Journal Articles
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Item Comparison of the effects of 7.2% hypertonic saline and 20% mannitol on electrolyte and acid-base variables in dogs with suspected intracranial hypertension(Wiley Periodicals LLC. on behalf of the American College of Veterinary Internal Medicine, 2021-01-31) Hoehne SN; Yozova ID; Vodondo B; Adamik KNBackground Hyperosmolar agents frequently are used to decrease intracranial pressure but their effects on electrolyte and acid-base variables have not been prospectively investigated. Objectives Compare duration and magnitude of changes in electrolyte and acid-base variables after hyperosmolar treatment. Animals Twenty-eight client-owned dogs with intracranial hypertension caused by various pathologies. Methods Prospective, randomized, nonblinded, experimental cohort study. Fifteen dogs received a single dose (4 mL/kg) of 7.2% hypertonic saline (HTS), 13 dogs received 20% mannitol (MAN) 1 g/kg IV. Electrolyte and acid-base variables were measured before (T0), and 5 (T5), 60 (T60), and 120 (T120) minutes after administration. Variables were compared between treatments and among time points within treatment groups. Results Mean plasma sodium and chloride concentrations were higher after HTS than MAN at T5 (158 vs 141 mEq/L; 126 vs 109 mEq/L) and significant differences were maintained at all time points. After HTS, plasma sodium and chloride concentrations remained increased from T0 at all time points. After MAN, plasma sodium and chloride concentrations decreased at T5, but these changes were not maintained at T60 and T120. Plasma potassium concentration was lower at T5 after HTS compared with T0 (3.6 vs 3.9 mEq/L) and compared to MAN (3.6 vs 4.1 mEq/L). At T60 and T120, plasma ionized calcium concentration was lower after HTS than MAN (1.2 vs 1.3 mmol/L). No significant differences were found in acid-base variables between treatments. Conclusions and Clinical Importance At the administered dose, dogs receiving HTS showed sustained increases in plasma sodium and chloride concentrations, whereas dogs receiving MAN showed transient decreases. Future studies should assess the effects of multiple doses of hyperosmolar agents on electrolyte and acid-base variables.Item Widespread occurrence of benzimidazole resistance single nucleotide polymorphisms in the canine hookworm, Ancylostoma caninum, in Australia(Elsevier Ltd on behalf of the Australian Society for Parasitology Incorporated, 2025-03) Abdullah S; Stocker T; Kang H; Scott I; Hayward D; Jaensch S; Ward MP; Jones MK; Kotze AC; Šlapeta JCanine hookworm (Ancylostoma caninum), a gastrointestinal nematode of domestic dogs, principally infects the small intestine of dogs and has the potential to cause zoonotic disease. In greyhounds and pet dogs in the USA, A. caninum has been shown to be resistant to multiple anthelmintics. We conducted a molecular survey of benzimidazole resistance in A. caninum from dogs at veterinary diagnostic centers in Australia and New Zealand. First, we implemented an internal transcribed spacer (ITS)-2 rDNA deep amplicon metabarcoding sequencing approach to ascertain the species of hookworms infecting dogs in the region. Then, we evaluated the frequency of the canonical F167Y and Q134H isotype-1 β-tubulin mutations, which confer benzimidazole resistance, using the same sequencing approach. The most detected hookworm species in diagnostic samples was A. caninum (90%; 83/92); the related Northern hookworm (Uncinaria stenocephala) was identified in 11% (10/92) of the diagnostic samples. There was a single sample with coinfection by A. caninum and U. stenocephala. Both isotype-1 β-tubulin mutations were present in A. caninum, 49% and 67% for Q134H and F167Y, respectively. Mutation F167Y in the isotype-1 β-tubulin mutation was recorded in U. stenocephala for the first known time. Canonical benzimidazole resistance codons 198 and 200 mutations were absent. Egg hatch assays performed on a subset of the A. caninum samples showed significant correlation between 50% inhibitory concentration (IC50) to thiabendazole and F167Y, with an increased IC50 for samples with > 75% F167Y mutation. We detected 14% of dogs with > 75% F167Y mutation in A. caninum. Given that these samples were collected from dogs across various regions of Australia, the present study suggests that benzimidazole resistance in A. caninum is widespread. Therefore, to mitigate the risk of resistance selection and further spread, adoption of a risk assessment-based approach to limit unnecessary anthelmintic use should be a key consideration for future parasite control.Item Papillomaviruses and Papillomaviral Disease in Dogs and Cats: A Comprehensive Review.(MDPI (Basel, Switzerland), 2024-12-01) Munday JS; Knight CG; Materniak-Kornas M; Rola-Łuszczak M; Woźniakowski GPapillomaviruses (PVs) frequently infect humans as well as non-human species. While most PV infections are asymptomatic, PVs can also cause hyperplastic papillomas (warts) as well as pre-neoplastic and neoplastic lesions. In this review, the life cycle of PVs is discussed, along with the mechanisms by which PVs cause hyperplastic and neoplastic diseases. The humoral and cell-mediated immune responses to PVs are reviewed, giving context to the later discussion on the use of vaccines to reduce canine and feline PV-associated disease. Both dogs and cats are infected by numerous different PV types classified into multiple different PV genera. The taxonomic classification of PVs is reviewed, along with the significance of this classification. The PV-associated diseases of dogs and cats are then described. These descriptions include the clinical presentation of the disease, the causative PV types, the histological features that allow diagnosis, and, where appropriate, possible treatment options. The review is comprehensive and contains the latest information about PVs and the diseases they cause in dogs and cats.Item A blinded, placebo-controlled study on the clinical effects of vitamin E supplementation in dogs with osteoarthritis(Wiley Periodicals LLC. on behalf of the American College of Veterinary Internal Medicine., 2023-07-31) Gordon CL; Reeves SJ; Burchell RK; Thomson C; Gal A; Lopez-Villalobos N; Webster NSL; Litster KM; Mitchell RASBACKGROUND: Vitamin E has a positive effect in the management of osteoarthritis in humans, and in a previous study of dogs. It has been suggested to decrease C-reactive protein concentrations and liver enzyme activities in humans and animals. OBJECTIVE: To assess the effect of vitamin E supplementation on lameness, pain, pain medication requirement, clinical pathology variables, and quality of life in large-breed dogs with naturally occurring osteoarthritis. ANIMALS: Fifty-seven client-owned dogs with naturally occurring osteoarthritis. METHODS: Dogs received either vitamin E or placebo for 90 days in a randomized, placebo-controlled, double-blinded, prospective clinical trial. Clinical lameness scores, pain medication requirements, and owner questionnaires were used to assess response to treatment every 30 days. Blood samples were collected at enrollment and at the end of the study period. RESULTS: Vitamin E administration did not improve pain, lameness, or quality of life as assessed by owners and veterinarians. Vitamin E supplementation did not decrease the requirement for rescue pain relief. No changes in clinical pathology variables were observed after 90 days of vitamin E supplementation. Body weight was negatively associated with the lameness scores and requirement for rescue pain relief. CONCLUSION: Vitamin E supplementation did not have any observable positive effects in dogs with naturally occurring osteoarthritis.Item Loss of body weight and lean mass in long-stay, hospitalized canine patients(Wiley‐VCH GmbH, 2023-11-01) Leung YB; Cave N; Wester TJA high prevalence of malnutrition occurs in human hospitals and has been associated with detrimental consequences. By comparison, much less is known in hospitalized veterinary patients. The aims of this study were to evaluate the prevalence of malnutrition and body composition changes in long-stay hospitalised patients using an isotopic dilution technique. An additional objective was to compare the changes in composition with commonly used methods measuring body fat and lean mass. The dogs consumed on average 77.5% of their estimated resting energy requirements during their stay. The majority (78.3%) of dogs lost body weight, of which a greater proportion was lean mass (61.8%) than fat mass (FM) (38.2%). There was a moderate correlation between body condition score and percentage FM measured at admission (Kendall's τ = 0.51; p = 0.002), and at discharge (Kendall's τ = 0.55; p = 0.001). However, there was no correlation between muscle condition score and fat-free mass at either admission or discharge (p > 0.1). Duration of stay was positively associated with loss of body weight (p < 0.001), but was not associated with changes in either lean or FM expressed as a percentage of body weight or in absolute terms (p > 0.1), which was presumed to be explained by small sample size and variation. Food intake was not found to a significant factor for lean or FM loss (p > 0.1). These findings indicate that weight loss is common in hospitalized canine patients, which is not explained by simple under-eating. Other factors such as inflammation and inactivity should be evaluated in future studies to determine their role in influencing muscle and FM changes in hospitalized canine patients.Item Euthanasia of dogs and cats by veterinarians in New Zealand: protocols, procedures and experiences.(Taylor and Francis Group, 2023-04-25) Gates MC; Kells NJ; Kongara K; Littlewood KEAIMS: To collect data on protocols used by New Zealand veterinarians to perform euthanasia of dogs and cats, and to explore opinions towards the training they received in euthanasia during veterinary school. METHODS: A cross-sectional survey was administered to all veterinarians registered with the Veterinary Council of New Zealand. The survey asked respondents about their practices' policies for euthanasia; protocols for performing euthanasia of dogs and cats; opinions towards euthanasia training received in veterinary school; and subsequent experiences with euthanasia in practice. Descriptive statistics were provided for all quantitative study variables and thematic analysis was performed on the free-text comments. RESULTS: The survey was completed by 361/1,448 (24.9%) veterinarians in companion or mixed animal practice. The mean numbers of dogs and cats euthanised each month were 7.2 (median 5; min 0; max 60) and 7.9 (median 5; min 0; max 60), respectively. Fewer than half of respondents reported that their clinic had a standard protocol for euthanising dogs (147/361; 40.7%) or cats (157/361; 43.5%). For euthanasia of dogs, 119/361 (32.9%) always used sedation while 71/361 (19.7%) indicated that they would not use sedation. For euthanasia of cats, 170/361 (47.1%) always used sedation while 53/361 (14.7%) indicated that they would not use sedation. Placement of IV catheters, methods for patient restraint, preferences towards the presence of owners during euthanasia, services provided with euthanasia, and discussions with owners were also highly variable and handled case-by-case depending on the client, patient, and clinical scenario. When asked about the euthanasia training received at veterinary school, it was generally ranked as below satisfactory, with approximately one-third of respondents indicating that they received no training in dealing with emotional clients (113/361; 31.3%), sedation protocols for euthanasia (107/361; 29.6%), or managing compassion fatigue (132/361; 36.6%). Most respondents (268/361; 74.2%) received no formal training in euthanasia after graduation and learned from experience or discussions with colleagues. Providing animals and owners with a good experience during the euthanasia process was highlighted as important for managing compassion fatigue. CONCLUSIONS: Euthanasia is a common procedure in companion animal practice and there is considerable variation in how veterinarians approach both the technical and non-technical elements. Training provided during veterinary school was generally considered below satisfactory, particularly regarding managing compassion fatigue and clients' emotional needs. CLINICAL RELEVANCE: Providing veterinarians with additional training on adapting their euthanasia protocols to different clinical scenarios may improve the experience for patients, owners and veterinary staff.Item Canis Familiaris Papillomavirus Type 26: A Novel Papillomavirus of Dogs and the First Canine Papillomavirus within the Omegapapillomavirus Genus.(MDPI (Basel, Switzerland), 2024-04-12) Munday JS; Bond SD; Piripi S; Soulsby SJ; Knox MA; Christensen NDomestic dogs are currently recognized as being infected by 25 different canine papillomavirus (CPV) types classified into three genera. A short sequence from a novel CPV type was amplified, along with CPV1, from a papilloma (wart) from the mouth of a dog. The entire 7499 bp genome was amplified, and CPV26 contained putative coding regions that were predicted to produce four early proteins and two late ones. The ORF L1 showed less than 62% similarity for all previously sequenced CPV types but over 69% similarity to multiple Omegapapillomavirus types from a variety of Caniform species including the giant panda, Weddel seal, and polar bear. Phylogenetic analysis confirmed CPV26 clusters within the Omegapapillomavirus genus. Specific primers were used to investigate the presence of CPV26 DNA within a series of 37 canine proliferative lesions. CPV26 DNA was amplified from one lesion, a cutaneous papilloma that also contained CPV6. This is the first time a PV type within the Omegapapillomavirus genus has been detected in a non-domestic species and this provides evidence that the omegapapillomaviruses infected a common ancestor of, and then co-evolved with, the Caniform species. Whether CPV26 causes disease is uncertain, but the absence of an E7 protein may suggest low pathogenicity.Item Unambiguous identification of Ancylostoma caninum and Uncinaria stenocephala in Australian and New Zealand dogs from faecal samples.(John Wiley and Sons, Inc., 2023-10-01) Stocker T; Scott I; Šlapeta JHookworms (Ancylostomatidae) are well-known parasites in dogs due to their health impacts and zoonotic potential. While faecal analysis is the traditional method for detection, improvements in husbandry and deworming have decreased their prevalence in urban owned dogs. Drug resistance in Ancylostoma caninum is becoming a discussion point in small animal practices across the region. This study aimed to identify hookworm species present in Australian and New Zealand dogs using molecular techniques. The ITS-2 and isotype-1 β-tubulin assays were used to identify and quantify hookworm species. Results showed absence of coinfection in Australian samples from Greater Sydney region belonging either to A. caninum or Uncinaria stenocephala, while New Zealand samples were a mixture of A. caninum and U. stenocephala. The amplified isotype-1 β-tubulin sequences exhibited susceptibility to benzimidazole drugs. Rare mutations were identified in A. caninum and U. stenocephala sequences, representing a small percentage of reads. This study highlights the importance of molecular techniques in accurately identifying and quantifying hookworm species in dog populations.Item Retinopathy 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.Item Protothecosis in four dogs in New Zealand.(Taylor and Francis Group, 2023-09-04) Price PSA; Klobukowska HJ; Castillo-Alcala F; Foxwell JA; Orbell GMB; Brown S; Irving ACCASE HISTORIES: Medical records of four dogs diagnosed with protothecosis in New Zealand were reviewed. The dogs were aged between 4 and 9 years and three of the four dogs were female. Breeds were one Labrador, one Miniature Schnauzer and two crossbreeds. The reasons for initial veterinary evaluation were a cough and opaque appearance of the right eye (Case 1), diarrhoea (Cases 2 and 3), and cutaneous disease (Case 4). CLINICAL FINDINGS: The ocular signs were characterised by panuveitis, retinal detachment and secondary glaucoma. Gastrointestinal signs included chronic haemorrhagic diarrhoea due to colitis. Three cases had disseminated infection and developed both bilateral, blinding, ocular disease and chronic gastrointestinal disease. Cutaneous signs consisted of draining fistulae over the olecranon, multifocal cutaneous nodules, and ulceration and tracts of the foot pads. Disseminated protothecosis was confirmed by histopathology of biopsied ocular tissues in Cases 1 and 2 and by gastrointestinal biopsies in Case 3. Prototheca spp. were also identified in cytological specimens from Cases 1 and 4 and recovered by culture in Cases 2 and 4. Cutaneous protothecosis was diagnosed in Case 4 initially by cytology and histopathology of skin lesions, and Prototheca zopfii was confirmed by PCR of cultured organisms. TREATMENT AND OUTCOME: Prior to diagnosis of protothecosis, a variety of treatments were prescribed to treat the gastrointestinal and ocular signs. After diagnosis, only Cases 2 and 4 received medication aimed at treating the protothecal infection, which was itraconazole in both cases. Following the progression of clinical signs and concerns about quality of life, all four dogs were euthanised. DIAGNOSIS: Disseminated protothecosis in three dogs, cutaneous protothecosis in one dog. CLINICAL RELEVANCE: Canine protothecosis is rarely reported, despite the ubiquity of the causal algae, and the disease usually carries an extremely grave prognosis when infection is generalised. In New Zealand, protothecosis should be considered as a differential diagnosis in dogs with panuveitis, chorioretinitis or retinal detachment, colitis, or nodular, ulcerative or fistulating cutaneous lesions.