Over the past 50 years, owning a pet has become very popular all over the world. In the United States alone, dog ownership has tripled since the 1960s. One negative consequence of this trend has been a dramatic increase in the number of feral dogs. According to some estimates, there are about 100 million feral dogs and cats living in the streets of America today.

Unfortunately, the biggest factor behind the growing number of feral dogs is irresponsible owners. Some people buy a puppy because they can’t resist how cute it is. Eventually, the dog grows up and everything changes. Now it’s less about heart-melting cuteness and more about going out for walks every day, picking up poop, and paying for dog food and veterinarian bills when the dog gets sick. How do some owners deal with these responsibilities? They don’t. Instead, they choose to abandon their pet on the street.

Another factor contributing to the problem is the trend of shrinking animal control budgets. Now that cities have less money to spend, they are less willing to fund programs that can help control feral pet populations. For example, one program that has been very effective in the past is the TNR approach.

This stands for "trap, neuter, and release." TNR programs help ensure that abandoned pets don’t breed. With no TNR programs, feral pet populations will continue to grow at an uncontrollable rate.

Most urban residents don’t feel that feral dogs are a problem, but this is exactly what feral dogs want them to think. Feral dog packs aren’t stupid, and they know that the less they’re seen, the safer they are. Thus, they tend to stay out of sight until very early in the morning. In total, they only spend about 10 percent of their time in places where humans can see them.

過去50 年來，飼養寵物已是全球普遍現象。光以美國為例，現今狗飼主的人數已是1960 年代的三倍。但是這項趨勢的負面效應，就是流浪狗的數量與日俱增。根據一些數據，現在美國約有1 億隻流浪貓狗露宿街頭。

不幸的是，流浪狗數量不斷增加的主因，就是沒有責任感的飼主。有些人買下幼犬的原因，純粹只是無法抵擋牠可愛的模樣。一旦狗兒長大，一切就都變了──狗兒少了能融化人心的稚氣，飼主多了必須每天外出溜狗、處理排泄物、購買狗食與醫藥費等責任。有些飼主無法妥善打理這些責任，轉而選擇棄養寵物，讓牠們流落街頭。

流浪動物問題的另一起因，則在於動物管制預算縮減。各城市預算緊繃，因此資助流浪寵物數量控管計劃的意願不高。舉例而言，過去曾有一項非常有效的「TNR 計畫」，意指捕捉後再絕育、回放動物。TNR 計劃能確保受到棄養的寵物不會再繁殖。如果沒有TNR 計劃，流浪寵物數量將持續以不受控的速率成長下去。

多數的都會居民對於流浪狗問題無感，但這就是流浪狗的目的。成群結隊的流浪狗並不傻，牠們知道只要越少現身，就越能確保自身安全。因此，牠們會躲得無影無蹤，直到清晨才會出現。牠們總共只花10% 的時間待在會撞見人類的地方。