Massey Documents by Type

Permanent URI for this communityhttps://mro.massey.ac.nz/handle/10179/294

Browse

Subject: search.filters.subject.Feline

Search Results

Now showing 1 - 6 of 6
  • Thumbnail Image
    Item
    The nutritional management of food hypersensitivity in dogs and cats : an assessment of a protein hydrolysate : a thesis submitted in partial fulfillment of the requirements for the degree of Master of Veterinary Science at Massey University
    (Massey University, 2001) Cave, Nicholas J
    Adverse reactions to food are exceedingly common reasons for the presentation of cats and dogs to veterinarians. Of those cases, a relatively small number involve a truly immune-mediated reaction to the food substance. However, differentiating those that are from the more common food intolerances is usually difficult and often impossible. In addition, certain individuals with a true food hypersensitivity are difficult to manage with conventional diets. The identification and availability of nutritionally complete commercially prepared diets with a protein component that is truly novel to the patient under investigation is often the stumbling block to successful diagnosis and management of food hypersensitivity. The recent development of protein hydrolysate based pet foods for dogs and cats provides an exciting tool for more reliable diagnosis and management or food hypersensitivity in those species. Chapter 1 of this thesis describes the immunological and pathophysiological basis of food hypersensitivity and presents some of the key areas of recent research that have lead to a deeper, if still incomplete understanding of the aetiological mechanisms responsible. The development and maintenance of oral tolerance is discussed including the key roles that the resident antigen presenting cells in the mucosa play. From that description follows a presentation of some of the current hypotheses regarding mechanisms by which oral tolerance is lost or not established. These include the action of mucosal adjuvants, parasitism, IgA deficiency and alterations in mucosal permeability. Building on this discussion is an examination of the methods currently available to veterinarians for the diagnosis of food hypersensitivity, their clinical usefulness and limitations. The importance of obtaining a complete and accurate dietary history is emphasized. The difficulties in doing so and the consequences of not doing so are discussed. As stated, the recent development of diets in which the protein content has been hydrolysed provides a new tool for the veterinarian. Some of the practical aspects behind producing hydrolysate diets are presented and the theoretical basis, especially the importance of the molecular weight of remaining polypeptide fragments, is emphasized. Finally recommendations as to their use and the role that they may play in the future are discussed. Chapter 2 describes the initial assessment of 2 candidate hydrolysates, one made from fish and the other from chicken proteins. The method used for this initial experiment was high-performance size-exclusion liquid chromatography. The investigation revealed the chicken hydrolysate to have the more favourable molecular weight profile of the two. The finding that 92.9% of the hydrolysate was of a molecular weight less than 5kDa is supportive of its potential value in a hypoallergenic diet. The molecular weight profile was then compared with a selection of those published in the human medical literature. Cow's milk hydrolysates have been widely available and used for the past 2-3 decades. The chicken hydrolysate appeared to compare very favourably to a number of extensively hydrolysed human infant formulae that have been demonstrated experimentally and clinically to be truly hypoallergenic. Despite the extensive use of molecular weight profiles to compare hydrolysates, they remain unreliable as predictors of allergenicity. Chapter 3 describes the experimental evaluation of the antigenicity of the chicken hydrolysate. Following successful immunization of dogs to the intact parent protein, an IgG inhibition ELISA was developed using sera from the immunized dogs. It was demonstrated that the hydrolysate retained some ability to bind IgG but that at equal levels of antibody binding, the concentration of the hydrolysate solution required was 66 times greater than that of the intact parent protein. It is likely that this represents a clinically highly significant reduction in antigenicity. Of the limitations of the inhibition ELISA study, perhaps the greatest from the perspective of hydrolysate diet analysis is its inability to differentiate the molecular weight of the IgG-binding fragments. This is important since if they are less than 6-10kDa, they are unlikely to participate in IgE-mediated allergic reactions. Chapter 4 describes the experiment chosen to determine the size of the remaining IgG-binding fragments, namely Western blotting. It was established that the major antigenic fraction remaining in the parent protein following SDS-PAGE separation was a c.69kDa protein consistent with chicken serum albumin. It was demonstrated by both the Western blotting and the HP-SEC that this antigen was absent from the hydrolysate. The actual size of the few remaining binding fragments in the hydrolysate was not, however, clearly elucidated. It was concluded that the chicken hydrolysate assessed during this thesis is a promising candidate for inclusion as the peptide component of a diet for the diagnosis and management of food hypersensitivity in dogs and cats. In addition, the diet has theoretical promise for the prevention of food hypersensitivity during periods of mucosal inflammation such as idiopathic inflammatory bowel disease and acute gastroenteritis. Ultimately, clinical trials are required to conclusively demonstrate the value of the hydrolysate in the diagnosis and management of these disorders.
  • Thumbnail Image
    Item
    Studies in neuro-endocrinology : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Physiology at Massey University
    (Massey University, 1983) Kettle, Anthony
    Gonadectomy is the commonest surgical procedure carried out in the cat, mainly for fertility control. However, the effect of gonadectomy on body weight in the cat has received little study although this subject is well researched in other species, such as the rat. Part I of the present study involved gonadectomy at 20 weeks. The cats were housed in outdoor colony cages and given food ad libidum, adjusted to leave daily residues. Body weight was measured weekly and transformed to log10. For statistical analysis, differences in body weight of each cat were tested by one-way analysis of variance and serial covariance using the previous week's body weight as the covariate. Differences between groups were investigated with 't' tests and growth rates were studied by regression. Up to 32 weeks of age there was no statistically significant difference between the growth rates of entire versus the castrates in either sex. However, when extended to 55 weeks of age prepubertal gonadectomy in the female cat caused significantly increased growth. This was not observed for the male cat. Little information is available on the anatomy of the brain of the Australasian possum (Trichosurus vulpecula). Part II of the present study aims at presenting a simple description of the possum hypothalamus viewed in three planes of section and concentrating on some of the fibre tracts which are clearly visible. The main findings were that the mammillothalamic tract appears in a similar position to that as seen in other mammals such as the rat, cat, and sheep, while the fornix appears much steeper in its descent into the anterior hypothalumus. In addition, there is described a fibre tract emanating from the optic chiasma and passing to the caudal part of the paraventricular nucleus. This tract has not been described in other mammals, such as the rat, cat, and sheep.
  • Thumbnail Image
    Item
    The social behaviour of cats housed in laboratory cages : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Science in Zoology at Massey University, Palmerston North, New Zealand
    (Massey University, 2006) Song, Yuan
    Many species in the cat family, the Felidae, are listed as vulnerable to extinction. The tiger is one species facing extinction. Studies show that tigers can live in groups in captive environments and understanding the social behaviour of tigers could help tiger conservation. It is hard to study tigers in the wild and the domestic cat may be a good model to develop research methods to study tiger social behaviour. This study focused on the social behaviour of domestic cats, and the effects of group type, sex, relatedness, age, weight, and coat colour on social behaviour. There were significantly different behaviour patterns in established groups and newly formed groups of domestic cat. As age differences increased between pairs of cats, their agonistic behaviour decreased significantly. Affiliative behaviour increased significantly as the weight differences between pairs of cats increased. Sex, relatedness, and coat colour did not influence the social behaviour of domestic cats. In addition, weather did not significantly affect normal behaviour. Tigers were observed in three different captive environments. There were some differences in their behaviour in the three different environments. Tigers kept individually in small cages did more pacing than tigers in groups in a playground. However, a lack of data on the differences in tiger behaviour in different environments did not allow analysis. This study was carried to develop the observation technique for cat social behaviour.
  • Thumbnail Image
    Item
    Papillomaviruses in dogs and cats.
    (2017-07) Munday JS; Thomson NA; Luff JA
    Papillomaviruses (PVs) cause disease in both dogs and cats. In dogs, PVs are thought to cause oral papillomatosis, cutaneous papillomas and canine viral pigmented plaques, whereas PVs have been rarely associated with the development of oral and cutaneous squamous cell carcinomas in this species. In cats, PVs are currently thought to cause oral papillomas, feline viral plaques, Bowenoid in situ carcinomas and feline sarcoids. Furthermore, there is increasing evidence that PVs may also be a cause of cutaneous squamous cell carcinomas and basal cell carcinomas in cats. These diseases are discussed in this review. Additionally, there is a brief overview of PV biology, including how these viruses cause disease. Diagnostic techniques and possible methods to prevent PV infection are also discussed.
  • Thumbnail Image
    Item
    Hydrocortisone therapy in a cat with vasopressor-refractory septic shock and suspected critical illness-related corticosteroid insufficiency
    (Wiley & sons, 31/05/2017) Pisano SRR; Howard J; Posthaus H; Kovacevic A; Yozova ID
    A 27-month-old female cat was presented with septic peritonitis secondary to a ruptured pyometra and subsequent pyothorax. Vasopressor-refractory septic shock led to a suspicion of critical illness-related corticosteroid insufficiency, successfully treated with intravenous hydrocortisone. Previous megestrol acetate administration may have played a role in the development of adrenocortical dysfunction.
  • Thumbnail Image
    Item
    Dietary format alters fecal bacterial populations in the domestic cat (Felis catus)
    (John Wiley and Sons, 2013) Bermingham EN; Young W; Kittelmann S; Kerr KR; Swanson KS; Roy NC; Thomas DG
    The effects of short-term (5-week) exposure to wet or dry diets on fecal bacterial populations in the cat were investigated. Sixteen mixed-sex, neutered, domestic short-haired cats (mean age = 6 years; mean bodyweight = 3.4 kg) were randomly allocated to wet or dry diets in a crossover design. Fecal bacterial DNA was isolated and bacterial 16S rRNA gene amplicons generated and analyzed by 454 Titanium pyrosequencing. Cats fed dry diets had higher abundances (P < 0.05) of Actinobacteria (16.5% vs. 0.1%) and lower abundances of Fusobacteria (0.3% vs. 23.1%) and Proteobacteria (0.4% vs. 1.1%) compared with cats fed the wet diet. Of the 46 genera identified, 30 were affected (P < 0.05) by diet, with higher abundances of Lactobacillus (31.8% vs. 0.1%), Megasphaera (23.0% vs. 0.0%), and Olsenella (16.4% vs. 0.0%), and lower abundances of Bacteroides (0.6% vs. 5.7%) and Blautia (0.3% vs. 2.3%) in cats fed the dry diet compared with cats fed the wet diet. These results demonstrate that short-term dietary exposure to diet leads to large shifts in fecal bacterial populations that have the potential to affect the ability of the cat to process macronutrients in the diet.