Genetic Behavior Analysis?

Hello, Summarians!

Nature versus nurture. How much of each individual is governed by our genes and how much is due to the world we experience? An age-old question. One of these studies tries to unlock a piece of that dilemma. As you can imagine, it is a very complex issue.

This newsletter attempts to help us all cope with these types of questions and the deluge of information we face every day. It usually contains 3 summaries and citations related to animal health.

If you enjoy it please pass it along to a friend 😄 

Antibiotic Resistance in Equine Dermatology

The text explains that antibiotic resistance is a growing global concern, particularly when it involves bacteria like Staphylococcus aureus that can affect both animals and humans. In horses, skin infections often involve S. aureus, including methicillin-resistant strains (MRSA), which have been increasingly documented over the years. The article highlights that while colonization does not always lead to disease, it poses significant risks by facilitating transmission among horses, veterinarians, owners, and other handlers. This situation is especially alarming given that some of the antibiotics used in equine practice, such as third-generation cephalosporins, are considered critically important for human medicine by the WHO. 

The discussion further details how various studies have shown rising levels of antibiotic resistance in horses with skin infections, noting a marked increase in resistance to commonly used drugs like penicillin, ampicillin, cephazolin, and sulfonamides. The prevalence of MRSA in both horses and equine veterinarians underscores the zoonotic potential, as evidenced by high colonization rates and cases of cross-transmission. The text emphasizes that risk factors for MRSA colonization include hospitalization, prior antibiotic use, and close contact with infected individuals, which collectively contribute to the spread of resistant bacteria in equine hospitals and the broader community. 

Addressing this challenge requires a change in how antibiotics are used in veterinary medicine. The article argues for enhanced antibiotic stewardship that includes preventing infections by managing underlying conditions, prioritizing topical treatments over systemic antibiotics when feasible, and relying on culture and sensitivity testing to guide antibiotic selection. It also calls for the development of clinical guidelines tailored to equine dermatology, as current recommendations are often extrapolated from small animal or human medicine. The overall message is clear: responsible use of antibiotics, improved hygiene practices, and ongoing research are essential to mitigate the spread of resistance and protect both animal and human health. 

Marsella, R. (2025). Antibiotic resistance in equine dermatology: what should we do?. Journal of the American Veterinary Medical Association https://doi.org/10.2460/javma.24.11.0732 

Bottom line — We need to be aware of this growing resistance

Genetic Basis of Personality in Dogs

The study explores the influence of dog personality on owner relationships and welfare, emphasizing that many behavioral traits are thought to have a genetic basis. It reviews a range of research—from assessments of working dogs like guide and military dogs to studies on shelter dogs—and highlights the need for understanding both breed differences and heritability to guide breeding programs. Central to the discussion is the Behavior and Personality Assessment in Dogs (BPH), a standardized test developed by the Swedish Kennel Club that builds on earlier methods such as the Swedish Dog Mentality Assessment. Using factor analysis, the study identified five behavioral dimensions—playful behavior, flight and distancing behavior, sociality, socially threatening and fearful behavior, and submissive behavior—that together explain 24% of the variation observed. Although the heritability estimates for these factors are generally low to moderate, significant genetic variation exists across all breeds, suggesting that selection could modify these traits. Notably, flight and distancing behavior exhibited the highest heritability, while differences between breeds in certain behaviors were small relative to the variation within breeds. The findings reinforce the idea that while breed may provide some predictive value regarding behavior, individual differences and environmental factors play a substantial role. 

Anne Dorthe Nygaard Sødal Tygesen, Björn Forkman, Peer Berg, Behavioral genetic analysis on dogs, Journal of Veterinary Behavior, Volume 78, 2025, Pages 78-89, ISSN 1558-7878, https://doi.org/10.1016/j.jveb.2025.01.011. 

Bottom line — Flight and distancing showed the highest heritability

Western Diet and GI Changes in Dogs

The study examines how a Western-style diet (WD)—rich in fats, carbohydrates, and processed foods yet low in fiber, vitamins, and antioxidants—affects the intestinal health of clinically healthy dogs. Known for its association with numerous pathophysiological conditions in humans, the WD has been less explored in canines. Previous research has linked high-fat diets to changes in the canine microbiome and metabolome, but the direct relationship between WD, mucosal dysbiosis, bile acid dysmetabolism, and intestinal inflammation had not been established. In a 16‐week dietary intervention, dogs were transitioned from a control diet (CD) to WD and then back to CD, which allowed for the assessment of changes in colonic inflammation, oxidative stress, microbial composition, and fecal bile acid levels. 

The results revealed that dogs on WD exhibited increased mucosal expression of NF-ĸB, elevated systemic inflammatory markers such as hs-CRP and myeloperoxidase, and heightened apoptosis of mucosal lymphocytes. Additionally, significant shifts in the colonic microbiota were observed, notably an increased Clostridia: Bacteroides ratio, alongside modifications in fecal bile acid profiles—specifically, higher levels of primary bile acid (CA). Although the study’s WD only mimicked the macronutrient profile typical of the human Western diet and was administered in a controlled colony setting, the findings support the idea that even short-term consumption of WD can induce low-grade intestinal and systemic inflammation. This research underscores the potential of dogs as a preclinical model for studying the impact of dietary patterns on gastrointestinal health in humans. 

Mason, B., Sahoo, D.K., Iennarella-Servantez, C.A., Kathrani, A., Morgan, S.M., Bourgois-Mochel, A., Bray, A.M., Gabriel, V., Zdyrski, C., Groeltz, J.M., Cassmann, E., Ackermann, M.R., Suchodolski, J.S., Mochel, J.P., Allenspach, K. and Jergens, A.E. (2025), Effects of a Western Diet on Colonic Dysbiosis, Bile Acid Dysmetabolism and Intestinal Inflammation in Clinically Healthy Dogs. J Vet Intern Med, 39: e70035. https://doi.org/10.1111/jvim.70035 

Bottom line — Not good for people and not good or dogs.

Just putting things in perspective …