What Factors Influence Animals Outcomes in Shelters

In this report we examine a comprehensive data set of over 26 thousand inputs from the October 1st, 2013 to March 2016. This data set explores the consequences of animals who have left the shelter, from the Austin Animal Center in Texas. The dataset, was sourced from Kaggle, a well known platform for predictive modelling and analytics competitions. Users can create competitions, posting data sets for those looking to explore and draw conclusions on the data to predict outcomes. The dataset we are using was posted by a Kaggle user, however the data posted is straight from the animal shelters website. Therefore the data can be trusted and is reliable, with the intention to provided insights from the competition that could help shelters focus on specific animals to ensure the best outcome, adoption.

According to the American Pet Products Association, it’s estimated that 78 million dogs and 85.8 million cats are owned in the United States. Approximately 44% of all households in the United States have a dog, and 35% have a cat. According to the ASPCA Approximately 6.5 million companion animals enter U.S. animal shelters nationwide every year. Of those, approximately 3.3 million are dogs and 3.2 million are cats. Each year, approximately 1.5 million shelter animals are euthanized (670,000 dogs and 860,000 cats). Approximately 3.2 million shelter animals are adopted each year (1.6 million dogs and 1.6 million cats).

There are a number of health risks associated with neglecting to spay/neuter dogs and cats. For male dogs, the desexing procedure eliminates the small risk of dying from testicular cancer as well as reducing the risk of non-cancerous prostate disorders and perianal fistulas. In female dogs, the likeliness of developing tumours is suppressed (if desexed before 2.5 years of age). As well as female dogs, female cats avoid potential health problems like mammary cancers, viruses and a depressed immune system. If male cats are desexed, risks including: malignant tumours, prostate issues and contraction of the Feline Immunodeficiency virus (FIV) are all dramatically decreased.

Personality differences exist between the sexes of both dogs and cats. Intact male dogs may exhibit aggressive behaviour targeted towards other male dogs. The desexing procedure lowers the hormone levels of the male dog, therefore possibly reducing or eradicating this particular form of aggression. Similarly, intact male cats are more inclined to become aggressive as adults than male cats who have been spayed or neutered.

Does breed affect the animals outcome?

The vast majority of breeds that go through adoption centres are mixed breeds, and Austin Animal Shelter is no exception. However, although mixed, the dominating breed can be a major influence in the outcome of animal. However this is only evident among dogs. The following graphs shows the top 10 breeds of both dogs and cats that are adopted, transferred and euthanaised.

The graph above shows the Chihuahua Shorthair mix being the most adopted dog breed at the shelter, followed closely by the Labrador Retreiver Mix and Pit Bull Mix respectively. There is an major difference between the following breeds, indicating an evident trend in breed adoption.

The top 10 breeds that were transferred from the shelter remained the same as the ones adopted. However the Pit Bull Mix assumed 2nd most tranfserred breed over the Labrador Retriever Mix. The trend in the graph however was very much the same as previous. Transfers of dogs are to a partnering shelter, potentially due to insufficient room or resources at the Austin Animal Shelter. Due to similar trends in the two graphs this may suggest these three breeds are very popular in Austin or Texas as a whole.

Euthanasia at the shelter is due to either two factors, suffering or aggression. The trend is crystal clear with the Pit Bull Mix being the top euthanaised breed at the shelter, with no breed closely following. This can reflect the common stigma toward the Pit Bull breed. Pit Bulls are known to be trained fighting dogs and commonly labelled a “Dangerous Breed”. In the state of Texas Breed Specific Laws can target such “Dangerous Breeds”, with some cities even ruling against the breeds adoption.

However, for cat breeds the data shows a different story. One breed dominates every category, the Domestic Shorthair Mix, with no breed following closely. From this we can conclude the Domestic Shorthair Mix is a extremely common breed across Austin and/or Texas.

Breed clearly plays a role in the outcome of the animal, however it may be due to how common the breed is.

Desexed vs Nondesexed

Do animals that are desexed have a higher chance of adoption?

The desexing of pets is a popular and encouraged procedure. This can reduce aggression, dominace, territorial and other unwanted behaviours, particularly in males, as well as higher risk of many infections and illnesses. We have assessed the state of the animals to see its correlation to its outcome.

Dogs adoption rates are clearly influenced by whether the animal is desexed or not. However, for the transfer of the dogs, more desexed dogs are transferred with a noticable difference between intact and neutered males. However this may just be due to the procedure being more common. For the euthanasia of dogs, desexed dogs were less likely to be euthanaised. As mentioned before aggression was a factor which lead to euthansia and in males nondesexed males tend to show unwanted behaviours, this data may show this link. Also the issue of higher risk of disease in nondesexed animals may be another reason for the difference between the two.

Similarly, Cats show the same trends as the dogs. However for the transfer of cats, this may be to a partnering shelter or Austin’s Stray Cat Return Program (SCRP). And for desexed cats the outcome of transfer was higher. This may indicate more cats transferred to the SCRP to be returned to their owners who had previously desexed the animal.

The sex status of the animal does influence the outcome the animal. Adoption is heavily influenced on whether the animal is desexed or not.

What is the Optimal Age for Adoption?

Age can influence the outcome of the animal, as it comes down to kitten verus cat and puppy verus dog.

age = as.numeric(data$AgeuponOutcome)
y <- age
hist(y,main = "Histogram of Age of Cats and Dogs", xlab ="age",col = "lightblue")

quantile((as.numeric(data$AgeuponOutcome)))
##   0%  25%  50%  75% 100% 
##    1   10   23   30   45

This histogram looks at the age of both cats and dogs within the Austin Animal Shelter. Showing that younger animals tend to have higher adoption rates. This makes sense as adopters may want to spend more time with their adopted pet, thus it is more favorable to adopt a younger cat or dog.

age = as.numeric(data$AgeuponOutcome)
boxplot(y,main="Boxplot of the Age of Cats and Dogs in Animal Shelter",horizontal = T,col = "pink")

mean(age)
## [1] 22.74639
sd(age)
## [1] 11.5528
IQR(age)
## [1] 20
quantile(age)
##   0%  25%  50%  75% 100% 
##    1   10   23   30   45
data1=(age[type =="Dog"])
data2=(age[type =="Cat"])

boxplot(data1,main="Boxplot of Dog Ages",horizontal = T,col ="blue")

mean(age[type =="Dog"])
## [1] 23.32183
sd(age[type =="Dog"])
## [1] 12.10975
IQR(data1)
## [1] 23
quantile(data1)
##   0%  25%  50%  75% 100% 
##    1    9   23   32   45
boxplot(data2,main="Boxplot of Cat Ages",horizontal = T,col = "lightblue")

mean(age[type =="Cat"])
## [1] 21.94234
sd(age[type =="Cat"])
## [1] 10.6714
IQR(data2)
## [1] 13
quantile(data2)
##   0%  25%  50%  75% 100% 
##    1   15   22   28   45
summary(y)
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##    1.00   10.00   23.00   22.75   30.00   45.00
quantile((as.numeric(data$AgeuponOutcome)))
##   0%  25%  50%  75% 100% 
##    1   10   23   30   45

This box plots looks at the spread of ages of cats and dogs who have entered the shelter. It shows that there is a relatively even spread of the medians between cats and dogs. However, the weights of the dog ages seem to carry more variables.

table2 = data$OutcomeType
plot(table2,col="lightgreen")

summary(table2)
##                        Adoption            Died      Euthanasia 
##               1           10769             197            1555 
## Return_to_owner        Transfer 
##            4786            9422

This graph shows the outcome of animals that have left the shelter. Adoption and transfer have the highest outcome for over 20 thousand cases for both cats and dogs. However, these are mainly for the younger cases.

age = as.numeric(data$AgeuponOutcome)
table3 = table(data$AgeuponOutcome)
table3 = (sort(table3,decreasing = T))
barplot(table3,main = "Age and Amount of Cats and Dogs within Shelter",col = "yellow")

Most animals within the shelter were between or less than 1 to 4 years old. In which they have a greater tendency to be adopted/transferred.

Overall, these graphs show that younger cats and dogs are in greater abundance within the shelter and have a higher rate of being adopted or transfered.

Findings and Conclusions

What we can obtain from this data is the ability to understand what are the greatest and most prominent outcomes for animals within shelters, why this might be the case and how people who work in these field areas. This being animal shelters, local councils or people who may want to adopt, may be in great interest for them. These insights could help shelters worldwide, to focus their energy on specific animals who need extra attention to ensure the best outcome, for adoption. Adoption is heavily influenced by breed, sex status and age. However many factors must be considered when drawing conclusions as drawn on throughout our report.