Symptoms of Rabies: Key Indicators Explained

Characteristics of Rabies

Rabies virus is capable of infecting all mammals and birds. Dogs infected with rabies are the primary sources of transmission to humans and domestic animals, with wildlife, dogs, and bats serving as the main reservoirs for the disease. Transmission primarily occurs through bites, where the virus enters the wound via saliva. It can also be inhaled through virusladen aerosol particles, or ingested when consuming the meat of infected animals. In cases where pets consume each other, the disease can be transmitted via the gastrointestinal tract.

Symptoms

The incubation period of rabies varies depending on the distance of the wound from the central nervous system, the virulence, and quantity of the virus侵入. It typically ranges from 20 to 60 days, with the shortest known case occurring in as little as 8 days and the longest extending beyond a year. Symptoms are generally categorized into two types: the furious type and the paralytic type.

（1）Furious Type

The rabid dog enters a 12 day period of depression, followed by disorientation, restlessness, drooling, and possibly lying down in a quiet place or walking restlessly with its tail between its legs. It may suddenly stop, bark, and exhibit an increased reflex excitement, being highly sensitive to external stimuli like sounds, bright lights, and touch, often appearing in a state of fear or jumping. Difficulty breathing, diaphragmatic spasms, and dilated pupils are common. There may be a loss of appetite, increased saliva production, and paralysis of the hind limbs. The excited phase lasts for 24 days, during which the dog may become manic, alternating between excitement and depression, and may become aggressive, often running away from home. Gradually, it may lose consciousness and exhibit erratic biting. The terminal paralysis phase, lasting 12 days, is characterized by drooling, tongue prolapse, sagging lower jaw, paralysis of the hindquarters, and lying down. Death usually results from respiratory paralysis or exhaustion. The entire course of the disease is typically 610 days.

（2）Paralytic Type

The excited phase is very short, usually 24 days, or may be不明显. It then progresses into the paralytic phase. Due to paralysis of the head muscles, the dog may drool, have difficulty swallowing, open its mouth, and experience paralysis of the jaw, hindquarters, and larynx, leading to death within 24 days. Some dogs may not exhibit a typical course, so a history of bites should be considered.

Pathological Changes

The appearance of the body is generally unremarkable, with signs of emaciation, dehydration, and rough hair. The oral and gastrointestinal mucosa may be congested and eroded. Histological examination reveals nonsuppurative encephalitis, with eosinophilic inclusions in the cytoplasm of nerve cells.

Differential Diagnosis

The following are some key differences to consider when diagnosing rabies:

（1）Rabies vs. Pseudorabies

Both diseases present with symptoms such as restlessness, aggression, drooling, and biting various objects. However, rabies patients exhibit disorientation, paralysis of the jaw, the "hydrophobia" phenomenon, and are aggressive towards humans and animals. Pseudorabies patients often die suddenly, exhibit intense itching, and are not aggressive towards humans and animals.

（2）Rabies vs. Tetanus

Both diseases involve increased reflex excitement to sounds and lights, as well as neurological symptoms and a history of wound infection. Tetanus patients typically present with rigid spasms, resembling wooden horses, without hydrophobia. Rabies patients have a history of dog bites and the disease is transmitted through the wound.

（3）Rabies vs. Canine Encephalitis

Both diseases present with symptoms such as excitement, restlessness, depression, fear, biting when captured, and sensitivity to sounds. However, canine encephalitis patients do not have infectiousness, have an elevated body temperature, and the neurological symptoms are mainly characterized by circling, convulsions, and sometimes aimless running, not avoiding obstacles, and vomiting.

（4）Rabies vs. Organophosphate Poisoning

Both diseases present with symptoms such as drooling, ataxia, difficulty breathing, and convulsions. Rabies patients often have a history of dog bites, are infectious, and exhibit drooling with the lower jaw hanging down. Organophosphate poisoning patients have a history of exposure to organophosphate pesticides, present with acute outbreaks or sudden onset, vomiting, abdominal pain, diarrhea, and a garliclike odor in the gastrointestinal contents.

（5）Rabies vs. Sodium Fluoroacetate Poisoning in Dogs

Both diseases present with symptoms such as aimless running, barking, and rapid breathing, and hiding in the dark. Rabies patients exhibit aggression towards humans and animals, drooling, and chewing on wood, stones, and other objects, with significant neurological symptoms during the paralytic phase. Sodium fluoroacetate poisoning in dogs lacks these symptoms and the animals die quickly.

（6）Rabies vs. Lead Poisoning in Dogs

Both diseases present with symptoms such as restlessness, aimless movement, and barking. Lead poisoning patients have a history of ingesting leadpainted materials or dyes, vomiting, diarrhea, and do not exhibit the behavior of biting foreign objects or attacking humans and animals.

Reminders

A preliminary diagnosis can be made based on the symptoms of rabid pets, such as aggressive behavior, drooling, attacking humans and animals, and later motor disorders, combined with a history of bites. Laboratory tests are necessary for confirmation. Prevention and Control Measures include:

（1）Strengthening public health management and strictly controlling stray dogs and cats.

（2）Enhancing management of working dogs, domestic dogs, and companion pets, ensuring they are all vaccinated against rabies.

（3）Promptly culling infected dogs and other animals with rabies, and administering emergency vaccinations to companion pets that may have been exposed. The second dose should be administered 35 days after the first. For highrisk cases, hightiter antirabies serum should be administered within 3 days of a dog bite, at a dosage of 0.5 milliliters per kilogram of body weight, followed by vaccination.