Efficacy and adverse events of L-Asparaginase administration as a first-line treatment for feline large-cell gastrointestinal lymphoma.

L-Asparaginase (L-Asp) is often used to induce remission in feline large-cell gastrointestinal lymphoma (LCGIL). However, no study has evaluated the efficacy and adverse events following the initial use of this drug as a first-line treatment in feline LCGIL. We retrospectively reviewed medical records of cats with LCGIL treated with L-Asp to induce remission. This study included 43 cats. The response rate (RR) after the first administration of L-Asp was 37.2% (Complete remission: 7.0%, partial remission: 30.2%). RR was significantly higher in cases with primary gastric lesions (64.3%) than in those with primary intestinal lesions (24.1%) (P=0.018), and it was also higher in cases without anemia (57.1%) than those with anemia (15.0%) (P=0.009). The most common adverse event was hyperammonemia, which occurred in 10 of 12 cases where we could compare plasma ammonia concentrations before and after the first dose of L-Asp. Plasma phosphate concentrations were also significantly increased (P<0.001) within 24 hr after the first dose. Decreased appetite, vomiting, and diarrhea were also observed in five, three, and seven cases, respectively, and Grade 3 or higher gastrointestinal signs were observed as adverse events in three cases. The median overall survival of all cats was 150 days (range, 5-1,065 days), and the median progression-free survival was 104 days (range, 2-978 days). In conclusion, L-Asp was effective to induce remission, and severe adverse events were uncommon in feline LCGIL.

Unilateral retrobulbar haemorrhage in a cat secondary to suspected anticoagulant rodenticide intoxication.

A 6-month-old intact female mixed-breed kitten presented with severe exophthalmos of the left eye. Periocular lesions, including subconjunctival haemorrhage, third eyelid protrusion, and left eyelid oedema, were detected in the absence of globe retropulsion. The left intraocular pressure was increased, and ocular ultrasonography revealed ipsilateral retrobulbar fluid. Coagulation panels were markedly prolonged and severe anaemia was detected. Ultrasound-guided retrobulbar centesis performed to decrease intraocular pressure yielded blood. Based on the history and clinical findings, anticoagulant rodenticide intoxication was suspected. Treatment included partial tarsorrhaphy and the administration of topical antibiotics, artificial tears, and vitamin K1. Fresh whole blood and fresh frozen plasma were transfused for supportive therapy. Coagulation parameters improved after 7 days of hospitalisation. The periocular lesions resolved within 14 days, despite persistent optic nerve damage and blindness. This case report raises the possibility that anticoagulant rodenticide toxicity may result in retrobulbar haemorrhage in the absence of other typical cavitary bleeding. Although uncommon, anticoagulant rodenticide toxicity should be considered in cats with retrobulbar haemorrhage.

First analytical confirmation of drug-induced crystal nephropathy in felines caused by GS-441524, the active metabolite of Remdesivir.

GS-441524 is an adenosine nucleoside antiviral demonstrating significant efficacy in the treatment of feline infectious peritonitis (FIP), an otherwise fatal illness, resulting from infection with feline coronavirus. However, following the emergence of COVID-19, veterinary development was halted, and Gilead pursued clinical development of a GS-441524 pro-drug, resulting in the approval of Remdesivir under an FDA emergency use authorization. Despite lack of regulatory approval, GS-441524 is available without a prescription through various unlicensed online distributors and is commonly purchased by pet owners for the treatment of FIP. Herein, we report data obtained from the analytical characterization of two feline renal calculi, demonstrating the propensity for GS-441524 to cause renal toxicity through drug-induced crystal nephropathy in vivo. As definitive diagnosis of drug-induced crystal nephropathy requires confirmation of the lithogenic material to accurately attribute a mechanism of toxicity, renal stone composition and crystalline matrix were characterized using ultra-performance liquid chromatography photodiode array detection (UPLC-PDA), ultra-performance liquid chromatography mass spectrometry (LCMS), nuclear magnetic resonance (NMR) spectroscopy, X-ray powder diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). This work serves to provide the first analytical confirmation of GS-441524-induced crystal nephropathy in an effort to support toxicologic identification of adverse renal effects caused by administration of GS-441524 or any pro-drug thereof.

Use of orally administered dexmedetomidine to induce emesis in cats.

CASE SERIES SUMMARY: This case series describes the use of orally administered dexmedetomidine at a dose of 20 µg/kg to induce emesis in six cats. Emesis was successfully induced in 5/6 cats, with each of the cats vomiting once. The reasons for inducing vomiting included known or suspected ingestion of lilies, onions, acetaminophen (paracetamol) or acetylsalicylic acid. Four of the five cats in which emesis induction was successful did not develop any clinical signs of toxicity associated with the toxin ingested; the fifth cat developed clinicopathological changes consistent with acetaminophen toxicity. All six cats exhibited moderate to profound sedation, as expected, but no other adverse effects were documented. RELEVANCE AND NOVEL INFORMATION: Induction of emesis in cats is notoriously difficult. This case series describes a novel route of administration of dexmedetomidine, a commonly available medication, with a high success rate observed for inducing emesis in this group of cats.

Cats are notoriously more difficult to elicit vomiting in than dogs. This case series describes the use of a novel way of giving cats a commonly available veterinary medication to cause vomiting. The medication, dexmedetomidine, was given by mouth to six cats, of which five vomited. All six cats had eaten toxins: lilies, acetaminophen (paracetamol), aspirin or onions. Four of the five cats that vomited did not develop any signs of toxicity. All six cats that received the medication became sedated, but no other side effects were noted.

Chemical pneumonitis secondary to accidental pulmonary polyethylene glycol-electrolyte solution infusion in a cat.

OBJECTIVE: To describe the successful conservative management of chemical pneumonitis and presumed acute respiratory distress syndrome in a cat secondary to inadvertent pulmonary polyethylene glycol-electrolyte solution (PEG-ELS) instillation. CASE SUMMARY: PEG-ELS is commonly used in small animals for bowel cleansing and to treat constipation. There have been several instances of aspiration or accidental instillation of this solution into the lungs of both people and dogs. PEG-ELS was inadvertently infused into the lungs of the cat in the current report. After 10 days in the ICU, during which time treatment with oxygen therapy, antibiosis, diuretics, and corticosteroids was provided, the cat was successfully discharged. NEW OR UNIQUE INFORMATION PROVIDED: To the authors' knowledge, this is the first report of instillation of PEG-ELS in a cat resulting in chemical pneumonitis and lung injury. We describe the successful management of this condition with conservative management and without the need for invasive interventions such as bronchoscopy and lavage or mechanical ventilation.

Alpha-chloralose poisoning in 25 cats: clinical picture and evaluation of treatment with intravenous lipid emulsion.

OBJECTIVES: The aims of this study were to describe the clinical picture and progression in cats with alpha-chloralose (AC) intoxication and to determine if treatment with intravenous (IV) lipid emulsion (ILE) influenced either the serum concentration of AC or the clinical signs. METHODS: Cats with suspected AC poisoning admitted to a university small animal hospital were included. The cats were randomised into two groups: one receiving 20% ILE at a dose of 300 mg/kg as a 2 min bolus, followed by a 1500 mg/kg continuous rate infusion over 30 mins (IL+ group) and the other receiving IV fluid therapy with Ringer's acetate (IL- group). Serum samples were drawn at 0, 2, 12 and 24 h after admission. Samples were tested for AC with a novel validated, quantitative, ultra-high-performance liquid chromatography-tandem mass spectrometry method. Vital and predefined clinical signs were noted at the times of sampling and patients were scored using a previously described intoxication severity score. Telephone interviews were conducted after discharge to assess outcome. RESULTS: A total of 25 cats were enrolled: 13 cats in the IL+ group and 12 in the IL- group. The most common clinical signs at presentation were tremor (n = 22, 88.0%), cranial nerve deficits (n = 20, 80.0%) and bradycardia (n = 19, 76.0%). No significant difference in AC concentration or change in intoxication score over time was found between the IL+ and IL- groups at any time point (P >0.05). All cats recovered within 72 h. CONCLUSIONS AND RELEVANCE: ILE did not have any effect on the AC serum concentration or clinical signs in AC-poisoned cats. All cats survived until follow-up. In cats with an acute onset of the described neurological signs, AC intoxication is an important differential diagnosis with an excellent prognosis.

Neurological adverse effects of isoxazoline exposure in cats and dogs.

BACKGROUND: Isoxazolines are rarely reported to be associated with neurological adverse events in cats and dogs, but information about the onset and duration of neurological signs is lacking in the summary of product characteristics of these medicines. METHODS: The Veterinary Poisons Information Service and the Dutch Poisons Information Center databases were searched using the Veterinary Dictionary for Drug-Related Affairs terms for ataxia, muscle tremor, convulsions or hyperesthesia in cats and dogs exposed to isoxazolines. RESULTS: There were 22 cases with and 57 cases without outcome information, mostly involving fluralaner or sarolaner. In both groups, muscle tremors and convulsions were the most common signs. In dogs, neurological signs occurred with oral therapeutic dose and overdosage. In cats, most fluralaner cases involved therapeutic topical exposure, and all sarolaner cases involved oral exposure. In all cases with outcome information, the animals recovered. LIMITATIONS: Cases discussed with poison centres tend to involve more severe signs. CONCLUSION: The true incidence of neurological adverse effects from isoxazolines remains unclear. The delay between the administration and onset of signs can be long, and the association may be missed. A lack of timing information in the summary of product characteristics could also contribute to missed attribution of adverse effects.

Filgrastim Use in the Treatment of Azathioprine-Induced Myelosuppression Toxicity After Prescription Error in the Feline.

Only one report on the successful use of filgrastim (granulocyte colony-stimulating factor) in cats for severe neutropenia following azathioprine toxicity exists. Here, we report on a case in which a cat was prescribed methimazole but the medication was filled incorrectly with azathioprine tablets and the prescription label indicated a methimazole dosing regimen that was administered for three days before recognition of the error. On presentation, the cat's physical examinations were consistent with previous examinations before ingestion of azathioprine. A complete blood cell count revealed neutropenia and leukopenia. The cat later developed hyporexia, dehydration, and vomiting. Treatment included antinausea and appetite stimulant medications, filgrastim, and antibiotics. Filgrastim given as subcutaneous injections over the course of treatment increased neutrophil cell counts after suppression. The cat made a full recovery after responding to the treatment protocol. Based on the perceived response to filgrastim in this single feline case report, its use can be considered for the treatment of azathioprine-induced neutropenia in cats.

Dysphagia as a Missing Link Between Post-surgical- and Opioid-Related Pneumonia.

PURPOSE: Postoperative pneumonia remains a common complication of surgery, despite increased attention. The purpose of our study was to determine the effects of routine surgery and post-surgical opioid administration on airway protection risk. METHODS: Eight healthy adult cats were evaluated to determine changes in airway protection status and for evidence of dysphagia in two experiments. (1) In four female cats, airway protection status was tracked following routine abdominal surgery (spay surgery) plus low-dose opioid administration (buprenorphine 0.015 mg/kg, IM, q8-12 h; n = 5). (2) Using a cross-over design, four naive cats (2 male, 2 female) were treated with moderate-dose (0.02 mg/kg) or high-dose (0.04 mg/kg) buprenorphine (IM, q8-12 h; n = 5). RESULTS: Airway protection was significantly affected in both experiments, but the most severe deficits occurred post-surgically as 75% of the animals exhibited silent aspiration. CONCLUSION: Oropharyngeal swallow is impaired by the partial mu-opioid receptor agonist buprenorphine, most remarkably in the postoperative setting. These findings have implications for the prevention and management of aspiration pneumonia in vulnerable populations.

Application of eprinomectin-containing parasiticides at label doses causes neurological toxicosis in cats homozygous for ABCB11930_1931del TC.

The feline MDR1 mutation (ABCB11930_1931delTC) has been associated with neurological toxicosis after topical application of eprinomectin products labeled for feline use. Information was collected from veterinarians who submitted samples for ABCB11930_1931delTC genotyping. In most cases, the submission form indicated an adverse event involving eprinomectin, in other cases submitting veterinarians were contacted to determine whether the patient had experienced an adverse drug event involving eprinomectin. If so, additional information was obtained to determine whether the case met inclusion criteria. 14 cases were highly consistent with eprinomectin toxicosis. Eight cats were homozygous for ABCB11930_1931del TC (3 died; 5 recovered). Six cats were homozygous wildtype (2 died; 4 recovered). The observed ABCB11930_1931delTC frequency (57%) was higher than the expected frequency (≤1%) in the feline population (Fisher Exact test, p < 0.01). Among wildtype cats, four were concurrently treated with potential competitive inhibitors of P-glycoprotein. Results indicate that topical eprinomectin products, should be avoided in cats homozygous for ABCB11930_1931delTC. This is a serious, preventable adverse event occurring in an identifiable subpopulation treated with FDA-approved products in accordance with label directions. Acquired P-glycoprotein deficiency resulting from drug interactions may enhance susceptibility to eprinomectin-induced neurological toxicosis in any cat, regardless of ABCB1 genotype.

Oral mirtazapine decreases the gastrointestinal adverse effects in cats on doxorubicin chemotherapy.

Anorexia, depression, and vomiting are the common adverse effects of chemotherapy in humans and animals. Mirtazapine is primarily used as an appetite stimulant and antiemetic in dogs and cats. Therefore, we evaluated the efficacy of mirtazapine in reducing the gastrointestinal adverse effects in cats receiving doxorubicin chemotherapy. This single-masked, placebo-controlled crossover study enrolled 11 cats with malignant mammary gland tumors. The cats were randomly assigned to receive either mirtazapine (1.88 mg/cat) or placebo every 48 h for 2 weeks from the first initiation of doxorubicin chemotherapy. Each cat was then crossed over to the alternate group on the subsequent chemotherapy with a 1-week wash-out period. The owners were asked to record appetite score, activity score, episodes of vomiting and diarrhea for 2 weeks after each doxorubicin administration. Cats treated with mirtazapine showed significantly increased bodyweight compared with those on placebo (P = 0.010). The appetite and activity scores during mirtazapine treatment was significantly higher than those during placebo treatment (P = 0.005 and 0.018, respectively). Furthermore, the prevalence of episodes of vomiting during mirtazapine treatment was significantly lower than that during placebo treatment (P = 0.026). Our results demonstrate that mirtazapine can significantly increase bodyweight, appetite, and activity and reduce vomiting in cats after doxorubicin chemotherapy.

Pharmacodynamic effects of molidustat on erythropoiesis in healthy cats.

BACKGROUND: Inhibition of hypoxia-inducible factor prolyl hydroxylase (HIF-PH) stimulates erythropoiesis in rats, dogs, monkeys, and humans. HYPOTHESIS/OBJECTIVE: Determine if molidustat, a novel HIF-PH inhibitor, stimulates erythropoiesis in healthy cats. ANIMALS: Seventeen healthy adult laboratory cats. METHODS: Randomized, placebo-controlled study. Cats were treated PO once daily with suspensions of 0 (Group 1; n = 6), 5 (Group 2; n = 6), or 10 (Group 3; n = 5) mg/kg of molidustat. Effects on red blood cell parameters, reticulocyte indices and plasma erythropoietin (EPO) concentrations were evaluated. Molidustat treatment was stopped when hematocrit (HCT) exceeded 60%. RESULTS: Compared to placebo, a significant increase in mean HCT was evident starting on Day 14 (Group 2:54.4% vs 40.3%, P < .001, 95% confidence interval [CI] for the difference [8.95-19.28]; Group 3:61.2% vs 40.3%, P < .001, 95% CI [15.48-26.43]) and remained significantly higher for the entire treatment period. In molidustat-treated groups, HCT exceeded 60% on Day 21 (Group 2) and Day 14 (Group 3). Mean HCT in molidustat-treated cats returned to within the reference range (29%-45%) after Day 56 and was numerically comparable to placebo from Day 70 onwards. Red blood cell count and hemoglobin concentrations followed a similar pattern as HCT. Mean EPO concentrations significantly increased after molidustat administration on all assessment days. Molidustat treatments were well tolerated. CONCLUSIONS AND CLINICAL IMPORTANCE: Marked erythropoietic effects were identified after daily administration of molidustat to healthy cats and additional studies are warranted to evaluate the effects in anemic cats.

A review of the pharmacology and clinical applications of levetiracetam in dogs and cats.

OBJECTIVE: To review and summarize the pharmacology of the antiepileptic drug (AED), levetiracetam (LEV), and to discuss its clinical utility in dogs and cats. DATA SOURCES: Veterinary and human peer-reviewed medical literature and the authors' clinical experience. SUMMARY: LEV is an AED with mechanisms of action distinct from those of other AEDs. In people and small animals, LEV exhibits linear kinetics, excellent oral bioavailability, and minimal drug-drug interactions. Serious side effects are rarely reported in any species. LEV use is gaining favor for treating epilepsy in small animals and may have wider clinical applications in patients with portosystemic shunts, neuroglycopenia, and traumatic brain injury. In people, LEV may improve cognitive function in patients with dementia. CONCLUSION: LEV is a well-tolerated AED with well-documented efficacy in human patients. Although its use is becoming more common in veterinary medicine, its role as a first-line monotherapy in small animal epileptics remains to be determined. This review of the human and animal literature regarding LEV describes its role in epileptic people and animals as well as in other disease states and provides recommendations for clinical usage.

Veterinary Psychopharmacology.

The stress response affects the central nervous system and multiple other systems in the body. Chronic mental and behavioral pathologies are associated with inflammation, dysfunctions in the immune response and an increased risk for other chronic inflammatory and metabolic diseases. Psychiatric treatments alleviate fear, stress and anxiety, increase the qualify of life and lifespan for dogs and cats. Multiple safe psychoactive medications that can be used in association are available to help veterinary patients. Clinicians should understand the function of neurotransmitters and hormones on emotional processing, cognition and behavior, and drug mechanism of action so medication selection is appropriate for each individual patient.

Cutaneous lesions and clinical outcomes in five cats after frunevetmab injections.

CASE SERIES SUMMARY: This case series describes five cats with cutaneous adverse events after subcutaneous administration of frunevetmab, a felinised anti-nerve growth factor monoclonal antibody, including histopathological findings in one case. All cats displayed moderate to severe pruritus resulting in self-trauma to the neck and/or head, causing lesions ranging from superficial dermatitis to alopecia and ulcerations. There were no reactions at the injection sites. In one cat, clinical signs developed after the second frunevetmab dose the cat received, with no reaction noted after the first dose. For the remaining cats, clinical signs were observed after their first dose of frunevetmab. The onset of the first episode of pruritus and self-trauma was 3-18 days after the most recent frunevetmab injection. Three cats had one or more additional frunevetmab injections after the original adverse event and all had subsequent reactions. Subsequent reactions were either similar in time frame or occurred more rapidly, with similar or more severe pruritus compared with the original reactions. Treatments and outcomes varied between cases. RELEVANCE AND NOVEL INFORMATION: Frunevetmab is a novel, monthly injectable monoclonal antibody for the management of pain associated with osteoarthritis in cats. This is the first published report detailing the nature of cutaneous adverse events associated with this treatment, and the first report of the histopathological findings.

Incidences of steroid-induced diabetes mellitus and congestive heart failure in cats given non-immunosuppressive doses of methylprednisolone acetate: 1042 cats.

Objective: Corticosteroids are indicated to treat many feline diseases. However, side effects are a limiting factor in their use. The most concerning side effects are steroid-induced diabetes mellitus (SI-DM) and steroid-induced congestive heart failure (SI-CHF). This study aims to determine the incidences of these diseases in a large population of domestic cats seen at a privately-owned, feline-only practice. Animals: Cats in the study were client-owned patients of Alamo Feline Health Center in San Antonio, Texas. Control cats (controls) were examined as part of their routine health care. Procedures: The records of 732 cats that received methylprednisolone acetate (MPA) for various clinical indications were reviewed to determine how many developed SI-DM and SI-CHF. A similar record review of 310 controls was made to determine the incidence of spontaneous diabetes mellitus (Sp-DM) and spontaneous congestive heart failure (Sp-CHF). Control cats never received any oral or injectable corticosteroids. Results: Of the cats that received MPA, 28 developed SI-DM (3.83%) and 6 developed SI-CHF (0.82%). Of the controls, 22 developed Sp-DM (7.10%) and 6 developed Sp-CHF (1.90%). Conclusion: The incidences of developing SI-DM and SI-CHF were 3.83% and 0.82%, respectively; and the risk was not increased even when repeated doses of MPA were given. Clinical relevance: The authors consider the risk-benefit ratio sufficient to justify the use of MPA when it is indicated, especially if another drug cannot be substituted with the same therapeutic results.

Incidences du diabète sucré et de l'insuffisance cardiaque congestive induits par les stéroïdes chez des chats ayant reçu des doses non immunosuppressives d'acétate de méthylprednisolone : 1042 chats. Objectif: Les corticoïdes sont indiqués pour traiter de nombreuses maladies félines. Cependant, les effets secondaires constituent un facteur limitant leur utilisation. Les effets secondaires les plus préoccupants sont le diabète sucré induit par les stéroïdes (SI-DM) et l'insuffisance cardiaque congestive induite par les stéroïdes (SI-CHF). Cette étude vise à déterminer l'incidence de ces maladies dans une large population de chats domestiques vus dans une pratique privée exclusivement féline. Animaux: Les chats de l'étude étaient des patients appartenant à des clients du Alamo Feline Health Center à San Antonio, au Texas. Les chats témoins (témoins) ont été examinés dans le cadre de leurs soins de santé de routine. Procédures: Les dossiers de 732 chats ayant reçu de l'acétate de méthylprednisolone (MPA) pour diverses indications cliniques ont été examinés afin de déterminer combien d'entre eux ont développé du SI-DM et du SI-CHF. Un examen similaire des dossiers de 310 témoins a été réalisé pour déterminer l'incidence du diabète sucré spontané (Sp-DM) et de l'insuffisance cardiaque congestive spontanée (Sp-CHF). Les chats témoins n'ont jamais reçu de corticostéroïdes oraux ou injectables. Résultats: Parmi les chats ayant reçu du MPA, 28 ont développé du SI-DM (3,83 %) et 6 ont développé du SI-CHF (0,82 %). Parmi les témoins, 22 ont développé du Sp-DM (7,10 %) et 6 ont développé du Sp-CHF (1,90 %). Conclusion: Les incidences de développement de SI-DM et de SI-CHF étaient respectivement de 3,83 % et 0,82 %; et le risque n'a pas augmenté même lorsque des doses répétées de MPA ont été administrées. Pertinence clinique: Les auteurs considèrent le rapport bénéfice/risque suffisant pour justifier l'utilisation du MPA lorsqu'il est indiqué, notamment si un autre médicament ne peut lui être substitué avec les mêmes résultats thérapeutiques.(Traduit par Dr Serge Messier).

Foreign body ingestion due to detachment of pill dispenser tips in cats: a retrospective study of 13 cases.

OBJECTIVES: The aim of this study was to evaluate and describe 13 cases in which a pet piller broke during the administration of medication, and the tip was accidentally ingested by the cat. METHODS: A total of 15 presentations to the clinic were identified in a private practice database involving 13 cats in which the silicone tip broke. Two of these cats ingested foreign bodies on two separate occasions. Routine radiographic examination enabled the identification of silicone tips in all animals. On 2/15 occasions, the cats did not receive an emetic drug. Intramuscular xylazine (0.2 mg/kg) and dexmedetomidine (6 µg/kg) were administered to 12/15 and 1/15 cats, respectively. RESULTS: The cats were aged 3-17 years (mean age 11.00 ± 4.35 years). Vomiting occurred in 13 cats that received alpha-2 adrenoceptor agonists, although the silicone tip was recovered in only five occurrences. In 9/15 occurrences, endoscopy was performed under general inhalation anesthesia, and the silicone tip was successfully removed. Natural elimination occurred in only one case. CONCLUSIONS AND RELEVANCE: The use of pet pillers with detachable silicone tips increases the risk of accidental foreign body ingestion by animals. Therefore, guidelines regarding safety standards for manufacturing would be beneficial. No cat in this series developed clinical signs related to the ingestion of the piller tip, probably because of the quick presentation by the owners and early intervention, including endoscopic retrieval. Surgical intervention was not required in any case, including one in which the foreign body was lodged within the small intestine before being passed naturally by the cat.

Dermatologic adverse effect of subcutaneous furosemide administration in a cat.

Background: Furosemide is a mainstay of treatment in congestive heart failure (CHF) and is widely prescribed to dogs and cats by several formulations, including the subcutaneous one. In canine and human medicine, dermatologic adverse effects of subcutaneous furosemide (SF) have been documented; conversely, no prior case has been published describing skin reactions to this therapeutic protocol in cats. In this report, we describe, for the first time in feline medicine, a suspected dermatologic adverse effect after SF in a cat. Case Description: A 2-year-old domestic shorthair cat was presented for CHF associated with lung edema and pleural effusion. Echocardiography revealed asymmetric left ventricular myocardial thickening and severe left atrial dilation. The cat was hospitalized and initially treated with oxygen, intravenous furosemide, and clopidogrel. After discharge, the route of administration of furosemide was switched from intravenous to oral. Within the following 2 weeks, the cat experienced two relapses of lung edema despite the progressive increase of the furosemide dose, the addition of spironolactone and adherence to the therapeutic protocol by the owners. The dose of furosemide was further increased and its route of administration at home was switched from oral to parental. As the owner was not able to administrate intramuscular injections, SF was prescribed. This allowed the prevention of further episodes of lung edema. However, although the cat had never presented skin problems before, multiple well-defined circular, crusted ulcerative cutaneous lesions associated with alopecia developed at the sites of furosemide injections 2 weeks later. After ruling out several differential diagnoses for these lesions, a rare side effect of furosemide, not yet described in cats but already known in canine and human medicine, was strongly suspected as the possible cause. Therefore, the ongoing injectable formulation of furosemide was interrupted and substituted with an alternative brand, maintaining the same dose and route of administration. Thanks to this change, the dermal ulcerations disappeared within 1 month. Subsequently, the cat experienced neither further skin problems nor a recurrence of lung edema. Conclusion: Although SF is sometimes prescribed in small animal practice, it should be noticed that this may lead to dermatologic adverse reactions in the cat.

A retrospective evaluation of phenobarbital-induced hematologic changes in 69 cats.

BACKGROUND: Phenobarbital (PB) is used as a first-line treatment for recurrent epileptic seizures in cats. While hematologic abnormalities are well-known side effects of antiepileptic therapy with PB in humans and dogs, little is known about such alterations in cats. OBJECTIVES: The aim of this retrospective study was to investigate the prevalence and clinical relevance of cytopenia during PB treatment in cats. METHODS: In this single-center, retrospective clinical study, 69 cats-with suspected idiopathic epilepsy admitted to the Small Animal Clinic of the University of Veterinary Medicine in Vienna (VMU)-were included. A complete blood count for each patient was performed, and changes in hematocrit, leukocytes, neutrophils, and thrombocytes were documented and graded. RESULTS: Fifty-three out of 69 cats (76.8%) showed cytopenias with a reduction of at least one cell fraction during PB treatment. The most frequent change was neutropenia (60%), followed by leukopenia (49.3%), thrombocytopenia (24.1%), and anemia (20.3%). Most of the changes were mild or moderate; only one patient (1.5%) showed severe leukopenia and neutropenia, and one was a life-threatening neutropenia (1.5%) with a serum PB concentration within or even below the therapeutic range. These patients did not present with clinical symptoms other than those related to epileptic episodes. Cats who received combination therapy showed lower hematocrits than those who received monotherapy. A tendency for leukocytes and neutrophils to decrease during PB treatment was also seen. CONCLUSIONS: Blood cytopenias may frequently occur in cats on chronic PB therapy, even when serum drug levels are within the therapeutic range. However, clinical signs are typically mild to moderate and rarely severe.