Localised tetanus in two cats after ovariohysterectomy

Clinical findings and outcome in feline tetanus: a multicentric retrospective study of 27 cases and review of the literature

Tetanus is a toxigenic illness caused by the action of Clostridium tetani neurotoxin (TeNT), which results in partial or generalized muscle stiffness in infected mammals and birds. The disease is rarely reported in cats due to their innate resistance to the toxin. This multicentric retrospective study aimed to describe a significant population of cats with a diagnosis of tetanus and report their signalment, clinical and neurological signs, diagnostic findings, treatment, and outcome. A retrospective search through medical records from 11 referral centers in Europe resulted in the identification of 27 cases of feline tetanus from July 2005 to April 2023. These cases were further compared with previously reported cases in the veterinary literature. Young cats were more commonly represented than older cats, with a median age of 4 years. Clinical signs were initially characterized by a lame and/or stiff limb, near the primary injury site, in 17/26 (65%) cats. Signs were focal or multifocal in 21/27 (78%) cats of this study and one typical sign was the inability to flex the most severely affected limbs. Electrodiagnostic studies revealed characteristic changes, such as continuous spontaneous motor unit discharges in both agonist and antagonist muscles. Such studies are particularly useful in focal and multifocal cases and should be performed to further support the diagnosis. The toxin was successfully identified in one case using the mouse bioassay. Treatment included antibiotherapy (metronidazole) in most cases, muscle relaxants, appropriate nursing cares and handling of potential complications. Overall, the outcome appeared to be positive, with only 1/27 (3.7%) cats being euthanized due to financial restrains. 23/25 (92%) cats returned to an independent ambulatory capacity on all limbs within a median delay of 25 days. Mild to moderate long-term sequelae were reported in eight (30%) cats. This multicentric study is the first to bring together such a large number of cats affected with tetanus. Presentation of the disease in cats differs from that observed in humans and dogs, with most cats being locally affected. Compared to previous reports of tetanus, this series of cats had a better outcome overall, especially for cats affected with generalized tetanus.

Case report: A severe case of generalized tetanus in a young cat

A 10-month-old, 3 kg, female spayed Domestic Shorthair cat was presented with a chronic, infected wound at the level of the proximo-lateral left pelvic limb. General physical examination revealed a weight-bearing lameness of the left pelvic limb, which was moderately and circumferentially swollen and edematous proximal to the tarsal joint. On the lateral aspect of the proximal thigh, there was a chronic wound of 1 cm in diameter and an additional exudative skin lesion was present throughout the whole length of the caudo-lateral thigh. Complete blood count and serum biochemistry profile revealed mild anemia, increased serum amyloid A, hyponatraemia, hypochloraemia, hypocalcaemia, hyperkalaemia, hypermagnesaemia, hyperglycaemia, increased creatine kinase, and increased liver parameters. Surgical exploration of the wound was performed, and necrotizing fasciitis was suspected. The affected limb was amputated and swabs for bacterial culture were taken from both the skin lesions and surgical site before wound closure. One day after surgery, mild muscular contractions on the forehead and an increased muscle tone of the right pelvic limb were evident. One day later, the cat developed a generalized increase in extensor tone, with intermittent opisthotonos, resulting in lateral recumbency. Based on these clinical signs, a diagnosis of generalized tetanus was made and treatment with midazolam, methocarbamol, and metronidazole was started. Despite an improvement of all blood parameters, the cat progressively deteriorated and 4 days after surgery, it developed episodes of tetanic convulsions, associated with hyperthermia and ventricular arrhythmias. Despite intensive care and medical management, the cat died following a cardio-respiratory arrest 3 days later. This case report describes a rare case of severe generalized tetanus in a young cat.

Coxofemoral luxation as a complication of localised tetanus in a cat

Case summary

A 9-month-old male neutered domestic shorthair cat presented 2 weeks after castration with a 48 h history of acute-onset lateral recumbency and severe hindlimb rigidity. Physical examination findings included hyperthermia, tachypnoea, hindlimb rigidity and a healed orchidectomy site. Neurological examination of the head and forelimbs was normal; however, there was a spastic, non-ambulatory paraparesis of the hindlimbs, which was more severe on the left. Abnormal findings included mildly elevated serum creatine kinase levels and on electromyography there was bilateral pathological spontaneous activity of the biceps femoris muscles. A tentative diagnosis of tetanus was made based on clinical presentation. Treatment was initiated with tetanus antitoxin, diazepam, metronidazole, buprenorphine and physiotherapy of the hindlimbs. There was an improvement over the following 20 days. Twenty-five days later the cat presented with acute, painful, non-weightbearing lameness of the left hindlimb. Physical examination was suggestive of craniodorsal coxofemoral joint luxation, which was confirmed radiographically. This was treated with analgesia and rest. A marked clinical improvement was observed at the 3-month follow-up.

Relevance and novel information

To our knowledge, there have been no previously published reports of spontaneous coxofemoral joint luxation as a complication of hindlimb localised tetanus infection in cats. This report suggests that coxofemoral luxation should be considered as a possible complication in young cats with hindlimb localised tetanus.

Changes in electromyography and F wave responses in two cats with presumed local tetanus: implications for diagnosis and prognosis

Two cases of focal tetanus in the cat are described. Clinical findings included severe muscular spasms of the pelvic limbs in one cat, and involvement of the thoracic limbs and muscles of the neck and face in the other. Electromyography in both cats showed spontaneous activity characterised by the presence of motor unit potentials. F waves, never previously reported in focal tetanus in animals, showed significantly increased F/M amplitude ratio in both cats and increased F wave duration in one cat. The electrodiagnostic findings provided relevant diagnostic and, possibly, prognostic information.

Focal canine tetanus: diagnostic value of electromyography

A four-year-old, male Italian hound was presented with severe spasticity of both thoracic limbs that worsened with external stimuli. The remainder of the neurological and general physical examination was normal. Complete blood cell count, chemistry profile, and serology for protozoal diseases were within normal limits. Survey radiography of the cervicothoracic spine and abdominal ultrasonography showed no abnormalities. Electromyography of the thoracic limbs demonstrated the presence of "doublets" and simultaneous activity in both agonist and antagonist muscles. These abnormalities may be explained by a defective glycinergic inhibition at the spinal cord level. Together with the history, progression of signs, and clinical findings, electromyography supported a presumptive diagnosis of focal tetanus. The dog received tetanus antitoxin and antibiotic treatment and gradually improved over four months.

Tetanus in the cat--an unusual presentation

Tetanus is rare in cats owing to their innate resistance. Clinical diagnosis may not be obvious in the early stages of the disease when characteristic signs of generalised tetanus are absent. However, the history of a penetrating/neglected wound and the presence of persistent involuntary muscle rigidity in a mentally alert animal should always lead to the suspicion of tetanus. Prompt diagnosis and treatment are the keys to a successful outcome.

Presumed localized tetanus in two cats

In this report two cases of localised tetanus in two young (<1 year) intact male and outdoor DSH cats, which had been missing, are described. Clinical examination revealed severe muscular spasms on the right (case 1) or both thoracic limbs (case 2). In the latter cat, wrinkling of the forehead and mild trismus were also seen. The routine diagnostic workup (CBC, survey radiographs of the spine, CSF analysis) did not reveal any abnormalities in both cats. EMG testing on the affected muscles in the second animal showed persistent spontaneous motor unit potentials, strongly indicating tetanus. The treatment, that was symptomatic (diazepam, metronidazole) and supportive (physical therapy, assist feeding and intravenous fluid therapy) resulted in the progressive improvement of limb rigidity and the restoration of motor dysfunction in a period of 5- (case 1) and 2- (case 2) month duration.