Canine Rotavirus Infection

1 Canine Rotavirus Infection

Epidemiology

The disease has no clear season, occurs more in late winter and early spring, and spreads mainly via the digestive tract. Puppies show severe signs; poor hygiene or adenovirus co-infection worsens it and raises mortality. Dogs and other susceptible animals can cross-infect. Sick animals and subclinically infected carriers (people, livestock) are important sources.

Clinical symptoms

The incubation period is generally 1-3 days. The dog is depressed, eats less and is reluctant to move.

It usually vomits first then develops diarrhea; the stools are yellow or brown, watery and foul-smelling; severe dehydration often ends in death. Puppies under 1 week old suddenly develop diarrhea, sometimes with mucus or blood in the stool; due to dehydration and acid-base imbalance the heart rate rises (sometimes 180-200/min), body and skin temperature drop, and they often die from exhaustion.

Pathological changes

Lesions are mainly in the small intestine, especially the jejunum and ileum in the posterior two-thirds; villi atrophy, columnar epithelium swells, necroses and sloughs; some segments show diffuse hemorrhage; intestinal contents are yellow-green with blood.

Differential diagnosis

(1) Canine rotavirus infection vs. canine coronavirus

Both show vomiting, diarrhea, depression and labored breathing.

Difference: rotavirus lesions center on the small intestine with no other organ changes; coronavirus has severe diarrhea, stools white/yellow/green/brown, sometimes projectile, with bleeding and sloughing of the gastric mucosa and enlargement of the spleen and gallbladder.

(2) Canine rotavirus infection vs. canine parvovirus

Both show vomiting, diarrhea, depression and labored breathing.

Difference: rotavirus lesions center on the small intestine with no other organ changes; parvovirus mostly affects 2-4 month puppies, and at necropsy the small-intestinal mucosa is congested and bleeding, dark red, with necrosis and sloughing, enlarged congested bleeding lymph nodes, and non-suppurative necrosis of the myocardium or endocardium with a soft heart muscle.

(3) Canine rotavirus infection vs. canine infectious hepatitis

Both show depression, anorexia, vomiting, diarrhea and bloody stool.

Difference: rotavirus is mainly a digestive-tract lesion; infectious hepatitis has temperature above 41°C, after the first rise it falls to normal within 1-6 days then rises again, marked tenderness over the xiphoid (liver area), purulent nasal discharge and conjunctivitis.

(4) Canine rotavirus infection vs. canine ordinary gastroenteritis

Both show vomiting, diarrhea, blood in the stool, foul smell and anorexia.

Difference: ordinary gastroenteritis has temperature 40-41°C, is not contagious, with abdominal pain and cyanotic oral and conjunctival mucosa; gastritis-predominant cases show jaundice.

(5) Canine rotavirus infection vs. canine coccidiosis

Both occur mainly in puppies and show vomiting, diarrhea, mucus and blood in the stool, and reduced appetite.

Difference: coccidiosis shows progressive emaciation and only occasional vomiting, with pale slightly yellow mucosa; at necropsy the small-intestinal mucosa has white nodules containing cysts, and saturated-salt flotation finds oocysts in the feces.

(6) Canine rotavirus infection vs. canine acute hemorrhagic gastroenteritis syndrome

Both show vomiting then diarrhea, foul stool and depression.

Difference: acute hemorrhagic gastroenteritis syndrome is not contagious; vomiting starts abruptly 2-3 days before diarrhea, with jam-like or jelly-like stools.

(7) Canine rotavirus infection vs. canine pancreatitis

Both show vomiting, diarrhea and foul stool.

Difference: pancreatitis is not contagious, with abdominal tenderness; chronic cases have abnormally increased appetite and thirst, more stools and urine, and stools high in fat and protein.

Notes

Rotavirus occurs in the cold late-winter and early-spring season, mainly affects young dogs and cats, causes sudden simple diarrhea, has high incidence but low mortality, and lesions are mainly in the small intestine; based on these features a preliminary diagnosis is made, and confirmation needs laboratory tests.

Prevention and treatment

(1) Prevention

1. Prevention mainly uses the seven-way modified-live vaccine.

2. When the disease occurs, isolate sick dogs immediately and disinfect their area and equipment.

(2) Treatment

The treatment principle is antiviral therapy, prevention of secondary infection and symptomatic treatment.

1. Antiviral.

Ribavirin: 5-7 mg/kg subcutaneously or intramuscularly once daily.

Acyclovir: 5-10 mg/kg by intravenous drip once daily for 10 days.

Interferon: 100,000-200,000 IU per dose subcutaneously or intramuscularly every 2 days.

2. Antidiarrheal.

Smectite (dioctahedral montmorillonite): 250-500 mg/kg orally twice daily for 2-4 days.

Videcon (Weidikang): 0.02-0.08 g/kg orally twice daily for 2-4 days.

3. Gastrointestinal mucosal protection.

Aluminum sulfate: 0.5-1 g per 25 kg body weight orally 2-4 times daily.

4. Fluid therapy.

Inject lactated Ringer’s solution, 50% glucose-saline and 5% sodium bicarbonate solution to prevent dehydration and metabolic acidosis.