Statistically Speaking

CLICK BELOW FOR 2011 statistics:

2011 Task+Force+Report Phases I and II

Statistics Following 46 Montana Spay/Neuter Task Force Visits to Montana Communities

In gathering the statistics (where records are kept) from the Montana Spay/Neuter Task Force visits to communities throughout Montana over the past seven years, we have arrived at a number of conclusions. In every instance, the spay/neuter event has had a major impact on those communities in which statistics were available. In larger urban areas, the immediate impact is about a 19% drop in animals impounded and about a 24% drop in animals destroyed. Dog bites decreased by 33%. In almost every case, the impact on animals destroyed is greater than for animals impounded. In smaller, more compact areas, such as in Native American Nations, the immediate and long-term impact was greater, varying from a decrease of 20% to over 50%, in the animals impounded or destroyed. The effect of the decrease is generally most notable about six months after the spay/neuter event and, in almost all instances, there is a steady drop in animals impounded or destroyed for one to two years after the spay/neuter event. The impact of additional visits is to bring about a steady decrease in animals impounded or destroyed (70% to 75% below what was occurring before the first Task Force visit). All of the differences (before versus after) were significant at the .01 level of significance (Chi Square). In Montana, most animals are impounded from May to October. Consequently, wherever possible, the statistics were corrected for seasonal variations. Many communities issue spay and neuter certificates, some aggressively. However, we have found little or no evidence for the positive impact of these certificates. Increasing the number of certificates lead to an increase in animals impounded for that year almost as often as decreasing the certificates. Using a Spearman Rank Order Correlation, we found no significant relationships between intake or animals destroyed and the number of certificates issued. Sign Tests comparing changes in the number of certificates in a given year and changes in intake again were non-significant.

The larger the spay/neuter event (in some cases over 1,000 surgeries), or the smaller and more compact the community, the greater the impact. Repeated visits lead to a long term and more permanent control of animal overpopulation. The cost effectiveness of one large- scale clinic on the operation of a shelter, the cost of impounding, caring for, and destroying animals, was shown to be between $104,000 and $147,000. Large clinics followed by three or four visits seem to be much more effective than the issuance of spay/neuter certificates or occasional surgeries.

Impact Statistics to Montana Communities Following 46 Montana Spay/Neuter Task Force Visits

Summary: Analyses of Impacts

In gathering the statistics (where records are kept) from the Task Force visits to communities throughout Montana over the past seven years, we have arrived at a number of generalizations. Each Task Force visit helped a community bring together its resources to create a pet care event, the centerpiece of which was a free, demonstration spay/neuter clinic, to help solve a community problem, and, in doing so, own the solution. The Task Force brought a small van carrying supplies and equipment to set up in an existing building a spay/neuter clinic with from 2 to 6 or more surgery tables. In every instance, a pet care and spay/neuter event sponsored by the Task Force with and at the invitation of local authorities has had a major impact on those communities in which statistics were available. In larger urban areas, the immediate impact is about a 19% drop in animals impounded and about a 24% drop in animals destroyed. In almost every case, the impact on animals destroyed is greater than for animals impounded. In smaller, more compact areas, such as in Native American Nations, the immediate and long-term impact was greater, varying from a 20% to over a 50% decrease in the animals impounded or destroyed. The effect of the decrease is generally most notable about six months after the spay/neuter event, a drop of 35% to 60%. In almost all instances, there is a steady drop in animals impounded or destroyed for one to two years after the spay/neuter event. The impact of additional visits is to bring about a steady decrease in animals impounded or destroyed (70% to 75% below what was occurring before the first Task Force visit). In some cases, this steady decline over time might best be accountable by a change of attitudes toward animals within the community.

In Montana, most animals are impounded from May to October. Late fall, winter and early spring, the colder months, are the slow periods. Consequently, wherever possible, the statistics were corrected for seasonal variations by comparing the same months before the event with the same months after the event. Many communities issue spay and neuter certificates, some aggressively. However, we have found little evidence for the positive impact of these certificates. Increasing the number of certificates lead to an increase in animals impounded for that year almost as often as decreasing the certificates. Using a Spearman Rank Order Correlation, we found n0n-significant relationships between intake or animals destroyed and the number of certificates issued. Rs varied from a negative 0.49 to 0.43 in different communities. Most correlations were slightly positive in the neighborhood of .20. Sign Tests comparing changes in the number of certificates in a given year and changes in intake again were non-significant (p> .50 one-tailed test). It can be concluded that the observed values differ from zero only by chance.

The larger the size of the spay/neuter event, the longer the event, or the smaller and more compact the community, the greater was the likelihood for change. Repeated visits or increasing the likelihood of more spay/neuter services by greater veterinary participation can lead to a long term and more permanent control of animal overpopulation.

Statistics for the years 1998-2004 are available here.