Further evidence that zinc sulphate compromises the efficacy of dipping treatments using diazinon to control sheep lice (Bovicola ovis)

Objective To compare the wettability and efficacy of diazinon dip wash made with and without the addition of zinc sulphate.
Design Field experiments using a shower and a plunge dip complemented by in-vitro wettability experiments.
Procedure A flock of infested sheep was divided into groups and treated in a shower dip with clear or cloudy dam water plus up to 1.5% zinc sulphate. Another infested line of sheep was treated using a plunge dip with nil or 1% zinc sulphate. In both experiments, wetting was assessed after dipping and louse counts were conducted for 9 months after treatment. Five in-vitro experiments compared the wettability of dip wash containing diazinon with up to 1.5% zinc sulphate added.
Results In the shower dipping experiment, live lice were found at 1 month after dipping in the cloudy water groups with 0.75%, 1.0% and 1.5% zinc sulphate and at 2 months in the 0.75% zinc sulphate group. No lice were found at subsequent inspections or at any time in the groups that were plunge dipped. Zinc sulphate decreased the amount of dip wash retained by wool staples in all in-vitro experiments (P < 0.05).
Conclusion Zinc sulphate should be considered as a risk factor that could cause failure to eradicate a lice infestation. The risk can be overcome by ensuring that all sheep are saturated at dipping and that the dip wash, and any holding tanks, are agitated throughout the dipping event.     

Feline congenital myotonia

FELINE infections peritonitis (FIP) is a systemic, fatal, immune-mediated vasculitis caused by a feline coronavirus (FCoV). Historically, FIP virus (FIPV) and feline enteritis by a feline enteric coronavirus (FECV). Recent studies have shown that there is essentially only one FCoV in the field, although laboratory strains may vary in virulence.     

Resistance to synthetic pyrethroid pour-on insecticides in strains of the sheep body louse Bovicola (Damalinia) ovis

Groups of sheep infested with strains of Bovicola (Damalinia) ovis were obtained from flocks either with a history of failure to control lice with synthetic pyrethroid (SP) pour-on insecticides, or from farms where SP compounds were not used. The sheep were treated according to the manufacturer's recommendations with registered "off-shears" SP formulations. All treatments were applied under ideal conditions with doses calculated on an individual body weight basis and applied to the dorsal mid-line from the base of the neck to the butt of the tail. Treated sheep were kept in pens and maintained in separate groups. The pour-on SP treatments significantly reduced the lice population but failed to eliminate the infestation in 7 of 13 experiments in sheep carrying strains of lice with resistance factors of greater than 4 to at least one of the SP compounds. Failures occurred with all three of the SP pour-ons currently registered for lice control in NSW and with both water-based and organic solvent-based formulations.     

Bufo marinus intoxication in dogs: 94 cases (1997-1998)

OBJECTIVE: To determine history, clinical and electrocardiographic abnormalities, treatment, and outcome of dogs exposed to toxins produced by the Bufo marinus toad. DESIGN: Retrospective study. ANIMALS: 94 dogs. PROCEDURE: Medical records of dogs examined between July 1997 and July 1998 for which a diagnosis of toad intoxication had been made on the basis of history and physical examination findings were reviewed. RESULTS: Most (66) dogs were treated during the spring and summer. For 54 dogs, exposure to toads had been witnessed. For the remaining 40, toad intoxication was diagnosed on the basis of history and clinical signs. The most common clinical signs were neurologic abnormalities, hyperemic mucous membranes, ptyalism, recumbency or collapse, tachypnea, and vomiting. The oral cavity was lavaged with tap water in all dogs. Fifty-two dogs were hospitalized for treatment. Body weight of dogs hospitalized > 2 hours was significantly less than that of dogs treated as outpatients. The most common electrocardiographic findings were sinus arrhythmia, sinus tachycardia, and normal sinus rhythm. Eighty-nine dogs recovered fully, 4 died, and 1 was euthanatized. CONCLUSIONS AND CLINICAL RELEVANCE: In areas in which B marinus toads are endemic, toad intoxication should be considered in the differential diagnosis for dogs with an acute onset of neurologic abnormalities, hyperemic mucous membranes, and ptyalism, especially during the spring and summer months. The prognosis is good for dogs with toad intoxication that receive appropriate treatment.     

Acute Water Intoxication in a Dog

A one-year-old female labrador Retriever dog was admitted to the Emergency Service after playing in a lake for several hours. Physical examination revealed coma, hypothermia, and bradycardia. Marked diuresis was noted. A serum biochemical profile revealed hyposmolality, hyponatremia, and hypoproteinmia suggestive of dilution of serum constituents. Acute water intoxication was diagnosed. Recovery was complete and occurred without specific therapy. Acute water intoxication should be considered in the differential diagnosis of coma. (Vet Emerg & Crit Care, 1999, 9: 19–25)     

Pathology of skin diseases in crocodiles

Objective To establish which skin diseases occur in crocodiles, particularly those on farms, to indicate the relative frequency of each particular disease and to provide information on pathogenesis, especially in regard to lesions with two or more pathogens present.
Design A gross and microscopic retrospective (period of 1989 to 1995) and current (1996 to 1997) examination of skin lesions in crocodiles in Queensland and the Northern Territory.
Result Skin lesions were obtained from crocodiles on nine farms, from a group of experimental animals and from one adult found dead in the wild. A total of 203 lesions from 180, mostly young, crocodiles was examined; 119 lesions were from retrospectively examined cases and 84 were recent. The relative frequencies of four presumed primary pathogens in lesions were Dermatophilus s p 28.1 %, fungi 14.8%, poxvirus 3.4% and probable Mycobacterium s p 2.5%. In addition, other bacteria of unknown significance were present in many lesions, and there was one case of presumed Paratrichosoma crocodilus infection. In 32.5% of lesions, multiple pathogens were identified.
Conclusion Dermatophilosis is the most common and probably the most important skin disease of crocodiles in Australia, but it is frequently complicated by concurrent infection with fungi or other microorganisms.     

Observations of fibropapillomatosis in green turtles (Chelonia mydas) in Indonesia

Objective To determine the prevalence and manifestations of fibropapillomatosis in green turtles in Indonesia, to identify any relationship between fibropapillomatosis and concurrent parasitic infection, to ascertain the effect of fibropapil-lomatosis on health, and to examine whether environment might have an effect on the prevalence of fibropapillomatosis.
Procedure 4407 green turtles ( Chelonia mydas ) and 401 hawksbill turtles ( Eretmochelys imbricata ) were examined. The occurrence of fibropapillomatosis was correlated with sex, maturity, curved carapace length, body weight/curved carapace length ratio, the number and distribution of tumours on the skin, parasite burdens, some haematological variables and the region of capture.
Results Fibropapillomatosis was seen only in green turtles, and the overall prevalence in these was 21.5%. This prevalence increased with the curved carapace length up to 85 cm. The average number of tumours per affected turtle was 5 SD 4.1 (range, 1 to 29), and was negatively correlated with the body weight/curved carapace length ratio (rs = -0.8; P = 0.001). The red blood cell count in turtles with fibropapilloma was lower than in non-fibropapilloma turtles captured and examined at the same time (P = 0.001). The prevalence of fibropapilloma in turtles captured near densely populated, industrial regions (26.3%) was greater than in turtles from sparsely populated areas (17.7%).
Conclusion Fibropapillomatosis in green sea turtles in Indonesia is of moderate occurrence; young mature turtles (curved carapace length = 85 cm) are most frequently affected. Fibropapilloma adversely affects health of turtles. Fluke infestation seems not to be a causal factor, but viral infection, perhaps with concurrent stress of environmental origin, seems likely.     

Clinical findings in 40 dogs with hypersensitivity associated with administration of potentiated sulfonamides

The purpose of this study was to summarize the clinical findings in 40 dogs with systemic hypersensitivity reactions associated with the administration of potentiated sulfonamides. Dogs ranged from 6 months to 14 years of age, with a mean of 5.7 +/- 3.2 years. Spayed female dogs were overrepresented (24 of 40, or 60% of the dogs), as were Samoyeds (3 of 40; 8%) and Miniature Schnauzers (5 of 40; 13%). Mean dosages of potentiated sulfonamides were 47.0 +/- 14.9 mg/kg/d (range, 23.4-81.4 mg/kg/d). The time from the 1st administration of the drug to the onset of the clinical signs of hypersensitivity ranged from 5 to 36 days, with a mean of 12.1 +/- 5.9 days. There was no relationship between either the dosage or type of sulfonamide given and the time to the onset of the clinical signs. Fever was the most common clinical sign observed (55% of the dogs); thrombocytopenia was 2nd (54%), and hepatopathy (28%) was 3rd. Neutropenia, keratoconjunctivitis sicca (KCS), hemolytic anemia. arthropathy, uveitis, skin and mucocutaneous lesions, proteinuria, facial palsy, suspected meningitis, hypothyroidism, pancreatitis, facial edema, and pneumonitis were also observed in some patients. Of 39 dogs with adequate follow-up, 30 (77%) recovered, whereas 8 (21%) either died or were euthanized, and 1 recovered clinically but had persistent increases in alanine aminotransferase (ALT) activity. Dogs with hepatopathy generally had a poorer prognosis (46% recovery) than dogs without hepatopathy (89% recovery; P = .0035). Sixty-three percent of the dogs with thrombocytopenia recovered, compared to 90% of the dogs without thrombocytopenia (P = .042). Recovery was not associated with sex, age, breed, or type of sulfonamide administered.