Changes

===Clinical Signs===

===Clinical Signs===

Because of their high natural resistance to tetanospasmin (compared to the horse and man), affected dogs may have a longer incubation period and clinical signs may be mild; a change in gait may be the only reported historical abnormality. The localised form of tetanus that develops in the dog may be difficult to diagnose, particularly if no wound is apparent. Unlike the generalised spastic paralysis described in horses, dogs may present with a wound to a single limb (often a thoracic limb) and unyielding stiffness or rigidity in the surrounding area. The rigidity may spread to the contralateral limb and then begin to advance cranially, becoming generalised as the disease progresses. As reported in horses, dogs may display hypersensitivity to auditory or tactile stimuli. Affected animals have also been reported to display caudal displacement of the ears, lateral canthi and commissures of the eyes. Prolapse of the nictating membranes, trismus (excess jaw tone) and retracted lips (risus sardonicus) are other clinical features.  

Because of their high natural resistance to tetanospasmin (compared to the horse and man), affected dogs may have a longer incubation period and clinical signs may be mild; a change in gait may be the only reported historical abnormality. The localised form of tetanus that develops in the dog may be difficult to diagnose, particularly if no wound is apparent. Unlike the generalised spastic paralysis described in horses, dogs may present with a wound to a single limb (often a thoracic limb) and unyielding stiffness or rigidity in the surrounding area. The rigidity may spread to the contralateral limb and then begin to advance cranially, becoming generalised as the disease progresses. As reported in horses, dogs may display hypersensitivity to auditory or tactile stimuli. Affected animals have also been reported to display caudal displacement of the ears and wrinkling of the forehead. Prolapse of the nictating membranes, trismus (excess jaw tone) and retracted lips (risus sardonicus) are other clinical features.  

Other neurological diseases causing limb spasticity may need to investigated; myelography for example will assist in ruling out an extramedullary lesion. A complete blood cell count, serum biochemistry, survey radiographs of the thoracic spine and serology for protozoal diseases should also be performed in order to exclude other neurological differential diagnoses.  

Other neurological diseases causing limb spasticity may need to investigated; myelography for example will assist in ruling out an extramedullary lesion. A complete blood cell count, serum biochemistry, survey radiographs of the thoracic spine and serology for protozoal diseases should also be performed in order to exclude other neurological differential diagnoses.  

Electromyography may be used to help to support a presumptive diagnosis of tetanus. Abnormalities relating to a defect in glycinergic inhibition and persistent motor activity may be recorded, including the presence of "doublets" and simultaneous activity in both agonist and antagonist muscles.   

Electromyography may be used to help to support a presumptive diagnosis of tetanus. Abnormalities relating to a defect in glycinergic inhibition, including the presence of "doublets" (double discharges of the same motor unit at

short intervals) and simultaneous activity in both flexor and extensor muscles.   

   

   

==Treatment==

==Treatment==

The approach to treatment in the dog is the same as that described for the horse. it is important however to exercise caution in the intravenous administration of equine tetanus antitoxin as this may cause anaphylaxis if used in dogs.

The approach to treatment in the dog is the same as that described for the horse. It is important however to exercise caution in the intravenous administration of equine tetanus antitoxin, as this may cause anaphylaxis if used in dogs. An intradermal test may be performed prior to the administration of the antitoxin in order to prevent anaphylaxis. Metronidazole and amoxcillin-clavulanic acid PO have been used successfully to treat tetanus in the dog. The use of acetylpromazine has been reported to reduce sensitivity to external stimuli.

 

Noise and external stimuli should be kept to a minimum. The dog should be kept in a quiet, darkened kennel positioned away from other dogs.  

Noise and external stimuli should be kept to a minimum. The dog should be kept in a quiet, darkened kennel positioned away from other dogs.  

In the recovery stage, physiotherapy may be of some benefit.  

Supportive nursing care such as catheterisation and/or enemas may be required. Bedding should be thick and changed regularly, and the patient should be turned regularly in order to prevent decubital ulcer formation. The dog may require hand feeding and assistance drinking.

==Prognosis==

==Prognosis==