How Horses Grieve

Hello Summarians!

From practical to theoretical, here are a few studies that address some pertinent questions.

These are good examples of how current research can have immediate impacts and also provide avenues for further exploration.

If you enjoyed them, please pass them on to a friend.

Best Way To Cool Working Dogs

Working dogs perform highly demanding physical and mental tasks, and their intense drive, energy, and stoicism make them especially susceptible to heat stress. Heatstroke is the leading cause of accidental nontraumatic death in these dogs, and immediate, effective field cooling is critical for survival. However, current recommendations—such as immersion in cold water or wetting with ventilation—are often impractical in field settings where water and equipment are limited. This study compared various cooling protocols to determine feasible, effective interventions that handlers could apply immediately after exertional hyperthermia. 

In the first trial, only ice water ingestion significantly lowered core temperature. Topical methods, such as applying water or alcohol to the coat or using a cooling blanket, were ineffective—likely because hair insulation impeded evaporation or conduction. Cooling effectiveness depends on heat dissipation through convection, radiation, conduction, and evaporation, all of which are influenced by microcirculation in glabrous skin regions. Therefore, subsequent interventions targeted glabrous areas (axillae, groin, ventral abdomen, ear pinnae) using alcohol or water to promote heat loss. Still, these single interventions had limited success. 

A second trial combined liquid application with airflow. While alcohol, water, or fans alone failed to reduce body temperature, combining either liquid with airflow produced significant cooling effects. Alcohol plus fan application led to earlier reductions in rectal temperature (by 5–15 minutes) compared to water plus fan (significant at 15–30 minutes). These results indicate that combining evaporative and convective cooling enhances efficiency and can be implemented easily in the field using portable fans and readily available liquids. Cold water ingestion also lowered core temperature and may provide adjunctive benefit, though small volumes should be used to avoid risk of gastric dilatation-volvulus. 

No significant differences were observed in heart or respiratory rates across treatments, likely due to the limited thermal effect of most interventions and the dogs’ habituation to exercise. The study’s environmental parameters—ambient temperature, humidity, and airflow—were consistent between trials, supporting comparability. However, experiments were conducted in moderate indoor conditions rather than high heat and humidity typical of fieldwork, and only one breed of well-conditioned working dogs was included. Future research should test these methods in diverse breeds and under more extreme conditions, incorporating infrared thermography and refined fan specifications. 

In conclusion, while immersion remains the gold standard for cooling overheated dogs, it is often impractical in field settings. This study demonstrates that applying alcohol or water to glabrous regions combined with increased airflow provides an effective, feasible, and early-stage method to reduce core temperature, minimizing the risk of heat-related injury or death in working dogs. 

Gillette, R. L., Alves, J. C., & Shull, S. (2025). Evaluation of methods to reduce exercise-induced heat stress in working Labrador Retrievers. American Journal of Veterinary Research https://doi.org/10.2460/ajvr.25.06.0228 

Bottom line — Immersion is best. Alcohol and fan is the next best alternative.

Grieving In Horses.

This study explored how horses behave following the death of a companion, aiming to understand whether they show grief-like responses comparable to those seen in other social mammals. Using an online survey, researchers gathered information from owners of 325 surviving horses regarding the circumstances of the companion’s death, the pair’s relationship, and any behavioural changes observed immediately after and up to six months later. 

The majority of owners reported that surviving horses exhibited notable behavioural alterations within 24 hours of their companion’s death. These changes most often involved heightened arousal, modified interactions with other horses and people, increased alertness, and vocalisation. Statistical analyses revealed that the nature of the prior relationship strongly influenced these reactions: horses that had affectionate or dependent bonds with their companions were significantly more likely to show excitement at feeding or social times and changes in their behaviour toward humans than those whose relationships were merely tolerant. Many of these behavioural modifications persisted for up to half a year. 

Witnessing the death appeared to intensify certain responses. Horses that saw their companion die were more likely to alter sleep and feeding patterns within 24 hours and to display shifts in excitement and vigilance. Interestingly, being allowed to spend time with the body did not influence behaviour in the first day but did appear to reduce certain changes later on. Within six months, horses that had time with the body were less likely to show altered vocalisation or feeding-related excitement, whereas those denied this opportunity were more prone to ongoing arousal and vigilance differences. 

These findings indicate that equids can display complex behavioural responses following the loss of a companion, consistent with grief-related behaviour reported in other social species such as elephants, dolphins, and primates. The study underscores the potential welfare impact of social loss in horses and highlights the importance of allowing owners and caretakers to manage bereavement sensitively, while also emphasising the need for controlled empirical studies to confirm and better characterise these grief-like reactions. 

Claire Ricci-Bonot, Emily Wilson, Stefania Uccheddu, Daniel Simon Mills, Grief-like distress responses in horses after the death of a conspecific, Applied Animal Behaviour Science, Volume 292, 2025, 106799, ISSN 0168-1591, https://doi.org/10.1016/j.applanim.2025.106799. 

Bottom line — Great species-specific tips.

Canine Skin Organoids

Skin disease is among the most frequent concerns reported by dog owners, yet studying these conditions typically relies on live-animal models. Organoids—three-dimensional cell cultures that replicate tissue structure and function—offer a promising alternative. In humans, epidermal organoids have already been used to study disease mechanisms and treatment responses, and similar epidermal organoids (keratinocytoids) have now been developed in dogs. This study compared the morphology and ultrastructure of canine keratinocytoids with that of normal canine epidermis using light microscopy and transmission electron microscopy (TEM) to assess their suitability as an in vitro model. 

The findings revealed that keratinocytoids closely resemble natural canine epidermis in both histological and ultrastructural features. Key epidermal structures—tight junctions, desmosomes, and lamellar bodies—were present in both, supporting their functional similarity. Lamellar bodies, vital for forming the skin’s lipid barrier that prevents water loss and defends against external insults, were well-developed in organoids. Keratinocytes in organoids showed varying glycogen accumulation, likely due to high-glucose culture conditions. While no basement membrane was evident because of the absence of dermis, basal cells exhibited early signs of hemidesmosome and microvillus formation, indicating potential attachment structures. Melanocytes were not observed, likely because the culture conditions did not promote their differentiation. 

Organoids displayed larger keratohyalin granules within the stratum granulosum, possibly reflecting heightened filaggrin expression or altered barrier dynamics induced by the growth medium. In the stratum corneum, both models showed similar keratin layers and corneodesmosomes, though the in vivo epidermis exhibited a more organized keratin structure. Lipid lamellar matrix visualization was unsuccessful in both samples due to the limitations of TEM staining for lipids. Light microscopy revealed a hyperplastic appearance of organoid epidermal layers, probably caused by growth factor stimulation in the culture system. 

The main limitation of the study was the small sample size (four dogs) and potential autolytic artifacts from post-mortem skin collection, though no major ultrastructural degradation was evident. Despite these limitations, the similarities between organoids and native skin strongly support keratinocytoids as a valid structural model for canine epidermis. The results highlight their potential as an ethical, reproducible, and cost-effective platform for investigating skin physiology, pathology, and therapeutic interventions in dogs. 

Lui CC, Wiener DJ, Groch KR, Stranahan LW, Heard CR, Armién AG. Evaluation of canine epidermis and keratinocytoids (keratinocytic organoids) by transmission electron microscopy. Vet Dermatol. 2025; 36: 696–702. https://doi.org/10.1111/vde.13356 

Bottom line — Potentially useful way to do skin research.

Just putting things in perspective …