Metritis is an economically significant problem in most dairy herds. Although mortality is low, morbidity is often high, and systemic illness may result in lowered feed consumption and decreased milk production, as well as losses incurred because of milk dumping due to antibiotic residues in milk from treated cows. Metritis significantly increases days to conception and services per conception, leading to losses ‘from reduced milk production associated with longer calving intervals and higher insemination costs. Fertility may be permanently inlpaired in sonle cows, causing higher culling rates and the associated increase in replacement costs. Culling because of decreased fertility often results in a loss of freedom to cull for other factors such as low production, and may result in the culling of genetically superior animals.
Much work has been done to identify the species of bacteria associated with metritis. It has been found that most, if not all, bovine uteri are bacterially contaminated in the immediate postpartum period. Culture at this time will usually yield a wide range of bacteria, including Actinomyces pyogenes, Streptococcus, Staphylococcus, and Clostridium spp., coliforms, and gram negative anaerobes.
The presence of these organisms at this time should not be considered abnormal. In the normal postpartum uterus, bacterial numbers should drop rapidly after parturition, and bacteria will be absent or present only in very low numbers within three to four weeks of calving.
Metritis results because of an alteration in the normal clearing ofthese organismsfrom the uterus. In the early postpartum period, retained fetal membranes and/or uterine inertia often result in an explosion of coliform and Clostridium spp. bacteria. The retained membranes provide an ideal substrate for bacterial growth. The lack of mechanical expulsion is a major factor in this increase. Bacterial exotoxin and endotoxin absorption may result in toxic metritis at this time. Later in the postpartum period, the bacterial speciescommonly associated with metritis include Actinomyces pyogenes and anaerobic gram negative bacteria, usually Fusobacterium necrophorum or Bacteroides Spp.8 Coliform bacteria are an uncornmon finding at this time.
These later infections are rarely associated with systemic illness and because there is often little or no external drainage of purulent material from the vagina, these infections often go unnoticed.
Animals suffering from metritis show both local and general symptoms. Toxaemia, septicemia and pyrexia develop very commonly.
The temperature of affected cows may be elevated to 40 – 41°C, but is more often subnormal. There is a rapid pulse rate (around 100/minute) and there may be elevated respiration. Animals are anorectic and dehydrated; they often have a toxemia – induced diarrhea and exhibit signs of shock. It is common for the infection to extend through the uterine wall into the peritoneum, causing a localized or general peritonitis.
The uterus contains a large amount of toxic, fetid, reddish, serous exudates, containing pieces of degenerating fetal membranes. Exudate is frequently discharged from the vagina by straining efforts of the animal. Vaginal and uterine exploration of an affected case causes acute discomfort and is accompanied and followed by the most severe and persistent expulsive efforts.
The cotyledons are swollen and the fetal membranes often remain firmly attached. The vaginal mucosa is inflamed and thickened, and the cervix is partially open. If untreated, the cow rapidly becomes recumbent, dehydrated and comatose. Death may ensure within few hours.
AKACIN for uterine cleaning.
GLUCO-K-C for oral solution.