60% of human population is at risk of getting Rabies and 97% of human patients are attributed to dog bites. Sixty thousand human deaths occur yearly in the world and India contributes its one-third (20,000). The number of stray dogs may be more in big Indian cities, but their human:dog ratio is better (Mumbai 1:31, Bangalore 1:37, New Delhi 1:43 and Chennai 1:100) than Srinagar (13:1). With the currently available vaccines and tools for veterinary and public health interventions, it is possible to eliminate the dog mediated Rabies. However, more comprehensive and integrated approach to strengthen coordination and technical and institutional capacities should get top priority.
As a Veterinary Surgeon and Head of the Referral University Veterinary Hospital (Division of Veterinary Clinical Complex, FVSc & AH, SKUAST-Kashmir), I am regularly being asked several questions regarding Rabies in general and the pros and cons of various strategies currently available to manage the stray dog over-population in particular. While the world medical and veterinary professionals (with a hope to win the fight against Rabies up to 2030) are engaged in spreading awareness during this week (14th World Rabies day, 28-09-2020), I wish to clarify a few common doubts regarding the current dog stabilization protocols:
Impact of stray dog overpopulation on public health:
Dogs transmit approximately 300 diseases including the dreaded Rabies to humans. The saliva of a rabid (or rarely carrier) dog with full load of the virus enters the tissues via the bite wound/s. It passes specifically through the nerves to the brain resulting in its acute infection and dreadful death in 8 to 10 days.
Impact of stray dog overpopulation on livestock & wild life:
One to several livestock particularly grazing sheep are killed or badly mutilated in every dog attack occurring in all seasons. They also suffer from Rabies and several other acute and chronic diseases transmitted by the dogs. The economic loss of losing productive animals, and the amount spend on treatment of the wounded ones is enormous for the farming community. Unfortunately, these figures are generally not highlighted. Stray dogs don’t even spare the wild animals. Their significant role in extinction of 11 vertebrates and threat to the survival of 188 more species has been reported. They are contributing in pathogen pollution, predation, competition and hybridization of several endangered wild animal species.
Key area to eradicate rabies:
A treatment protocol for the people and the animals is yet to emerge but the fact that the disease is completely preventable keeps the medicos and the veterinarian’s hopeful. The mass vaccination of at least 70% dogs and their population management are the key areas for achieving success in eradicating Rabies.
Mass killing of dogs by poisoning:
The countries that practiced mass poisoning, could kill a maximum of 24% dogs only in a year with no significant impact on the disease. Where ever the dogs are removed others migrate into the area to fill the ecological niche. The left-over Strychnine offered with food (as bait) to the animals is a potential environmental hazard. The distressing and painful experience prior to death of dogs by poisoning is not acceptable to majority of the people. Therefore, the practice of poisoning to kill is now strongly discouraged by WHO.
Putting large number of stray dogs in the shelters throughout the remaining life may raise several animal welfare issues and feeding them for several years will be too expensive for the governments in the developing countries. Despite efforts less people come forward to adopt the sheltered dogs in a few rich nations where roaming dogs are sheltered.
Contraceptives for dogs:
Fertility control using various hormones and their analogues as contraceptives is feasible in pet dogs. They only delay conception for a variable period of time and have to be repeated frequently with chances of developing side effects.
Use of vaccines for fertility control in dogs:
Efforts to develop vaccines for sterilizing dogs have till date resulted in products either not giving long lasting effects or producing side effects and complications in the vaccinated animals.
Procedure currently adopted to stabilize the stray dog population:
Major surgical intervention with the advantage of ensuring permanent sterilization and reduction in the aggressive biting behaviour in animals, undertaken as Animal Birth Control (ABC) – Rabies Vaccination campaign is the only viable option to manage stray dog population. The procedure involves catching or trapping the dogs, neutering them, providing food and postoperative care for three days and releasing them in the areas wherefrom they were trapped. Although expensive and requiring expert vets and skilled dog catchers, the protocol when followed aggressively has shown satisfactory results in several cities within and outside India.
Minimally invasive surgeries for sterilizing dogs:
In bitches’ the laparoscopic sterilization is too expensive for mass sterilization. Minimally invasive chemical sterilization of male dogs using zinc gluconate – arginine has shown promise but is not affordable in resource poor countries. The cheaper materials like calcium chloride etc. have also been tried but don’t ensure total sterility and also result in severe tissue reaction in many dogs, hence their use is not gaining popularity. An alternative, Pinhole castration a minimally invasive procedure has been standardised in stray dogs in Faculty of Veterinary Sciences, SKUAST-Kashmir. The technique was subsequently used in mass dog sterilization programme named Big Fix in Uganda with encouraging results. The procedure is effective, reduces expenditure and time of surgery, can be accomplished with only a few instruments.
The research on development of targeted cytotoxins and gene-silencing is currently being pursued vigorously to develop safe products that would be hundred percent effective after single use?
Comprehensive protocol for reducing incidence of Rabies:
It is essential that public awareness to prevent dog bites, proper disposal of garbage and aggressive dog sterilization campaign should be followed not only in cities but also in districts, towns and blocks. Collaborative efforts by medical and veterinary institutions and departments along with various municipalities are now badly needed. The whole programme will achieve the desired targets only if the government funding is liberal particularly in the beginning and the monitoring mechanism is efficiently designed and sincerely implemented.
Mujeeb Fazili is Prof. & Head, Division of Veterinary clinical Complex, Faculty of Veterinary Sciences, SKUAST-Kashmir