Heather Simpson | |
---|---|
Other names | Heather Vivian Simpson |
Academic background | |
Alma mater | Massey University |
Thesis | |
Doctoral advisor | Donald Alexander Titchen, Maurice Lancaster, Cam Reid |
Academic work | |
Institutions | Massey University |
Heather Vivian Simpson is a New Zealand animal physiologist,and is professor emerita at Massey University,specialising in the biology of gastrointestinal parasites of sheep.
Simpson earned a Bachelor of Science with Honours at the University of Queensland in Australia. [1] Simpson then joined Massey University in New Zealand as a part-time demonstrator,while also completing her PhD. Her dissertation was titled Water and electrolyte transfers in ruminants,and was finished in 1969,and supervised by Donald Titchen,Maurice Lancaster and Campbell Reid. [2] Simpson joined the faculty at Massey in 1976,initially part-time as she was raising two children. She was appointed senior lecturer by 1994,and associate professor in 2000,rising to full professor,as Professor of Animal Physiology,in 2007. [3]
During her time at Massey,Simpson taught nearly every veterinary student to graduate in New Zealand,and was patron of the Veterinary Students Association. She published more than 60 papers and supervised 21 postgraduate students. [3] Simpson's research focused on agriculturally important gastrointestinal parasites of sheep,such as Teladorsagia spp. and Haemonchus contortus ,which she found interesting because of "the relationship between two organisms and the struggle between them". [3]
When Simpson retired in 2015,she was the longest-serving academic at Massey,having at that point spent fifty years at the university,forty-five of them on staff. [3] The previous longest-serving academic was Sylvia Rumball. [3] Simpson retained an honorary position at AgResearch,and continued to supervise her remaining doctoral students after her retirement. [3]
Simpson is married to Dr Bruce Simpson. Her hobbies include growing orchids,and collecting shells and stamps. [3]
Haemonchus contortus, also known as the barber's pole worm, is a very common parasite and one of the most pathogenic nematodes of ruminants. Adult worms attach to abomasal mucosa and feed on the blood. This parasite is responsible for anemia, oedema, and death of infected sheep and goats, mainly during summer in warm, humid climates.
Doramectin, sold under the brand name Dectomax among others, is a veterinary medication approved by the US Food and Drug Administration (FDA) for the treatment of parasites such as gastrointestinal roundworms, lungworms, eyeworms, grubs, sucking lice, and mange mites in cattle. It is available as a generic medication. It is available as a combination with levamisole under the brand name Valcor.
Egg hatch assay (EHA), also called an egg hatch test (EHT), is a method used to determine a given parasite's resistance to extant drug therapy.
Moxidectin is an anthelmintic drug used in animals to prevent or control parasitic worms (helminths), such as heartworm and intestinal worms, in dogs, cats, horses, cattle, sheep and wombats. Moxidectin kills some of the most common internal and external parasites by selectively binding to a parasite's glutamate-gated chloride ion channels. These channels are vital to the function of invertebrate nerve and muscle cells; when moxidectin binds to the channels, it disrupts neurotransmission, resulting in paralysis and death of the parasite.
Trypanosoma congolense is a species of trypanosomes and is the major pathogen responsible for the disease nagana in cattle and other animals including sheep, pigs, goats, horses and camels, dogs, as well as laboratory mice. It is the most common cause of nagana in east Africa, but is also a major cause of nagana in west Africa. This parasite is spread by tsetse flies. In its mammalian host, Trypanosoma congolense only lives in blood vessels, and causes in particular anaemia.
Anthelmintics or antihelminthics are a group of antiparasitic drugs that expel parasitic worms (helminths) and other internal parasites from the body by either stunning or killing them and without causing significant damage to the host. They may also be called vermifuges or vermicides. Anthelmintics are used to treat people who are infected by helminths, a condition called helminthiasis. These drugs are also used to treat infected animals, particularly small ruminants such as goats and sheep.
Oxfendazole is a broad spectrum benzimidazole anthelmintic. Its main use is for protecting livestock against roundworm, strongyles and pinworms. Oxfendazole is the sulfoxide metabolite of fenbendazole.
The Gulf Coast Native is a breed of sheep found in the U.S. states bordering the Gulf Coast. Also occasionally known as the Louisiana Scrub, Pineywoods Native or simply Gulf Coast sheep, the breed is a mix of many of the sheep varieties brought to the Southern United States during the European colonization of the region. It is now an exceedingly rare breed, but one valuable for its ability to adapt to the hot humid climate of the Gulf Coast.
Teladorsagia circumcincta is a nematode that is one of the most important parasites of sheep and goats. It was previously known as Ostertagia circumcincta and is colloquially known as the brown stomach worm. It is common in cool, temperate areas, such as south-eastern and south-western Australia and the United Kingdom. There is considerable variation among lambs and kids in susceptibility to infection. Much of the variation is genetic and influences the immune response. The parasite induces a type I hypersensitivity response which is responsible for the relative protein deficiency which is characteristic of severely infected animals. There are mechanistic mathematical models which can predict the course of infection. There are a variety of ways to control the infection and a combination of control measures is likely to provide the most effective and sustainable control.
Paramphistomum is a genus of parasitic flatworms belonging to the digenetic trematodes. It includes flukes which are mostly parasitising livestock ruminants, as well as some wild mammals. They are responsible for the serious disease called paramphistomiasis, also known as amphistomosis, especially in cattle and sheep. Its symptoms include profuse diarrhoea, anaemia, lethargy, and often result in death if untreated. They are found throughout the world, and most abundantly in livestock farming regions such as Australia, Asia, Africa, Eastern Europe, and Russia.
FAMACHA is a selective treatment method for controlling the level of parasitic barber's pole worm among domesticated small ruminant populations. In contrast with earlier, more aggressive approaches, under FAMACHA only certain sheep or goats in a flock are selected for treatment. Selection for treatment is based on the degree of anaemia the animals are displaying in their mucous membranes, which is assessed through a colour guided chart.
Cooperia oncophora is one of the most common intestinal parasitic nematodes in cattle in temperate regions. Infections with C. oncophora may result in mild clinical symptoms, but can lead to weight loss and damage of the small intestine, especially when co-infections with other nematodes such as O. ostertagi occur. Infections are usually treated with broad-spectrum anthelmintics such as benzimidazole, but resistance to these drugs has developed in the last decades and is now very common. C. oncophora has a direct life cycle. Infective larvae are ingested by the host. The larvae grow to adults, which reproduce in the small intestines. Eggs are shed onto the pasture with the faeces, which leads to new infections. Co-infections with other gastro-intestinal nematodes such as O. ostertagi and H. contortus are common.
Ostertagia ostertagi, commonly known as the medium stomach worm or brown stomach worm, is a parasitic nematode of cattle. O. ostertagi can also be found to a lesser extent in sheep, goats, wild ruminants, and horses. It causes ostertagiosis, which is potentially fatal in cattle. It is found worldwide and is economically important to cattle industries, particularly those found in temperate climates.
Cooperia is a genus of nematode from the Cooperiidae family that is one of the most common intestinal parasitic nematodes in cattle in temperate regions. Infections with Cooperia may result in mild clinical symptoms, but can lead to weight loss and damage of the small intestine, especially when co-infections with other nematodes such as Ostertagia ostertagi occur. Infections are usually treated with broad-spectrum anthelmintics such as benzimidazole, but resistance to these drugs has developed in the last decades and is now very common. Cooperia has a direct life cycle. Infective larvae are ingested by the host. The larvae grow to adults, which reproduce in the small intestines. Eggs are shed onto the pasture with the faeces, which leads to new infections. Co-infections with other gastro-intestinal nematodes such as O. ostertagi and Haemonchus contortus are common.
A trypanotolerant organism is one which is relatively less affected by trypanosome infestation.
The American Association of Veterinary Parasitologists is a professional association for veterinary parasitology. Despite the name it primarily serves both the United States and Canada and to a lesser degree the entire world. The AAVP connects veterinary parasitologists to each other and provides recommendations as to research and practice methods.
Carlos E. Lanusse is an Argentine scientist and a professor of Pharmacology. He is the Director of the Veterinary Research Center and the Science and Technology Center of the Argentina National Council of Research in Tandil.
Monepantel is an anthelmintic approved for use in sheep and cattle to control gastrointestinal nematodes. It belongs to a new class of anthelmintics called aminoacetonitrile derivatives (AAD). It is marketed by Elanco as Zolvix as a single active, or Zolvix Plus in combination with the macrocyclic lactone abamectin.
Jennifer Faith Weston is a New Zealand veterinary scientist, and as of 2023 is a full professor at Massey University, specialising in dairy animals and their diseases.