Amongst canines, glaucoma is a prevalent eye condition. Dachshunds diagnosed with glaucoma experience intraocular pressure (IOP) or heightened pressure in the eye. To evaluate the effects of eye pressure in DOGS, researchers at the University of Minnesota College of Veterinary Medicine studied 26 canines to assess whether the pressure induced by neck collars triggered an elevation in intraocular pressure (IOP). Intraocular pressures were evaluated before and after neck pressure was applied on the subjects. Both the pressure of the DOG leash and a harness were assessed to measure variations in pressure. The findings of the study showed that when collar pressure was applied, intraocular pressures drastically increased from the baseline levels. However, the DOG harnesses did not show any changes in pressure.

According to the primary author of the clinical study Amy Pauli, DVM, an ophthalmology resident at the University of Minnesota College of Veterinary Medicine, even the most brief increases of pressure in canines afflicted with any type of ocular disease (in example: glaucoma) can trigger damaging effects on the eye. Additional pressure may , be detrimental to both the retina and the optic nerve. For DOGS with a feeble to thin cornea, glaucoma, or other conditions where the IOP may be increased should not wear a collar. Alternatively, a harness can prevent further damage.

In conclusion, dachshunds who have the tendency to exert force on the leash during a walk fare better from a harness opposed to the major complications associated with an increased IOP. Moreover, the canine studies evaluated different pedigrees (in example: breeds bred to pull). For instance, Siberian Huskies and Alaskan malamute were found to rather resistant to elevated pressure in IOP.