Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.
BMC Vet Res. 2012 Dec 5;8:236. doi: 10.1186/1746-6148-8-236.
Mass vaccinations of domestic dogs have been shown to effectively control canine rabies and hence human exposure to rabies. Knowledge of dog population demography is essential for planning effective rabies vaccination programmes; however, such information is still rare for African domestic dog populations, particularly so in urban areas. This study describes the demographic structure and population dynamics of a domestic dog population in an urban sub-Saharan African setting. In July to November 2005, we conducted a full household-level census and a cross-sectional dog demography survey in four urban wards of Iringa Municipality, Tanzania. The achievable vaccination coverage was assessed by a two-stage vaccination campaign, and the proportion of feral dogs was estimated by a mark-recapture transect study.
The estimated size of the domestic dog population in Iringa was six times larger than official town records assumed, however, the proportion of feral dogs was estimated to account for less than 1% of the whole population. An average of 13% of all households owned dogs which equalled a dog:human ratio of 1:14, or 0.31 dogs per household or 334 dogs km-2. Dog female:male ratio was 1:1.4. The average age of the population was 2.2 years, 52% of all individuals were less than one year old. But mortality within the first year was high (72%). Females became fertile at the age of 10 months and reportedly remained fertile up to the age of 11 years. The average number of litters whelped per fertile female per year was 0.6 with an average of 5.5 pups born per litter. The population growth was estimated at 10% y-1.
Such high birth and death rates result in a rapid replacement of anti-rabies immunised individuals with susceptible ones. This loss in herd immunity needs to be taken into account in the design of rabies control programmes. The very small proportion of truly feral dogs in the population implies that vaccination campaigns aimed at the owned dog population are sufficient to control rabies in urban Iringa, and the same may be valid in other, comparable urban settings.
大规模给家养犬接种疫苗已被证实能有效控制犬狂犬病并降低人类接触狂犬病的风险。了解犬种群的数量结构对于规划有效的狂犬病免疫接种计划至关重要；然而，非洲家养犬种群的相关信息仍然很少，尤其是在城市地区。本研究描述了在撒哈拉以南非洲城市环境中家养犬种群的数量结构和种群动态。2005 年 7 月至 11 月，我们在坦桑尼亚伊林加市的四个城区进行了一次全面的家庭普查和横断面犬数量结构调查。通过两阶段免疫接种运动评估了可实现的免疫接种覆盖率，并通过标志-重捕样线研究估计了流浪犬的比例。
伊林加的家养犬估计数量是官方城镇记录的六倍，但流浪犬的比例估计不到整个犬群的 1%。平均每个家庭拥有 13%的犬，相当于 1:14 的犬：人比例，或每户 0.31 只犬或 334 只犬/km2。犬雌雄比例为 1:1.4。该种群的平均年龄为 2.2 岁，52%的个体小于一岁。但一岁内的死亡率很高（72%）。雌犬在 10 个月时具有生育能力，据报道其生育能力可持续至 11 岁。每只可育雌犬每年平均产仔数为 0.6 窝，每窝平均产仔数为 5.5 只。种群增长率估计为 10%/年。
如此高的出生率和死亡率导致抗狂犬病免疫个体迅速被易感个体所取代。在设计狂犬病控制计划时需要考虑到这种群体免疫的损失。犬群中真正流浪犬的比例很小，这意味着针对家养犬的免疫接种运动足以控制伊林加市的狂犬病，在其他类似的城市环境中也可能如此。
