Pulmonary Histopathology in Cats and Dogs with Fatal Tick Paralysis.

The objective of this study was to evaluate critically the nature and prevalence of histological pulmonary lesions in dogs and cats that had died or were euthanized because of tick paralysis. A retrospective and prospective case study of 11 cats and 23 dogs was carried out. Retrospective cases were gathered from the Veterinary Laboratory Services database at The University of Queensland (UQ). Prospective cases were provided by Veterinary Specialist Services and UQ VETs Small Animal Hospital. Lung and other tissue samples were collected for histopathological analysis. All tick intoxicated animals demonstrated evidence of pulmonary parenchymal changes: alveolar oedema, interstitial and alveolar congestion and alveolar fibrin exudation. Eleven of 23 (48%) dogs exhibited mild to severe bronchopneumonia. A lower rate (18%) of bronchopneumonia was found in cats, with one case of aspiration pneumonia. A novel pulmonary histological grading scheme was developed to evaluate the correlation between clinical presentation and histopathological changes. Novel extrapulmonary lesions in cats included hepatic necrosis and acute renal tubular necrosis attributed to hypoxia. We concluded that both dogs and cats with high clinical grade tick paralysis are extremely likely to have pulmonary pathology. High-protein oedema and fibrin exudation are predicted to be present in most cases of canine and feline tick paralysis.

Tick paralysis

Tick paralysis is caused by neurotoxins secreted by adult female ticks, primarily in North America and on the east coast of Australia. Sporadic illness is also recorded in Europe and Africa. In the European countries, including Poland, there are 6 species of ticks capable of causing tick paralysis. The disease occurs in people of all ages, but is most commonly diagnosed in children under 8 years of age. Paralysis can take different forms - from rare isolated cranial nerve infections to quadriplegia and respiratory muscles paralysis. After the tick remove, the symptoms resolve spontaneously. In severe cases with paralysis of respiratory muscles, when there is no possibility of mechanical ventilation, the disease may lead to death.

Can Subclinical Infestation by Paralyzing Dermacentor andersoni (Acari: Ixodidae) Induce Immunity to Tick Paralysis in Sheep?

Cattle and sheep can develop immunity to paralysis caused by Dermacentor andersoni Stiles; however, this has been reported only in animals that were initially challenged with a high dose of ticks and exhibited clear symptoms of paralysis. Paralysis in sheep occurs in a dose-dependent fashion, with no paralysis occurring in sheep exposed to <0.2 ticks per kilogram sheep weight, and 100% paralysis in sheep exposed to >0.8 ticks per kilogram. This experiment was conducted to determine if sheep exposed to a low dose of ticks would also develop immunity to paralysis. Sheep were exposed to either a low (0.2 ticks per kilogram) or high dose of ticks (0.8 ticks per kilogram), then re-exposed to a second challenge of a paralyzing dose of ticks. All naïve sheep (eight of the eight) were paralyzed, while paralysis occurred in only four of the eight sheep previously exposed to a low dose, and one of the eight sheep previously exposed to a high dose. Results indicate that immunity can develop when sheep are exposed to a subclinical dose of paralyzing ticks, but in a smaller percentage of animals than those exposed to a high dose of ticks. Vaccine development perhaps remains the best option for nonacaricidal control of tick paralysis.

Acute lower motor neuron tetraparesis.

Flaccid nonambulatory tetraparesis or tetraplegia is an infrequent neurologic presentation; it is characteristic of neuromuscular disease (lower motor neuron [LMN] disease) rather than spinal cord disease. Paresis beginning in the pelvic limbs and progressing to the thoracic limbs resulting in flaccid tetraparesis or tetraplegia within 24 to 72 hours is a common presentation of peripheral nerve or neuromuscular junction disease. Complete body flaccidity develops with severe decrease or complete loss of spinal reflexes in pelvic and thoracic limbs. Animals with acute generalized LMN tetraparesis commonly show severe motor dysfunction in all limbs and severe generalized weakness in all muscles.

Neurotoxin-induced paralysis: a case of tick paralysis in a 2-year-old child.

BACKGROUND: Tick paralysis is an arthropod-transmitted disease causing potentially lethal progressive ascending weakness. The presenting symptoms of tick paralysis overlap those of acute inflammatory diseases of the peripheral nervous system and spinal cord; thus, the condition is often misdiagnosed, leading to unnecessary treatments and prolonged hospitalization. PATIENT: A 2-year-old girl residing in northern New York and having no history of travel to areas endemic to ticks presented with rapidly progressing ascending paralysis, hyporeflexia, and intact sensory examination. Investigation included blood and serum toxicology screens, cerebrospinal fluid analysis, and brain imaging. With all tests negative, the child's condition was initially mistaken for botulism; however, an engorged tick was later found attached to the head skin. Following tick removal, the patient's weakness promptly improved with no additional interventions. CONCLUSION: Our patient illustrates the importance of thorough skin examination in all cases of acute progressive weakness and the necessity to include tick paralysis in the differential diagnosis of paralysis, even in nonendemic areas.

Histopathological changes in the lungs from dogs with tick paralysis: 25 cases (2010-2012).

OBJECTIVE: To determine the prevalence and nature of histological lung lesions in dogs with tick paralysis. METHODS: A prospective study of 25 client-owned dogs that died during treatment for tick paralysis or were euthanased because of either the severity of the disease process or financial constraints was conducted at a veterinary emergency hospital in Queensland, Australia. Lung specimens were collected postmortem for histopathological examination. RESULTS: All 25 dogs had significant pulmonary changes: 9 exhibited congestion and alveolar oedema, with no obvious inflammatory cell infiltrate; 1 exhibited a mild increase in the number of alveolar macrophages in addition to congestion and alveolar oedema; the remaining 15 dogs had moderate or severe bronchopneumonia, with 2 showing evidence of aspiration pneumonia. CONCLUSION: Dogs with clinically severe tick paralysis are likely to have pulmonary parenchymal disease. Bronchopneumonia may be present in a significant proportion of cases and may reflect aspiration.

Distribution, seasonality and risk factors for tick paralysis in Australian dogs and cats.

Tick paralysis is a serious and potentially fatal condition of Australian companion animals induced by the paralysis ticks, Ixodes holocyclus and Ixodes cornuatus. Limited published information is available on the distribution, seasonality and risk factors for tick paralysis mortality in dogs and cats. This study describes 3479 cases of canine and feline tick paralysis in Australia using data extracted from a real-time disease surveillance program. Risk factors for mortality were identified, and maps of the distribution of cases were generated. Cluster analysis was performed using a space-time permutation scan statistic. Tick paralysis was found to be distinctly seasonal, with most cases reported during spring. Most cases were located on the eastern coast of Australia with New South Wales and Queensland accounting for the majority of reported cases. A cluster of cases was identified on the south coast of New South Wales. Dogs were found to be at significantly higher risk (P<0.05) of death if less than 6 months of age or if a toy breed. No significant risk factors for mortality were identified for cats. Some animals receiving chemoprophylactic treatment for tick infestation experienced tick paralysis during the products' period of effectiveness. There is a high risk of tick paralysis in dogs and cats on the eastern coast of Australia during the spring months. The risk factors for mortality identified can be used by veterinarians to determine prognosis in cases of canine tick paralysis and potentially to improve the treatment of cases. Daily tick searches of pets - particularly in high risk areas and during high risk periods - are recommended since the prevention of tick paralysis via chemoprophylaxis is not 100% guaranteed across the whole population.

Asymmetrical focal neurological deficits in dogs and cats with naturally occurring tick paralysis (Ixodes holocyclus): 27 cases (1999-2006).

OBJECTIVE: To describe basic epidemiological features, clinical characteristics and outcomes of asymmetrical focal neurological deficits identified in dogs and cats with naturally occurring tick paralysis (Ixodes holocyclus). DESIGN: A retrospective study. PROCEDURE: Computer records were reviewed for all dogs and cats treated for tick paralysis between July 1999 and June 2006 at a suburban veterinary hospital in Newcastle, New South Wales. RESULTS: Neurological deficits were identified in 17/197 dogs and 10/89 cats and included unilateral facial paralysis (14 dogs; 2 cats), anisocoria (4 dogs; 7 cats), unilateral loss of the cutaneous trunci reflex (1 dog; 1 cat) and Horner's syndrome in 2 cats with anisocoria. Occurrence of deficits was not linked to season, severity of tick paralysis, breed, age, sex or body weight. With facial paralysis and anisocoria, the site of tick attachment was invariably on the head or neck and always ipsilateral to the facial paralysis. By contrast, with anisocoria alone, no consistent relationship was noted between any one pupillary dimension and the side of tick attachment. With cutaneous trunci deficits the site of tick attachment was the ipsilateral caudal axilla. Compared with recovery times from generalised signs of tick paralysis, those for facial paralysis were significantly longer (days to weeks; P < 0.001), those for anisocoria showed no significant difference (P = 0.25) and those for cutaneous trunci deficits lagged by 6 and 7 days. CONCLUSIONS: Asymmetrical focal neurological deficits are a consistent finding in a proportion of dogs and cats with naturally occurring tick paralysis due to I. holocylcus.

Tick paralysis.

The one tick-borne disease that rarely comes under the auspices of the infectious disease specialist is not caused by an infectious agent, but is tick paralysis. This condition is caused by tick bite and typically presents as a flaccid ascending paralysis. This article discusses this entity partly because of completeness, but also because tick paralysis, or tick toxicosis as it is sometimes called, is worth the infectious disease consultant's consideration. The differential diagnosis includes entities that are infectious or caused by toxins of infectious agents, such as epidural abscess, some causes of transverse myelitis, and botulism. Lastly, in an era of antibiotic toxicity, multidrug-resistant bacteria, antigen-switching viruses, and complex antibiotic regimens, the cure for tick paralysis-removing the tick-is as simple as it is gratifying.

An outbreak of tick paralysis in free-ranging mouflon (Ovis ammon musimon).

During November 2006, two live and one dead mouflon (Ovis ammon musimon) were presented with a history of weakness, tremors, and paralysis. After a detailed gross and histologic examination and a bacteriologic, parasitologic, and rabies evaluation, a preliminary diagnosis of tick paralysis was established. A thorough field search revealed 13 affected mouflons found in the open hunting ground "Sveti Juraj" near the town of Senj (Croatia), along with an additional 35 mouflon carcasses. All 13 mouflons were placed in a quiet, semidark stable. All detectable ticks were removed manually, and the animals were topically treated with 250 ppm of Amitraz water emulsion (Taktic 12.5% EC, Intervet International, 5830 Boxmeer, Netherlands). The collected ticks were identified as Ixodes ricinus, Dermacentor marginatus, and Haemaphysalis punctata. In the following 24 hr, all treated animals recovered fully. This report describes a naturally occurring outbreak of tick paralysis in free-ranging mouflons from a karst habitat.

Tick paralysis: 33 human cases in Washington State, 1946-1996.

Tick paralysis is a preventable cause of illness and death that, when diagnosed promptly, requires simple, low-cost intervention (tick removal). We reviewed information on cases of tick paralysis that were reported to the Washington State Department of Health (Seattle) during 1946-1996. Thirty-three cases of tick paralysis were identified, including 2 in children who died. Most of the patients were female (76%), and most cases (82%) occurred in children aged <8 years. Nearly all cases with information on site of probable exposure indicated exposure east of the Cascade Mountains. Onset of illness occurred from March 14 to June 22. Of the 28 patients for whom information regarding hospitalization was available, 54% were hospitalized. Dermacentor andersoni was consistently identified when information on the tick species was reported. This large series of cases of tick paralysis demonstrates the predictable epidemiology of this disease. Improving health care provider awareness of tick paralysis could help limit morbidity and mortality due to this disease.

Infestation in the dog by the paralysis tick Ixodes holocyclus. 1. Clinical and histological findings.

Under laboratory conditions 8 dogs were infested with Ixodes holocyclus and the clinical signs and histological findings were recorded. Seven of the dogs developed clinical signs of the disease, died and were subjected to a post-mortem examination, while the eighth dog remained normal. The clinical signs were consistent between animals and enabled the course of the disease to be subdivided into 5 stages to facilitate analysis of data in future experiments. The most prominent feature of the disease was dysfunction of the efferent motor system although some disturbance of the afferent pathways and involvement of the autonomic nervous system did occur. The period elapsing between attachment of the ticks and onset of signs varied from 5.5 to 7 days, while the mean duration of the disease was 23.3 h. The histopathology demonstrated moderate to severe congestion of the liver, kidney and lungs, and in some lung sections pulmonary oedema was present.

[Fatal neurological syndrome in a collared dove (Streptopelia decaocto) and fixation of ixodes pari (= I. frontalis) tick (author's transl)]. / Syndrome neurologique mortel chez une tourterelle turque (Streptopelia decaocto) et fixation de la tique (Ixodes pari (= I. frontalis).

Tick paralysis is probably a common condition in wild birds, but rarely observed. The authors report the case of a collared dove (S. decaocto) presenting a fatal neurological syndrome associated with the fixation of a Ixodes pari female above the right eye. Virological studies of bird's tissues and of the tick were negative. These findings were compatible with tick paralysis or a minor equivalent of this syndrome. In addition, it was the first time that a collared dove is found as host for I. pari.