Rabies is a devastating viral disease that targets the central nervous system of mammals, making it a serious concern for both animal and public health. This infection is nearly always fatal once clinical signs appear, and its zoonotic nature means it can be transmitted from animals to humans, typically through a bite. Understanding the observable changes in a dog is important for safety and for the immediate reporting of potential exposure. Symptoms manifest primarily as dramatic shifts in behavior and physical function.
Initial and Subtle Changes
The first phase of rabies, known as the prodromal stage, is characterized by vague and non-specific signs that can easily be mistaken for other illnesses. This stage usually lasts for two to three days as the virus progresses toward the brain. A dog may exhibit a noticeable change in temperament, which represents a departure from its normal personality.
A friendly dog might become shy, anxious, or seek solitude, while a nervous animal may become unusually affectionate and docile. Restlessness, a mild fever, and lethargy are also common during this time. The dog may also show unusual attention to the site of the original bite wound, often licking or chewing the area excessively. These subtle behavioral shifts are the earliest indicators of a central nervous system disturbance.
The Furious Presentation
The furious form of rabies is the presentation most often associated with the disease, marked by exaggerated excitability and aggression. Dogs in this stage become hyper-reactive to sight and sound, leading to extreme irritability and unpredictable behavior. They may pace constantly and display unprovoked aggression toward people, other animals, or even inanimate objects.
Disorientation is common, and the animal may bite or snap at imaginary objects, a behavior known as “snapping at air.” The classic sign of “foaming at the mouth” results from increased salivation and an inability to swallow. The virus causes pharyngeal muscle spasms (dysphagia), which allows saliva to accumulate and froth up when the dog pants or struggles.
The Paralytic Presentation
The paralytic form, often called “dumb rabies,” is the more common presentation in dogs and is characterized by weakness rather than aggression. This manifestation is particularly dangerous because the dog may appear depressed, withdrawn, or simply ill. The infection causes progressive muscle weakness, often beginning in the hind limbs, which results in incoordination, staggering, and a noticeable wobbly gait.
A defining feature of this form is the paralysis of the facial and throat muscles, which causes the lower jaw to droop open. This dropped-jaw appearance prevents the dog from being able to close its mouth or swallow, leading to constant drooling of saliva. The excess saliva is not foamy but appears as a thick, continuous stream. Paralysis eventually spreads throughout the body, leading to respiratory failure and death.
Immediate Safety Measures
If a dog is exhibiting any of these signs, remember that rabies is a fatal disease transmissible to humans through saliva. Retreat immediately and maintain a safe distance without attempting to capture, comfort, or touch the animal. Secure all pets and children indoors to prevent any possible contact with the suspected animal.
Contact local animal control or public health authorities to report the location and behavior of the dog. Do not attempt to transport the animal yourself, as this increases the risk of exposure. If an exposure, such as a bite or scratch, has occurred, the wound should be thoroughly washed and flushed with soap and water for a minimum of fifteen minutes. Seek immediate medical attention to determine the need for post-exposure prophylaxis.