Are Breed Pain Differences Real ???

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Breed Differences in Pain Sensitivity

In a study conducted by Gruen et al. (1), it was found that veterinarians and the general public believed that dog breeds differ in their sensitivity to pain. However, there is no scientific evidence to support this belief. The study aimed to investigate whether veterinarians' breed-specific pain sensitivity ratings align with measures of pain sensitivity in dogs. The study used quantitative sensory testing (QST) methodologies to evaluate pain sensitivity across different dog breeds. QST is a noninvasive and semi-objective research tool that assesses the response of the somatosensory system to standardized stimuli. The study included various QST methods, such as mechanical and thermal stimuli, applied to different body locations. The findings of the study revealed that veterinarians' pain sensitivity ratings did not explain the observed breed differences in pain sensitivity thresholds measured by QST. However, breed differences in pain sensitivity thresholds were detected across multiple QST methods, suggesting that breed-related differences in pain sensitivity do exist. The study also identified breed differences in emotional reactivity, indicating that certain breeds may exhibit different behavioral responses. The study highlights the importance of understanding breed-related differences in pain sensitivity, as it can guide the development of pain-scoring systems and treatment recommendations for dogs. However, it also emphasizes the need to investigate when and how veterinarians developed these distinct breed-specific beliefs about pain sensitivity. The study concludes that while breed differences in pain sensitivity thresholds exist, veterinarians' pain sensitivity ratings do not fully explain these differences. Future research should focus on identifying the factors that influence veterinarians' breed-specific pain sensitivity beliefs and further investigate the biological mechanisms underlying breed differences in pain sensitivity. This knowledge can improve pain management in dogs and help tailor approaches to specific breeds. 

Caddiell, R. M., Cunningham, R. M., White, P. A., Lascelles, B. D., & Gruen, M. E. (2023). Pain sensitivity differs between dog breeds but not in the way veterinarians believe. Frontiers in Pain Research, 4, 1165340. https://doi.org/10.3389/fpain.2023.1165340 

Bottom line — They exist and can help with pain management plans although further study is needed

Epilepsy monotherapy results from caregivers

This passage discusses a study conducted to compare the outcomes of dogs with idiopathic epilepsy (IE) treated with different antiseizure drugs (ASDs) as monotherapy. The study aimed to evaluate caregivers' perceptions of seizure control, presence of adverse effects (AEs), and quality of life (QoL) for dogs treated with phenobarbital (PB) versus levetiracetam (LEV) or zonisamide (ZNS) as monotherapy. The study found that the majority of caregivers reported a favorable outcome with all three ASDs. Approximately three-quarters of the dogs showed improvement in seizure frequency, and a significant improvement in QoL was reported by caregivers for all treatment groups. However, the PB monotherapy group had a higher overall incidence of AEs compared to the LEV and ZNS groups, and the number of AEs per dog was also greater with PB. The most commonly reported AEs across all treatment groups were sedation and ataxia. Despite the higher incidence of AEs, the PB monotherapy group did not have a significantly different drug withdrawal rate compared to the other groups, and AEs did not significantly impact QoL. The study also noted that dogs on PB monotherapy had a greater improvement in cluster seizures compared to ZNS, but no difference was observed in whether cluster seizures resolved with monotherapy. Additionally, the study found that dogs in the PB monotherapy group had a significantly lower age at seizure onset compared to the ZNS group. However, the study had several limitations, including its retrospective nature, variability in follow-up time, recall bias, and subjective nature of caregiver-reported data. The small sample size in each monotherapy group and the study population being from a referral institution were also limitations. In conclusion, the study provided some insights into caregivers' perceptions of the outcomes of dogs with IE treated with PB, LEV, or ZNS as monotherapy. However, a randomized controlled clinical trial is needed to further assess the comparative safety and efficacy of these drugs in dogs with IE. 

Gristina, B. R., Waldron, R. J., Nettifee, J. A., & Muñana, K. R. (2023). Comparison of caregivers’ assessments of clinical outcome in dogs with idiopathic epilepsy administered levetiracetam, zonisamide, or phenobarbital monotherapy, Journal of the American Veterinary Medical Association, 261(7), 1020-1027.https://doi.org/10.2460/javma.22.10.0469 

Bottom line — All work but there are differences

Ca Gluconate and Emergency Care in Horses

This study evaluated the effects of calcium gluconate supplementation on the resuscitation of endurance horses in emergency care, regardless of their calcium status. The researchers hypothesized that calcium supplementation would lead to decreased heart rate, improved gastrointestinal sounds, and decreased need for additional IV fluids. They also expected to see increases in plasma calcium and phosphorus concentrations.The study involved intravenous infusion of calcium gluconate at a specific rate diluted in isotonic crystalloid fluids. The results showed that this infusion rate increased plasma calcium concentrations. The heart rate decreased significantly compared to horses that did not receive calcium. There were small increases in plasma phosphorus concentration, but gastrointestinal sounds did not improve significantly with calcium supplementation.The decrease in heart rate observed could be attributed to higher baseline heart rates in the clinical cases and concurrent administration of crystalloid fluids. The mechanisms for this decrease could be related to improved cardiac index and perfusion, calcium-mediated vasoconstriction inducing hypertension and reflex bradycardia, or direct effects of calcium on the heart.Plasma total calcium concentrations at the end of the study were higher than normal, and further research is needed to understand the potential additional effects and adverse effects of these high calcium concentrations on cardiovascular physiology. Unexpectedly, the administration of calcium gluconate was associated with a decrease in muscle enzyme activities, but the reasons for this are unclear.Contrary to the researchers' hypothesis, gastrointestinal sounds improved more in the control group than in the group that received calcium. This could be due to calcium-induced vasoconstriction of splanchnic vessels. Further research is needed to evaluate changes in blood pressure associated with calcium administration.The study had limitations, including a smaller sample size than expected and the use of a single dose of calcium gluconate. A larger sample size and multiple doses may have provided more insights into the effects of calcium supplementation.In conclusion, the study suggests that intravenous infusion of calcium gluconate at the given rate can be used in resuscitating endurance horses in emergency care. However, it leads to higher than normal calcium concentrations and increases in plasma phosphorus concentrations, which require further study. The infusion is associated with a decrease in heart rate, improvements in muscle enzyme activities, and potential negative effects on gastrointestinal sounds, which also need further research. The findings may be dose-dependent.

 Fielding, CL, Deane, EL, Major, DS, et al. Effects of calcium supplementation to resuscitation fluids in endurance horses: A randomized, blinded, clinical trial. J Vet Intern Med. 2023; 37( 3): 1216- 1222. doi:10.1111/jvim.16715 

Bottom line — Helpful for heart rate but questions remain about GI system

Just putting things in perspective …