Recently, Ho Chi Minh City University of Medicine and Pharmacy conducted tests on 292 dog fecal samples, revealing that 196 samples contained intestinal parasites, with 152 samples showing the presence of Ancylostoma caninum (which can be transmitted and cause illness in humans) and 40 samples containing Ascaris lumbricoides eggs; 11 samples had Toxocara canis eggs.
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| Children are the most susceptible to dog worm larvae (Photo: digital-slr-guide) |
When dogs are infected with worms, they can release millions of worm eggs into the environment with each bowel movement. Tests have shown that 1 gram of dog feces can contain up to 15,000 worm eggs. The eggs released onto the ground are already fertilized and can hatch into larvae when it rains.
Children are particularly vulnerable to ingesting these larvae orally or anally. Once the larvae enter the body, they travel to the small intestine and can migrate through the bloodstream to the liver, lungs, brain, and eyes. Although the larvae do not develop into adult worms, they can form cysts or calcify, causing damage to the tissues in those areas.
In the eyes, they can cause blindness. In the brain, they can compress nerve tissues, leading to neurological disorders. In the liver and spleen, the larvae can create numerous cysts, weakening these organs or potentially leading to death from infections. The cysts produced by dog worm larvae often cause allergic reactions, asthma attacks, difficulty breathing, hives, and skin rashes, as well as fungal infections of the scalp and lungs.
One of the dangerous parasites commonly found in the small intestine of dogs is the tapeworm. There are three main types of tapeworms. Echinococcus granulosus larvae, a small type of tapeworm, can grow to lengths of 3-6 mm, with a head featuring four suckers and a double row of hooks, and a body made up of three segments, with the last segment containing hundreds of eggs. The eggs of this species can survive outside in the environment for several weeks to months on soil, grass, or vegetables.
When humans consume raw vegetables or pet dogs, the tapeworm eggs can cling to their hands and enter the body, often residing in the lungs, liver, spleen, or brain. Here, the eggs can develop into cysts that appear as tumors. These tumors can grow to a diameter of 1-7 cm and contain over 2 million tapeworm heads. A cyst in the liver can compress bile ducts, leading to jaundice. When a cyst in the left heart bursts, the tapeworm heads can move to the brain, spleen, kidneys, or liver. In the right heart, the tapeworm heads can migrate to the lungs.
Cysts in the kidneys can cause back pain and blood in the urine. Tumors in the spleen can cause pain near the ribs and protruding bones. Tumors in the vertebrae can damage the spinal cord. Tumors in the bones can make them porous and prone to fractures. When a cyst ruptures, it often leads to itching, hives, fluctuating body temperature, digestive disturbances, difficulty breathing, cyanosis, fainting, and coma. If the fluid in a cyst and blood can lead to anaphylactic shock.
The larvae of Spirometra mansoni or Spirometra erinacei reside in the small intestine of dogs. The eggs are released with feces and can be found in ponds, lakes, drains, and ditches. The eggs hatch into ciliated embryos that swim in water and are consumed by red larvae. The red larvae are then eaten by tadpoles, becoming stage II larvae in frogs or toads. Eels, snakes, mice, and chickens that eat red larvae or frogs carrying these larvae can transmit them to humans. Infection often occurs through poorly cooked frog meat, drinking contaminated water containing infected larvae, or applying crushed frog meat to the eyes to treat conjunctivitis. Once in the small intestine, the tapeworm penetrates the intestinal wall and can migrate to the skin, causing dermatitis.
The species Dipylidium caninum can grow to lengths of 15-70 cm, with about 60-175 segments, a head featuring four suckers, and a raised section with 3-7 rows of hooks. Each segment carries an egg sac containing 15-25 eggs. The eggs are clustered, white, and oval-shaped. The segments containing the eggs are excreted with feces, releasing the eggs. These eggs can cling to the fur or around the anus of dogs. When humans pet dogs, the eggs can stick to their hands and then enter the human body. Inside the human body, the eggs develop into larval cysts with tails. After about 20 days in the small intestine, the cysts mature into adult tapeworms, causing abdominal pain, diarrhea, skin irritation, and allergies.
In dog urine, there are also infections of the Leptospira bacteria. This bacteria can adhere to vegetables and food, transmitting to humans. Infection with Leptospira can cause jaundice, muscle pain, conjunctivitis, and meningitis (headaches).
Dogs are also very sensitive to tuberculosis bacteria and can easily transmit the disease to humans.
Although modern medicine has developed treatments for various types of tapeworms, detecting and treating diseases transmitted from dogs at healthcare facilities, especially at the grassroots level, remains challenging. Most cases fail to identify the causes, leading to misdiagnosis as other diseases and ineffective treatments. If the tapeworm larvae have already settled and calcified in tissues, they can be very difficult to treat, and patients may suffer lifelong disabilities.
To prevent diseases transmitted from dogs, families that own dogs should deworm them twice a year. Do not allow dogs near slaughterhouses. Do not feed dogs raw meat or offal. Regularly maintain hygiene, bathe, and treat dogs for fleas. Most importantly, remember to wash your hands immediately after petting dogs.
