The pathogen of dog tapeworm and its life history

1. Canine tapeworm (Diplopodium caninum, Melon tapeworm)

The body of the dog tapeworm is light red and 10- 50cm. Mature body segments are 7 mm long, 2-3 mm wide, elongated oval, and look like cucumber seeds. Each mature segment contains two sets of male and female reproductive organs, with the genital pore opening in the center of both sides of the segment. Fleas and hairlice are the intermediate hosts of dog tapeworms, in which they develop into cysticerci-like cysts. The final host becomes infected by ingesting a flea or tick containing cysticerci, which develop into adult worms in the small intestine in about 3 weeks.

2. Midline tapeworm (midline tapeworm)

The length of the worm is between 30 and 250 cm, and the widest part is 3 mm. The mature segments are almost at right angles to each segment's set of reproductive organs. The uterus is located in the center of the segment and is a long longitudinal sac. Therefore, there appears to be a longitudinal thread running through the central portion of the tapeworm chain. It is known that Taenia intermedius requires two intermediate hosts. The first intermediate host is M. faecalis, in which cysticercus-like larvae are formed. The second intermediate hosts are snakes, frogs, birds and rodents, which form four post-alveolar cercariae in the body, most of which are located in the abdominal cavity, liver, lungs and other organs of the second intermediate host. After four alveolar larvae are swallowed by the final host, they mature into adults 16-20 days later.

3. Taenia bullae (taenia marginale)

The body length of the tapeworm is 75 to 500 cm. The anterior segments are wide and short, and the posterior segments gradually lengthen. The length and width of the mature segments are 10 ~14mm*4~5mm. The uterus has 5 to 10 pairs of large lateral branches, which are further divided into smaller branches. Each segment has a set of reproductive organs, and the genital pores open irregularly alternately on one side of the segment. The intermediate hosts are cattle, sheep, pigs and other domestic animals. The larvae are Cysticercus tenuitus, which parasitizes in the liver, omentum and mesentery of the intermediate host. Dogs are infected after swallowing the internal organs containing Cysticercus tenuitus. After 36-73 They develop into adult worms in the small intestine.

4. Taenia taeniataensis (Seratotooth tapeworm)

The body length of the insect is 60 to 200 cm. The genital pores are irregularly opened alternately on one side of the segments and are slightly protruding, making the side edges of the insect body appear. Jagged. The length and width of mature body segments are 10 to 15 mm x 4 to 7 mm. The uterus has 8 to 14 pairs of side branches. The intermediate hosts are rabbits and hares, and the larvae are cysticerci, which parasitize in the liver, omentum, mesentery, etc. of rabbits. Dogs ingest the internal organs containing leguminous cysticerci, which develop into adult worms in 35 to 46 days.

5. Taenia multicephalus (Taenia polycephalum)

The length of the worm is 40-100 cm, the widest part is 5 mm, and the uterus has 9-26 contralateral branches. The intermediate hosts are cattle and sheep, and the larvae are polycephalic cercariae that parasitize in the brain of the intermediate host and sometimes in the medulla or spinal cord. Dogs become infected by swallowing brains containing polycercariae, which develop into adults after 41-73 days.

6. Echinococcus granulosus

The body consists of 1 scolex and 3 to 4It consists of segments, with a total length not exceeding 7 mm. There is a set of reproductive organs in the mature segments. The length of the gestational segment exceeds half of the entire length of the insect. The uterus is sac-shaped, with no side branches and only some protrusions. The larvae of Echinococcus granulosus are Echinococcus, which parasitizes in the liver, lungs and other organs of a variety of animals and humans. Dogs become infected after eating organs containing Echinococcus.

7. The tapeworm Mansoni (Schizocephalus mansoni)

The body of the tapeworm is about 100 cm long and 2 to 2.5 cm wide. The scolex is finger-shaped, with a longitudinal suction groove on the dorsal and ventral sides. The neck segment is slender. Proglottids are generally wider than long. The length and width of the proglottids are almost equal. There is a set of reproductive organs in the mature proglottids. There is a circular male genital pore in the center of the front part of the proglottids. The uterus is spirally coiled and located in the middle of the proglottids. The end opening of the uterus and the vaginal opening are located below the male genital pore respectively. The body of the insect is yellow-gray, and the center of the body segment is a gray-black dot-like line connected by the uterus and eggs; the tapeworm Mansoni needs two intermediate hosts: the first intermediate host is a freshwater copepod (such as Daphnia); They develop into protocercariae in their bodies. The second intermediate hosts are frogs and snakes (fish, birds and even humans can be used as transit hosts), in which sparganoides develop. Cats and dogs are the final hosts, and sparganoides develop into adult worms in their small intestines.

Clinical symptoms of canine taeniasis

Mild infection is usually not obvious in sick dogs, except for the occasional discharge of mature segments. Severe infections are manifested by abnormal appetite (overeating, heterophilia), vomiting, chronic enteritis, diarrhea, alternating constipation, anemia, weight loss, excitability or depression, some convulsions or paralysis of the limbs. When worms accumulate, the intestines can become blocked, leading to acute abdominal conditions such as intestinal obstruction, intussusception, volvulus, and intestinal rupture.

How to diagnose

If it is found that the anus of a sick dog has a gestational tapeworm segment that has not yet landed, and short tapeworm segments are mixed in the feces, it can help to diagnose the disease. The proglottids are white, the smallest ones are like rice grains, and the larger ones can be about 9 mm long.

Measures for the prevention and control of tapeworm in dogs

1. Therapeutic deworming:

Use arecoline hydrobromide at a dosage of 1.5 to 2 mg/kg body weight, orally. Make the sick dog fast for 12 to 20 hours and then administer the drug. In order to prevent vomiting, dilute iodine tincture (10 ml of water, two drops of iodine tincture) should be given 15-20 minutes before taking the medicine. Or use praziquantel, the dosage is 5 to 10 mg/kg body weight? times, orally. Or use butamidine hydrochloride at a dosage of 25-50 mg/kg body weight, once orally, to expel Echinococcus granulosus, use 50 mg, and then use it once every 48 hours.

2. Preventive deworming:

Preventive deworming treatment should be carried out four times a year (once per quarter), and breeding dogs should be carried out 3 to 4 weeks before mating. During the pesticidal treatment process, dogs should be isolated within a certain range to collect excreted worms and feces to completely eliminate them and prevent the spread of pathogens.

3.NotePay attention to cleanliness and eliminate sources of infection:

Properly dispose of slaughter waste, prevent dogs from eating intermediate hosts containing tapeworm larvae or their uncooked organs, keep kennels and dog bodies clean, and frequently Use insecticide to kill fleas and ticks on your dog and get rid of rodents.