Browsing by Author "Hunt H"
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- ItemAn outbreak of ischaemic teat necrosis in a dairy herd in Taranaki, New Zealand.(2024-08-26) O'Connell JP; Lawrence KE; Taylor H; Orbell G; Bestbier ME; Crowley K; Hunt HCASE HISTORY: In spring 2021, on a seasonally calving, pastorally based, Taranaki dairy farm, 12 first-calving heifers (≤ 30 days post-calving) developed similar dry, red to black, crusting lesions on the medial aspect of the teat udder junction extending down the medial teat. Some cows had multiple teats affected. Treatment was initially unrewarding and did not slow the progression of the disease. Overall, 8/12 cows recovered, and 4/12 cows were culled, with three of the cows culled after a teat sloughed and the fourth after surgical amputation of a teat. Outbreaks of the same condition, on the same farm but affecting fewer animals, occurred in spring 2022 (n = 6) and spring 2023 (n = 3). CLINICAL FINDINGS: An initial scab-like or crusting lesion progressed to resemble a thick eschar consisting of very dry and hard dead tissue. The unaffected areas of the teat felt normal but immediately under the dead tissue, there was a warm, firmer area consistent with an inflammatory reaction. Removing the scab led to profuse bleeding, with no visible bed of granulation underneath the scab. There was no leaking of milk in those cows that lost a teat, and no smell to the lesions themselves. Serology and virology ruled out the involvement of bovine alphaherpesvirus (BoHV-2) bovine gammaherpesvirus (BoHV-4), orthopoxviruses (cowpox) and parapoxviruses (pseudocowpox). Histopathology of an affected and surgically amputated teat showed multifocal erosion and ulceration of the epidermis, covered by a thick serocellular crust. In areas of ulceration, there were numerous neutrophils, and the dermis was expanded by granulation tissue with variable numbers of neutrophils, eosinophils, and lymphocytes around small blood vessels. DIAGNOSIS: Based on the similarity of the history, presentation, and histopathological changes to those described for a novel disease reported in the UK, a diagnosis of ischaemic teat necrosis (ITN) was made. CLINICAL RELEVANCE: If ITN is an emerging condition in New Zealand and becomes as prevalent as it has in the UK, clinicians will be confronted with a significant new welfare problem in dairy cows. Anecdotally, there have been reports of other ITN outbreaks in New Zealand, and the Ministry for Primary Industries would be interested in collating reports from other New Zealand veterinarians.
- ItemDetection of a Novel Papillomavirus Type within a Feline Cutaneous Basal Cell Carcinoma(MDPI (Basel, Switzerland), 2022-12-01) Munday JS; Hunt H; Orbell G; Pfeffer H; Bennett PA 4 cm diameter exophytic mass was excised from the left flank of a 10-year-old domestic short-haired cat. Histology of the superficial aspects of the mass revealed epidermal cells arranged in nests and trabeculae while the deeper parts of the mass consisted of small round cells arranged in sheets or bundles of elongate spindle-shaped cells. A diagnosis of basal cell carcinoma (BCC) was made. Approximately 40% of the cells throughout the neoplasm contained prominent papillomaviral (PV)-induced cell changes. The BCC recurred three months after excision and grew rapidly. At this time a smaller mass was observed on the thorax. Due to the rapid recurrence of the BCC, the cat was euthanatized. As in the initial mass, histology of the recurrent mass revealed pleomorphic cells that often contained PV-induced cell changes. In contrast, the thoracic mass appeared as a more typical BCC and contained no histological evidence of PV infection. A novel PV DNA sequence was amplified from the flank BCC. While the sequence was most (75.1%) similar to Felis catus papillomavirus (FcaPV) 6, the level of similarity between the sequences is consistent with a novel PV type. No PV DNA was amplifiable from the thoracic mass. The case is unique due to the histological features of the BCC and the presence of a putative novel PV type. Observations from the present case add to the number of PV types associated with disease in cats as well as increasing the spectrum of PV-induced lesions in this species.
- ItemLongitudinal assessment of systolic anterior motion of the mitral valve in cats with hypertrophic cardiomyopathy.(Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine, 2024-09-26) Seo J; Novo Matos J; Munday JS; Hunt H; Connolly DJ; Luis Fuentes VBACKGROUND: The proportion of cats with hypertrophic cardiomyopathy (HCM) that lose systolic anterior motion of the mitral valve (SAM) in the long term is unknown. HYPOTHESIS/OBJECTIVES: Cats with HCM will lose SAM in the long term. Loss of SAM will be associated with greater age, longer scan-interval, and altered left ventricular (LV) dimensions. ANIMALS: Sixty unsedated cats with HCM, not receiving beta blockers or pimobendan. METHODS: A retrospective cohort study from 2 referral centers. Cats were eligible if they had been diagnosed with HCM and had a repeat echocardiogram ≥1 year later. Clinical and echocardiographic data of the left heart variables were collected. RESULTS: Thirty-eight cats had SAM at the initial scan. After a median follow-up time of 2.1 years (range: 1.0-5.9), 7 cats had lost SAM (18%) and 5 cats (23%) gained SAM. On follow-up, cats with SAM at the initial scan had a larger left atrium (P = .037), lower left atrial fractional shortening (P = .014), greater LV internal diameter in end-systole (P = .002), and lower LV fractional shortening (P < .001). Four cats with SAM developed congestive heart failure. There were no new cases of congestive heart failure or change in left heart variables in cats without SAM at the initial scan. The gain or loss of SAM was not associated with age or time between scans. CONCLUSIONS AND CLINICAL IMPORTANCE: Similar proportions of cats gained or lost SAM. Cats with SAM at baseline had more evidence of disease progression than cats without SAM.
- ItemPharmacokinetics and effect on renal function and average daily gain in lambs after castration and tail docking, of firocoxib and meloxicam.(Taylor and Francis Group, 2023-07-16) Kongara K; Purchas G; Dukkipati V; Venkatachalam D; Ward N; Hunt H; Speed DAIMS: To evaluate and compare the pharmacokinetics of IM and oral firocoxib, and IM meloxicam, and detect their effect on renal function and average daily gain (ADG) in lambs undergoing tail docking and castration. METHODS: Seventy-five male Romney lambs, aged 3-6 weeks, were randomised into five treatment groups (n = 15 per group): IM firocoxib (1 mg/kg); oral firocoxib (1 mg/kg); IM meloxicam (1 mg/kg); normal saline (approximately 2 mL, oral); or sham. Following the treatment administration, hot-iron tail docking and rubber ring castration were performed in all groups except the sham group, which did not undergo the procedures, but the animals were handled in the same manner as castrated and tail docked lambs. Blood samples were collected before and 1, 2, 4, 6, 8, 24, 48, 72, 96 and 120 hours after treatment administration, and drug concentrations in plasma were quantified by liquid chromatography and mass spectrometry. Plasma urea and creatinine concentrations were determined at a commercial laboratory. Lamb body weights were recorded before and 2, 4 and 8 weeks after tail docking and castration. The pharmacokinetic analysis was carried out using a non-compartmental approach. Between-group and between-time-point differences were compared using mixed model analyses. RESULTS: There was no evidence for a difference in plasma elimination half-life between firocoxib given IM (LSM 18.6 (SE 1.4) hours), firocoxib given orally (LSM 18.2 (SE 1.4) hours), and meloxicam given IM (LSM 17. 0 (SE 1.4) hours). Firocoxib (IM) had a significantly greater volume of distribution (LSM 3.7 (SE 0.2) L/kg) than IM meloxicam (LSM 0.2 (SE 0.2) L/kg). Lambs in the meloxicam group had higher (p < 0.05) plasma urea and creatinine concentrations than those in the firocoxib, saline and sham groups. Lambs' ADG was decreased (p < 0.01) compared to the other treatment groups in the 0-2 week period following meloxicam administration. CONCLUSIONS AND CLINICAL RELEVANCE: Both formulations of firocoxib had a long plasma elimination half-life and large volume of distribution. There was a transient reduction in ADG in the meloxicam group, possibly due to mild renal toxicity. Comparative studies on dose-response effects of firocoxib and meloxicam in lambs following the procedures are required.
- ItemPrevalence of cardiomyopathy and cardiac mortality in a colony of non-purebred cats in New Zealand.(Taylor and Francis Group, 2024-09-29) Seo J; Owen R; Hunt H; Luis Fuentes V; Connolly DJ; Munday JSAims To evaluate the prevalence of subclinical cardiomyopathy and cardiac mortality in a research colony of non-purebred cats, established as a model of the wider cat population in New Zealand. Methods All apparently healthy, compliant, non-pregnant, non-neonatal cats in the colony at the Centre for Feline Nutrition (Massey University, Palmerston North, NZ) underwent physical examination and echocardiography using a 4.4–6.2-MHz probe by a board-certified veterinary cardiologist. Cardiac phenotype was classified following current guidelines. Hypertrophic cardiomyopathy (HCM) phenotype was defined as an end-diastolic left ventricular wall thickness ≥ 6 mm. Colony mortality data from February 2012 to February 2022 was reviewed to determine cardiac mortality. Results Cats (n = 132; 65 females and 67 males) included in the study had a median age of 4.1 (IQR 3.0–8.0) years. Thirty-two (24%) cats had a heart murmur, and three (2%) cats had an arrhythmia. Echocardiography revealed heart disease in 24 (18.2%) cats, including 23 with an HCM phenotype and one with a restrictive cardiomyopathy phenotype. Of the cats with the HCM phenotype, 3/23 had systemic hypertension or hyperthyroidism or both, and these cats were excluded from the final diagnosis of HCM (20/132; 15.2 (95% CI = 9.5–22.4)%). Between 2012 and 2022, 168 colony cats died, with 132 undergoing post-mortem examination. Heart disease was considered the cause of death in 7/132 (5.3%; 95% CI = 2.2–10.6%) cats; five had HCM, one a congenital heart defect, and one myocarditis. The overall prevalence of death related to HCM in the colony during this period was 3.8% (95% CI = 1.2–8.6%). Three cats with HCM and the cat with a congenital heart defect died unexpectedly without prior clinical signs, while congestive heart failure was observed prior to death in two cats with HCM and the cat with myocarditis. Additionally, 30/132 (22.7%) cats had cardiac abnormalities but died for non-cardiac reasons. Conclusions Subclinical cardiomyopathy, specifically HCM, was common in cats in the colony. Given that the colony originated as a convenience selection of non-purebred cats in New Zealand, the true prevalence of HCM in the wider New Zealand population is likely to fall within the 95% CI (9.5–22%). The proportion of deaths of colony cats due to HCM was lower (3.8%) supporting the conclusion that subclinical cardiomyopathy may not progress to clinical disease causing death. Clinical relevance Veterinarians should be aware of the high prevalence of subclinical HCM when treating cats. Abbreviations CAM: Systolic anterior motion of the chordae tendineae; CFN: Centre for Feline Nutrition; HCM: Hypertrophic cardiomyopathy; LA/Ao: Left atrial to aortic ratio; LV FS: Left ventricular fractional shortening; LVIDd: Left ventricular internal diameters in end-diastole; LVIDs: Left ventricular internal diameter in end-systole; LVWT: Max Maximum left ventricular wall thickness; SAM: Systolic anterior motion of the mitral valve; 2D: Two-dimensional
- ItemPrevalence of Hypertrophic Cardiomyopathy and ALMS1 Variant in Sphynx Cats in New Zealand(MDPI (Basel, Switzerland), 2024-09-10) Seo J; Loh Y; Connolly DJ; Luis Fuentes V; Dutton E; Hunt H; Munday JS; Montoya-Alonso JARecently, hypertrophic cardiomyopathy (HCM) in Sphynx cats has been associated with a variant in the gene encoding Alström syndrome protein 1 (ALMS1). The primary aims of this study were to describe the prevalence of HCM in Sphynx cats in New Zealand, and to assess the association between HCM and the ALMS1 variant in this population. In this prospective study, 55 apparently healthy Sphynx cats from registered Sphynx breeders and pet owners in New Zealand were screened by a cardiologist. A total of 42 of these cats had a repeat cardiac examination after median 1.8 years (range: 1.6-2.2). The frequency of the ALMS1 variant was 70.9% (11 homozygous and 28 heterozygous). At the median age of 5.8 years (range: 2.4-13.1), the prevalence of HCM was 40% (20 out of 55 cats). Three cats with HCM died during the study with congestive heart failure. All three cats had focal but extensive myocardial ischemia or infarction at necropsy. The ALMS1 variant was not associated with the HCM diagnosis. In summary, HCM was common in the studied cohort, suggesting Sphynx cats are predisposed to this disease. While the ALMS1 variant was also frequently detected, it was not associated with HCM in this population.
- ItemRetinopathy in Greyhound dogs: Prevalence, fundoscopic, and histopathological findings.(John Wiley and Sons, Inc., 2024-07-01) Price PSA; Hunt H; Cox NR; Mitchell NL; Irving ACOBJECTIVES: To determine the prevalence of retinal lesions and describe the fundoscopic findings of retinopathy in Greyhound dogs in the Manawatu/Whanganui region of New Zealand. To examine possible associations between sex, age, and racing variables with retinopathy in the study population. To describe retinal histologic findings in seven Greyhounds with retinopathy in New Zealand. METHODS: Two hundred Greyhound dogs from the Manawatu/Whanganui region of New Zealand underwent fundoscopy and fundic photography to identify and score the degree of retinopathy. Associations between retinopathy and age, sex, as well as racing variables, were examined. Histologic examination of the retina was undertaken on the eyes of seven Greyhounds from the Manawatu and Canterbury regions previously diagnosed with retinopathy by fundoscopy. RESULTS: Fifty dogs (25.1%) were identified with retinopathy of varying degrees of severity. In at least one eye, 7.5% of dogs had mild retinopathy, 11.6% moderate retinopathy, and 6.0% severe retinopathy. Males were more likely to be affected in both eyes and with moderate or severe grades, than females. Increasing age was not associated with increased prevalence of retinopathy, nor increased grade of severity. Retinal histology identified multifocal retinal detachment in 5 of the 7 cases examined and other common lesions included choroidal necrosis and outer to full-thickness retinal atrophy in the absence of significant inflammation. CONCLUSIONS: Retinopathy is prevalent in Greyhounds in the Manawatu/Whanganui region of New Zealand, but more research is required to elucidate the etiopathogenesis. Consideration should be made to include mandatory eye health examination in racing Greyhound dogs.
- ItemSudden death due to aortic rupture in New Zealand sheep.(Informa UK Limited, trading as Taylor & Francis Group, 2024-09-23) Eames M; Vaatstra BL; Lawrence KE; Hunt HCASE HISTORY: Over a period of 2 months in the spring and early summer of 2021, 13 cases of sudden death in cull ewes due to aortic rupture were diagnosed at a small number of New Zealand abattoirs. CLINICAL FINDINGS: In 12/13 (92%) cases, a large blood clot was present in the thorax, and in one case the blood clot was seen in the tissues dorsal to the heart. There were no obvious signs of external trauma. The pluck (heart and lungs) or fixed aorta was submitted for histological examination in seven cases and in all of these, a tear in the aorta was found. Comparing the microscopic appearance of the proximal aorta in these seven cases to three clinically normal ewes from unaffected farms, the aortic wall thickness appeared thinner in the case ewes than the unaffected ewes. Subjectively, there was increased collagen in the tunica media in 3/7 and decreased elastin fibres in 5/7 case ewes compared to the control ewes. Further investigations on the index farm (where the first cases originated), found that the mean liver and serum Cu concentrations in 10 similarly aged, clinically normal ewes were within the normal reference range for New Zealand sheep. Similarly, the liver Cu concentrations of the seven case ewes were within the normal reference range. DIAGNOSIS: Aortic rupture due to an unknown aetiology. CLINICAL RELEVANCE: Clinicians should be aware of this condition as a differential diagnosis for sudden death in older sheep and to assist the Ministry for Primary Industries in establishing the extent of this problem in New Zealand.
