into the blood vessels and are carried by the blood stream to, and through, the heart to lodge in the arteries in the lung (aka the pulmonary arteries). There, they mature and breed (disgusting, I know). The females then give birth to new microfilariae which circulate in the blood for up to two years, just waiting to be sucked up by another mosquito, thus beginning the cycle once again.
The entire process, from initial infection to having adult worms residing in the pulmonary arteries, takes approximately 7 months. The portion of the process occurring in the mosquito takes 2-7 weeks and is dependent upon ambient temperature. A minimum of two weeks of temperatures of 80 degrees or above is required for the the part of the cycle occurring in the mosquito.
Interestingly, heartworm infections are more severe in active dogs than in “couch potato” dogs. Presumably, this is due to the fact that increased heart rate leads to increased circulation of nutrient-rich blood, allowing the worms to mature and proliferate at a greater rate. Since few dogs are as active as coyotes, you can see coyotes really “take it on the chin” when it comes to heartworms. In severe cases (like this one), heartworms spread to the right side of the heart and the great vessels leading into and out of the heart. Left untreated, death is due to congestive heart failure due to all those worms “clogging the plumbing”. The heart essentially wears itself out due to the strain of trying to pump blood through all that matted mass of worms.
Humans represent accidental hosts of heartworms on occasion. The worms are usually found in the lung tissue near the outer surfaces of the lungs. In humans, most worms die before reaching adulthood. The dead worm produces a nodule of reactive inflammatory tissue called a granuloma. The significance of human infection is that these granulomas may be seen on chest X-rays and (initially) mistaken for lung cancer. Only after the portion of the lung is removed (not something you want to have done just for fun) is the truth discovered. I’ve personally seen two cases in which I’ve found remnants of the dead worm.
As far as other such things that coyotes harbor, a 2009 University of Georgia study of 41 coyotes at the Savannah River Site near Augusta, Ga. found that 60% of their coyotes tested positive for West Nile virus, 38% were positive for Eastern Equine Encephalitis virus, and 15% were positive for Canine Distemper virus. Only one adult carried Parvovirus. Various intestinal parasites were also identified. The most significant of these (in terms of prevalence and significance to humans) was hookworm (Ancyclostoma), which was present in over 50%.
Heartworms were first identified in coyotes in 1992, right down the road from where I hunt. Our average annual rainfall is 53" and our average annual high temperature is 79 degrees. Even though mosquitos spend their entire lives only within 70-100 yards of where they hatched, we have mosquitos here everywhere and all the time. Consequently, most of our local coyotes (75%) have heartworms, and most acquire them in their first summer of life. Since coyotes are an invasive species here and are relative newcomers to the area, it remains to be seen how they will adapt. Most authorities believe that heartworms will represent a significant source of natural mortality for them in our area, and I believe they are the main reason we will never have the numbers of coyotes of you guys out west.
All that being said, any of you ever found any creepy crawlies in any of your yotes?
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