Cavalier health: Feeding and Inbreeding

Interesting research to take a look at. First a study about the amount of times a dog is fed each day. Feeding pet dogs just once a day might keep them healthier as they age.

'Dogs fed once a day are less likely to be diagnosed with age-related conditions than dogs fed more often, according to an analysis of surveys completed by 24,000 owners of pet dogs.
For now, dog owners should stick with their current regime, says Matt Kaeberlein at the University of Washington in Seattle. “Based on this study, we are not recommending that people make a change in the way they are feeding their dogs.”
In 2019, Kaeberlein helped establish the Dog Aging Project to study the genetic and environmental causes of ageing in dogs and other animals, including people. Any dog owner in the US can take part by filling in a survey once a year.
There is some evidence that intermittent fasting can slow ageing in some animals, such as mice. Kaeberlein analysed the project data to see if dogs fed once a day were more or less likely to be diagnosed with various categories of age-related conditions, from cancers to the canine equivalent of dementia, than those fed more often.
In most cases, dogs fed once per day were significantly less likely to have had such a diagnosis. “In my view, it’s pretty compelling correlative evidence,” says Kaeberlein.
However, the study hasn’t established causation, he says. The total amount that a dog eats, rather than how often it eats, might explain the correlation. Dogs fed twice a day or more might be more likely to be obese, for instance.'
Read more: https://www.newscientist.com/article/2298623-feeding-pet-dogs-just-once-a-day-might-keep-them-healthier-as-they-age/#ixzz7EZaZtlpv

Secondly research into the effect of inbreeding in dogs comes to the conclusion that Cavaliers' inbreeding value is nearly twice that of breeding littermates, a UC-Davis study finds.

 'In a December 2021 article, University of California at Davis researchers (Danika Bannasch [right], Thomas Famula, Jonas Donner, Heidi Anderson, Leena Honkanen, Kevin Batcher, Noa Safra, Sara Thomasy, Robert Rebhun) examined the DNA records of 49,378 dogs of 227 breeds to determine the levels of inbreeding and consequences on health. Using estimated levels of inbreeding (coefficient of inbreeding [F] values), they found that, overall for the 227 breeds, the mean F value was 0.249. To put that value in context, they observed that "the breeding of two first cousins produces F = 0.0625, two half siblings F = 0.125, and two full siblings or parent-offspring F = 0.25." So, that mean F value of 0.249 is the equivalent of breeding two full siblings or a parent to an offspring.As for cavaliers, that breed's level of inbreeding was 0.411, nearly double the mating of two littermates or a parent to offspring (0.25).'
​Read more: The effect of inbreeding, body size and morphology on health in dog breeds

'One must consider that the majority of dog breeds displayed high levels of inbreeding well above what would be considered safe for either humans or wild animal populations. The effects of inbreeding on overall fitness have been demonstrated experimentally using mice, where an overall reduction in fitness between mice with F = 0.25 compared to F = 0 was determined to be 57% [54]. While this high level of inbreeding was less relevant to many captive and wild species, it is highly relevant to purebred dogs, based on the average inbreeding identified in this study. However the rate of inbreeding between these mouse experiments and what has occurred in dogs breeds is not the same and could have an effect on health. In humans, modest levels of inbreeding (3–6%) were shown to be associated with increased prevalence of late onset complex diseases [55] as well as other types of inbreeding depression [11]. These findings in other species combined with the incredibly strong breed predispositions to complex diseases like cancers and autoimmune diseases highlight the potential relevance of high inbreeding in dogs to their health.'