Acute type of bovine viral diarrhea:

It is common in young calves, with high mortality, upper respiratory symptoms, elevated body temperature (40°C-42°C), and biphasic fever at the initial stage of onset. Runny nose, cough, shortness of breath, tearing, salivation, mental atrophy, etc., leukopenia, erosion or ulceration of oral mucosa in the future, and diarrhea symptoms, loose stools are watery, light yellow at the beginning, and often accompanied by intestinal mucosa and blood in the later period , Dung stench. Sick calves have decreased appetite, weight loss, mental fatigue, and some suddenly die without diarrhea. Dairy cows reduce or stop lactation, pregnant cows may have abortions, or give birth to calves with congenital defects, such as cerebellar hypoplasia, ataxia, and some have interdigital skin ulcers, crown inflammation, laminitis and corneal edema. Severely ill cows died of acute dehydration and exhaustion within 5-7 days. Pathological changes showed oral, esophagus, gastrointestinal mucosal bleeding, edema and erosions. Among them, small erosions in the esophagus are the most characteristic. There are many large bleeding lesions in the lungs, under the capsule of the kidney, and most of the renal cortex. Changes in bleeding spots.　

Chronic type of bovine viral diarrhea:

Mostly from the acute type, there are few obvious symptoms of inflammation, necrosis and ulcers in the oral mucosa rarely occur, but the gums are usually red, intermittent diarrhea, runny nose, dry nose, and then become nasal erosion, which can be connected Into one piece. Eyes are tearful or viscous and transparent secretions, some corneas are cloudy, some show glaucoma, some have chronic laminitis and severe interdigital necrosis, and the sick cow is lame. Some also showed limited hair loss and epidermal keratosis, stunted growth of sick cows, exhaustion and death.