Chiropractic in Horses

Hello, Summarians!

How do we measure positive and negative responses in alternative therapy scenarios? This study gives us one perspective …

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OTC Antihistamine Drop for Allergic Conjunctivitis in Dogs

Canine allergic conjunctivitis is a common eye condition in dogs characterized by symptoms like conjunctival redness, swelling, itchiness, and eye discharge. It often occurs due to allergens entering the body through inhalation, ingestion, or direct contact with the eye, and can accompany broader allergic reactions affecting the skin, ears, or other body areas. The main mediator of this response is histamine, which is released by mast cells. Diagnosis typically relies on the clinical history and examination, with tests like cytology and histopathology as supportive tools, although allergen-specific tests are less common in veterinary practice. 

Treatment frequently involves topical corticosteroids, although prolonged use can risk systemic absorption, potentially affecting the dog’s adrenal system and leading to side effects like lipid keratopathy. As an alternative, topical immunomodulators, such as cyclosporine, antihistamines, and mast cell stabilizers, may be considered, though evidence supporting their efficacy in dogs remains limited. 

This study evaluated the efficacy of olopatadine hydrochloride, a selective histamine H1 antagonist and mast cell stabilizer approved for humans, to treat or prevent experimentally induced allergic conjunctivitis in dogs. Using a histamine-based model developed by Sebbag et al., researchers induced conjunctivitis with a 10 mg/mL histamine solution to consistently provoke clinical signs. Findings showed that a 0.7% olopatadine solution could reduce eye swelling when administered an hour before histamine exposure, suggesting a partial protective effect. Although the overall scores for conjunctivitis signs between treated and control groups did not significantly differ, the reduction in chemosis indicates olopatadine may block certain histamine receptors. 

The study did not find conjunctival lymphoid follicles, likely because they are more common in chronic cases, while this study focused on acute allergic reactions. Limitations included using a single grader, which may introduce subjectivity. Future studies might involve real-world testing with dogs exposed to environmental allergens, allowing owners to document clinical signs in natural conditions. Conclusively, olopatadine at 0.7% concentration appears to alleviate some acute symptoms of allergic conjunctivitis in dogs, making it a potential preventive option before allergen exposure. 

Mamo ET, Newbold GM, Moorehead SC. Efficacy of the topical antihistamine olopatadine in dogs with experimentally induced allergic conjunctivitis. Vet Ophthalmol. 2024; 27: 396-405. doi:10.1111/vop.13168 

Bottom line — It may be useful for allergic conjunctivitis.

Chiropractic for Horses

Chiropractic is a recognized healthcare profession focused on musculoskeletal health, widely practiced in human medicine and increasingly applied in veterinary contexts, particularly for cats, dogs, and horses. In equine care, chiropractic methods have been used to address issues such as lameness, neck or back pain, poor sports performance, and trauma. Despite its growing use, research on equine chiropractic is limited compared to human studies. Notably, while chiropractic treatments in humans can sometimes cause adverse effects like pain or headaches in about 30% of cases, no studies have investigated such adverse effects in horses. 

Given this gap, the authors hypothesized that chiropractic manipulations might cause transient discomfort and distress during treatment in horses but lead to relaxation and improvement in joint hypomobilities afterward. The study aimed to provide scientific evidence of chiropractic effects on healthy horses by measuring maximum eye temperature (MaxTE), salivary cortisol (SC), behavior, and heart rate variability (HRV) before, during, and after chiropractic treatment—parameters known to objectively indicate stress and pain in horses. 

The study involved eight healthy mares and used objective indicators to assess the effects of chiropractic treatment. The first hypothesis was partially confirmed: the chiropractic treatment did cause transient discomfort behaviors in the mares. However, this discomfort did not correspond with any significant shift toward sympathetic nervous system activity, as evidenced by stable salivary cortisol levels, eye temperature, and heart rate variability. The second hypothesis regarding post-treatment relaxation and improvement was also partially verified. Significant relaxation behaviors such as self-grooming, turning the head, eating, and drinking were observed after both grooming and chiropractic sessions. Additionally, an increase in the standard deviation of normal-to-normal intervals (SDNN) indicated a shift toward parasympathetic nervous system activity after chiropractic treatment. 

Despite these positive indicators, there was no significant decrease in joint hypomobilities between the first and second chiropractic treatments, suggesting that a single manipulation is insufficient to restore bodily equilibrium. The results are noteworthy, especially since the mares were accustomed to the environment and the tools used, and the treatments were administered by a qualified veterinary chiropractor. 

Discomfort behaviors like avoidance movements and alertness were more frequent during chiropractic treatment than during grooming. These behaviors suggest that the horses perceived the manipulations as potentially threatening or uncomfortable. In two mares, aggressive behaviors such as attempts to bite or kick were observed during chiropractic treatment, possibly due to the stimulation of painful areas. 

A general state of relaxation was observed after both grooming and chiropractic treatments compared to baseline measurements. However, there was no evidence that relaxation was greater after chiropractic treatment than after grooming. Heart rate variability parameters and maximum eye temperature remained stable, indicating that chiropractic treatment did not cause significant autonomic nervous system shifts or acute stress responses. The increase in SDNN after chiropractic treatment further supports the induction of a relaxed state. 

The study faced limitations, including the heterogeneity of measurement locations requiring separate ethograms, which hindered direct behavioral comparisons. Additionally, behaviors were recorded by an operator rather than using environmental cameras, potentially influencing the mares' behavior. 

In conclusion, this preliminary study demonstrates that chiropractic treatment is well tolerated by horses. While it may cause transient discomfort, it does not induce acute stress responses and promotes relaxation post-treatment. A single chiropractic session did not significantly reduce joint hypomobilities, indicating the need for multiple treatments to achieve bodily balance. Therefore, equine chiropractic can be considered a safe treatment for healthy horses when performed by qualified professionals. Further research with larger sample sizes is necessary to fully assess the risks and benefits of chiropractic treatment for horses with musculoskeletal disorders. 

Beatrice Benedetti, Francesca Freccero, Manuela Piscopiello, Martina Felici, Aurora Mannini, Martina Zappaterra, Maria Gaia Angeloni, Ilaria Arena, Pier Attilio Accorsi, Giovanna Marliani, Barbara Padalino,Effects of chiropractic manipulations on behavioral and physiological parameters in healthy horses: A preliminary investigation, Journal of Veterinary Behavior, Volume 76, 2024, Pages 25-33,  ISSN 1558-7878,  https://doi.org/10.1016/j.  jveb.2024.10.006. 

Bottom line — Well tolerated and safe.

Canine Biodetection

This study explored the use of a trained detection dog to identify wood decay in elm trees caused by the fungus Ganoderma adspersum. Utilizing the ANSI/ASB standard 088 (2020) for systematic evaluation, a dog named Dora was trained to detect the scent of the fungus. Her performance was first assessed in controlled tests and then validated in real-world conditions in Amsterdam and The Hague. Dora demonstrated an overall sensitivity of 91% in controlled environments and a positive predictive value of 81% during field assessments. Remarkably, she could examine 30–60 trees per hour, whereas traditional methods like sonic tomography require at least an hour per tree. The findings suggest that incorporating biodetection dogs into routine tree health inspections can significantly improve efficiency by enabling earlier detection of pathogens and better allocation of resources. 

Adee Schoon, Dennis de Goederen, Detection of wood-decay by Ganoderma adspersum in elm trees – A pilot study using a trained dog, Journal of Veterinary Behavior, Volume 76, 2024, Pages 1-7, ISSN 1558-7878, https://doi.org/10.1016/   j.jveb.

Bottom Line — Wow! Another amazing proof of canine ability.

Just putting things in perspective …