Here
are some facts you need to know for the health of your
pet!
Dogs
and Taurine:
New
studies have shown that extra Taurine is imperative
for Cardiovascular Health in dogs, especially in Large
and Giant Breeds.
Natural
Balance® has
always added Taurine to our Ultra Premium Dog Food.
Dilated
Cardiomyopathy (DCM) is one of the most common acquired
cardiovascular diseases in dogs. In
cats, a diet deficient in taurine clearly results in
DCM, but in dogs, the need for dietary taurine has not
been generally recognized because dogs are known to
be able to synthesize taurine from the sulfur amino
acids cysteine and methionine.
Yet,
during the past two years, veterinary nutritionist Andrea
Fascetti and her colleagues Quinton Rogers and Robert
Backus documented low plasma taurine concentrations
in dogs with clinical signs of DCM. Some animals died
(the prognosis is poor for dogs with this disease) while
some survived when given supplemental Taurine and supportive
care.
The
cause of taurine deficiency in the canine DCM cases
was not readily apparent, yet the common factor was
diet history. Some of the dogs had been eating home-made
diets, while others were eating similar commercial diets
which appeared sufficient in protein and sulfur amino
acid content, and had passed testing in accordance with
Association of American Feed Control Officials (AAFCO)
feeding trials for all life stages. These cases and
findings in several pilot studies suggest that diet
does affect taurine metabolism in dogs and may play
a role in the development of DCM.
Recent
evidence also suggests that Taurine stores and the development
of DCM may be affected not only by diet, but also by
a dog's size. There is a prevalence of DCM in families
of dogs and specific breeds, many of which are large
and giant breeds.
Dr.
Backus found evidence in a study of Newfoundland dogs
with taurine deficiency to support the idea that taurine
metabolism may be influenced by "metabolic" body size,
which takes into account that the amount of energy needed
by the body is correlated with total body surface area,
not just body weight. For example, calculations of metabolic
body size indicate that the caloric and protein intake
per unit of body weight in a large breed dog is actually
lower than in a small breed dog.
Dr.
Fascetti is currently investigating the influence of
both diet and metabolic body size on taurine metabolism
in small and large breed dogs. Information from the
studies will contribute to ongoing and subsequent research
on taurine metabolism in dogs, and will help clinicians
interpret taurine profiles to make appropriate therapeutic
recommendations. Dr. Fascetti hopes these studies will
increase veterinarian and client awareness in order
to prevent diet-related DCM and to improve the life
expectancy of dogs afflicted with the disease.
Investigating
Taurine: Dr. Fascetti and her colleagues
are carrying out a variety of investigations to find
out how diet composition affects taurine metabolism
in dogs, and how taurine deficiency may play a role
in the development of DCM, particularly in large-breed
dogs. Dr. Fascetti and her clinical nutrition resident,
Dr. Sean Delaney, have begun a scientific survey to
determine normal ranges for plasma and whole blood taurine
concentrations in dogs.
Reference
ranges for taurine concentrations in cats are known,
yet healthy ranges in dogs have not been determined.
Understanding normal ranges for taurine is essential
to understanding the factors that affect taurine metabolism
in dogs and the link between taurine deficiency and
DCM. Blood samples will be collected from client-owned
animals along with each dog's age, breed, weight and
other measurements, medical history and a complete diet
history. The effect of metabolic body size and diet
on the taurine levels will be determined.
Last
year Dr. Backus found diet-associated taurine deficiency
and cardiac insufficiency in more than half of a group
of 21 privately owned Newfoundland dogs, which excreted
extraordinary amounts of taurine in their urine. Drs.
Backus and Fascetti are now planning a larger project
to estimate the prevalence of a possible widespread
taurine deficiency in the Newfoundland breed. Non-invasive
clinical tests and feeding trials will determine if
taurine deficiency in Newfoundlands might result from
1) a reduction in protein digestibility, 2) a diminished
capacity to synthesize taurine from sulfur amino acids,
or 3) loss of taurine in urine. Pedigree analysis may
reveal a genetic basis for taurine deficiency.
Another
breed susceptible to DCM is the Doberman pinscher. In
a three year project partially funded by the Doberman
Pinscher Foundation of America, Morris Animal Foundation
and the CCAH, graduate student Dr. Cristina Torres is
working on developing a taurine-deficient adult dog
model that can be used to further study DCM in humans
and animals. Dogs in the study are given purified diets
and monitored for taurine concentrations and cardiac
changes. Upon depletion of taurine, the dogs are supplemented
with taurine until their physiology returns to normal.
The study investigates possible causes for taurine deficiency
and will determine the quantities of dietary taurine
and sulfur amino acids needed to prevent DCM in purified
and commercial diets.
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