Cast members Marissa O?Donnell and Sandy attend the opening night of the classic musical Annie in Hollywood. The musical tells the story of little orphan Annie (O?Donnell) and her dog Sandy. (Reuters)

The loss of a loved one to a fatal disease makes you want to delve deep and find out the ?hows? and ?whys?. A little stray pup I had been looking after began showing strange symptoms. He had a cough, a nasal drip and his breathing was very laboured. He kept whining and stumbled while trying to walk. He was obviously in a lot of pain. The vet put him on a drip, along with antibiotics, for three days. On the fourth day, he passed away. He had distemper.

Canine distemper is highly contagious and one of the most dangerous diseases pertaining to dogs. It is caused by a virus that attacks the intestinal, respiratory and, finally, the nervous systems of puppies and dogs.

Transmission: The distemper virus contaminates the atmosphere, making it an airborne disease that can be transferred among dogs even without body contact. An infected dog-owner must wash before touching other animals.

Dogs at risk: Though distemper can affect dogs of any age, puppies younger than four months old and dogs that have not been vaccinated against canine distemper are at greater risk.

Symptoms: It starts to show within two weeks of the infection. The first sign of distemper is diarrhoea that will probably subside after medication. Next, the dog may develop a transient fever, nasal discharge, coughing, lethargy, reduced appetite, vomiting, and a relapse of diarrhoea. After the respiratory stage, the animal gets the nervous signs that are either intermittent or continuous. In later stages, the virus may attack the nervous system, causing twitching, fits, walking in circles, partial or complete paralysis, involuntary movement of the feet, salivation, involuntary urination or defeacation. Even if a dog does not die from the disease, canine distemper virus can cause irreparable damage to a dog?s nervous system. Some may be left with persistent nervous twitches (chorea) and recurrent seizures.

Actress Jane Fonda holds her dog during the launch of her book Memories. (Reuters)

Diagnosis and treatment: Since the clinical signs of distemper are so varied, ruling it out in a sick dog makes it difficult. Vets diagnose canine distemper on the basis of clinical appearance and laboratory tests. Being a viral disease, there is no known cure. Treatment consists primarily of efforts to prevent secondary infections, control vomiting, diarrhoea or neurological symptoms and combat dehydration through administration of fluids. Ailing dogs should be kept warm, given good nursing care and be separated from other dogs.

Prevention: Vaccination and avoiding contact with infected animals are key elements of prevention. When you purchase a pup, make sure the dam or mother is fully vaccinated. This will ensure that the pup has a certain level of maternal protection. Puppies are very susceptible to infection, particularly because the natural immunity provided in their mothers? milk may wear off before their own immune systems are mature enough to fight off infection. Until a puppy has received its complete series of vaccinations, pet owners should be careful while taking their pets to parks or leaving them at kennels/creches. To combat this disease, please ensure that your dog?s distemper vaccination is up-to-date.