Many people with a lost pet think that a search dog is the best method for finding their pet. However, most people tend to have unrealistic expectations and a lack of understanding of how a search dog works. I previously wrote an article on considerations for Using a Search Dog, and in this series of articles, I plan to go more in-depth on how search dogs are used to search for different types of lost pets starting with lost outdoor-access cats, specifically those lost from their home. An outdoor-access cat is defined as a cat that is allowed outside and unsupervised. These are the most difficult type of lost pets to find because of the number of possible scenarios for their disappearance and due to the nature of their scent trails.
A Brief Overview of Scent & Types of Search Dogs
Our cats are constantly depositing scent wherever they go. Scent theory describes scent as small rafts of skin (i.e. clusters of skin cells) that are constantly being shed from the body and that are then being broken down by bacteria (Syrotuck 2000). Some scent is deposited with direct contact with the ground while additional scent flows off the top of the body through air currents and travels through the air before being deposited on the ground. Scent will be stronger in areas where a cat repeatedly walks such as on preferred travel routes throughout their territory or where they rest. Large concentrations of scent can also collect (i.e. scent pools) where a cat spends a period of time such as a sleeping spot or refuge such as under a porch.
There are several different types of search dogs that may be called by many different names: tracking dogs, trailing dogs, area detection dogs, air-scenting dogs, cat detection dogs or remains detection dogs to name a few. Scent-specific dogs (generally tracking or trailing dogs) are trained to follow the individual odor of a missing person or animal. This individual odor is composed of the skins rafts and personal bacteria of the individual and is catalyzed by body secretions of that individual (Syrotuck 2000). Tracking dogs are trained to follow the scent left by the actual tracks of the missing animal, while trailing dogs are trained to follow the greatest concentration of scent on the ground. Since scent is also deposited in air currents from the animal, this scent may travel several feet to over 100 feet from where the animal actually walked. Although there is technically a difference between tracking and trailing dogs, they are often both referred to as “tracking dogs” by the general public. For simplicity, I will also refer to tracks or trails interchangeably, but if you were to study scent theory, you would find that there can be a lot of variation between the two.
Area detection dogs (e.g. air-scenting or cat detection dogs) are trained to search an area and locate the concentrated scent of any cat. Ideally this scent is “air scent” coming off of the actual lost cat, but the dogs may also indicate on a scent pool such as under a deck where the cat hid for a while. Both tracking/trailing dogs and area detection dogs are usually also trained to indicate on the scent of a deceased cat though some dogs are trained to specialize in just this task. Most people tend to assume that a tracking/trailing dog is superior to an area detection dog, but once you understand the challenges of tracking a lost outdoor-access cat, you may find that this is not always the case.
Challenges of Tracking a Lost Outdoor-Access Cat that Disappears from His Home Range
Outdoor-access cats usually have a home range where they regularly travel and rest. This may also be referred to as the cat’s territory or home range though technically it is only truly a territory if the cat defends it from other non-resident cats. For more information on cat home range size, read this article. The following illustrations show a very simplified version of a cat’s home range and movements. The first series of pictures (Tracks 1-6) show a cat regularly traveling around his home range culminating in Track 7, which shows all his travels for that week.
If the cat then goes missing, you can now imagine how difficult it would be for a tracking or trailing dog to follow the scent trail of the missing cat. A well trained dog can differentiate between an older and newer trail and direction of travel, but this is made more difficult with the many regularly traveled trails that will have an accumulation of scent and trails going in both directions.
The difficulty of locating the lost cat is made more difficult if there isn’t an uncontaminated scent article. The scent article is an item that smells like the missing cat that will be presented to the search dog. This tells the search dog what scent trail to follow. Many cat owners have more than one cat or dogs in the home, and it can be very difficult to find an item that is unique to the missing cat (i.e. uncontaminated from other pet scents). If the scent article also contains scents of other cats/dogs that go outside, then the search dog may also follow the numerous additional trails left by these pets. A well trained search dog will be trained in “missing member searches.” This is where the search dog is presented with a contaminated scent article and is then allowed to smell all the other pets in the house, and determine which pet is missing.
How Different Probabilities Influence the Effectiveness of the Search Dog
When an outdoor-access cat goes missing from their home, there are different probability categories (or scenarios) for what might have happened to the lost cat. These include: 1) Theft, 2) “Rescue” (i.e. when someone takes your cat because they think it is a stray), 3) Intentional Transport (e.g. a cat hating neighbor or angry ex-boyfriend kidnaps your cat and dumps him somewhere), 4) Unintentional Transport (e.g. your cat gets into the plumbers van), 5) Trapped (e.g. stuck in the neighbor’s shed), 6) Injury, Illness or Death (e.g. hiding because sick or injured or deceased due to illness or hit by car), 7) Wildlife Kill (i.e. victim of a predator attack), and 8) Displacement (e.g. chased out of their home range or otherwise leaves their home range). When an outdoor-access cat is lost away from home, this is a very different scenario and will be discussed in a future article. In some search probabilities, specifically theft, rescue, or any type of transport, the tracking/trailing dog has no chance of successfully finding the lost cat because the cat has been removed by a person and there isn’t a scent trail to follow. A search dog will also be unable to locate a cat outside if the cat is actually hiding or trapped inside the home, and this happens more frequently than people assume.
A tracking or trailing dog might be able to locate a missing cat within their home range (or just outside of it) if the cat is trapped somewhere outside, hiding and injured (such as from a severe cat fight or hit by a car) or deceased (such as hit by a car or killed by a predator). An area detection dog can also be used to successfully locate a cat under most of these circumstances. The picture below shows examples of where a cat might be located in each scenario.
Keep in mind that this is a very simplified scenario, and most cats will have a larger home range (usually 3 yards or more in each direction) which contains many more scent trails for the tracking/trailing dog to work through. In neighborhoods where the houses are close together and fenced, a tracking/trailing dog will have a much more difficult time because he will be unable to follow the trails made by the cat since cats frequently climb under or over fences from yard to yard. In these cases, an area search dog may be more effective to quickly check each yard for any sign of your cat.
Additional Challenges of Locating the Displaced Cat
One of the more common scenarios for a lost outdoor-access cat is that the cat has become displaced from his home range. This may occur if he is new to the area and becomes lost or if he is scared out of his territory (such as by fireworks, construction, a loose dog, or another cat) and either becomes lost or is afraid to come back. As much as we cat lover’s want to deny it, some “lost” cats will also choose to leave their homes when there is a significant change in the household such as a new baby, puppy or roommate. Some cats are more sensitive than others and may leave due to a change in routine (such as a prolonged injury or illness of their owner) or even a small change in circumstances (such as a remodeled living room or change in brand of cat food). In either case, the lost cat has left his home range and there may only be one scent trail leading to his new location. The photo below shows an example of this scenario where the lost cat traveled to the neighbor’s home and got in a fight with their new cat and was chased across the busy road.
When a lost cat is displaced from their home range, it can be challenging for a tracking/trailing dog to work through all the scent trails and scent pools to find the one most recent track that leads away from their home. This is made more difficult the longer the cat has been missing because the scent deposited throughout the home range might be an accumulation of years of scent while the trail leading out of the home range is only a single scent trail. How long scent survives is a whole other discussion that I will blog about in a future article. There has been some research that accumulated scent pools/trails may be viable for up to six months (Phillips 2006) while there is considerable debate on whether a single scent trail lasts for only 12 hours, a week or two, or even a month or more. Personally I am skeptical of those who proclaim to track scents more than a month old.
If the search dog does successfully find the displaced cat’s scent trail, it is unlikely that they will actually locate the lost cat during the search. These are referred to as “walk-up” finds and they usually only occur in less than 20% of searches and rates of only 5% or less are not uncommon. Unless the lost cat is stationary (e.g. hiding, trapped, severely sick or injured or deceased), it is unlikely that the search dog will be able to find the exact location of the cat. A cat that is being searched for by a dog will likely feel hunted and will evade the search dog team. In fact, a well trained search dog team will likely stop the track for your lost cat if the search dog indicates that the scent is very fresh and the cat is likely nearby. Using a search dog in this situation can provide some very useful information including where your cat went after leaving their home range and the area that they are currently hiding out. This information can help you determine where to put up additional posters, distribute flyers, and perhaps set up a wildlife camera and/or humane trap. Sadly, many people put all their hope (and often money) into hiring a tracking/trailing dog and then do not follow-up with the necessary search tactics after the search dog leaves.
Jones, Phillip. 2006. Scents and Sense-Ability. Forensic Magazine (online edition). April/May 2006.
Syrotuck, William G. Scent and the Scenting Dog. 2000. Barkleigh Productions, Inc. Mechanicsville, PA.