Veterinary Toxicology and Pharmacology Commons^™

The Evidence For Pain In Fish: The Use Of Morphine As An Analgesic, Lynne U. Sneddon

Veterinary Science and Medicine Collection

This paper discusses the evidence for pain perception in fish and presents new data on morphine analgesia in fish. Recent anatomical and electrophysiological studies have demonstrated that fish are capable of nociception, the simple detection of a noxious, potentially painful stimulus and the reflex response to this. To prove pain perception, it must be demonstrated that an animal’s behaviour is adversely affected by a potentially painful event and this must not be a reflex response. The present study examined the acute effects of administering a noxious chemical to the lips of rainbow trout (Oncorhynchus mykiss) to assess what changes occurred …

Absence Of Detectable Pharmacological Effects After Oral Administration Of Isoxsuprine, J. Daniel Harkins, G. D. Mundy, S. Stanley, W. E. Woods, R. A. Sams, D. R. Richardson, S. C. Grambow, Thomas Tobin

Maxwell H. Gluck Equine Research Center Faculty Publications

Isoxsuprine is reported to be a peripheral vasodilator used in human and veterinary medicine to treat ischaemic vascular disease. In horses, it is generally administered orally to treat navicular disease and other lower limb problems. To deflne the scope and duration of its pharmacological responses after oral administration, 6 horses were dosed with isoxsuprine HCI (1.2 mg/kg bwt) q. 12 h for 8 days and then tested to assess the duration and extent of pharmacological actions. There was no significant difference between isoxsuprine and control treatment values for heart rate, spontaneous activity, sweat production, anal muscle tone, core and skin …

An Overview Of The Methylxanthines And Their Regulation In The Horse, J Daniel Harkins, W. Allen Rees, G. D. Mundy, Scott D. Stanley, Thomas Tobin

Maxwell H. Gluck Equine Research Center Faculty Publications

Caffiene, theophylline and theobromine are naturally occurring members of the methylxanthine family;pentoxfylline, dyphylline and enprofylline are structurally related synthetic pharmaceuticals. Caffiene has predominantly central nervous system effects, theophylline, dyphylline and enprofylline have predominantly bronchodilator effects, while theobromine is associated with diuretic responses. Pentoxfylline is thought to increase red cell deformability and facillitate blood flow through capillary beds. The methylxanthines are not highly potent agents; they are typically administered in gram doses and they tend to have relatively long half-lives. They remain detectable in plasma and urine for relatively long periods. Similarly, traces of the naturally occurring members of this family …

The Pharmacologic Effects Of Isoxsuprine, J. Daniel Harkins, Thomas Tobin

Maxwell H. Gluck Equine Research Center Faculty Publications

Isoxsuprine is a therapeutic medication used to treat navicular disease and other lower limb problems in horses and is one of the more frequently detected therapeutic agents in racing horses. In crossover studies, horses were administered intravenous and oral isoxsuprine to determine the character and duration of pharmacological effects. Following intravenous administration, isoxsuprine significantly increased heart rate, spontaneous activity, and sweat production. There was an apparent, although statistically insignificant, increase in cutaneous blood flow. Skin temperature decreased below control values, and there was a significant decrease in core temperature. Isoxsuprine also reduced smooth muscle tone. In contrast, after oral dosing, …

Lupin Stubbles : Getting The Best With Weaner Sheep, Keith Croker, Colin Mcdonald, Jeremy Allen

Journal of the Department of Agriculture, Western Australia, Series 4

Sweet lupins are now grown on about a million hectares in Western Australia each year. If half of the State's seven million weaners were grazed as recommended on half of the lupin stubbles, it could generate about $15 million from reduced supplementary feeding, greater wool production and other advantages. But correct management is important, particularly knowing when to take weaners out. Research by the Department over the last five years is now indicating how this should be done.

Hordenine : Pharmacology, Pharmacokinetics And Behavioural Effects In The Horse, M. Frank, T. J. Weckman, T. Wood, W. E. Woods, Chen L. Tai, Shih-Ling Chang, A. Ewing, J. W. Blake, Thomas Tobin

Maxwell H. Gluck Equine Research Center Faculty Publications

Hordenine is an alkaloid occurring naturally in grains, sprouting barley, and certain grasses. It is occasionally found in post race urine samples, and therefore we investigated its pharmacological actions in the horse. Hordenine (2.0 mgkg bodyweight [bwt]) was administered by rapid intravenous (iv) injection to 10 horses. Typically, dosed horses showed a tlehmen response and defecated within 60 secs. All horses showed substantial respiratory distress. Respiratory rates increased about 250 per cent and heart rates were approximately double that of resting values. All animals broke out in a sweat shortly after iv injection, but basal body temperature was not affected. …

Phomopsis-Resistant Lupin Stubbles As Feed For Weaner Sheep, Colin Mcdonald, Keith Croker, Jeremy Allen

Journal of the Department of Agriculture, Western Australia, Series 4

The breeding of sweet, narrow-leafed lupins with increased resistance to Phomopsis leptostromiformis, the fungus that causes lupinosis in sheep, is a breakthrough for the summer nutrition of weaner sheep. The new resistant varieties, Gungurru for the medium (325 to 450 mm) rainfall areas and Yorrel for low rainfall areas (less than 325 mm), were released by the Department of Agriculture in 1988.

This article discusses progress in a four-year project which is examining liveweight and wool production of weaners grazing Gungurru stubbles.

The Sandplain Lupin : Its Nutritional Value And Grazing Management, P W. Morcombe

Journal of the Department of Agriculture, Western Australia, Series 4

The sandplain lupin or Western Australian blue lupin (Lupinus cosentinii) was introduced to the West Midlands at the turn of the last century. Since that time it has been used as a self-regenerating summer forage for sheep and cattle.

Being deep rooted, it has adapted well to the sandy soils from Perth to Northampton, and plantings now cover more than 100,000 ha.

As few other improved pasture species will persist on these deep sands the sandplain lupin provides an important source of summer feed for grazing livestock. A stand can be grazed throughout summer at stocking rates of 10 to …

Effects Of Methylxanthines On Newborn Rat Respiration, Craig Gatto

Masters Theses

Methylxanthines (MX), such as theophylline, are commonly used in the treatment of recurrent apnea due to their stimulant effects on the respiratory center. Structure-activity studies have demonstrated that substitution of alkyl groups on the 3-position of the xanthine nucleus results in increased bronchodilator potency, while substitution on the 1-position is important for adenosine antagonism and CNS stimulation. Three different alkylxanthines were studied to determine the structural requirements for respiratory stimulation. Respiratory rates and volumes were determined in 4- to 7-day-old rats using a volume displacement body plethysmograph. Measurements were made before and at 5 minute intervals after subcutaneous (s.c.) injection …

The Effects Of Xanthine And Adenosine Analogs On Rat Pup Diaphragmatic Contractility, Liam C. Farrell

Masters Theses

Methylxanthines are commonly used in the treatment of respiratory disorders such as asthma, apnea of prematurity and Cheyne-Stokes respiration. Recently, certain methylxanthines have been found to potentiate the contraction of the diaphragm and increase contraction strength of the fatigued diaphragm. The mechanism of action of the methylxanthines is unknown. Three theories have been proposed but each has its supportive and negative points. One theory is that methylxanthines inhibit cyclic AMP phosphodiesterase (PDE) which facilitates contraction by increasing cyclic AMP levels in the cell. Another theory is that methylxanthines antagonize adenosine, thus blocking the adenosine-induced inhibition of contraction. The third theory …

Phenylbutazone In The Horse: A Review, Thomas Tobin, S. Chay, S. Kamerling, W. E. Woods, T. J. Weckman, J. W. Blake, P. Lees

Maxwell H. Gluck Equine Research Center Faculty Publications

Phenylbutazone is an acidic, lipophilic, nonsteroidal anti-inflammatory drug (NSAID). It is extensively metabolized in the horse. The metabolites so far identified, oxyphenbutazone, y-hydroxyphenylbutazone and y-hydroxyoxyphenbutazone. account for some 25-30% of administered dose over 24 h. The plasma half-life of phenylbutazone and termination of its pharmacological action are determined primarily by its rate of hepatic metabolism. Phenylbutazone acts by inhibiting the cyclooxygenase enzyme system, which is responsible for synthesis of prostanoids such as PGE?. It appears to act on prostaglalidin-H synthase and prostacyclin synthase, after conversion by prostaglandin-H synthase to reactive intermediates. It markedly reduces prostanoid-dependent swelling, edema, erythema, and hypersensitivity …

T-61 Use In The Euthanasia Of Domestic Animals: A Survey, Andrew N. Rowan

Veterinary Science and Medicine Collection

A variety of techniques have been proposed and employed for the killing of domestic animals but relatively few have survived as suitable agents for euthanasia-namely, the induction of painless, suffering-free death. Some agents, such as strychnine, curariform agents, or potassium salts cause suffering while others have other disadvantages. 'lbday, dogs and cats are commonly euthanatized with sodium pentobarbital or with T-61 which is a mixture of a central nervous system narcotic, a paralytic agent, and a local anesthetic. The use of T-61 was first reported in the United States in 1963 (Quin 1963). The substance gradually became more popular because …

Review Of Literature On Use Of T-61 As An Euthanasic Agent, Laura Dalia Barocio

Veterinary Science and Medicine Collection

The tools of evaluating the degree of distress in animals being killed include electroencephalography (EEG), electrocardiography (ECG), and measurement of blood pressure and respiration. Sound clinical and behavioral observations should also not be abandoned in the evaIuation process.

There are many methods which may be employed to reach the same end results, but the ideal method should satisfy several criteria: 1. It should be painless; 2. It should cause unconsciousness instantaneously and death within minutes; 3. It should not cause undue anxiety, alarm, fear, panic, behavior, struggling, vocalization, muscle spasms or clinical signs of automatic activation (e.g., convulsions) before unconsciousness; …

Prostaglandin F2a Induced Nest Building Behavior In The Non-Pregnant Sow, And Some Welfare Considerations, Judith K. Blackshaw

Agribusiness Collection

Nest building behavior, induced with intramuscular injections of prostaglandin F2_a (PGF2_a), was studied in non-pregnant sows. Acute effects, which included salivation, scratching, vomiting, defaecation and ataxia, were also recorded. Sows (Large White x Landrace) were housed in two different environments; six sows in bare pens and six sows in pens provided with bedding material. In all cases except one (bare pen) nest building sequences of differing intensities were recorded. Welfare suggestions include questioning the justification of using a drug (PGF2_a) in pig husbandry, which has unpleasant acute effects, and the suggestion that the provision of …

Pharmacokinetics And Protein Binding Of Morphine In Horses, Joan Combie, Thomas E. Nugent, Thomas Tobin

Maxwell H. Gluck Equine Research Center Faculty Publications

Morphine could be detected in horses dosed with 0.1 mg of drug/kg of body weight for up to 48 hours in blood and 144 hours in urine. This dose of morphine elicited no observ­able effects and is a suggested an­algesic dose. Computer analysis revealed that a 3-compartment open system was the best fitting model with a serum half life of 87.9 minutes and a urine half life of 101.1 minutes. Binding to equine serum proteins was linear over a drug con­centration range of 3.88 x 10-5M to 3.50 x 10-aM and averaged 31.6%. In RBC-partitioning experiments, 78.1 % of the …

Toxic Ferns Of Western Australia, T E H Aplin, P Steele, M C. Nottle

Technical Bulletins

Botanical descriptions and notes on the distribution of six species of ferns are given. These plants contain the enzyme thiaminase, which may induce thiamin deficiency, or other constituents toxic to animals. The clinical signs of both thiamin deficiency and fern toxicity in affected livestock are described.

Argt Caused By Toxic Antibiodies : Research Report, P Vogel

Journal of the Department of Agriculture, Western Australia, Series 4

A fortunate coincidence, discovered recently, has provided annual ryegrass toxicity researchers with valuable knowledge which may help them understand how the ARGT toxins affect animals, and further their investigations into vaccine development. A toxic antibiotic, identified years ago, has proved to be closely related to the ARGT toxins. Antibiotics are generally regarded as effective agents for the control of many bacterial and fungal infections. However, some of them are toxic to both the bacteria and the host, whether man or animal.

Drugs And The Performance Horse, Thomas Tobin

Veterinary Science Books

This book presents an unprecedented account of the actions, effects and consequences of drug use in performance horses. Written for horsemen by a veterinarian and world authority on equine drugs, it deals with all classes, types, and uses of drugs. Professor Tobin describes how the drugs act, how they influence performance, and the problems they may cause. He explains the drug testing process and presents the best information available on the clearance times for drugs in horses. The text is written in plain language and with a touch of humor.

Bulletin 3967 - Cyanogenetic Plants Of Western Australia, T E H Aplin

Bulletins - 3000 - 3999

This article deals with those native, naturalized and cultivated plants, which by virtue of contained cyanogenetic glycosides, are known to be poisonous or potentially poisonous to livestock in Western Australia.

Cyanogenetic glycosides are chemical compounds which contain a cyanogen (cyanide) radical combined with a sugar molecule. The sugar moiety may differ in glycosides obtained from different plants, and as a consequence glycosides from different plants, containing different sugar moieties, may be given different names.

When a cyanogenetic glycoside is broken down by enzyme action, through injury to the plant or by microbial action in the digestive system of the animal, …

Lupinosis : A Disease Still With Us, Jeremy G. Allen, P. Mcr. Wood, K. P. Crocker, J. Hamblin

Journal of the Department of Agriculture, Western Australia, Series 4

Current research on lupinosis continues to reveal what a complex problem it is, but the improved understanding should help to reduce losses.

Controlling Annual Ryegrass Toxicity, C H. Trotman

Journal of the Department of Agriculture, Western Australia, Series 4

Eight years of intensive work has changed annual ryegrass toxicity from an unknown killer to a manageable problem.

Ryegrass Disease Could Spread, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

The disease annual ryegrass toxicity kills sheep and cattle grazing pastures which contain infected annual ryegrass. In Western Australia the first confirmed outbreak was in 1968 in the Gnowangerup area.

The disease has noe spread over a range of 450 kilometres and with a total area of perhaps 100 000 hectares. because annual ryegrass is the major sown pasture grass in W.A. the disease could spread throughout the South-West.

There are some precautions that can be taken.

Bulletin No 3863 - Plants Which Cause Kimberley Horse Disease, A. L. Payne

Bulletins - 3000 - 3999

Crotalaria crispata and Crotalaria retusa (Rattlepod), two plants responsible for Kimberley horse disease*, are, unfortunately, fairly widespread throughout the Kimberleys. Both species are apparently toxic in all stages of growth.

This bulletin is to assist pastoralists to:-

• Identify the two plants;

• Recognise the type of country and conditions under which they grow; and

• Locate horse paddocks on country where the plants are least likely to occur.

Lupinosis And Rates Of Stocking Of Lupin Stubbles, K P. Croker, J. G. Allen, C. R. Lester, R. B. Guthrie

Journal of the Department of Agriculture, Western Australia, Series 4

Lupin stubbles provide valuable summer sheep feed but under some conditions the fungus Phomopsis rossiana (for which lupins are the host plant) produces a toxin that causes lupinosis. Results from research at Badaingarra Research Station over the 1973-74 and 1974- 75 summers have shown that sheep liver damage associated with lupin stubble grazing is likely to be more severe at high than low stocking rates.

Treflan And The Oxygen Consumption Of Green Sunfish (Lepomis Cyanellus), Barbara Jo Warner

Masters Theses

Oxygen consumption rates of 51 green sunfish (Lepomis cyanellus, Rafinesque) were monitored over five hours exposure to Treflan E.C. concentrations of 0, 0.32, 0.56, 1.0, and 2.0 ppm. There was a great variation in the responses of the fish at each concentration; and Student's t-tests revealed no significant differences. However, graphs of the mean hourly oxygen consumption rates showed certain trends. During the fifth hour of exposure, there appears to be an acclimation to the Treflan at concentrations of 0.32 and 0.56 ppm; but no such acclimation at the higher concentrations of 1.0 and 2.0 ppm. Hourly oxygen …

Pesticide Residues In The Illinois Wild Turkey, John M. Bridges

Masters Theses

Adipose tissue from 55 turkeys, killed during the 1974 hunting season in southern Illinois, was grouped by age and location of the birds, and the pesticide concentrations in them were determined by gas/liquid chromatography. Twelve different pesticides were identified in the samples with only four, total DDT, heptachlor epoxide, toxaphene, and linuron, being present in all samples. Concentrations ranged from 0.02 ppm to 0.88 ppm.

An Investigation Of The Behavioral Effects Of Methylphenidate Hydrochloride On Schedule-Induced Polydipsia In Rats, Linda Sederquist Smith

Masters Theses

The influence of methylphenidate hydrochloride injections on six male Charles River rats displaying schedule induced polydipsia was examined in this study. Bar pressing, licking, and water consumption were measured during a total of 63 daily one hour trials conducted with a variable interval 60-second schedule of bar pressing for pellets with water constantly available. The polydipsic response was acquired by subjects during the first 28 trials. Subjects were then divided into experimental and control groups. The experimental subjects recieved a 1 mg/kg injection of methylphenidate prior to regular trials 29-49 and extinction trials 50-63. Control subjects were injected with a …

Development Of A Selective Bait For Rabbits, A J. Oliver, S. H. Wheeler

Journal of the Department of Agriculture, Western Australia, Series 4

It has long been recognised that a means of killing rabbits selectively in the presence of stock would be a major advance in rabbit control. It would enable a whole farm to be treated for rabbit control at one time, saving operational costs and cutting down reinfestation of rabbits into treated areas from untreated areas.

A literature search and some pilot trials indicated that indandione derivatives were more toxic to rabbits than to ruminants.

Pindone (2- pivalyl-l,3-indandione) was selected for evaluation.

Annual ('Wimmera') Ryegrass Toxicity, Geoffrey A. Pearce, O. M. Goss, P. H. Berry, J. L. Wise

Journal of the Department of Agriculture, Western Australia, Series 4

Because annual ryegrass is one of the most widespread pasture plants in Western Australia, annual ryegrass toxicity is a threat to livestock in many agricultural areas—even though the area now affected is small.

The problem is being intensively studied by the Department of Agriculture and a working group has been set up to investigate potential control measures.

In this article the group reviews the problem and reports progress in its investigations to the end of 1973.

Wimmera Ryegrass Toxicity, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

Wimmera ryegrass toxicity has been reported for many years to affect sheep and occasionally cattle in New Zealand, South Australia and the United States of America.

In Western Australia, occasional reports since 1959 and severe outbreaks of staggers in the Katanning- Gnowangerup areas over the last two years prompted the investigation reported below.