Veterinary Abstracts
Metabolic Considerations
Thyroid | Pancreatitis | Diabetes | Obesity
Thyroid
From the Merck Veterinary Manual 8th Edition Page 416 - The Thyroid Gland
Clinical Findings: Although onset is variable,
hypothyroidism is most common in dogs 4-10
years old. It usually affects mid-to large-size
breeds and is rare in toy and miniature breeds.
Breeds reported to be predisposed include the
Golden Retriever, Doberman Pinscher, Irish
Setter, Miniature Schnauzer, Dachshund, Cocker
Spaniel, and Airedale Terrier. There does not
appear to be a sex predilection, but the risk
of developing hypothyroidism appears to be
higher in spayed females than in intact females.
Pancreatitis
J Am Vet Med Assoc, 214(1): 46-51 1999
Evaluation of risk factors for fatal
acute pancreatitis in dogs.
Hess RS , Kass PH , Shofer FS , Van Winkle
TJ , Washabau RJ
OBJECTIVE: To identify risk
factors associated with fatal acute pancreatitis in dogs.
DESIGN: Case-control study. ANIMALS:
70 case dogs with clinical evidence and histopathologic
confirmation of fatal acute pancreatitis and 104
control dogs that had trauma, underwent necropsy,
and did not have histologic evidence of acute
pancreatitis.
PROCEDURE: Information on signalment,
weight, body condition, medical history, concurrent
disease, and results of histopathologic examination
was obtained by reviewing medical records. Logistic
regression analysis included calculation of univariate
and multivariate (adjusted) odds ratios and 95%
confidence intervals.
RESULTS AND CLINICAL IMPLICATIONS: Dogs with fatal acute pancreatitis were largely
middle- to older-aged dogs. Risk of developing
fatal acute pancreatitis was increased by overweight
body condition, diabetes mellitus, hyperadrenocorticism,
hypothyroidism, prior gastrointestinal tract disease,
and epilepsy. Additionally, Yorkshire Terriers
were at increased risk, and Labrador Retrievers
and Miniature Poodles were at decreased risk,
of developing fatal acute pancreatitis. Males
and neutered females appeared to have an increased
risk of developing fatal acute pancreatitis, compared
with sexually intact females. Thrombus formation
was more likely in dogs that developed fatal acute
pancreatitis than in control dogs.
Diabetes
Source: Am J Vet Res, 43(3): 465-70 1982
Epizootiologic patterns of diabetes
mellitus in dogs.
Author: Marmor M , Willeberg P , Glickman
LT , Priester WA , Cypess RH , Hurvitz AI
A case-control study
of spontaneous diabetes mellitus in dogs was undertaken,
using 2 veterinary data bases. The Veterinary
Medical Data Program (VMDP) contained records
of 1,019 cases of canine diabetes from 14 university-affiliated
veterinary hospitals. The Animal Medical Center
(AMC), a private veterinary hospital which has
not participated in the VMDP, contained records
of 449 diabetes cases. Each data base was analyzed
separately, control groups being chosen from all
admissions, excluding diabetic animals. Summary
odds ratios by sex adjusted for age and breed
indicated significantly (P less than 0.05) elevated
risks for entire females and neutered females
compared with that for entire males. The VMDP
data indicated a significantly elevated risk for
castrated males, whereas the risk derived from
AMC data was not significantly different from
1. Analysis of risks by breed adjusting for age
and sex identified Poodles as being at significantly
excess risk, and German Shepherd Dogs, Cocker
Spaniels, Collies, and Boxers at significantly
decreased risk in both data sets. The male-female
risk ratio changed with age from 1 at less than
1 year of age to a predominance of females at
older ages. In the AMC data base, diabetes was
significantly associated with cataracts in dogs
of both sexes combined. Diabetes was also significantly
associated with benign mammary tumors in female
dogs.
Obesity
Source: J Anim Physiol Anim Nutr (Berl),
90(9-10): 355-60 2006
Hormonal disturbances associated with
obesity in dogs.
Author: Martin LJ , Siliart B , Dumon HJ
, Nguyen PG
Obesity is associated
with multiple endocrine alterations and changes
in the concentration of circulating hormones. However, few studies have explored such alterations
in dogs with naturally acquired excess weight.
In the present study, we investigated the effect
of naturally acquired obesity on cortisol,
insulin-like growth factor (IGF)-1 and prolactin
secretion in dogs. Thirty-one overweight dogs
were enrolled in the trial. Blood samples were
collected before and after adrenocorticotrophic
hormone (ACTH) injection. Free thyroxine (fT4),
cortisol, thyroid-stimulating hormone (TSH),
IGF-1, prolactin and fructosamine were assayed.
Body weight excess increased
significantly with age and neutered dogs were
more obese than entire ones. The ACTH stimulation test
was within the normal range for 26 of 31 dogs.
Prolactinaemia was increased in seven dogs
and IGF-1 in six dogs. Twenty dogs had a fructosamine
concentration >340 microm. Interestingly,
18 of 31 dogs showed disturbances of thyroid
function based on high TSH and/or low fT4 baseline
concentration, with 11 dogs showing both. According
to these parameters only six of 31 dogs were
free of hormonal disturbances. These
results revealed the high incidence of such
disturbances, especially thyroid dysfunction,
in obese, but
otherwise apparently healthy dogs. They demonstrate
the importance of examining endocrine function
during the initial evaluation of obese dogs
to avoid failure of any nutritional treatment.
Vet Rec, 118(14): 391-6 1986
Study of obesity in dogs visiting
veterinary practices in the United Kingdom. Edney
AT , Smith PM
A total of
8268 dogs were surveyed in 11 veterinary practices
in the United Kingdom during a period of six
months in 1983. The primary purpose of the
survey was to assess the level of obesity on
a five point scale with properly identified
criteria. Information on the clinical condition
of each dog was also recorded as well as proportions
of food types fed, particulars of breed, sex,
age, sexual status and the dog's name. Results
showed that 21.4 per cent of dogs in the survey
were judged to be obese and 2.9 per cent gross;
1.9 per cent were judged as thin, 13.5 per
cent lean and 60.3 per cent were optimum. Labradors
were found to be the most likely breed to become
obese. Neutered females
were about twice as likely to be obese as entire
females. The same trend was evident with neutered
males. Circulatory
problems were associated with dogs over 10
years old and those which were gross, rather
than obese. A similar trend was discernable
with articular/locomotor problems. Skin and
reproductive problems showed little relationship
with age or obesity. Neoplasia was much more
prevalent in dogs over 10 years old but had
little relationship with either sexual status
or obesity rating. There was a high rate of
usage of prepared food for all categories.
The amount of fresh food fed decreased rapidly
as the proportion of canned food increased,
but the obese and non-obese dogs showed very
little difference in the type of food fed.