A visit to a petting zoo usually means excited children playing around with a few goats. But in North Carolina, an ordinary animal encounter has triggered a public health warning after four baby goats linked to a mobile petting zoo tested positive for rabies.The goats belonged to Farm Adventures, a mobile petting zoo based in Harmony, North Carolina. Three goats tested positive for rabies at the North Carolina State Laboratory of Public Health on August 28, while a fourth was not tested but was presumed infected. All the four animals were euthanised. Health officials are now urging anyone who touched or held the baby goats between July 28 and August 27 to contact their local health department and find out whether preventive treatment is needed. The animals had appeared at events across several North Carolina counties during that period. A Skunk Could Have Been The SourceAccording to the North Carolina Department of Health and Human Services (NCDHHS), the goats were most likely exposed when a skunk entered their pen in late July.The petting zoo said the goats were too young to receive rabies vaccinations at the time and staff did not know they had been bitten. The animals also showed no obvious signs of rabies, making the infection difficult to spot before testing. That brings us to one of the most unsettling features of rabies. An infected animal does not necessarily look obviously sick at the time a person encounters it.NCDHHS said the goats “may have been in direct contact with people at events while infectious” and is working with local health departments and event organisers to identify people who could have been exposed.Also read: Bird Flu In US: Are Cats Spreading A Deadly Disease? How Does Rabies Spread From Animals To Humans?Rabies is caused by a virus that attacks the central nervous system. The most common route is an infected animal's bite, because the virus is present in saliva. Scratches contaminated with saliva can also pose a risk. Simply being near an infected animal does not mean you are exposed to rabies.Once the virus enters the body, it can travel through peripheral nerves towards the brain and spinal cord. This helps explain why there can be a considerable gap between exposure and symptoms. It can last weeks to months, depending partly on where the exposure occurred and how far the virus has to travel to reach the brain.Also read: Is There A Difference Between Zoonotic, Non-Zoonotic And Reverse Zoonotic Diseases Why Is Rabies Almost Always Fatal Once Symptoms Begin? This is where rabies becomes particularly dangerous. In the early stage, symptoms can resemble many ordinary illnesses, including fever, weakness and headache. There may also be pain, tingling or itching around the site of the bite. But once the virus reaches the brain, the disease can progress to encephalitis, causing confusion, agitation, hallucinations, difficulty swallowing, excessive salivation, seizures and paralysis.The CDC states that once clinical signs of rabies appear, the disease is nearly always fatal. There. By the time neurological symptoms appear, the virus has already established itself in the nervous system, where eliminating it becomes extremely difficult.Window To Prevent Rabies Is Before SymptomsRabies is preventable even after an exposure, provided treatment is started promptly and before symptoms develop. Post-exposure prophylaxis, or PEP, generally includes thorough wound cleaning, rabies immune globulin for people who have never previously been vaccinated, and a course of rabies vaccine. This is why North Carolina officials are not telling exposed visitors to wait for symptoms. Instead, NCDHHS says people who had contact with the goats should contact their local health department to determine whether medication is needed.