R. D. Marshall

Long-term safety, efficacy and palatability of oral meloxicam at 0.01-0.03 mg/kg for treatment of osteoarthritic pain in cats.

Osteoarthritis is a chronic, painful condition that is now recognised as affecting a large proportion of cats. Non-steroidal anti-inflammatory drugs (NSAIDs) have proven efficacy in dogs and humans but there are limited published data on the use of NSAIDs in the long-term management of this condition in cats. This prospective study aimed to assess the long-term safety and palatability of oral meloxicam and its efficacy in treating osteoarthritic pain in cats when given at a dose of 0.01–0.03 mg/kg once daily. Forty cats diagnosed with osteoarthritis completed the trial with a mean treatment duration of 5.8 months. Gastrointestinal upset in 2/46 (4%) cats was the only adverse effect noted. No deleterious effect on renal function was detected in cats studied. Owners subjectively assessed treatment efficacy as good or excellent in 34/40 (85%) of cases. The results of this study showed oral meloxicam to be safe and palatable long-term treatment for osteoarthritis in cats when given with food at a dose of 0.01–0.03 mg/kg.

Treatment of newly diagnosed diabetic cats with glargine insulin improves glycaemic control and results in higher probability of remission than protamine zinc and lente insulins.

Glycaemic control and remission probabilities were compared in 24 newly diagnosed diabetic cats treated twice daily with either glargine, protamine zinc (PZI) or lente insulin and fed a low carbohydrate diet. After day 17, the probability of remission was substantially higher for cats with lower mean 12 h blood glucose concentrations on day 17, irrespective of insulin type. Glargine-treated cats had lower mean 12 h blood glucose concentrations on day 17 than PZI- or lente-treated cats, and all eight glargine-treated cats achieved remission compared to three PZI- and two lente-treated cats. The probability of remission was greater for cats treated with glargine than cats treated with PZI or lente insulin. In newly diagnosed diabetic cats, twice daily treatment with glargine provides better glycaemic control and higher probability of remission compared to twice daily treatment with PZI or lente insulin. Good glycaemic control soon after diagnosis is associated with increased probability of remission and should be the goal of insulin therapy.

Glargine and protamine zinc insulin have a longer duration of action and result in lower mean daily glucose concentrations than lente insulin in healthy cats

The pharmacological effects of glargine, protamine zinc (PZI), and lente insulins were evaluated in nine healthy cats. A 3-way crossover study was performed and plasma concentrations of insulin and glucose were determined for 24 h after a single subcutaneous injection of each insulin at 3-day intervals. Time to onset of action did not differ between insulins. Mean time to first nadir glucose was longer for glargine (14 h) relative to PZI (4 h) and lente (5 h). PZI was biphasic in action with nadirs at 4 and 14 h with the second nadir occurring at a similar time to glargine. Nadir glucose did not differ significantly between insulin types. The duration of action was similar for glargine and PZI and was longer than that for lente insulin. Mean daily glucose after glargine and PZI were also similar and were lower than after lente insulin. Time to reach peak insulin did not differ between insulin types. Time to return to baseline insulin level for PZI was longer than glargine but did not differ significantly from lente. In conclusion, healthy cats injected subcutaneously with glargine, compared to those injected with lente insulin, have a later glucose nadir and longer duration of action. Glargine and PZI had similar durations of action in study cats but a larger study is required to obtain precise comparisons of duration of action.

Intramuscular glargine with or without concurrent subcutaneous administration for treatment of feline diabetic ketoacidosis

OBJECTIVE To describe treatment response and outcome in 15 cats with diabetic ketoacidosis (DKA) initially stabilized with glargine administered intramuscularly (IM) with or without subcutaneous (SC) glargine. MATERIALS AND METHODS Fifteen cats diagnosed with DKA were initially administered IM glargine (1-2 U) and in most cats (12/15 cats) this was combined with SC glargine (1-3 U). This was followed by intermittent IM glargine as required at intervals of 2 or more hours (range 2-22 h) and SC glargine (1-2 U) every 12 hours. KEY FINDINGS All 15 cats survived and were discharged from hospital (median 4 d; range 2-5 d) and one-third (5/15) of cats subsequently achieved remission (median time 20 d; range 15-29 d). Complications included hypokalemia and hypophosphatemia, which were likely the result of DKA therapy rather than glargine treatment specifically. SIGNIFICANCE This study demonstrates that glargine administered IM is an effective treatment for DKA in cats, and may provide an alternative to regular insulin. The same vial used for initial treatment of DKA can then be used for subsequent management with SC glargine injections. Future prospective randomized controlled trials evaluating clinical outcomes in cats with DKA using different types and routes of administration of insulin are warranted. A prospective randomized controlled trial is required to compare outcomes for IM and IV administration of glargine and regular insulin in DKA cats with or without SC glargine.

Focal pulmonary granuloma caused by Cladophialophora bantiana in a domestic short haired cat

Following a 4-week history of coughing, a 12-year-old cat with a history of insulin-dependent diabetes mellitus was diagnosed with a pulmonary granuloma caused by Cladophialophora bantiana. Thoracic radiographs revealed consolidation of the right caudal lung lobe and cytology confirmed the presence of mycotic pneumonia. Results of clinical investigations showed no evidence of extra-pulmonary infection. A thoracotomy and lung lobe resection was performed. Histological examination of the mass revealed black pigmented fungal hyphae and pyogranulomatous inflammation. Cultures inoculated with portions of these tissues yielded a dark walled fungus consistent with an etiologic agent of phaeohyphomycosis and DNA sequencing confirmed the presence of Cladophialophora bantiana. The cat was treated with itraconazole for 4 weeks post-operatively and then with posaconazole for 7 months but was euthanized 13 months after initial diagnosis due to a hepatocellular carcinoma. On post-mortem examination there was no evidence of recurrent fungal infection. This is the first report of localized pulmonary C. bantiana infection in a cat.

Insulin glargine has a long duration of effect following administration either once daily or twice daily in divided doses in healthy cats

The pharmacological effects of glargine administered once or twice daily were compared in six healthy cats. A two-way crossover study was performed with insulin and glucose concentrations measured following subcutaneous administration of glargine once daily (0.5 U/kg) or twice daily (0.25 U/kg, repeated after 12 h). Nadir glucose concentration and mean daily glucose concentration did not differ significantly following insulin administration once daily or twice daily in divided doses. Time to reach last glucose nadir differed, with longer intervals occurring following twice daily dosing. Blood glucose failed to return to baseline concentration by 24 h in three of six cats in each treatment group. Insulin variables were not significantly different following once or twice daily dosing. This study in healthy cats demonstrates that glargine has a long duration of action with carry-over effects to the next day likely, regardless of dosing regimen. A study in diabetic cats is required to determine the best dosing regimen.

Glycemic Status and Predictors of Relapse for Diabetic Cats in Remission

Background It is unknown if diabetic cats in remission have persistent abnormalities of glucose metabolism and should be considered prediabetic, or have normal glucose tolerance. Objective To characterize glycemic status of diabetic cats in remission and to determine predictors of relapse. Animals A total of 21 cats in diabetic remission and 28 healthy control cats. Methods At a median of 107 days after remission, screening blood glucose concentration was measured on entry to the clinic. After a 24‐hour fast in hospital, fasting blood glucose, fructosamine and feline pancreatic lipase concentrations were measured, and 3 hours later, a simplified IV glucose tolerance test (1 g glucose/kg) performed. Twenty cats were monitored for relapse for at least 9 months. Results Of the 21 cats in remission, 19% (4/21) had impaired fasting glucose concentration and 76% (16/21) had impaired glucose tolerance. Of cats followed up for 9 months after testing, 30% (6/20) had relapsed and required insulin treatment. Fasting blood glucose concentration ≥7.5 mmol/L (≥135 mg/dL) (odds ratio [OR] = 12.8) and severely impaired glucose tolerance (≥5 hours to return to <6.5 mmol/L or <117 mg/dL; OR = 15.2) were significantly associated with relapse. Blood glucose concentration >14 mmol/L; 252 mg/dL at 3 hours was significantly associated with relapse (OR = 10.1). Conclusion and Clinical Importance Most cats in diabetic remission have impaired glucose tolerance and a minority have impaired fasting glucose concentration and should be considered prediabetic. More severe glucose intolerance and impaired fasting glucose concentration are predictors of relapse. Ongoing glucose monitoring of diabetic cats in remission is recommended.

Cutpoints for screening blood glucose concentrations in healthy senior cats

Objectives The objectives of this study were to determine the reference interval for screening blood glucose in senior cats, to apply this to a population of obese senior cats, to compare screening and fasting blood glucose, to assess whether screening blood glucose is predicted by breed, body weight, body condition score (BCS), behaviour score, fasting blood glucose and/or recent carbohydrate intake and to assess its robustness to changes in methodology. Methods The study included a total of 120 clinically healthy client-owned cats aged 8 years and older of varying breeds and BCSs. Blood glucose was measured at the beginning of the consultation from an ear/paw sample using a portable glucose meter calibrated for cats, and again after physical examination from a jugular sample. Fasting blood glucose was measured after overnight hospitalisation and fasting for 18–24 h. Results The reference interval upper limit for screening blood glucose was 189 mg/dl (10.5 mmol/l). Mean screening blood glucose was greater than mean fasting glucose. Breed, body weight, BCS, behaviour score, fasting blood glucose concentration and amount of carbohydrate consumed 2–24 h before sampling collectively explained only a small proportion of the variability in screening blood glucose. Conclusions and relevance Screening blood glucose measurement represents a simple test, and cats with values from 117–189 mg/dl (6.5–10.5 mmol/l) should be retested several hours later. Cats with initial screening blood glucose >189 mg/dl (10.5 mmol/l), or a second screening blood glucose >116 mg/dl (6.4 mmol/l) several hours after the first, should have fasting glucose and glucose tolerance measured after overnight hospitalisation.

Severe muscle fasciculations and tremor in a cat with hypochloraemic metabolic alkalosis secondary to duodenal obstruction

Case summary An 18-month-old, female spayed, Australian Mist cat presented with a 24 h history of muscle tremors and inappetence progressing to collapse with generalised muscle fasciculations. The cat was diagnosed with a hypochloraemic metabolic alkalosis due to a duodenal foreign body found to be a trichobezoar at coeliotomy. The cat made a complete recovery after enterotomy to remove the trichobezoar, with cessation of neuromuscular clinical signs and normalisation of its electrolyte and acid–base imbalances. Relevance and novel information Muscle fasciculations and tremors in cats can be caused by intoxications, metabolic derangements, encephalomyelitis, feline hyperaesthesia syndrome and cerebellar diseases. The presenting clinical signs of severe muscle fasciculations and tremors have not previously been reported in association with an intestinal obstruction in the cat.