Purpura in dog uterus
Estrus cycle and pathogenic bacteria
The estrus cycle of dogs refers to a series of periodic changes in the reproductive organs and the whole body after the bitch develops into estrus, which goes on and on until it stops sexual activity. The estrus cycle of dogs is generally divided into pre-estrus, estrus, post-estrus (estrus cycle) and estrus (estrus cycle). Preestrus is the time from the discharge of blood secretion from vagina to the beginning of mating, which generally lasts for 5 days to 15 days, with an average of 9 days. Estrus lasts for 7 days to 12 days, with an average of 9 days. Estrus is marked by the bitch refusing to mate until the reproductive organs return to normal, which lasts for 70 to 90 days, with an average of 75 days. During estrus, the reproductive organs of bitches are in a static state, usually 50 to 60 days. Dogs that only estrus once a year have been in this period for nearly a year.
Purpura in dog uterus mainly occurs in the first half of the late estrus, which is obviously related to the increase of progesterone level in the late estrus. Progesterone can reduce the resistance of uterus, which is the main reason why uterine empyema often occurs in the late estrus. Most studies have proved that urethral pathogenic Escherichia coli is the main bacteria causing uterine empyema and urinary tract infection. In addition, Staphylococcus, Streptococcus, Pseudomonas, Proteus, Aeromonas and Nocardia can also cause uterine empyema. Urethral pathogenic Escherichia coli can enter the uterus through the loose cervix during estrus, and its unique pathogenic factors of urethral infection can help bacteria adsorb and colonize the urethra and uterine mucosa, providing necessary nutrition for the growth and reproduction of bacteria. In the late estrus, the resistance of the body's uterine mucosa decreases, and the pathogenic bacteria that enter through the loose cervical canal during estrus can multiply in large numbers, which makes the dog prone to uterine empyema in the late estrus.
X-ray photos show that the abdominal density of sick dogs generally increases, but the edge contour is not obvious.
Other factors
The onset age of pyometra in dogs can range from 4 months to 16 years old, and pyometra can occur in adult bitches of all ages. However, the incidence of pyometra is higher in infertile bitches and bitches over 6 years old. This is because old dogs are prone to ovarian dysfunction, mainly manifested as ovarian atrophy, ovarian cysts and persistent corpus luteum. Long-term continuous secretion of progesterone by corpus luteum acts on endometrium, causing endometrial cystic hyperplasia and pyometra.
Dog pyometra can occur in any breed of dog, but it is more common in the following breeds: Rottweiler, Saint Bernard, Songlion, Golden retriever, Beard, Irish Terrier, Elgud Terrier, Knight Charles Hound, Coarse-haired Shepherd and Burnham Hill Dog.
Symptoms and treatment
At the beginning of the disease, the appetite is generally unaffected, the spirit and body temperature are normal, and the symptoms of dogs are not obvious. Generally, after 15 ~ 30 days of infection, sick dogs have abdominal distension, listlessness, loss of appetite, excessive drinking, dysuria and sometimes vomiting. Open pyometra discharges a large amount of purulent secretions from vulva, which are gray or reddish brown. , often accompanied by stench. There is no secretion and pus accumulation in atresia uterus and vulva, the abdominal circumference is enlarged, the palpation has a sense of fluctuation, the course of disease is old, and the swollen uterus compresses the diaphragm, which leads to an increase in respiratory frequency. B-ultrasound examination showed that the thickness of the uterus on both sides was uniform, forming more than two cystic masses, with thin and smooth walls, clear boundaries and no echo area in the contents. If there are many cell components in the contents, scattered lumps or scattered strong echo areas can be seen. It is not easy to observe the echo image of liquid in open uterine empyema. If the inflammation lasts for a long time, the uterine wall can be thickened by 1~2 times, forming a strong reflection echo. X-ray photos show that the abdomen of the sick dog is obviously swollen and the density is generally increased, but the edge contour is not obvious.
Drug therapy is mainly used for open uterine empyema. Drugs stimulate uterine smooth muscle contraction and promote uterine empyema emptying. At present, oxytocin, prostaglandin and ergotine derivatives can induce uterine smooth muscle contraction, among which prostaglandin is the most effective drug in clinical treatment. When the bitch has no vulvar secretion after several days of treatment, she can stop taking the drug. At the same time, antibiotics can be used for systemic treatment. Cephalosporins can be injected intravenously at 25~35 mg/kg body weight, and oxytetracycline, tetracycline or ciprofloxacin can also be injected into uterus via vagina. Surgical removal of uterus and ovary is the most effective method to treat this disease. Because the recurrence rate of pyometra in aged bitches is above 50%, ovariectomy is needed for bitches that do not need breeding.
In view of the importance of the disease in the reproductive system of dogs, it is suggested that adult bitches should be ligated as soon as possible without mating, and all ovaries and uterus should be removed to avoid leaving residual tissues, which may lead to estrus again, pregnancy and uterine empyema, and reduce the occurrence of the disease.