What is Meant by the Probability of Detection?

Probability of detection (POD) is the chance that the missing animal could be detected by searchers if it was indeed within the search area. Searchers should not focus on looking for the missing animal, but rather they should look for clues such as physical evidence. This will ensure that any evidence is not missed during the search for a missing animal. 

There are various factors that will raise or lower a POD. These factors include the size of the search are, rugged terrain vs. flat ground, and heavy brush vs. groomed lawns. 

In traditional search and rescue when searching for missing persons, an average grid search team (which is when searchers space out in a line and conduct a systematic sweep of an area) takes 3.5 hours to cover one mile. Under these conditions, the POD is: 

• 90% if the searchers are spaced 20 feet apart
• 70% if the searchers are spaced 60 feet apart
• 50% if the searchers are spaced 100 feet apart 

In a grid search, the more space allowed between the searchers, the higher the probability that the searchers will NOT be able to find what they’re looking for, and so the POD will be low. 

In relation to missing animal searches, the POD will be dictated by the specific behavior of the animal being sought, the accessibility of the search area, and the resources available. 

A POD is used for missing animals where an area search is conducted. This is mot often conducted on animals such as cats, reptiles, and ferrets which are often found within a close proximity of the “place last seen.” For animals that are likely to travel, such as dogs, birds, and horses, other search methods would be used.

The Pros and Cons of Microchipping

Microchips are basically tiny transponders about the size of a grain of rice. They are made up of a memory circuit and a miniaturized coil inside of a glass and can be injected with a hypodermic syringe because of their small size. Your veterinarian or other technician implants the microchip just under the skin between the shoulder blades, and the whole procedure takes only a minute or so. The chip’s memory circuit contains a unique number registered to your pet, which can be read by special scanners found in many veterinary offices and shelters. 

Here are some Pros and Cons of getting your pet microchipped: 

• The microchip is permanent. It can’t be dislodged once it’s been implanted and has a lifetime of 75 years.
• Implanting a microchip takes less than a minute with no anesthetic required
• Once implanted, the animal doesn’t even know it’s there.
• Microchips are a way of deterring theft of the pet or make theft easy to prove if the culprit is caught with the animal.
• Implanted chips are tamper-proof
• Microchips don’t disfigure a pet like tattoos.
• Microchips are, however, more expensive
• Because the technology is somewhat new, people still don’t think to take a found animal to a vet or shelter to have them scanned.
• Chips are becoming standardized, but there are still a couple of registries which can cause confusion. 

Microchipping is a great tool to help reunite pets with owners but they’re not foolproof. When a lost pet is picked up by an animal control officer or is taken to an animal shelter or human society, the workers there will use a handheld scanner, scan the animal, and determine if a microchip has been implanted. Microchips implanted before 2003 can be scanned and read by shelters and vets. Microchips that came into use in late 2003 are not readable by most shelters and vets because the chips require different kinds of scanners. So there is not yet one universal scanner than can read all different types of chips. 

While each owner must decide for himself or herself which method might be best, after researching this article, I am personally inclined to take a “shotgun approach” with a combination of microchipping and collar with tags. The microchip would be the source of a permanent record and the tags would give the owner’s name, phone number, and the fact that the animal is chipped.

 

  

 

  

The Basics Of Forensic Testing

Want to try your hand at being a CSI? If you live too far from a pet detective, you still can help yourself find your lost pet. If you find blood or fur in the area and want to determine if it’s your lost animal, there are several identification tests that you can run. 

If you locate a stain but are not positive whether or not it’s blood, you can run a quick and easy analysis by running what is called a Hemident test. Basically, it’s an ampoule which when broken turns blue/green if positive. The Hemident test will verify that the sample is blood but that’s where it ends. You won’t know if it’s animal or human blood. 

The Hexagon test takes things a step further and verifies whether or not the blood is human blood. The problem with this test is that you need to keep in mind that just because the test results indicate that the stain is non-human blood doesn’t necessarily mean it’s animal blood. The test results will show one blue stripe if the stain is anything that is not human blood like catsup or motor oil. So, you would first need to run a Hemident test in order to verify that it’s blood before you run a Hexagon test to verify that the stain is not human. 

The most definitive test that could be run would be a DNA analysis. A DNA test can be used in lost pet investigations in 2 ways. First, it can be used to help make a positive identification. The is done by running a test to see if there’s an identical match between the DNA that was extracted from a sample of the missing pet which is then compared with the suspected stain containing DNA. The limitations of this test are that if you don’t have a control sample of the missing pet’s DNA then you can’t run a comparison. 

The second DNA test that can be done is simply an analysis of one DNA sample that can determine the species of the animal. It’s not recommended to start with a DNA test on a suspected stain because you might swab and send off to the DNA lab something like motor oil by mistake! Mistakes can be expensive, so that’s why it’s recommended to first verify that the stain is indeed blood with a Hemident test. So always conduct a Hemident test followed by the Hexagon test and then a DNA test.

What’s The Probability That Your Pet’s In A Certain Area?

You’ll never have enough time to search an area for you pet inch by inch. You’ll need to target your energies into the areas where the missing animal is most likely to be. This is called determining a Probability of Area (POA) and is determined by various factors: 

• The type of animal that’s missing 
• The patterns of behavior in that particular species
• The environment of the animal 
• The temperament of the individual animal 
• The motivation of the animal 
• The terrain of the search area 
• The weather 

Let’s say you suspect your animal is missing in one particular yard. Try breaking the yard up into 4 equal areas. If you search one part completely, then the probability increases that the animal will be found in one of the other three parts. In simple math terms, each of the 4 areas of a yard is 25% of the total. If you search one area then the chances go up higher (33%) that the animal is in one of the other 3 areas. 

It’s rare that an area can be searched with a 100% POD. Therefore a search is forced to be undertaken in a given area at under 100%. This means that is an area is searched and the missing animal isn’t found, even with a 95% POD, there’s the possibility (5% chance) that the missing animal might have been missed or that the missing animal wasn’t in the search area to begin with. This is ok as you can now cross off your list a potential place to look!