Tolerability and efficacy of the intestinal phosphate binder Lantharenol® in cats

Single and combined ecotoxicological effects of ocean warming, acidification and lanthanum exposure on the surf clam (Spisula solida)

Lanthanum (La) is one of the most abundant emergent rare earth elements. Its release into the environment is enhanced by its use in various industrial applications. In the aquatic environment, emerging contaminants are one of the stressors with the ability to compromise the fitness of its inhabitants. Warming and acidification can also affect their resilience and are another consequence of the growing human footprint on the planet. However, from information gathered in the literature, a study on the effects of ocean warming, acidification, and their interaction with La was never carried out. To diminish this gap of knowledge, we explored the effects, combined and as single stressors, of ocean warming, acidification, and La (15 μg L^-1) accumulation and elimination on the surf clam (Spisula solida). Specimens were exposed for 7 days and depurated for an additional 7-day period. Furthermore, a robust set of membrane-associated, protein, and antioxidant enzymes and non-enzymatic biomarkers (LPO, HSP, Ub, SOD, CAT, GPx, GST, TAC) were quantified. Lanthanum was bioaccumulated after just one day of exposure, in both control and climate change scenarios. A 7-day depuration phase was insufficient to achieve control values and in a warming scenario, La elimination was more efficient. Biochemical response was triggered, as highlighted by enhanced SOD, CAT, GST, and TAC levels, however as lipoperoxidation was observed it was insufficient to detoxify La and avoid damage. The HSP was largely inhibited in La treatments combined with warming and acidification. Concomitantly, lipoperoxidation was highest in clams exposed to La, warming, and acidification combined. The results highlight the toxic effects of La on this bivalve species and its enhanced potential in a changing world.

Emerging lanthanum (III)-containing materials for phosphate removal from water: A review towards future developments

The last two decades have seen a rise in the development of lanthanum (III)-containing materials (LM) for controlling phosphate in the aquatic environment. >70 papers have been published on this topic in the peer-reviewed literature, but mechanisms of phosphate removal by LM as well as potential environmental impacts of LM remain unclear. In this review, we summarize peer-reviewed scientific articles on the development and use of 80 different types of LM in terms of prospective benefits, potential ecological impacts, and research needs. We find that the main benefits of LM for phosphate removal are their ability to strongly bind phosphate under diverse environmental conditions (e.g., over a wide pH range, in the presence of diverse aqueous constituents). The maximum phosphate uptake capacity of LM correlates primarily with the La content of LM, whereas reaction kinetics are influenced by LM formulation and ambient environmental conditions (e.g., pH, presence of co-existing ions, ligands, organic matter). Increased La solubilization can occur under some environmental conditions, including at moderately acidic pH values (i.e., < 4.5-5.6), highly saline conditions, and in the presence of organic matter. At the same time, dissolved La will likely undergo hydrolysis, bind to organic matter, and combine with phosphate to precipitate rhabdophane (LaPO₄·H₂O), all of which reduce the bioavailability of La in aquatic environments. Overall, LM use presents a low risk of adverse effects in water with pH > 7 and moderate-to-high bicarbonate alkalinity, although caution should be applied when considering LM use in aquatic systems with acidic pH values and low bicarbonate alkalinity. Moving forward, we recommend additional research dedicated to understanding La release from LM under diverse environmental conditions as well as long-term exposures on ecological organisms, particularly primary producers and benthic organisms. Further, site-specific monitoring could be useful for evaluating potential impacts of LM on both biotic and abiotic systems post-application.

Assessment of the application for renewal of authorisation of Lantharenol® (lanthanum carbonate octahydrate) for cats

Lantharenol^® is a feed additive consisting of lanthanum carbonate octahydrate. It is currently authorised as a zootechnical additive (decrease in phosphorous excretion via urine) for cats; this opinion concerns the renewal of the authorisation. In 2007, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) adopted an opinion on the safety and efficacy of Lantharenol^® as a feed additive for cats. The applicant has provided data demonstrating that the additive complies with the conditions of authorisation. The available evidence, including the results of the post‐market monitoring plan, confirms that the use of Lantharenol^® in cat food at the maximum authorised concentration of 7.5 g/kg of complete feed is safe for cats. In the absence of new data, the FEEDAP Panel reiterates its previous conclusion that Lantharenol^® does not pose a risk by inhalation and is not an irritant to skin or eye and not a dermal sensitiser. The FEEDAP Panel considers that there is no need for a continuation of a specific post‐market monitoring plan.

Update on Mineral and Bone Disorders in Chronic Kidney Disease

The inappropriate phosphorus retention observed in chronic kidney disease is central to the pathophysiology of mineral and bone disorders observed in these patients. Subsequent derangements in serum fibroblast growth factor 23, parathyroid hormone, and calcitriol concentrations play contributory roles. Therapeutic intervention involves dietary phosphorus restriction and intestinal phosphate binders in order to correct phosphorus retention and maintain normocalcemia. Additional therapies may be considered to normalize serum fibroblast growth factor 23 and parathyroid hormone.

ISFM Consensus Guidelines on the Diagnosis and Management of Feline Chronic Kidney Disease

PRACTICAL RELEVANCE

Chronic kidney disease (CKD) is one of the most commonly diagnosed diseases in older cats. In most cats, CKD is also a progressive disease and can be accompanied by a wide range of clinical and clinicopathological changes. These ISFM Consensus Guidelines have been developed by an independent panel of clinicians and academics to provide practical advice on the diagnosis and management of this complex disease.

CLINICAL CHALLENGES

Although CKD is a common clinical problem in cats, the manifestations of disease vary between individuals. Thus there is a need for careful and repeat evaluation of cats with CKD and adjustment of therapy according to individual needs. In addition to addressing problems arising from CKD and improving quality of life (QoL) for the patient, therapy may also target slowing the underlying progression of disease and hence prolonging life. While maintaining QoL is of paramount importance in our patients, this can be challenging when multiple therapies are indicated. In some cases it is necessary to prioritise therapy, given an understanding of what is likely to most benefit the individual patient.

EVIDENCE BASE

In preparing these Guidelines, the Panel has carefully reviewed the existing published literature, and has also graded the quality of evidence for different interventions to help to provide practical recommendations on the therapeutic options for feline CKD. This is a field of veterinary medicine that has benefited from some excellent published clinical research and further research findings will undoubtedly modify the recommendations contained in these Guidelines in the future.

Comparative palatability of five supplements designed for cats suffering from chronic renal disease

Background

Intestinal phosphate binders, uremic toxin binders and some other types of supplements are an integral part of the management of chronic kidney disease (CKD) in various species, including cats. This pathology in domestic carnivores requires life-long nutritional and medical management. In this context, the compliance of owners and patients cannot be achieved without an adequate level of palatability for oral medication or supplementation. Knowing that hyporexia and anorexia are among the most commonly seen clinical signs in cats suffering from CKD this is already, in itself, a serious obstacle to acceptable compliance in sick animals. The aim of the present study was to investigate the palatability of four commercially available products designed for cats suffering from CKD: Ipakitine® (Vetoquinol, France), Azodyl® (Vetoquinol, USA), Renalzin® (Bayer, France), Rubenal® (Vetoquinol, France) and an additional recently developed product: Pronefra® (Virbac, France). The study was performed with a group of previously-characterised cats, all living in an enriched and well-being securing environment of an independent centre housing panels of pets expert in palatability measurement. In total 172 monadic testings were performed. The palatability of each product was assessed by measuring their rates of prehension and consumption, and the consumption proportions were also analysed.

Results

The most palatable presentation (based on useful consumption) was Pronefra®, which was significantly higher than Azodyl® (p = 0.046), Ipakitine® (p < 0.0001), Renalzin® (p < 0.0001) and Rubenal® (p < 0.0001). The product with the highest rate of prehension was also Pronefra®, which was significantly higher than Azodyl® (p = 0.0019), Ipakitine® (p = 0.0023), Renalzin® (p = 0.0008) and Rubenal® (p < 0.0001).

Conclusion

Pronefra® was the most palatable presentation tested, meaning it may be useful for improving ease of supplementation in CKD cats.

Feline CKD: Current therapies - what is achievable?

PRACTICAL RELEVANCE

Treatment of feline chronic kidney disease (CKD) tends to focus on minimising the adverse effects of reduced renal function, rather than addressing an underlying cause. Despite this, and the progressive nature of CKD, treatment can improve quality of life and enable many cats to have long survival times.

EVIDENCE BASE

Strong evidence supports the provision of renal diets, which are protein and phosphorus restricted; compliance is improved by gradual dietary transition. Additional phosphorus restriction is achieved by the use of phosphate binding agents, although it is unknown if these yield similar survival benefits to those provided by renal diets. Interventions to control hypokalaemia and hypertension in affected cats are important to prevent serious complications. Administration of benazepril to cats with proteinuric kidney disease has been shown to significantly improve their appetite but not their survival. As CKD progresses, many cats will benefit from treatment to control clinical signs of uraemic gastroenteritis and anaemia.

Nonuraemic nonfatal idiopathic calciphylaxis in a kitten

BACKGROUND

Calciphylaxis is a rare cutaneous disorder, characterized by vascular calcification and progressive skin necrosis, not yet described in cats. It is scarcely reported in animals, mostly due to iatrogenic or uraemic disturbances of the calcium-phosphate balance. In human patients, it is most commonly seen with end-stage renal disease, but several nonuraemic disorders, including inherited dysfunctions of tissue calcification inhibitors, have also been described.

HYPOTHESIS/OBJECTIVES

To describe a case of nonuraemic calciphylaxis in a cat.

ANIMALS

A 10-week-old male domestic short hair kitten was presented with hyperacute skin lesions. Initial dermatological signs were characterized by sharp demarcated erosions and ulcerations on the face, including the nasal planum and lips. Cutaneous lesions rapidly progressed into thick crusts with ulcerations, involving parts of the face and pinna as well as abdominal skin.

METHODS

Complete blood count, serum chemistry profile, urinalysis, parathyroid hormone measurement and histopathological examination of skin biopsies.

RESULTS

Histopathology from newly developed abdominal skin lesions revealed severe epidermal necrosis and calcification, multifocal pannicular calcification and calcified subcutaneous vessels, supporting a diagnosis of calciphylaxis. Treatment consisted of systemic and topical antimicrobials, analgesics, pentoxifylline, Lantharenol(®) , sodium thiosulfate and vitamin K. After initiation of therapy, no further progression was noticed; all medications could be discontinued eventually, and no relapse was seen in the following 2 years.

CONCLUSIONS AND CLINICAL IMPORTANCE

Calciphylaxis should be considered as a differential diagnosis for ulcerative cutaneous disorders in young cats. More information on this disease is needed to elucidate the pathomechanism.