The Apple & the Tree

child and dog photo

Retrievers can retrieve tennis balls until exhaustion. An Australian shepherd might herd you until you hide in a closet. At the Western Veterinary Conference last month I attended presentations on neurology, nutrition, and behavior medicine. Almost everything influences behavior. Environment and personal encounters are big but it all starts with genetic coding.

Dr. Leanne Lilly is head of behavioral medicine at The Ohio State University Veterinary Medical Center. She explained that beyond an individual’s inherited tendencies, events surrounding its birth, called epigenetics, can alter the way DNA drives behavior. It’s complicated but the apple often doesn’t fall far from the tree.

Working breeds are more excitable and energetic but interested in learning and play with their people. Many are aggressive toward other dogs. Jack Russel terriers, Chihuahuas, Rhodesian ridgebacks, American Staffordshire terriers, and Bernese Mountain dogs can be harder to train but, as Dr. Lilly stressed, the statistical differences are small. Breed accounts for only 9% of the variations in behavior.

Understanding the heritability of some behaviors, like compulsive flank sucking in Dobermans, can help with diagnosis and treatment. The DNA of some English bull terriers has them spinning, putting their heads under furniture and then freezing in place. Spinning is also common in Malinois and Staffordshire terriers. Tail chasing is a genetic trait of German shepherds and Australian cattle dogs but the abnormal brain pathways responsible for repetitive behaviors can also occur in unrelated breeds.

Behavioral genetics can be confusing. Dog breeds who share physical appearances, but that are not closely related, may still show similar behaviors. For example, small dogs of different breeds are prone to stranger-danger and have a greater tendency for separation anxiety.

There are more variations among individuals of the same breed than there are genetic differences between breeds. And it’s not just dogs. Compulsive wool or fabric sucking is seen almost exclusively in Siamese and Burmese cats and their crosses. We all want choosing the right pet to be simple but it just isn’t so. We do our best but it’s still a bit of a crap shoot.
For help with behavior problems, you can sign-up for a Zoom Group Conference on my website,

Dr. Jeff Nichol is a residency-trained veterinary behaviorist. He provides consultations in-person and in groups by Zoom (505-792-5131). Each week he shares a blog and a video to help bring out the best in pets and their people. Sign up at no charge at Post pet behavioral or physical questions on or by US Post to 4000 Montgomery Blvd. NE, Albuq, NM 87109.