o'cockaigne

Diet and Cardiomyopathy – the History, Debate and Implications for Deerhounds (March 16, 2021) ~ compiled by Barbara Heidenreich (“Fernhill Scottish
Deerhounds”)

Let’s start with a bit of history. Before WWII, more than 90% of commercial pet food came in cans, and contained mostly (if not only) meat. However, metal was needed for the military, and by the time the war ended, 85% of pet food was dry kibble. It still contained a good amount of meat, and this is what prevented taurine deficiencies from occurring. The primary machinery for producing what we now know as dry food is called an extruder. This piece of equipment was introduced in the 1950’s. To get the correct consistency of dough for the extruder, the recipe called for a minimum amount of starch. This started the trend of ever-increasing quantities of cereal grain, such as corn, in dry foods. At the same time, meat processors were becoming increasingly proficient at getting more meat from livestock carcasses. So, pet food makers substituted other leftover animal tissues or “by-products.” Over time, the result was a high-grain, low-meat dry food, for which the profit margin was – conveniently – much higher than for canned food. In the late 1970’s, cats started going blind or dying of congestive heart failure due to a condition called dilated cardiomyopathy (DCM). Many of those cats were eating the same pet food specifically designed for dogs (Hill’s Science Diet), and this was noticed by researchers at UC Davis. In the mid 1980’s, they published the results of their research showing that taurine deficiency was the cause of the issue…the pet food industry responded by adding supplemental taurine to cat food.

Dogs make their own taurine from sulfur-containing amino acids, primarily cysteine, but also methionine. It was thought that,  because they could produce it themselves, dogs didn’t need supplemental taurine. However, it is now known that large dogs produce taurine at a slower rate than small dogs, putting them at risk for a deficiency. Genetics also play a significant role, with certain breeds and family lines being predisposed to developing DCM.

The existence of a link between taurine deficiency and DCM in dogs has been known since 1997, and the simple fact is that some dogs can’t supply sufficient to meet their own taurine needs. L-carnitine, another amino acid found primarily in meat, may also play a role in the development of DCM in a small percentage of dogs. L-carnitine becomes unavailable in pet food through processing, and is generally not added back due to its high cost. It is now known that some dog breeds (certain lines of spaniels, retrievers (notably Golden Retrievers), and particularly Newfoundlands) develop the same taurinedependent form of DCM that had killed so many cats. No research has been done on whether Deerhounds might have the same taurine dependent DCM.

In July 2018, the United States Food and Drug Administration (FDA), a federal agency responsible for protecting public health by ensuring food and drug safety, announced that it had begun investigating reports of DCM in dogs eating certain pet foods, many labeled as “grain-free,” which contained a high proportion of peas, lentils, other legume seeds (pulses), and/or potatoes in various forms (whole, flour, protein, etc.). By December 2018 research expanded to include “BEG” diets (boutique companies, exotic ingredients, or grain-free diets) as also being implicated. In June 2019, the FDA did provide pet owners with a massive amount of data that included the brand names associated with the more than 500 case reports they have received. The flurry of research that followed has concluded (June 2020) “there is no scientific evidence that a grain-free diet causes canine dilated cardiomyopathy”. A highly qualified team of board-certified veterinary nutritionists, cardiologists and PhD researchers published a literature review on DCM in dogs in the Journal of Animal Science. This review, which examined more than 200 studies, came to the italicised conclusion above (Mansilla, W.D., et al., “Special topic: The association between pulse ingredients and canine dilated cardiomyopathy: addressing the knowledge gaps before establishing causation”. J. Anim. Sci. 2019. 97(3): 983-997). The issue is complex with both genetic and dietary factors likely being involved in the development of canine DCM.

The value of this food dispute and research to the Deerhound community has actually been extremely useful. Heart disease in Deerhounds is a top cause of mortality: UK (2014): 27% of reported Deerhounds died of heart disease ; USA (2011): 22 % of males died of heart disease with 15% from DCM & Bitches – 14% died of heart disease with 8% diagnosed as DCM. Summarised below are some of the research results that Deerhound owners should be aware of:

A. DCM is a common form of heart disease in dogs, especially in large and giant breeds, which produce less taurine than smaller dogs on the same diet. Diet is a possible factor in about 20-30% of dogs with DCM. “Appropriate levels of certain dietary nutrients have been shown to increase life span, improve life quality, reduce symptoms and physical evidence of disease, and decrease mortality
rates in these animals”(R.S.Dove. Altern Med Rev Sept.2001;6 (Suppl):S38-S45). There IS a relationship between diet and the development of heart disease in dogs.

B. Research found that some dogs can’t supply their own taurine needs (is this the genetic link to heart disease?). Although the methionine content in pulses is lower compared to animal-based proteins, this can be remedied by using ingredients rich in this amino acid or using supplementation. Remember that in the early 2000’s, before grain-free diets became mainstream, some lamb and rice
diets were identified as being correlated with low taurine and heart disease in dogs. Lamb is low in taurine…

C. There is significant research that indicates in domestic dogs that large body size is accompanied by shorter life span (Li Y, 1996; Galis, 2006; Greer, 2007; Kraus, 2013). The recent research revealing that large dogs may not produce taurine as efficiently may be a link to their shorter lifespan.

D. Older dogs produce taurine at a slower rate.

E. Cooking proteins can potentially lead to the destruction of amino acidswhich can decrease the amount of amino acids available to make taurine. Taurine from fish for example, is diminished by heat processing….around 30% is lost. “Taurine deficiency in dogs is suggested to result from reduced sulfur amino acid bioavailability in dietary ingredients that are heat processed, such as rendered meat meals” (3,16).

F. Inactivity has been linked to low taurine synthesis. 

Recommendations:

1. Do NOT feed only dry kibble. Dry/kibble pet foods remain the leading style of pet foods linked to DCM. Dry kibble is also directly linked to gastric dilatation volvulus (GDV/”bloat”) another leading cause of death in Deerhounds.

2. As Deerhounds are a “large” breed and yours may be genetically predisposed to not processing taurine efficiently, ensure that your dog is getting plenty of taurine by adding to each meal raw meats high in taurine and sources of the amino acid precursors, methionine and cysteine (raw dark turkey, chicken, muscle meats – including tongue and heart and seafood).

3. Exercise your dog daily and continue that regime throughout their lives…inactive dogs appear to be less able to synthesise taurine. This important finding has a direct link to a 2007 survey undertaken of double-digit Deerhounds (Claymore.May-June2007.pp.15-18) where it was very striking that a lifetime of dedicated daily exercise (several hours a day with free running) was reported by all owners of double digit deerhounds, a breed where self-motivation to exercise declines rapidly as they age.

4. Do not cook the proteins you are feeding your dog as cooking destroys the amino acids needed to make taurine.

5. As your Deerhound ages, again ensure that it is getting raw meat high in taurine and consider the addition of daily taurine-L- Carnitine-CoQ10 supplements. Supplemental taurine-L-carnitine-CoQ10 usually comes in capsules of 500 or 1000 mg. (and is very safe even at extremely high doses) and can be given at up to 1000 mg per day for every 40 pounds of the dog’s body weight. It also has very little taste and is easy to give.

6. Dogs and Cats also require two types of essential fatty acids: omega-6 and omega-3. Essential fatty acids have important roles in cell membranes, the immune system, and the circulatory system. In other words, they are essential for life. Current recommendations for pets suggest an Omega-6 to Omega-3 ratio of approximately 10:1 to 5:1 (or 9:1 Dr. Jean Dodds) be consumed. Among the various diseases potentially alleviated by these acids are allergies and autoimmune conditions, heart disease, joint problems, coat and skin problems, central nervous system disorders, as well as many cancers. Other cardioprotective compounds in addition to taurine and L-carnitine include the antioxidant vitamins such as E and the B complex vitamins, coenzyme Q10 (CoQ10) and Crataegus (hawthorn) extract.

7. Given the link between size and longevity…and large dogs not producing taurine as efficiently….in today’s Deerhounds, where size well exceeds the historic functional preference of not more than 30 inches/76.2 cm. at the shoulder, look to select “moderate size” for ownership and breeding and as a breeder do not focus on promoting Deerhounds into the “giant” category when the breed Standard describes “a rough-coated greyhound of larger size and bone.”

*****************************************************************************
References used in the paper Diet and DCM compiled by Barb Heidenreich, March 16, 2021

General overview articles relating diet/taurine to DCM:

Dr. Jean Hofve, Holistic Veterinarian, DVM. “Taurine, Dog Food, and Heart Disease in Dogs” Only Natural
Pet July 14 2020 https://www.onlynaturalpet.com/blogs/holistic-healthcare-library/taurine-dog-food -and-heart-disease-in-dogs-1fbclid=IwAR0nQoqx5RCveIxtffOaAqkTLgSlUKZnKPua_nXwUq0y1Rer2xD1U4NTJFQ

Ripps H, Shen W. Taurine: a “very essential” amino acid. Molecular Vision. 2012; 18:2673-2686.

Kramer GA, Kittleson MD, Fox PR, Lewis J, Pion PD. Plasma taurine concentrations in normal dogs and in dogs with heart disease. J Vet Intern Med. 1995;9:253–8.

United States Department of Health and Human Services National Institutes of Health [homepage on the Internet]. Bethesda: Program Announcement: PA-06–136; [updated 2006 Mar 3; cited 2006 Apr 25]. Nutrition and diet in the causation, prevention, and management of heart failure (R21); [about 30 screens]. Available from: http://grants.nih.gov/grants/guide/pa-files/PA-06–136.html

Simpson S, Rutland P, Rutland CS. Genomic Insights into Cardiomyopathies: A Comparative CrossSpecies Review. Veterinary Sciences. 2017; 4:19 (26 pages).

Fascetti AJ, Reed JR, Rogers QR, Backus RC. Taurine deficiency in dogs with dilated cardiomyopathy: 12 cases (1997–2001). J Am Vet Med Assoc. 2003;223:1137–41. https://avmajournals.avma.org/doi/abs/10.2460/javma.2003.223.1137

Bélanger MC, Ouellet M, Queney G, Moreau M. Taurine-deficient dilated cardiomyopathy in a family of golden retrievers. J Am Anim Hosp Assoc. 2005;41:284–91.

Sanderson SL, Gross KL, Ogburn PN, Calvert C, Jacobs G, Lowry SR, Bird KA, Koehler LA, Swanson LL. Effects of dietary fat and L-carnitine on plasma and whole blood taurine concentrations and cardiac function in healthy dogs fed protein-restricted diets. Am J Vet Res. 2001 Oct;62(10):1616–23. Erratum in. Am J Vet Res. 2001 Dec;62(12):1968.

Case, Linda DCM in Dogs: Taurine’s Role in the Canine Diet. What is taurine-deficiency dilated cardiomyopathy (DCM), and how can dog owners prevent it? Whole Dog Journal. August 15, 2018Updated:January 25, 2021 https://www.whole-dog-journal.com/food/dog_food/dcm-in-dogs-taurines-role-in-the-canine-diet/?fbclid=IwAR0K29Bj7ZVPt7yu5J8V92eZx-6Q7LQxpafiJOA9eQwcnX6CZb7AoeI13hg

Freeman LM, Rush JE, Brown DJ, et al. “Relationship between circulating and dietary taurine concentrations in dogs with dilated cardiomyopathy.” Veterinary Therapeutics 2001; 370-378.

Vollmar AC, Fox PR, Servet E, Biourge V. Determination of the prevalence of whole blood taurine in Irish wolfhound dogs with and without echocardiographic evidence of dilated cardiomyopathy. Journal of Veterinary Cardiology. 2013 Aug 22; 15(3):189-196]

Body size is directly linked to shorter lives:

There is significant research that indicates in domestic dogs that large body size is accompanied by shorter life span (Li Y, 1996; Galis, 2006; Greer, 2007; Kraus, 2013)

Delaney SJ, Kass PH, Rogers QR, Fascetti AJ. Plasma and whole blood taurine in normal dogs of varying size fed commercially prepared food. J Anim Physiol Anim Nutr (Berl). 2003;87:236–44.

Tôrres CL. The effects of dietary ingredients, bacterial degradation in the gut and amount of food consumed on taurine status of dogs of different body sizes [dissertation]. Davis, CA: University of California; 2003.

Tôrres CL, Backus RC, Fascetti AJ, Rogers QR. Taurine status in normal dogs fed a commercial diet associated with taurine deficiency and dilated cardiomyopathy. J Anim Physiol Anim Nutr (Berl). 2003;87:359–72.

Delaney SJ, Kass PH, Rogers QR, Fascetti AJ. “Plasma and whole blood taurine in normal dogs of varying size fed commercially prepared food.” Journal of Animal Physiology and Animal Nutrition 2003; 87:235-244.

Kealy RD, Lawler DF, Ballam JM, Mantz SL, Biery DN, Greeley EH, Lust G, Segre M, Smith GK, Stowe HD. Effects of diet restriction on life span and age-related changes in dogs. J Am Vet Med Assoc. 2002;220:1315–20.

Cooking affecting Taurine Concentrations:

Spitze AR, Wong DL, Rogers QR, Fascetti AJ. Taurine concentrations in animal feed ingredients; cooking influences taurine content. Journal of Animal Physiology and Animal Nutrition. 2003; 87:251–262.

Friedman M. Dietary impact of food processing. Annu Rev Nutr. 1992;12:119–37.

Piva G, Moschini M, Fiorentini L, Masoero F. Effect of temperature, pressure and alkaline treatments on meat meal quality. Anim Feed Sci Technol. 2001;89:59–68.

Effectiveness of Supplementation:

Beynen Anton C. 2020. Omega 6-3 ratio in dog food  https://www.researchgate.net/publication/341286652_Beynen_AC_2020_Omega_6-3_ratio_in_dog_food
https://www.researchgate.net/publication/341286652_Beynen_AC_2020_Omega_6-3_ratio_in_dog_food/references

Dove, R.S. Nutritional therapy in the treatment of heart disease in dogs – Heart Disease in Dogs. Alternative Medicine Review, Sept, 2001. 6(Suppl):S38-S45)

Pion PD, Sanderson SL, Kittelson MD. The effectiveness of taurine and levocarnitine in dogs with heart disease. Vet Clin North Am Small Anim Pract. 1998;28:1495–514.

Sanderson SL. Taurine and carnitine in canine cardiomyopathy. Veterinary Clinics of North America: Small Animal Practice. 2006 Nov;36(6):1325-43, vii-viii.

Sanderson SL, Gross KL, Ogburn PN, et al. Effects of dietary fat and L-carnitine on plasma and whole blood taurine concentrations and cardiac function in healthy dogs fed protein-restricted diets. American Journal of Veterinary Research. 2001 Oct; 62(10): 1616-1623.

Age, Exercise and activity increases plasma taurine concentrations:

Backus, Robert C., Kwang Suk Ko, Andrea J. Fascetti, Mark D. Kittleson, Kristin A. MacDonald, David J. Maggs, John R. Berg, Quinton R. Rogers. Low Plasma Taurine Concentration in Newfoundland Dogs is Associated with Low Plasma Methionine and Cyst(e)ine Concentrations and Low Taurine Synthesis. The Journal of Nutrition, Volume 136, Issue 10, October 2006, Pages 2525–2533, https://doi.org/10.1093/jn/136.10.2525

Ko KS, Backus RC, Berg JR, et al. “Differences in taurine synthesis rate among dogs relate to differences in their maintenance energy requirement.” Journal of Nutrition 2007; 137:1171-1175.

Beet Pulp/potato/grains implicated in decreasing Taurine

Ko KS, Fascetti AJ. “Dietary beet pulp decreases taurine status in dogs fed low protein diet.” Journal of Animal Science and Technology 2016; 58:29-39.

Wall T. Do peas and potatoes really cause heart disease in dogs? Petfood Industry. 2018 Jul 19; online bulletin