Positive Airway Cultures in Dogs and Cats Receiving Mechanical Ventilation for Tick Paralysis.

Animals with tick paralysis often require mechanical ventilation (MV) but previous publications have identified knowledge gaps regarding the development of bacterial pneumonia, and the specific pathogens involved. The objectives of this study were to describe the clinical course and culture and susceptibility profiles of bacteria isolated from airway samples of dogs and cats mechanically ventilated for tick paralysis that had positive airway cultures. Medical records were reviewed, and cases included if they had a positive airway sample culture during MV for tick paralysis. Twenty-four dogs and two cats were included. Most (85%) received empirical antimicrobials before airway sampling. The most common organisms isolated included Staphylococcus spp. (11), Klebsiella spp. (9), Enterococcus faecalis (8), Escherichia coli (6), Enterococcus faecium (3), Pseudomonas aeruginosa (4), and Mycoplasma spp. (3). Evidence of aspiration pneumonia was present in 22/25 (88%) cases that had thoracic radiographs performed. Seventy-seven percent of cases received antimicrobials to which the cultured bacteria were susceptible during hospitalisation. The median duration of MV was 4 days (range 1-10). Most (77%) survived to discharge, 19% were euthanised, and one died. In a multivariable logistic regression analysis it was identified that selection of antimicrobials to which the causative bacteria are susceptible was associated with survival to discharge (Odds ratio 45.8, p = 0.014; 95%CI 1.98-14,808), as was length of MV, with every day an animal is ventilated associated with a 4.7 times increased chance of survival (p = 0.015; 95% CI 1.21-78.4).

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.

Pathology of Fatal Australian Black Snake (Pseudechis sp) Envenomation in Two Adult Dogs.

Black snakes (Pseudechis spp) are a genus of venomous Australian elapid snakes that can cause major clinical envenomation in companion animals, which may be fatal, even with appropriate antivenom treatment. Despite its clinical significance, there is little published information on the pathology of black snake envenomation. We report the gross and microscopic lesions associated with black snake envenomation in two dogs, one with a definitive immunological species identification of red-bellied black snake (RBBS; Pseudechis porphyriacus), the other with a black snake immunotype on a venom detection kit. Both dogs were located in a geographical area where the RBBS is found. The prominent gross findings in both cases included icterus, localized facial oedema in the region of the presumed bite wound, pigmenturia and multicavitary serosanguineous effusions. Histopathology of the confirmed RBBS case revealed acute renal tubular necrosis with haemosiderosis, marked splenic haemosiderosis and centrilobular to midzonal hepatocellular necrosis with severe cholestasis. Defining the spectrum of lesions of elapid snake envenomation improves understanding of the pathogenesis, which may lead to improved patient outcomes and post-mortem diagnosis.

2021 ISFM Consensus Guidelines on the Collection and Administration of Blood and Blood Products in Cats.

PRACTICAL RELEVANCE: Blood and blood products are increasingly available for practitioners to use in the management of haematological conditions, and can be lifesaving and therapeutically useful for patients with anaemia and/or coagulopathies. It is important for feline healthcare that donors are selected appropriately, and transfusions of blood or blood products are given to recipients that will benefit from them. Complications can occur, but can be largely avoided with careful donor management and recipient selection, understanding of blood type compatibility, and transfusion monitoring. CLINICAL CHALLENGES: Feline blood transfusion, while potentially a lifesaving procedure, can also be detrimental to donor and recipient without precautions. Cats have naturally occurring alloantibodies to red cell antigens and severe reactions can occur with type-mismatched transfusions. Blood transfusions can also transmit infectious agents to the recipient, so donor testing is essential. Finally, donors must be in good health, and sedated as appropriate, with blood collected in a safe and sterile fashion to optimise the benefit to recipients. Transfusion reactions are possible and can be mild to severe in nature. Autologous blood transfusions and xenotransfusions may be considered in certain situations. EVIDENCE BASE: These Guidelines have been created by a panel of authors convened by the International Society of Feline Medicine (ISFM), based on available literature. They are aimed at general practitioners to provide a practical guide to blood typing, cross-matching, and blood collection and administration.

Severe acute pulmonary haemorrhage and haemoptysis in ten dogs following eastern brown snake (Pseudonaja textilis) envenomation: Clinical signs, treatment and outcomes.

This report describes a series of ten cases of fulminant pulmonary haemorrhage in dogs following envenomation by the eastern brown snake (Pseudonaja textilis) in south eastern Queensland, Australia. All cases were presented for veterinary treatment during 2011-2018 at a specialist veterinary emergency centre. Each case received prompt antivenom treatment and supportive care. Pulmonary haemorrhage was diagnosed based on clinical examination; overt haemoptysis; thoracic radiographic demonstration of a diffuse alveolar pattern; and, the presence of venom induced consumptive coagulopathy. The median elapsed time from hospital admission to onset of haemoptysis was 2 h (range 0-18 h). In 80% (8/10) of cases endotracheal intubation was required, whilst 20% (2/10) were successfully treated with mask oxygen supplementation alone, and 40% (4/10) received mechanical ventilation; but only 25% (1/4) of these survived to hospital discharge. Fresh frozen canine plasma was administered to 70% (7/10) of cases and 43% (3/7) of these survived. Of the total number of cases presented for treatment, 30% (3/10) survived to hospital discharge, 60% (6/10) were euthanised due to poor prognosis and 10% (1/10) died from cardiac arrest. Initial serum brown snake venom antigen levels were retrospectively measured from frozen serum samples by venom specific sandwich ELISA in two dogs at 154 ng/mL (survived) and 3607 ng/mL (euthanised); no free venom was detected post-antivenom. Dogs that survived were discharged from hospital without apparent complications. Pulmonary haemorrhage is an uncommon event following envenomation by P. textilis in dogs and has not been described in similarly envenomed humans. This case series highlights the potential for fulminant and fatal pulmonary haemorrhage in dogs following eastern brown snake envenomation.

Clinical presentations, treatments and risk factors for mortality in cats with tick paralysis caused by Ixodes holocyclus: 2077 cases (2008-2016).

Objectives The objective of this study was to describe seasonality, demographics, presentations, treatments, complications and outcomes for cats with Ixodes holocyclus causing tick paralysis, and to identify risk factors for mortality. Methods This was a retrospective single cohort study with 2077 cases occurring between 2008 and 2016, and presenting to one of four emergency clinics in south-eastern Queensland, Australia. Case mortality at 5 days post-presentation could be determined for 1742 cases, and potential risk factors for mortality were assessed using random-effects logistic regression. Results Cases occurred all year round, but there was a marked seasonal pattern with more cases presenting in spring than any other season. Overall, 54/1742 cases (3%) died by 5 days after presentation. Five day mortality incidence for cases that received polyclonal canine tick antitoxin serum (TAS) and recommended treatment was 28/1410 (2%) vs 4/52 (8%) for cases that did not receive TAS ( P <0.001). Mechanical ventilation was recommended for 131/2077 cases (6%). Where mechanical ventilation was recommended but not implemented, mortality incidence was 15/17 (88%), whereas 4/22 cases (18%) that received mechanical ventilation died by day 5. From multivariable analyses, initial gait score (overall P = 0.047) and body temperature on presentation (overall P <0.001) were independently associated with mortality; cases with higher gait scores and those with body temperatures <35°C were at greater risk of death. Cases that had an adverse reaction to TAS were also more likely to die ( P = 0.002). Additional ticks were detected at coat clipping for 80/872 (9%) the cases that were clipped, and coat clipping was associated with a reduced risk of mortality ( P = 0.020). Risk of mortality did not differ significantly by time of year, clinic location, breed, sex, neuter status, age, weight, coat length or number of ticks found. Conclusions and relevance The overall mortality risk for cats treated for tick paralysis caused by I holocyclus is low. Risk factors for mortality include advanced gait and respiratory scores, and hypothermia at presentation. Coat clipping and TAS reduce the risk of mortality, whereas the occurrence of a TAS reaction increases the risk. Mechanical ventilation reduces mortality risk in cats with respiratory failure due to tick paralysis.