Induction of canine pyometra by inoculation of Escherichia coli into the uterus and its relationship to reproductive features

• Published in: Animal reproduction science 2005-07, Vol.87 (3), p.301-308
• Main Authors: Tsumagari, S., Ishinazaka, T., Kamata, H., Ohba, S., Tanaka, S., Ishii, M., Memon, M.A.
• Format: Article
• Language: English
• Subjects: animal age; Animals; Animals, Newborn; Beagle; Bitch; blood serum; Dinoprost - therapeutic use; disease incidence; dog diseases; Dog Diseases - drug therapy; Dog Diseases - microbiology; Dogs; Escherichia coli; Escherichia coli - growth & development; Escherichia coli Infections - drug therapy; Escherichia coli Infections - microbiology; Escherichia coli Infections - veterinary; Escherichia infections; estrus; Estrus - physiology; Experimental pyometra; Female; females; host-pathogen relationships; Litter Size; luteinization; Luteinizing Hormone - blood; Male; metestrus; Parasympatholytics - therapeutic use; Pregnancy; pregnancy rate; Progesterone; Progesterone - blood; prostaglandins; pyometra; Pyrrolidines - therapeutic use; Random Allocation; Reproductive features; Uterine Diseases - drug therapy; Uterine Diseases - microbiology; Uterine Diseases - veterinary; uterus
• ISSN: 0378-4320; 1873-2232
• DOI: 10.1016/j.anireprosci.2004.11.006

To characterize oestrus-related factors affecting the induction of and recovery from pyometra in bitches, 60 clinically healthy beagle bitches were used for induction of pyometra by inoculation of Escherichia coli into the uterus during oestrous and metoestrous stages. The animals were classified into the following six groups according to inoculation time: Days 1–10, 11–20, 21–30, 31–40, 41–50 and 51–60 after LH surge. The incidence of pyometra during the periods Days 11–20 and 21–30 after LH surge was 90.9% and 78.9% respectively, while that during Days 1–10 and 51–60 after LH surge was less than 20%, and the patterns of the incidence of pyometra and the serum progesterone levels were similar. There was no difference in the incidence of pyometra induced in bitches less than 5 years old compared to bitches over 6 years old. Oestrus in all of the bitches with pyometra induced by E. coli returned with or without PGF 2α treatment, unlike in bitches with spontaneous pyometra. The duration of the oestrous cycle in the non-treated and PGF 2α-treated groups was 231.4 ± 55.2 days and 162.1 ± 40.6 days ( P < 0.001), respectively, and there was no difference in the rate of return of oestrus between the two groups. The conception rate in all of the bitches in which oestrus had returned was 81.8%. The above findings indicate that the period during which severe pyometra could be induced was limited to the early stage in metoestrus.