Monday, January 19, 2009

25 G Health Issues May Affect Dog's Ability to Detect Scents

If you rely on a dog to alert you using smell, such as a diabetic alert dog or an allergy alert dog, you need to be vigilant about detecting illness in your dog. If you notice any decline in the ability to detect scent level changes, you should first rule out health issues.

While I couldn't find any actual studies online for dogs to support this assertion, I did find several references for humans (see 1 below). Many sporting dog people have noted that when their dogs are ill or taking antibiotics, their capacity to accurately scent decreases. This was often observed when a normally accurate dog started making errors such as missing a scent of a bird. A dog that has an infected tooth, bladder or kidney infection, tick-based infection (Rocky Mountain Spotted fever (see 2) , Lyme's Disease see 3), fungal infection, kennel cough (Bordatella bronchiseptica), hypothyroid (see 4) etc may have a reduced ability to scent. Dogs with chronic ear infections may be affected as well. Nasal infections in dogs are less common than humans but can be complications of a disease.

Watch for any typical signs of infection or disease from draining eyes and nose, coughing, frequency straining during urination to lethargy, refusing to eat, fever etc.

Dogs noses need the presence of good bacteria in their nasal passage to capture and detect particles of scents from the air. If the level of good bacteria declines, so does their scenting ability (see 5). Infections and other diseases cause this imbalance as can antibiotics. Antibiotics wipe out the good bacteria along with the pathogens.

If you rely on a dog for medical scenting, make sure you put additional detection assistance in place or take more caution than usual while your dog is recovering from an infection or on antibiotics. If you are choosing a dog to train as a scent indication dog, be careful in your choice as some lines and breeds are susceptible to health issues that may limit their scenting ability.

If you would like to do more research, there seems to be more mention of this in hunting dogs. (dogs, infection, scenting ability and side effects, antibiotics) Talk to your vet to get their take on this.

1. Decline in Smell in Humans
2. Disease affecting scenting (hunting) ability
3. Lyme's
4. Hypothyroid
5. Antibiotic Use in Dogs Side Effects

Here is one peer-reviewed paper on which diseases affect a dog's sense of smell: It doesn't seem to be available easily on the web.
Myers, Lawrence J.: Use of innate behaviors to evaluate sensory function in the dog, pp. 389-399 in: Advances in Companion Animal Behavior (Veterinary Clinics of North America, Vol. 21 (2). 1991.
See the abstract in this link