Bernese Mountain Dog Aseptic Meningitis

 

Severe necrotizing vasculitis of the central nervous system resulting

in signs of meningitis inflammation has been recognized in Bernese

Mountain Dogs. Young dogs 3 to 12 months of age are most commonly

affected. There is no apparent sex predilection.

Affected dogs experience a sudden onset of the classic signs of

meningitis, including fever, cervical rigidity, spinal pain, and stilted

gait. The signs may be episodic initially, resolving without treatment

in mildly affected dogs with pain-free intervals lasting days to months.

Most dogs, however, are severely affected and require treatment.

Progression to signs of parenchymal nervous system involvement, including

paralysis, blindness, and seizures, has occurred in some dogs in which

therapy was not instituted. Most affected dogs have peripheral

neutrophilia. Cerebrospinal fluid analysis reveals moderately increased

protein and an extreme neutrophilic pleocytosis of 50 to 2000 cells/ul.

No infectious agents have been isolated.


Immunosuppressive treatment with prednisone at 2 to 4 mg/kg/day results

in rapid resolution of clinical signs in most dogs. After 2 weeks the

corticosteroid dosage should be decreased slowly until the dog is

maintained on 1 mg/kg of prednisone every other day. Long term therapy

is necessary to maintain remission of clinical signs. Resolution of the

disorder after 4 to 6 months of treatment without the need for continuing

medication is common. Some dogs, however, have had relapses when the

corticosteroid dose was reduced, requiring prolonged high-dose

corticosteroid treatment or the addition of a more potent immunosuppressive

drug. Although experience is limited, administration of azathioprine

(imuran) at a dose of 2 mg/kg every 24 hr in these cases has met with

some success. Approximately 10% of dogs require lifelong treatment

(Presthus, personal communication, 1990). In spite of aggressive therapy, a

few dogs have been euthanized because of recurrences and progressive

parenchymal involvement.


At necropsy an extensive suppurative leptomeningitis is found in

association with severe arthritis and fibrinoid necrosis of vessel walls.

Tissue ischemia and hemorrage account for the neurologic signs. The etiology

of the central nervous system vasculitis in these dogs has not been

determined. No underlying concurrent disease process has been uncovered,

and there is little evidence for a systemic or generalized immune disorder.

This aseptic suppurative meningitis syndrome is common in the Bernese

Mountain Dog breed, with an estimated 1 to 2% of the breed affected

(Presthus, personal communication, 1990). Many affected dogs have been

closely related, and in most affected litters, approximately one quarter

of the pups will be affected. Test mating of affected dogs has produced

affected puppies. A syndrome with very similar clinical and pathologic

features has been described as a rere disorder in young German shorthaired

pointers (Meric, 1988).

 

 Source: Current Veterinary Therapy XI, Small Animal Practice; Kirk R, Bonagura J. (editors)

 Philadelphia, PA: WB Saunders; 1992: pg 1008

 

------------------------------

 

Articles Published in the October 1994 THE ALPENHORN

 

Bernese Mountain Dog Aseptic Meningitis


Canine meningitis and meningoencephalomyelitis may occur

as a result of infection with bacterial, viral, protozoal, mycotic, rickettsial, 

or parasitic pathogens. Syndromes of canine meningitis that have no identifiable 

infectious etiology and are thought to have an immunological basis have also been recognized. 

These syndromes are being diagnosed with increasing frequency, and include

granulomatous meningoencephalomyelitis (GME) and a steroid-responsive aseptic

suppurative meningitis of young dogs. In addition to these clinical

syndromes, a group of breed-specific meningitis disorders has been

recognized. Bernese Mountain Dogs are one of these breeds.

This aseptic suppurative meningitis syndrome is common in the Bernese

Mountain Dog breed, an estimated 1 to 2 percent of the breed being affected

(Presthus, 1990) Many affected dogs have been closely related, and in most

affected litters approximately one quarter of the pups will be affected.

Test mating of affected dogs has produced affected puppies.


BMD Aseptic Meningitis-Severe necrotizing vasculitis of the central nervous

system resulting in signs of meningeal inflammation has been recognized in

Bernese Mountain Dogs. Young dogs 3 to 12 months old are most commonly

affected and there is no apparent sex predilection. Affected dogs

experience sudden onset of the classic signs of meningitis, including fever,

cervical rigidity, spinal pain, and stilted gait. Signs may be episodic

initially, resolving without treatment in mildly affected dogs with pain-free

intervals lasting days to months. Most dogs, however, are severely affected

and require treatment. Progression to signs of parenchymal nervous system

involvement, including paralysis, blindness, and seizures has occured in some

dogs in which therapy was not instituted. Most affected dogs have peripheral

neutrophilia. Cerebrospinal fluid analysis reveals moderately increased

protein and an extreme neutrophilic pleocytosis of 50 to 2000 cells/ul. No

infectious agents have been isolated.

The cluster of cases in related young BMDs indicated the need for careful

observation and data collection in order to address the issue of possible

genetic susceptibility. Necrotizing vasculitis involving the meninges has

been reported in other breeds of dogs and may be part of a more widespread

vasculitis sometimes associated with immune complex deposition in the walls

of the involved vessels.


Immunosuppressive treatment with prednisone at 2 to 4 mg/kg/day results in

rapid resolution of clinical signs in most dogs. After 2 weeks, the

corticosteroid dosage should be decreased slowly until the dog is maintained

on 1 mg/kg of prednisone every other day. Long-term therapy is necessary to

maintain remission of clinical signs. Resolution of the disorder after 4 to

6 months of treatment without the need for continuing medication is common.

Some dogs have had relapses when the corticosteroid dose was reduced,

requiring prolonged high-dose corticosteroid treatment or the addition of a

more potent immunosuppressive drug. Although experience is limited,

administration of azathioprine (Imuran) at a dosage of 2 mg/kg every 24

hours in these cases has met with some success. Approximately 10 percent of

dogs require lifelong treatment (Presthus, 1990).

 

---------------------------------------------------------

In July 1986 Meric, Child, and Higgins reported on three littermate BMDs with 

clinical and clinicopathological findings consistent with aseptic suppurative meningitis. 

The illness begin acutely with fever, pain along the spine, and flaccid paralysis of one or

more limbs, variable in severity. A complete blood count showed marked

elevation of the white blood count, chiefly neutrophils and monocytes. The

serum alkaline phosphatase, SGOT, and cholesterol levels were increased. The

cerebrospinal fluid showed increased white blood cells, mostly neutrophils.

No infectuous organisms were found on direct examination or culture of

cerebrospinal fluid, and blood cultures were negative. Course of illness

not affected by antibiotic treatment, but there was dramatic response to

corticosteroids. One of the dogs had residual abnormal neurological findings

while on corticosteroids, one showed complete resolution of clinical

abnormalities but relapsed on withdrawal of corticosteroids, and one remained

in remission after corticosteroid withdrawal.
-

Presthus reported on 11 closely related BMDs with a similar illness. 3 were

examined by the author and histories of the remaining were available to the

author for analysis. The 3 examined dogs ranged from 8 months to 23 months.

All presented with fever, stiff gait, and cervical pain. No neurological

abnormalities were found, but all three had peripheral blood leukocytosis and

neutrophilia; two of the 3 had cerebrospinal fluid neutrophilia. One of the

3 dogs had 3 episodes of the condition over a period of one year. This

group of affected dogs showed rapid response to corticosteroids; 2 of the 3

achieved prolonged remission off corticosteroids (one also had an

ovariohysterectomy). The remaining 8 BMDs, 3 to 13 months, all had stiff

gait and fever; 7 of the 8 had cervical pain. Laboratory findings and course

were similar to those found in the examined group. It appears 2 of the 3

dogs reported by Meric et al. had a disease more severe than that in the dogs

reported by Presthus in that frank paralysis was noted. The overall clinical

picture supports the hypothesis that all 14 reported dogs had the same

disease. An autoimmune etiology is suspected but to date unsupported by

autoimmune-associated findings.


--------------------------------


Breeders and owners should be aware of a disease effecting Bernese

Mountain Dogs. Definitely hereditary so dogs affected should not be

used for breeding. Recovery rate is good in most cases. Canine

meningitis and meningoencephalomyelitis may occur as a result of

infection with bacterial, viral, protozoal, mycotic, rickettsial, or

parasitic pathogens. Syndromes of canine meningitis that have no

identifiable infectious etiology & are thought to have an immunologic

basis have also been recognized. These syndromes being diagnosed with

increasing frequency, and include granulomatous meningoencephalomyelitis

(GME) and a steroid-responsive aseptic suppurative meningitis of young

dogs. In addition to these clinical syndromes, a group of breed

specific meningitis disorders has been recognized-Beagles, Bernese

Mountain Dogs, Pugs.

 

BERNESE MOUNTAIN DOG ASEPTIC MENINGITIS


Severe necrotizing vasculitis of the central nervous system resulting in signs

of meningeal inflammation has been recognized in Berners. Young dogs 3

to 12 months old most commonly affected. No apparent sex predilection.

Affected dogs experience sudden onset of classic signs of meningitis,

including fever, cervical rigidity, spinal pain, and stilted gait.

Signs may be episodic initially, resolving without treatment in mildly

affected dogs with pain-free intervals lasting days to months. Most

dogs, however, are severly affected and require treatment. Progression

to signs of parenchymal nervous system involvment, including paralysis,

blindness, and seizures, has occured in some dogs in which therapy was

not instituted. Most affected dogs have peripheral neutrophilia.

Cerebrospinal fluid analysis reveals moderately increased protein and an

extreme neutrophilic pleocytosis of 50 to 2000 cells/ul. No infectious

agents have been isolated. Immunosuppressive treatment with

prednisone at 2 to 4 mg/kg/day results in rapid resolution of clinical

signs in most dogs. After 2 weeks, corticosteroid dosage should be

decreased slowly until dog maintained on 1 mg/kg of prednisone every

other day. Long-term therapy necessary to maintain remission of

clinical signs. Resolution of disorder after 4 to 6 months of treatment

without need for continuing medication is common. Some dogs have had

relapses when corticosteroid dose reduced, requiring prolonged high-dose

corticosteroid treatment or the addition of a more potent

immunosuppressive drug. Although experience is limited, administration

of azathioprine (Imuran) at a dosage of 2mg/kg every 24 hours in these

cases has met with some success. Approximately ten percent of dogs

require lifelong treatment (Presthus, 1990). This aseptic suppurative

meningitis syndrome is common in the Bernese Mountain Dog breed, an

estimated one to two percent of the breed being affected. (Presthus,

1990) Many affected dogs have been closely related and in most affected

litters approximately one-quarter of the pups will be affected. Test

mating of affected dogs has produced affected puppies.


Susan M. Meric,
DVM 

University of Saskatchewan 

Dept. of Veterinary on Internal Medicine 

Saskatoon, Saskatchewan

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