Susceptibility to Pug Dog Encephalitis
Approximately 1.2% of Pug dogs
die of necrotizing meningoencephalitis (NME), also known as Pug dog encephalitis (PDE). NME is an inflammatory disease
of the central nervous system that is usually progressive and fatal. Symptoms of NME include seizures, depression, ataxia,
abnormal gait and blindness (1). Female, fawn-colored Pug Dogs younger than 7 years of age are more apt to develop
NME than older, male and non-fawn colored individuals (2). Recent research has revealed that susceptibility to NME is associated
with the dog leukocyte antigen (DLA) region of dog chromosome 12 (3). The association is at or near the region containing
the DLA class II genes. Dogs that have two identical copies of the NME associated markers in this region, have an observed
risk (OR) of 12.75 for NME in their lifetime over Pugs that have only one or no copies of these markers (OR 0-1.08).
ORDER TEST KITS - Allow 5-10 business days for test results.
Results reported as:
- No copies of the NME associated markers (homozygous for normal). These dogs have a low risk of developing NME.
N/S - One copy of the NME associated markers (heterozygous for susceptibility).
These dogs have a low risk of developing NME.
S/S - Two copies of the NME
susceptibility associated markers. These dogs are 12.75 times more likely to develop NME in their lifetime.
of matings based on NME test results:
1. N/N x N/N = all
puppies will have two copies of the low NME risk markers (N/N) and will have a significantly reduced risk of developing NME
during their lifetime.
2. N/N x N/S = One half of the puppies will have two copies of the low NME risk markers
(N/N), and have a significantly reduced risk of developing NME during their lifetimes. One half of the puppies will carry
one copy of the susceptibility markers (N/S), but will also be at low risk for developing NME.
x N/S = One fourth of puppies will be N/N and at low risk for NME; one half will be N/S, carry the susceptibility marker,
but will also be at low risk for NME; one fourth will be S/S and will be at high risk for NME.
4. N/S x
S/S = One half of the puppies will carry the susceptibility marker (N/S), but will not be at increased risk of NME; one half
of the puppies will have two copies (S/S) of the susceptibility marker and be at high risk of NME.
5. N/N x S/S = All
of the puppies will carry one copy of the susceptibility markers (N/S), and be at low risk for developing NME.
x S/S = All of the puppies will carry two copies of the susceptibility marker (S/S) and be at high risk for NME.
This is not a diagnostic test for NME in Pug Dogs or for NME disease or risk in other breeds. The test is only
to determine risk for developing NME in Pug Dogs and for selecting matings that will produce puppies that are at decreased
risk (N/N, N/S). Although a significant proportion (11%) of Pug Dogs is S/S, only about 1 in 8 of this group will develop
NME during their lifetime.
Also, breeders are advised against breeding out the S genotype, because
40% of Pug Dogs have the S genotype in a heterozygous (N/S = 29%) or homozygous state (S/S = 11%). Eliminating the S
genotype will lead to a considerable loss of genetic diversity. Therefore, breeders should carefully select matings
that do not produce S/S puppies.
The NME report includes DNA types for a panel of 8 markers selected
from the International Society of Animal Genetics (ISAG) canine parentage panel. These markers provide individual identification
for each sample tested.
1. Talarico LR, Schatzberg SJ. Idiopathic granulomatous and necrotising
inflammatory disorders of the canine central nervous system: a review and future perspectives. J Small Anim Pract 2010:
2. Levine JM, Fosgate GT, Porter B et al. Epidemiology of necrotizing meningoencephalitis
in Pug dogs. J Vet Intern Med 2008: 22: 961–968.
3. Greer KA, AK Wong, H Liu, TR Famula,
NC Pedersen, A Ruhe, M Wallace and MW Neff. Necrotizing meningoencephalitis of Pug Dogs associates with dog leukocyte antigen
class II and resembles acute variant forms of multiple sclerosis. Tissue Antigens 2010: 76:110-118.