The diagnosis and management of snakebite in dogs--a southern African perspective

Cases of snakebite envenomation are frequently presented to veterinary practitioners in southern Africa. Despite this, no published guidelines exist on how this medical emergency should be managed. Southern African snake venoms can be classified into 3 main types based on the main mechanism of venom action and clinical presentation. A polyvalent antivenom is manufactured in South Africa and contains antibodies against the most important southern African snake venoms. The cytotoxic venoms are represented mainly by the puff-adder (Bitis arietans), Mozambique spitting cobra (Naja mossabica), black-necked spitting cobra (Naja nigricollis) (in the Western Cape and Namibia) and the stiletto snake (Atractaspis bibronii). These venoms may cause dramatic local swelling, high morbidity and low mortality and infrequently require the use of antivenom for survival (the only cytotoxic venoms used to prepare the antivenom are the puff-adder and Mozambique spitting cobra). The neurotoxic venoms (represented chiefly by the non-spitting cobras and mambas) cause high mortality due to rapid onset of paresis and require antivenom and mechanical ventilatory support which is life-saving. The boomslang (Dispholidus typus) and the vine snake (coagulopathic venom) rarely bite humans but dogs may be bitten more frequently. These venoms cause a consumption coagulopathy and successful treatment of boomslang bites requires the use of snake species-specific monovalent antivenom. There is no antivenom available for treating vine snake (Thelotornis capensis), berg adder (Bitis atropos), night adder (Causus spp.), stiletto snake and other lesser adder bites. There are some important differences between the way snakebites are managed in humans and dogs.     

Snake bites recorded by veterinary practices in Australia

Objective To determine the extent of the snake bite problem in domestic animals, its regional significance and the effects of antivenom treatment.
Design A questionnaire was designed seeking information on the number and type of domestic animals referred, whether treated or untreated, type of snakes and management of the bite.
Procedure The survey form was sent to 10% of veterinary surgeons, selected at random throughout Australia.
Results The response of 106 veterinary surgeons revealed that snake bite in domestic animals is frequent, with an estimated 6200 cases reported annually. Bites were more prominent in rural (78%) than urban areas (22%) with brown, tiger and black snakes accounting for 76%, 13% and 6% of cases, respectively. Cats and dogs were the most frequently reported victims. Ninety-one percent of cats and 75% of dogs survived following the administration of antivenom whereas 66% of cats and 31% of dogs survived without antivenom. Overall, in 33% of cases antivenom was not used, and venom detection kits were used in only 1% of cases. A number of drugs were used in various combinations with or without antivenom and intravenous fluids in the treatment of animals with snake bite, but their role in reducing the severity of envenomations was not assessed.
Clinical implications Antivenom significantly improves the chances of survival of domestic animals bitten by snakes.     

Snake envenomation in dogs in New South Wales

OBJECTIVE: To obtain baseline data on the prevalence of elapid snake envenomation in dogs presented to veterinary practices in New South Wales and to assess attitudes of veterinarians to this clinical entity. PROCEDURE: A mailed questionnaire, sent to all veterinary clinics within New South Wales, was utilised to collect epidemiological information regarding elapid snake envenomation in dogs. RESULTS: A response rate of 68% was obtained and a yearly prevalence of snake envenomation in dogs across New South Wales veterinary clinics was estimated as 0.31%. The most common species reported to be responsible for envenomation within NSW was the Red Bellied Black snake (Pseudechis porphyriacus) followed by the Brown snake (Pseudonaja textilis) and then Tiger snake (Notechis scutatus). The reported envenomation syndromes caused by these common snake species were perceived to be similar for Brown and Tiger snakes but differed for Red Bellied Black snakes. Diagnosis of snake envenomation was based predominantly on the recognition of clinical signs. Specific diagnostic tests, such as venom detection kits, were used infrequently. The most common treatment was reported to be a combination of intravenous fluid therapy and antivenom, and monitoring of response to this treatment was usually through assessment of clinical signs. Survival after antivenom administration was reported to be highest for Red Bellied Black snake species. Survival was perceived to be associated with time between envenomation and presentation to the veterinary clinic and with antivenom administration. CONCLUSIONS: Current attitudes and perceptions of veterinarians have been defined. Diagnosis of species-specific snake envenomation is shown to be made on the basis of clinical signs which are, however, reported as similar for each species. Clearer definition of these envenomation syndromes and identification of accessible diagnostic testing procedures are needed.     

Four cases of snake envenomation responsive to death adder antivenom

Death adder envenomation is rare in humans and there is only one brief report previously in dogs. This paper details three cases of canine common death adder (Acanthophis antarcticus) envenomation and one case of bardick (Echiopsis curta) envenomation which were responsive to death adder antivenom. The available literature on death adder envenomations is also reviewed. The main clinical sign in the four dogs was severe lower motor neuron paralysis. There was no clinical evidence of coagulopathy or myopathy. Use of a snake venom detection kit was essential for selection of appropriate antivenom. Death adder and bardick envenomation in dogs potentially has a good prognosis if sufficient antivenom is administered and intensive supportive care is available.     

Letter to the Editor

To the editor: During the preparation of an article on the repair of rupture of the cranial cruciate ligament in dogs, I made a survey of the members of the American College of Veterinary Surgery in active practice with a special interest in orthopedics. They were asked to specify their preferences for treatment of this condition in small (under 16 kg) and large dogs.
A total of 111 replies were obtained. Repair in small dogs was to a great extent achieved by lateral suture stabilization by using a variety of materials such as fishing line, multifilament nonabsorbable suture, and stainless steel wire. Lateral extracapsular techniques were also used in large dogs; however, the tibial plateau leveling osteotomy was also used frequently. The data are summarized as follows:     

SnakeMap: four years of experience with a national small animal snake envenomation registry

SnakeMap is a national cloud-based, veterinary snakebite registry. It was designed to prospectively collect data of the clinical circumstances and temporospatial information on cases of snake envenomation in dogs and cats. We herein introduce the project and summarise the data from the first 4 years of SnakeMap. The registry is a veterinary community-based online database allowing case entry from veterinary hospitals across Australia. Registry data comprise hospital characteristics, patient characteristics, envenoming snake type, treatment and outcome variables, including time and geolocation of the snake bite. We present summative information on select key variables from the SnakeMap registry (1 July 2015 to 30 June 2019). Twenty-eight hospitals from 6 states/territories entered 624 cases into the registry, including 419 dogs (67%) and 205 cats (33%). Bite time was available in 216 animals of which 90 (42%) were reported to be bitten in the 3 hours between 03:00 pm and 05:59 pm; median bite to presentation interval was 60 (interquartile range [IQR] 30, 211) minutes in dogs and 95 (IQR 41, 238) minutes in cats. Bites occurred in the owner's yard in 356 dogs (85%) and 53 cats (26%). A snake venom detection kit was used in 172 cases (28%) and antivenom was administered in 523 cases (85%). Most animals (n = 534, 88%) survived to discharge (median hospitalisation of 25 [IQR 16, 62] hours). SnakeMap effectively collects relevant clinical data from dogs and cats with presumed snake bite and provides locally specific information on the epidemiology of snake envenomation in small animals.     

小动物肠道异物性梗阻和出血性胃肠炎诊治的比较研究

小动物肠道异物引起犬肠道梗阻是犬常见肠道疾病之一。在临床上容易和出血性胃肠炎发生混淆。本试验通过一例患犬的病史,结合血常规检查、CRP检查、内窥镜检查,并与出血性胃肠炎鉴别诊断,确定为犬肠道异物性梗阻,并对患犬尝试使用剖腹探查术治疗,术后以消炎、补充营养和体液、修复胃肠道粘膜为主,取得明显的治疗效果。研究结果可为宠物犬肠道异物性梗阻和出血性胃肠炎的鉴别诊治提供可参考的诊治方案。     

Some toxicity thresholds for the clinical effects of common tiger snake (Notechis scutatus) envenomation in the dog

SUMMARY Common tiger snake (Notechis scutatus) venom was administered experimentally to dogs at doses from 0.25 lethal dose (LD) to 20 LD. Haemolysis and increased creatine kinase values occurred rapidly after injection of sublethal (subparalytic) doses, but the clotting time of blood was extended and blood became incoagulable only when dogs were dosed with 10 LD or more of venom. Haemolysis, although of a low threshold of toxicity, was not severe and should not greatly affect the lethality of the venom. Coagulopathy is a sign that the dog has been lethally envenomed and will need to be given antivenom if skeletal muscle paralysis is to be overcome.     

A randomized multicenter trial of Crotalidae polyvalent immune Fab antivenom for the treatment of rattlesnake envenomation in dogs

Objective – To determine clinical efficacy of the Crotalidae polyvalent immune F_ab (ovine) antivenom (OPCA) against progressive crotalid envenomation in the dog as reflected in stabilization or improvement of snakebite severity scores (SSS). Additionally, due to the potential decreased half‐life of the F_ab antibodies in dogs we compared SSS between dogs receiving 2 different dosing regimes. Design – Prospective, clinical trial. Setting – Five veterinary emergency and critical care facilities. Animals – One hundred and fifteen client‐owned Crotalid (rattlesnake) snake bitten dogs in whom worsening of the envenomation syndrome was observed before OPCA treatment. Interventions – In a multicenter randomized clinical trial a single dose (1 vial) of OPCA alone was compared with 2 doses (1/2 vial each) administered 6 hours apart. Standard supportive care was provided in all cases. Measurements and Main Results – Data were available for 115 patients, 9 of which were fatalities. All patients' clinical condition was documented with a standardized SSS system accounting for each major body system. Each fatality received maximum severity scores of 20. The mean severity score of the 115 patients decreased from 4.19 to 3.29 points and there was no difference between the 2 treatment groups. The mean severity score of the 107 patients without fatalities decreased from 4.16 to 2.15. Antivenin‐related acute reactions occurred in 6 dogs (6%), and no serum sickness occurred within the 95 cases contacted at the 2‐week posttreatment follow‐up. Conclusions – In the first randomized trial in dogs of antivenin in the United States, OPCA effectively stabilized or terminated venom effects. There were no statistical differences detected between treatment groups within the study time frame.     

Survey of the prevalence, diagnosis and treatment of dermatological conditions in small animals in general practice

A survey was made of the prevalence, diagnosis and treatment of dermatological conditions in small animals in general practice in the UK. Out of 3707 small animal consultations in general practice that were observed and recorded, 795 (21.4 per cent) involved animals that had a dermatological problem. In dogs and exotic species, pruritus was the most common presenting sign, accounting for 30 to 40 per cent of the dermatological consultations. In cats, cutaneous swellings were the most common presentation (36 per cent). A diagnosis or recommendation for treatment was made on the basis of the presenting clinical signs and physical examination alone in 576 (72 per cent) of the cases, and various diagnostic tests were performed in the other cases. In dogs, parasitic infestations, bacterial infections and neoplasia accounted for the majority of the diagnoses. In cats, parasites and bacterial infections were the most common. In exotic species, parasites accounted for over 80 per cent of the dermatological diagnoses. In dogs, the most common final diagnoses were otitis, pyoderma, anal sac impaction, flea infestation and atopic dermatitis. In cats, abscesses, flea infestation, and otitis were the most common diagnoses. In exotic species, the most common diagnosis was an unspecified mite infestation. Systemic antibiotics were prescribed in 196 cases (25 per cent), systemic glucocorticoids were prescribed in 162 cases (20 per cent) and treatment with an ectoparasiticide was prescribed in 167 cases (21 per cent).     

Review of cobalamin status and disorders of cobalamin metabolism in dogs

Disorders of cobalamin (vitamin B₁₂) metabolism are increasingly recognized in small animal medicine and have a variety of causes ranging from chronic gastrointestinal disease to hereditary defects in cobalamin metabolism. Measurement of serum cobalamin concentration, often in combination with serum folate concentration, is routinely performed as a diagnostic test in clinical practice. While the detection of hypocobalaminemia has therapeutic implications, interpretation of cobalamin status in dogs can be challenging. The aim of this review is to define hypocobalaminemia and cobalamin deficiency, normocobalaminemia, and hypercobalaminemia in dogs, describe known cobalamin deficiency states, breed predispositions in dogs, discuss the different biomarkers of importance for evaluating cobalamin status in dogs, and discuss the management of dogs with hypocobalaminemia.     

Clinical characteristics and outcome in dogs with small cell T‐cell intestinal lymphoma

Small cell intestinal lymphoma has not been well characterized in dogs. The objective of this study was to describe clinical characteristics and outcome in dogs with small cell intestinal lymphoma. We hypothesized that affected dogs would have prolonged survival compared with high‐grade gastrointestinal (GI) lymphoma. Pathology records were searched for dogs with histologically confirmed small cell GI lymphoma. Seventeen dogs with confirmed small cell intestinal lymphoma were identified, and clinical and outcome data were retrospectively collected. Histopathology was reviewed by a board‐certified pathologist, and tissue sections were subjected to immunophenotyping and molecular clonality assessment. All dogs had small cell, T‐cell, lymphoma confirmed within various regions of small intestine, with 1 dog also having disease in abdominal lymph nodes. All dogs had clinical signs attributable to GI disease; diarrhoea (n = 13) was most common. Ultrasonographic abnormalities were present in 8 of 13 dogs with abnormal wall layering (n = 7) and hyperechoic mucosal striations (n = 7) representing the most common findings. In total, 14 dogs received some form of treatment. The median survival time (MST) for all dogs was 279 days and the MST for the 14 dogs that received any treatment was 628 days. Dogs with anaemia and weight loss at presentation had significantly shorter survival times and dogs that received a combination of steroids and an alkylating agent had significantly longer survival times. Small cell, T‐cell, intestinal lymphoma is a distinct disease process in dogs, and those undergoing treatment may experience prolonged survival.     

Placement of intraluminal stents for treating tracheal collapse in dogs

Tracheal collapse is a progressive disease particularly of small breed dogs. In the terminal stage, when dyspnea becomes the dominating sign and is no longer manageable with medical treatment, a surgical procedure is necessary. With increasing frequency intraluminal tracheal stents are implanted minimal-invasively. In individual animals this is a lifesaving procedure, leading to immediate elimination of dyspnea. In most dogs cough for some time has to be anticipated as the stent acts as a foreign body, but severe complications like excessive formation of granulation tissue, stent migration or stent fracture are rare. Stents represent an attractive treatment modality for tracheal collapse in dogs with dyspnea.     

Effects of serum vitamin E levels on skin vitamin E levels in dogs and cats

Skin problems are common in small animal practice. Oxidative stress, or the imbalance between prooxidants and the body's antioxidant defense system, likely plays a role in the development of skin disease. According to this study, increasing amounts of vitamin E in foods for dogs and cats increases serum and cutaneous concentrations of vitamin E. Based on available scientific data, these increases in vitamin E concentration are likely to be beneficial. However, the relationship between increases in serum and skin vitamin E concentrations and the prevention, development, and treatment of skin disease remains to be elucidated by intervention studies.     

Clinical approach to prostatic diseases in the dog

In small animal practice, prostatic diseases are increasingly encountered. All dogs may experience prostatic disease, but particular care should be addressed to breeding dogs, in which prostatic affection may lead to decrease in semen quality and fertility. The most common prostatic disease is the benign prostatic hyperplasia (BPH) followed by prostatitis, prostatic neoplasia and prostate squamous metaplasia. These diseases do not have pathognomonic symptoms, therefore, making a correct diagnosis may not be easy. An accurate clinical examination and a correct diagnostic protocol are essential in order to begin the most appropriate treatment, and also to do a good prophylaxis where it is possible. BPH therapy is usually recommended when mild‐severe signs are present or if symptoms disturb the patient. New therapeutic approaches, both medical and surgical, allow to maintain fertility in most animals with prostatic disorders. Prostate cancer is relatively infrequent. Elective therapy is the surgical one, but it is considered palliative and can result in important post‐operative complications. The aim of this paper is to lay down the most appropriate diagnostic process describing the aetiologies of prostatic disease, their symptoms, the right investigative tools and therapy.     

Non-pharmacological treatment options for refractory epilepsy: An overview of human treatment modalities and their potential utility in dogs

Refractory epilepsy is a common disorder both in humans and dogs and treatment protocols are difficult to optimise. In humans, different non-pharmacological treatment modalities currently available include surgery, the ketogenic diet and neurostimulation. Surgery leads to freedom from seizures in 50–75% of patients, but requires strict patient selection. The ketogenic diet is indicated in severe childhood epilepsies, but efficacy is limited and long-term compliance can be problematic. In the past decade, various types of neurostimulation have emerged as promising treatment modalities for humans with refractory epilepsy. Currently, none of these treatment options are used in routine daily clinical practice to treat dogs with the condition. Since many dogs with poorly controlled seizures do not survive, the search for alternative treatment options for canine refractory epilepsy should be prioritised. This review provides an overview of non-pharmacological treatment options for human refractory epilepsy. The current knowledge and limitations of these treatments in canine refractory epilepsy is also discussed.     

Enhanced intestinal permeability to 51Cr-labeled EDTA in dogs with small intestinal disease

Intestinal permeability in dogs with small intestinal disease was measured by quantitation of 24-hour urinary excretion of 51Cr-labeled EDTA following intragastric administration. Permeability was high in dogs with a variety of naturally acquired small intestinal diseases including wheat-sensitive enteropathy of Irish Setters, small intestinal bacterial over-growth, and giardiasis, and permeability was decreased after successful treatment. These findings indicate that the assessment of intestinal permeability may be a useful technique for detecting small intestinal disease and for monitoring the efficacy of treatment in dogs.     

Current British veterinary attitudes to perioperative analgesia for dogs.

In March 1996, a questionnaire was sent to 2000 veterinary surgeons, primarily involved in small animal practice, to assess their attitudes to perioperative analgesic therapy in dogs, cats and other small mammals. This paper is concerned only with the data relating to dogs. The veterinary surgeons considered that pain was a consequence of all the surgical procedures specified, but there were differences in their treatment of pain. Some veterinarians considered that a degree of pain was necessary postoperatively to prevent excessive activity. In general, women and more recent graduates assigned higher pain scores to the procedures and were more likely to treat the pain with analgesics. A significant number of veterinarians consider the use of opiates or non-steroidal anti-inflammatory drugs before surgical procedures, but relatively few appear to use combinations of different classes of analgesics either before or after operations.     

Autoantibodies against structures of the central nervous system in steroid responsive meningitis-arteriitis in dogs

Steroid-responsive meningitis-arteriitis (SRMA) is a disease of dogs familiar in small animal practice for decades. A combined evaluation of IgA in serum and cerebrospinal fluid (CSF) is an important diagnostic tool. It is suspected that immunpathological mechanisms are involved in the pathogenesis of SRMA because of the marked response to steroids. Excessive production of IgA seems to play a central role and might be caused by an immune reaction to self-antigens of the central nervous system (CNS). To test this hypothesis, we analyzed CSF samples from 55 dogs with SRMA using the western blot method. After blotting canine brain tissue, IgA, IgM and IgG of the CSF samples were tested for their binding to CNS antigens. We also evaluated CSF samples from 45 dogs with other brain diseases, including different encephalitides and intracranial tumors, and from healthy dogs as controls. Positive reactions (mostly IgA) were observed in the CSF samples from dogs with SRMA, different encephalitides and brain tumors (a total of 8% positive samples). The occurrence of autoantibodies against CNS structures was significantly higher in the control group "other brain diseases" than in the SRMA group (p = 0.0135). There was no significant difference in the number of positive samples between dogs with SRMA and the negative control group (healthy dogs, p = 0.1535). Despite the small number of positive samples, only dogs with abnormal findings in the CSF analysis also had autoantibodies in the CSF. There was no significant correlation between the occurrence of autoantibodies and levels of IgA, protein content and cell counts in the cerebrospinal fluid. However, there was a certain trend toward positive reactions in CSF samples with high protein content. The occurrence of autoantibodies in dogs with SRMA thus seems to be an epiphenomenona rather than the cause of the disease.