Low-dose ethanol in the treatment of ethylene glycol poisoning

A pharmacokinetic study was conducted to determine the effectiveness of lower doses of ethanol in the treatment of ethylene glycol (EG) poisoning. Four dogs were maintained at serum ethanol concentrations of 0, 35 and 140 mg/dl prior to EG (i.v., 2 ml/kg) administration. The serum EG concentration-time data showed that the 35 mg/dl ethanol level provided as effective an inhibition of EG metabolism as did the 140 mg/dl level. The average urinary excretion rate of oxalic acid post EG administration was reduced to control levels by ethanol. The 35 mg/dl serum ethanol level reduced the total body clearance of EG from 93.9 to 50.0 ml/h/kg and increased the effective half-life from 5.78 to 11.4 h. Clinical testing was accomplished by giving the dogs 12 ml EG/kg body weight orally. One hour later, the dogs were either not treated or treated with a sodium bicarbonate-ethanol solution to obtain a serum ethanol concentration of 50 mg/dl. The clinical test performed in the ethanol-treated dogs showed little change from normal limits. Urine calcium oxalate crystals were seldom found. The dogs given EG (12 ml/kg) but not treated with ethanol were in a coma at 13 h and showed severe metabolic acidosis, dehydration, mild hepatocellular disease and acute renal damage. Urine calcium oxalate crystals were found in high numbers. The rapid death associated with EG poisoning appeared to be due to metabolic acidosis in combination with dehydration.     

1,3 Butanediol treatment of ethylene glycol toxicosis in dogs

In order to assess the therapeutic value of 1,3 butanediol in ethylene glycol toxicosis, mixed-bred dogs were given an oral dose of commercial antifreeze at 6 ml/kg of body weight (0 hour) and treated (IV) 7 times at 6-hour intervals with 5.5 ml/kg of body weight 1,3 butanediol solution (20% in physiological saline solution) beginning at 8, 12, and 21 hours. Serum glycolic acid concentration was quantitated by high-pressure liquid chromatography. Three dogs that were given ethylene glycol, but no 1,3 butanediol treatment, died with elevated serum glycolic acid concentrations. Five dogs were given ethylene glycol and 1,3 butanediol treatment. Of 2 dogs treated at 8 hours, 1 survived and 1 died at 39 hours; 1 treated at 12 hours and 1 treated at 21 hours survived; 1 dog died soon (27 hours) after treatment was initiated at 21 hours. Four of the 5 dogs had dramatically decreased serum glycolic acid concentrations after 1,3 butanediol treatment, indicating its effectiveness in inhibiting alcohol dehydrogenase-dependent glycolic acid formation in vivo.     

Taste responses of dogs to ethylene glycol, propylene glycol, and ethylene glycol-based antifreeze

Although it is widely believed that ethylene glycol-based antifreeze (AF) is an attractive tastant to dogs and other animals, empirical data on this point are not available. In experiment 1, we examined the propensity of 178 adult mixed-breed dogs to approach, sniff, and lick a concentration of AF commonly used in automotive cooling systems (50%). Despite the fact that most of the dogs approached and sniffed the AF in these 5-minute tests, only 9% initiated lick responses and most of these were brief and not followed by additional licking. In experiment 2, the lick responses of five gastric-cannulated dogs to aqueous solutions of 20% sucrose, 50% ethylene glycol, 50% propylene glycol, water, and 50% AF were examined in 14-minute tests before and after periods of food and water deprivation. Under the latter conditions, 2 of the 5 dogs drank amounts of ethylene glycol that would have been lethal to uncannulated dogs. None of the five dogs drank potentially lethal amounts of AF. The preference order for these tastants was sucrose greater than water greater than ethylene glycol greater than AF = propylene glycol. Although these findings question the general belief that AF is highly palatable to most dogs, they do imply that large individual differences in responsiveness exist and that AF ingestion is likely influenced by motivational state. Furthermore, they suggest the possibility that unpleasant-tasting additives could be successfully developed to eliminate the ingestion of AF, because the initial attractiveness of AF is relatively low. Such additives would have to be stable in vehicular cooling systems and not adversely affect the functional aspects of AF performance.     

Boomslang envenomation in 2 dogs in Kwazulu-Natal, South Africa

Although snakebites are frequently seen in small animal practice in South Africa, boomslang (Dispholidus typus) bites are infrequent due to their shy habits. Boomslang venom is a potent procoagulent, causing a consumption coagulopathy and profuse haemorrhage. Boomslang monovalent antivenom is the most effective treatment. This case report describes and discusses 2 small dogs that were presented to a private practice after being bitten by the same boomslang. Boomslang monovalent antivenom administration to both resulted in cessation of bleeding within 45 minutes. One of the dogs developed severe adverse reactions to the antivenom, including vomiting, dyspnoea and nystagmus, which responded well to intravenous cortisone and symptomatic treatment.     

Hyperosmolemic changes following experimental ethylene glycol intoxication in dogs

Experimental ethylene glycol toxicosis in dogs produced a marked increase in serum osmolality. By comparing measured and calculated serum osmolality and relating this difference to plasma ethylene glycol, it was determined that ethylene glycol was primarily responsible for the hyperosmolemia. Osmometry may provide a useful adjunct to other diagnostic tests in identifying ethylene glycol intoxicated dogs during the early, most treatable, stage of toxicosis.     

First report of Fascioloides magna (Bassi, 1875) in South Africa

Fascioloides magna from a Brahman heifer recently imported from the USA is recorded for the first time in South Africa. The pathological findings are briefly described. The possibility of this parasite becoming established in this country is also discussed.     

Roquefortine in the stomach contents of dogs suspected of strychnine poisoning in Alberta

From April to September 1990, submissions in Alberta veterinary diagnostic laboratories for which strychnine analysis was requested were tested retrospectively for roquefortine, a diketopiperazine alkaloidal tremorgenic mycotoxin. Roquefortine was found only in strychnine-negative samples. The specific origins of the fungal-contaminated specimens could not be determined. Of the six roquefortine-positive cases, four dogs that vomited prior to treatment recovered. Two dogs which died had significant amounts of stomach contents present at the time of postmortem.

At the present time only one veterinary laboratory in Canada is routinely testing for roquefortine when samples are negative for strychnine. It appears that a low diagnostic rate for this type of poisoning may be occurring due to incomplete testing. The inability to differentiate between roquefortine and strychnine poisoning on a clinical basis in five of our six cases emphasizes that an accurate causative diagnosis requires laboratory examination.

Research in rats and sheep has shown that the tremorgenic mycotoxins penitrem A and roquefortine are excreted through bile. Although further research is required, the submission of bile and intestinal contents is recommended if stomach contents or vomitus are not available for laboratory testing. Both of these mycotoxins should be tested for when strychnine analysis is negative as fungi may produce both toxins at the same time. In this study we were unsure if roquefortine alone or in combination with other toxins was responsible for our findings.

     

疑似犬血虫净中毒1例

<正>1病例情况金毛犬,雄性,2岁,体重28 kg,正常免疫及驱虫,日常饮食主要是鸡骨架、米饭及青菜。该犬于2010年3月13日到某动物医院注射血虫净(主要成分为三氮脒)以预防血液原虫感染,剂量为5 mg/kg体重。用药后第二天患犬出现精神沉郁,食欲下降症状;第三天患犬出现明显的神经症状,主要表现为惊厥、角弓反张、站立不稳、呕吐、流涎及呻吟鸣叫。     

4-Methylpyrazole as treatment for naturally acquired ethylene glycol intoxication in dogs

Eight dogs with ethylene glycol intoxication were treated with 4-methylpyrazole, an alcohol dehydrogenase inhibitor. Dogs had clinical signs referable to ethylene glycol ingestion including ataxia, depression, vomiting, polyuria, and dehydration. Metabolic abnormalities included high anion gap metabolic acidosis, serum hyperosmolality, isosthenuria, and monohydrate and dihydrate calcium oxalate crystalluria. Serum and urine ethylene glycol concentrations were determined to confirm ingestion of ethylene glycol. A 50-mg/ml solution of 4-methylpyrazole in propylene glycol was administered iv as follows: initial treatment, 20 mg/kg of body weight; at 17 hours after admission, 15 mg/kg; at 25 hours after admission, 5 mg/kg. By 24 hours after admission, all dogs had clinical and metabolic improvement. Of the 8 dogs, 7 were released within 3 days of admission. Four of the 8 dogs returned for follow-up evaluation, at which time biochemical or hematologic abnormalities were not observed.     

Early renal ultrasonographic findings in dogs with experimentally induced ethylene glycol nephrosis

Renal ultrasonographic changes were evaluated in 5 dogs administered 10 ml of commercial antifreeze (95% ethylene glycol)/kg of body weight, PO, and in 2 dogs given placebos. Studies were made prior to and after ingestion on an hourly basis over a period of 8 to 10 hours. All dogs were anesthetized immediately after toxin or placebo ingestion for the duration of the study. Renal cortical echogenicity was evaluated in comparison with that of the adjacent liver and spleen. Echogenicity of the renal medulla and definition of the corticomedullary junction were assessed. Within 4 hours after ethylene glycol administration, renal cortical echogenicity of all intoxicated dogs increased from normal to surpass that of liver and approach or equal that of the spleen. Medullary echogenicity in all intoxicated dogs progressively increased over the course of the study, with changes recognized within 5 hours after ethylene glycol administration. An ultrasonographic pattern consisting of nearly equal, marked increase in cortical and medullary echogenicity and relatively hypoechoic corticomedullary junction and central medullary regions was recognized concurrent with the development of anuria in 3 of the 5 intoxicated dogs. Mild, transient increases in cortical and medullary echogenicity were observed in anesthetized control dogs. However, no statistical difference (P less than 0.05) was detected between baseline, peak, and terminal echogenicity values in these dogs. Blood and urine samples were collected hourly from intoxicated dogs to coincide with ultrasonographic studies. Most clinicopathologic values derived from these samples were not statistically different (P less than 0.05) from those reported in a study that used a similar intoxication protocol in nonanesthetized dogs.     

Detection of a Theileria species in dogs in South Africa

A Theileria species was detected by PCR in blood samples collected from dogs in the Pietermaritzburg area and was also found in dogs presented at the Outpatients Clinic of the Onderstepoort Veterinary Academic Hospital (OVAH), in the Pretoria area, South Africa. In the Pietermaritzburg area, 79 of the 192 samples were positive, while 3 out of 1137 of the Onderstepoort samples were positive. Three positive samples from Pietermaritzburg were co-infected with Ehrlichia canis. PCR positive samples were further analysed by the Reverse Line Blot (RLB) and sequence analysis. Phylogenetic analysis of the 18S rRNA full-length gene sequences of one sample (VT12) from Pietermaritzburg and two samples from OVAH (BC281 and BC295) revealed a close relationship with sequences of Theileria species (sable). Clinical signs of the dogs that were examined at Pietermaritzburg and OVAH included an immune-mediated condition with severe thrombocytopenia. These findings identify a Theileria sp. in dogs for the first time in South Africa and add yet another microorganism to the growing list of haemoprotozoan parasites infecting dogs worldwide. The clinical significance of this infection in dogs is poorly resolved.     

Early effects of ethylene glycol on the ultrastructure of the renal cortex in dogs

A sublethal dose of ethylene glycol was administered orally to 3 groups of dogs; dogs of a control group were given distilled water instead. Renal cortical biopsy samples were obtained from dogs of experimental and control groups at various times after treatment. Tissue was examined by use of light microscopy and transmission electron microscopy. In dogs of the control group, the light and electron microscopic appearances of tissue were within normal limits at all sample collection hours. In dogs of the experimental groups, renal corpuscular structure remained within normal limits by use of light and electron microscopy throughout the study, though morphologic change was seen in other structures of the cortex. Light microscopic lesions first appeared at 12 hours, and were similar to those reported in the literature. Ultrastructural lesions were first observed in the 5-hour samples, and similar to the light microscopic lesions, were most common in the proximal convoluted tubules (PCT). Initial PCT cellular changes included vacuolization of cells and distention of the parabasal extracellular spaces; PCT cellular lesions seen in later-hour samples included formation of apical buds and cellular rupture. Internalization or sloughing of the PCT brush border was not observed. Distal convoluted tubules (DCT) were frequently dilated and/or packed with cellular debris. A few DCT cells had degenerative or necrotic changes. In PCT and DCT, abnormal cells were frequently flanked by normal or nearly normal cells. During later hours, a few cells with types of changes first observed in early hours continued to be observed, implying ongoing response of cells to the toxin.     

Gastro-intestinal helminths of domestic dogs in the Republic of South Africa

Of the gastro-intestinal helminths found in 1 063 dogs from different parts of the country, Dipylidium caninum, the most prevalent cestode, occurred in 19,7% of the animals. Echinococcus granulosus was present in 10 dogs, 8 of which were from urban areas, and Taenia hydatigena in 69 dogs. Taemia multiceps was recovered from dogs only in the Cape Province and the Orange Free State. Toxocara canis was present in 81 of the necropsies carried out on 253 dogs from the Pretoria municipal area, while Ancylostoma spp. were present in 175 dogs. In the Pretoria area Ancylostoma caninum (11,9%) was more prevalent than Ancylostoma braziliense (6,2%).     

Helminth parasites of dogs from two resource-limited communities in South Africa

Biological samples were collected from dogs in resource-limited communities in the North-West and Gauteng Provinces of South Africa to assess the prevalence of helminth parasitism. These samples included adhesive tape peri-anal skin swabs and fresh faecal samples for helminth examination, and thick and thin blood films (smears) and whole-blood samples in anticoagulant for examination of filarial nematode microfilariae and haemoprotozoa. The eggs of Ancylostoma caninum, Toxocara canis, Toxascaris leonina, Dipylidium caninum and taeniids were identified. None of the blood samples and smears tested positive for microfilariae of Dirofilaria immitis or Dipetalonema spp. or for haemoprotozoa. The adhesive tape swabs were negative for cestode eggs and segments. Most of the helminth parasites identified in this study are zoonotic and consequently are regarded as a public health hazard.     

Helicopter-based censusing of domestic dogs in Gauteng Province, South Africa

Decision support in veterinary epidemiology often depends on density estimates of domestic animals. These estimates are usually based on ground surveys of various types. Ground surveys are difficult to undertake in the informal housing settlements that are frequently encountered in developing countries. In addition, they are time-consuming and expensive. In this study, field experience in enumerating wildlife from helicopters was used to count domestic animals in Gauteng Province, South Africa. Data for domestic dogs are analysed for precision and accuracy and the technique evaluated in terms of its value for decision support.