The 2023 World Small Animal Veterinary Association (WSAVA)

Background3 Definition3 Using the List of Essential Medicines3 Criteria for Selection of Essential Medicines3 Anaesthetic, Analgesic, Sedative and Emergency Drugs4 Antimicrobial Drugs6 Antibacterial and Antiprotozoal Drugs6 Systemic Administration6 Topical Administration7 Antifungal Drugs7 Antiparasitic Drugs7 Antiviral Drugs8 Behaviour Modifying Therapies9 Cardiorespiratory and Renal Systems9 Endocrinology10 Euthanasia Drugs11 Gastrointestinal System11 Immunomodulatory Drugs11 Neurology12 Oncology12 Ophthalmology13 Reproduction14 Vaccines14 Index16 The second version of the list of essential medicines is presented by members of the WSAVA Therapeutic Guidelines Group (TGG) following extensive internal and external peer-review. Internal peer-review was provided by TGG members in 2023, whereas external peer-review was performed by board-certified individuals and other WSAVA working groups. Additionally, there was a 3-month audit (January to March 2023) allowing any individual including WSAVA member affiliates to provide comments, suggestions and overall feedback. Any comment received was carefully considered by the TGG taking into consideration the definitions of core and complementary medicine. The updated (version 2) list is a product of several rounds of revision and based on expert consensus. This list of essential medicines should allow veterinarians to provide proper preventive care and treatment of the most frequent and important diseases in dogs and cats while maintaining appropriate animal welfare standards. The purpose of the list is to improve and facilitate regulatory oversight for ensuring appropriate medicines availability, drug quality, use and pharmacovigilance, while mitigating the growing black/counterfeit market of pharmaceutical products. The list of essential medicines is not intended to define what medicines should be always available within the clinic/hospital nor a drug compendium; rather that veterinarians should have ready access to these (medicines) if required for the prevention and treatment of specific diseases and conditions. Additionally, the committee understands that there is no “one-size fits all” and that there may be specific medicines used for endemic/epidemic diseases in some countries that the list does not cover. For example, the essential antimicrobials were defined as those medicines that are recommended as first line agents for treatment of at least one common disease condition but also taking into consideration the issue of antimicrobial resistance. Essential medicines are those that satisfy the primary health care and welfare needs of cats and dogs. The definitions of essential medicines are based on a similar list of essential medicines in human medicine by the World Health Organization (https://www.who.int/medicines/publications/essentialmedicines/en/). However, our current approach does not involve, e.g. extensive systematic reviews and meta-analysis to demonstrate evidence-based information for each medicine as this may not be always achievable in veterinary medicine. Medicines presented in the list may or may not be approved and/or licensed for use in veterinary medicine, which may vary from country to country. From a regulatory standpoint, the list should be adapted in accordance with specific regional or national needs and conditions. The presence of a medicine in the essential medicines list carries no assurance as to the pharmaceutical quality of products containing that medicine. It is the responsibility of the relevant national or regional drug regulatory authority to ensure that each product is of appropriate pharmaceutical quality (including stability) and that, when relevant, bioequivalent products can be interchangeable. Individuals should be also aware of potential different concentrations and formulations of each compound/medicine, and possible drug combinations present in a commercial product. Additionally, this list is not meant to be used as a reference for dosage regimens, drug interactions, indications or contra-indications, adverse effects or description of pharmacologic effects. It does not describe what medicines require monitoring, specific means of disposal/elimination/record keeping or follow-up consultations as the list should not be used as guidance for therapy. Essential medicines are presented in alphabetical order and divided by either drug category (anaesthetic, analgesics, immunomodulators, oncology drugs, sedatives, vaccines, antiparasitics and antimicrobials, including antibacterial, antifungal, antiprotozoal and antiviral drugs) or organ system/specialty (cardiorespiratory and renal, endocrinology, gastrointestinal, neurology, ophthalmology or reproduction). The essential list of medicines for dermatology is presented in other sections of the document (e.g. immunomodulators, antimicrobials, antiparasitics, etc.). Cross-reference between a drug category and an organ system is acknowledged where appropriate. Some veterinary specialties may not be listed as their lists of essential medicines have been merged into another drug category or organ system. Essential medicines are selected with due regard to disease prevalence and public/animal health relevance, evidence of clinical efficacy and safety, and comparative costs and cost-effectiveness. These medicines can be rarely replaced by other medicines and their absence could compromise public/animal health and welfare. The core list presents a list of minimum medicine needs for a basic health care system, listing the most efficacious, safe and cost-effective medicines for priority conditions. Priority conditions are selected based on current and estimated future public/animal health relevance, and potential for safe and cost-effective treatment. The complementary list presents essential medicines for priority diseases, for which advanced diagnostic or monitoring facilities, and/or advanced medical care, and/or advanced training are needed. In case of doubt, medicines may also be listed as complementary based on consistently higher cost or less attractive cost-effectiveness in a variety of settings and wide availability in the profession. (The WSAVA Global Pain Council has published the 2022 WSAVA guidelines for appropriate recognition, assessment and treatment of pain including protocols with different drug availability – https://onlinelibrary.wiley.com/doi/10.1111/jsap.13566. The WSAVA Global Pain Council has published information on the minimum analgesic availability – https://www.wsava.org/WSAVA/media/Documents/Committee%20Resources/WSAVA-GPC-Position-minimum-analgesic-availability.pdf.) Oral (PO) and injectable formulations are used in the treatment of rodenticide (e.g. warfarin, pindone, bromadiolone, etc.) toxicosis, and severe liver disease or biliary obstruction (parenteral formulation). These medicines are used for the treatment of osteoarthritis in dogs (bedinvetmab) and cats (frunevetmab). They may be beneficial when NSAIDs are contra-indicated or if pain is refractory to the administration of NSAIDs. Potentiated sulfonamides are recommended as a first line agent for treatment of bacterial cystitis and are useful antimicrobials for treating skin and other infections, including central nervous system infections caused by susceptible bacteria and protozoa. This bacteriostatic antimicrobial has a broad-spectrum activity against Gram-positive, Gram-negative and obligate anaerobic bacteria. It is suitable for treatment of intraocular and CNS infections. Due to concerns of resistance development, its use should be restricted to animals with infections resistant to other antimicrobials [available in injectable, oral and topical (ophthalmic) formulations]. This iodophor antiseptic is widely used as an alternative of chlorhexidine gluconate for perioperative skin antisepsis, post-operative application to surgical incisions and emergency antisepsis in patients with minor lacerations, abrasions and burns. This drug binds to fungal cell membrane ergosterol leading to increased permeability and intracellular cation loss. Amphotericin B has poor oral availability and is administered iv. Antifungal activity is highly dependent on the formulation administered. These drugs are agonists of nematode acetylcholine nicotinic receptors with drug specific spectrum of activity against gastrointestinal nematodes. The oral formulation is used for the treatment of canine and feline leishmaniosis as the disease is allowed to be treated in many countries of the world. Idoxuridine and trifluridine are used for the treatment of viral infections affecting the ocular surface. Remdesivir and/or GS-441524 are used for the treatment of feline infectious peritonitis. This can be used systemically for treatment of acute ocular disease caused by feline herpesvirus type 1. Used for the treatment of behavioural disorders related to anxiety and/or phobia. Amlodipine is used for feline and canine hypertension and is titrated orally to effect. They are indicated for the management of significant ventricular arrhythmias that are associated with important haemodynamic changes. This medication is used to treat thyroid hormone deficiency in canine hypothyroidism. It is available for oral or conjunctival administration and is used in the treatment of central diabetes insipidus in dogs and cats. This can also be administered iv or subcutaneously to dogs with von Willebrand's disease. This is also used for humane euthanasia once the animal is under general anaesthesia. See also anaesthetic, analgesic, sedative and emergency drugs. Lactulose acidifies the colonic contents. Ammonia is then trapped as ammonium and, in this form, the intestinal wall cannot absorb it. Lactulose is used to reduce ammonia concentrations in the treatment of hepatic encephalopathy, but also as an osmotic laxative in constipation. See neurology. Tricyclic antidepressant used as an appetite stimulant mostly in cats. Immunosuppressive drugs can produce different levels of immune suppression or immune regulation to treat different immune-mediated disease or some inflammatory disorders (i.e. myasthenia gravis, immune-mediated haemolytic anaemia or thrombocytopenia, skin diseases, inflammatory bowel disease, polyarthritis, systemic lupus erythematosus, etc.). They should not be used interchangeably. These therapies are generally used in combination with corticosteroids or used more in one species versus the other (i.e. azathioprine is only used in dogs and not recommended for cats, where chlorambucil is an alternative). Cyclosporine is licensed for the management of canine and feline atopic dermatitis and for topical use in ophthalmology for the treatment of keratoconjunctivitis sicca in dogs. Other than cyclosporine, these agents are not licensed veterinary medicines. This drug is used in specific conditions for immunosuppression. In ophthalmology, the drug is used for keratoconjunctivitis sicca refractory to treatment with other immunosuppressants/immunomodulators. Supplementation of thiamine or vitamin B1 is required in cases of deficiency in dogs and cats (in anorexic cats; inadequate diet; exposure to meat containing excessive sulphites). Multi-antiepileptic drug therapy is often required as refractory cases of epilepsy are not uncommon. Potassium bromide is inexpensive and can be used in dogs with hepatic dysfunction. Loading doses of potassium bromide are required to reach a steady state faster. Loading doses are associated with a higher prevalence of adverse effects. This drug should not be administered to cats. Imepitoin is approved in the veterinary market for use in dogs. Levetiracetam should be administered as an adjunct to other antiepileptic drugs. Gabapentin and pregabalin are poor anti-epileptic drugs but used for the treatment of painful conditions including neuropathic pain and to decrease stress during patient transportation. (The relapsed disease using rescue protocols or cases of toxicity with a specific drug cannot always be treated with this essential list of drugs). Vincristine is a first-line chemotherapeutic agent used in many lymphoma and leukaemia protocols and for the treatment of transmissible venereal tumour (TVT). It is used in a multiagent protocol for treatment of hemangiosarcoma. Vinblastine is commonly used for the treatment of mast cell tumours and transitional cell carcinomas. These drugs are targeted therapies that can block specific receptors that are frequently aberrantly expressed in certain tumours, especially mast cell tumours. The use of toceranib has been expanded to treat apocrine gland adenocarcinomas of the anal sac, GIST, pulmonary neoplasia, oral squamous cell carcinomas and most endocrine neoplasia such as insulinomas, thyroid carcinomas, pancreatic and adrenal carcinomas (anecdotal evidence). This drug is used in some types of glaucoma (e.g. primary glaucoma) and contraindicated in other types of glaucoma (e.g. anterior lens luxation, uveitic glaucoma). Proteinase inhibitors (EDTA, N-acetylcysteine and tetracycline antibiotics) are to be considered when the activity of matrix metalloproteinases is excessive, resulting in corneal melting, which can be common in geriatric dogs. This drug is used for metritis or during problems associated with delivery in dogs and cats. These drugs enhance foetal maturation just before caesarean section. Core vaccines are those that all dogs and cats should receive, after considering the geographical areas in which they live or to which they travel. Recommended vaccination schedules for puppies and kittens, and for adult dogs and cats, as well as for animals living in shelters and other group-housing situations, can be found in the WSAVA Vaccination Guidelines (The WSAVA Vaccination Guidelines relate to the use of companion animal vaccines of validated high quality that are produced by major global manufacturers. The Guidelines do not apply to regionally produced products of less certain quality. An issue facing veterinarians in many parts of the world is a limited range of available vaccines. In many countries, there is only access to multicomponent products including up to 12 different antigens (mixed core, non-core and not recommended vaccine components). This limits the ability of veterinarians to provide optimised, individualised patient care). All veterinary practices should develop a core vaccination programme for the dogs and cats under their care. Guidance on how to do this can be found in the WSAVA Vaccination Guidelines and, for some countries, in various evidence-based national and regional guidelines. Core vaccines for dogs, in all parts of the world, are those that protect against canine distemper virus (CDV), canine adenovirus (CAV) and canine parvovirus-2 (CPV). Wherever canine rabies is endemic, rabies vaccines should also be considered core for dogs. In many parts of the world, canine leptospirosis is endemic. In these places, if suitable vaccines are available to protect dogs against leptospirosis, these should also be considered core. Core vaccines for cats, in all parts of the world, are those that protect against feline parvovirus (FPV) (feline panleukopenia virus), feline herpesvirus-1 (FHV) and feline calicivirus (FCV). Wherever feline rabies is endemic, rabies vaccines should also be considered core for cats. In many parts of the world, feline leukaemia virus (FeLV)-related diseases are endemic. In these places, FeLV vaccines should be considered core for young cats (<1 year of age) and for adult cats with outdoor access or that live with other cats that have outdoor access. Complementary essential medicines are defined in this Essential Medicines List as those that require a measure of specialist input related to their use. None of the prophylactic vaccines described here require specialist input. So, strictly speaking, the complementary list should be empty. However, thoughtful, well informed selection of which non-core vaccines to recommend is required and this relies on specialised local knowledge. Therefore, the “non-core” vaccines are listed here as “complementary.” Selection of which non-core vaccines to recommend for a particular dog or cat should be based on knowledge of the local prevalence of relevant infectious diseases and on knowledge of the lifestyle and consequent exposure risks of that individual animal. Non-core vaccines can be as important as core vaccines, depending on local risk factors. Non-core vaccines should ideally be available as monovalent or limited component products that can be selected for appropriate use in individual animals. In many countries, such optimised products are unavailable. The WSAVA Vaccination Guidelines do not recommend the use of canine enteric coronavirus vaccine or Giardia vaccine. The WSAVA Vaccination Guidelines do not recommend the use of feline infectious peritonitis vaccine or vaccines against dermatophytosis. This first version of this document would not have been possible without the contribution of the following colleagues (in alphabetical order): Filipe Espinheira, Michael Day, Marilyn Dunn, Walt Ingwersen, Roberta Portela, Hélène Ruel, the Theriogenology service of the École nationale vétérinaire d'Alfort and the WSAVA Global Pain Council. The second version would not have been possible without the contribution of the WSAVA Global Pain Council, the WSAVA Oncology Group, the WSAVA Reproduction Control Committee, the WSAVA Vaccination Guidelines group, comments from members of the WSAVA OneHealth group and many WSAVA associations after the open audit. The WSAVA Therapeutics Guidelines Group is funded by Zoetis. The funder did not have any participation in the expert consensus, study or manuscript review and approval. This WSAVA List of Essential Medicines for Cats and Dogs has been published as submitted to JSAP and has not gone through the usual full peer-review process. Paulo V. Steagall: Conceptualization (equal); investigation (equal); methodology (equal); project administration (equal); supervision (equal); writing – original draft (equal); writing – review and editing (equal). Jennifer L. Granick: Investigation (equal); validation (equal); writing – review and editing (equal). Fergus Allerton: Investigation (equal); methodology (equal); validation (equal); writing – review and editing (equal). Pawel M. Beczkowski: Methodology (equal); validation (equal); writing – review and editing (equal). J. Scott Weese: Investigation (equal); methodology (equal); visualization (equal); writing – review and editing (equal). Andreja K. Hrček: Data curation (equal); methodology (equal); resources (equal); writing – review and editing (equal). Felisbina Queiroga: Methodology (equal); validation (equal); writing – review and editing (equal). Luca Guardabassi: Methodology (equal); validation (equal); writing – review and editing (equal).