Tick (Ixodes holocydus) paralysis in the dog – induction of immunity by injection of toxin

SUMMARY Three beagle dogs were immunised against the paralysing effects of holocyclotoxin, using toxic extracts derived from salivary glands of the Australian paralysis tick, Ixodes holocydus. Upon subsequent challenge with four ED50, of toxin the animals were completely immune, whereas during the early stages 2 of 3 dogs became paralysed after injection with 0.5 ED50. Three immunised beagles, on which 15 I. holocydus ticks had fed, showed no symptoms but a control beagle became paralysed after 4 I. holocydus females fed on it. Treatment was instituted immediately upon the onset of clinical signs and the dog recovered uneventfully.     

Osmotic pressure and aqueous humor formation in dogfish

Comparative chemical analyses show the aqueous humor of smooth dogfish has lower concentrations of urea and trimethylamine oxide than the blood plasma. Freezing-point depression determinations demonstrate that the aqueous humor has a correspondingly lower osmotic pressure. It would appear that water entering the aqueous humor from the plasma is moving against an osmotic gradient.     

In Vitro and In Vivo Evaluation of Ferric-Hyaluronate Implants for Delivery of Amikacin Sulfate to the Tarsocrural Joint of Horses

Objective— To assess the antimicrobial elution characteristics, toxicity, and antimicrobial activity of amikacin‐impregnated ferric‐hyaluronate implants (AI‐FeHAI) for amikacin delivery to the tarsocrural joint of horses. Study Design— Experimental study. Sample Population— AI‐FeHAI implants, equine cartilage, and synovium, and horses (n=6). Methods— In vitro study: Five AI‐FeHAI were placed in saline solution with daily replacement until implant degradation. Eluent was tested for amikacin concentration and bioactivity. Synovial and cartilage explants were incubated in the presence or absence of AI‐FeHAI for 72 hours and subsequently assessed for morphology, viability, and composition. Synovial explants were incubated with Staphylococcus aureus in the presence or absence of AI‐FeHAI. Spent medium was cultured daily and explants were assessed for morphology and viability after 96 hours. In vivo study: AI‐FeHAI were placed in 6 tarsocrural joints. Standard cytologic analysis and amikacin concentration (SFAC) were determined in synovia obtained regularly for 28 days thereafter. Similar analyses were conducted after a single intra‐articular injection of amikacin 6 months later. Results— In vitro study: Amikacin concentrations exceeded 16 μg/mL and inhibited S. aureus growth for 8 days. AI‐FeHAI had no effect on cartilage explants. AI‐FeHAI eliminated bacteria from synovial explants. In vitro study: After AI‐FeHAI placement, SFAC was highest (140.78+63.81 μg/mL) at first sampling time. By 24 hours SFAC was <16 μg/mL. After intra‐articular injection, SFAC was the highest (377.91 ± 40.15 μg/mL) at first sampling time. By 48 hours SFAC was <16 μg/mL. Conclusions— A single intra‐articular amikacin injection demonstrated superior pharmacokinetics than AI‐FeHAI prepared as described. Clinical Relevance— AI‐FeHAI cannot be recommended for clinical use.     

A Retrospective Evaluation of the Rectal Pull-through Technique Procedure and Postoperative Complications

Ten animals (8 dogs and 2 cats) with distal rectal lesions were treated by surgically resecting the affected segment of the rectum by the rectal pull-through technique. There were four malignant tumors, three benign tumors, two inflammatory lesions, and one malignant tumor that extended histologically to the margins of a previous surgical excision. Postoperative complications were tenesmus (7 animals), fecal incontinence (4 animals), rectal bleeding (4 animals), and abscess formation (1 animal). Dehiscence and stricture were not observed. The four animals with malignant tumors survived less than 12 months after surgery. One of the four animals still living has persistent fecal incontinence. The rectal pull-through technique is described and illustrated.     

A selective survey of potato cyst-nematode pathotypes in Great Britain

One hundred and forty-four samples of potato cyst-nematodes, the majority chosen to contain G. pallida , from England, Wales and Scotland were identified to pathotype. Where G. rostochiensis was present it proved to be pathotype Rol, there being no indication of other pathotypes of this species. Of G. pallida , a minority of samples incorporated pathotype Pa 1; many were pathotype Pa3 but distinction between Pa2 and Pa3 was unsatisfactory in many more. It is concluded that recognition of these latter two pathotypes is of little value. The proposed pathotype New Leake could not be recognized.