The Furry Family: Veterinary Pharmacy in Community Practice

Steph’s Note: Folks. Today is the day. Imagine my excitement when I opened my tl;dr email a few weeks ago to find a post suggestion email labeled “The Furry Family”. Yesssss, the heretofore untapped possibilities…a whole new area of pharmacy down which to rabbit hole…the MEMES AND CUTE PICTURES!!! (I love pharmacy, don’t get me wrong. But I LOVE some puppy memes.)

So who sent this exciting email?

Jenni Strand, PharmD is a community pharmacist at a large retail chain. She completed the veterinary medicine elective offered at her school of pharmacy and is also working through the PowerPak CE Veterinary Pharmacy program. As a public-facing community pharmacist, she receives questions about furry family members on a frequent basis and feels strongly that every pharmacist should know at least a little bit about these important patients. So Jen, take it away!

While working within community pharmacy, I am often asked for advice on medications for people’s pets, primarily dogs and cats. Although I often still feel less than prepared to answer questions about dosing medications for furry family members because of the differences in safety and the wide variety of products available, my course on veterinary pharmacy during pharmacy school and my continuing work towards a certificate in veterinary pharmacy have given me at least a basic understanding.

Hopefully, this post will help you to decode which of the numerous products in the OTC aisle may be safe and effective for pets, and it should give you an idea of what medications behind the counter may be used for patients named “Dog” and “Cat”. But before we begin, the most important piece of advice I can give you is this: if ever in any doubt, call a veterinarian. Refer to the vet for any issues that seem like they could become life-threatening, or if they are just strange and out of your scope of knowledge. 

Now, let’s get started.

Common Over the Counter Medications for Pets

Pain and Inflammation

Over the counter (OTC) products represent some of the most commonly encountered medications (and associated questions) for community pharmacists. However, just like with our human patients, this can also be one of the most tricky areas to give advice. Many OTC medications carry significant risks.

No OTC NSAIDs for you, omg-i-could-just-love-you-furever-Kitty! We will love any aches and pains away with cuddles, quantity infinity. (Image)

For instance, cats and NSAIDs are generally not a good mix. Any dose of naproxen will cause GI and renal toxicity in cats, and common human ibuprofen formulations, such as one itty-bitty 200mg tablet, can also be very GI toxic to cats. Most cats also metabolize aspirin too slowly for it to be effective for pain, and giving higher or more frequent doses that are helpful for pain relief often lead to toxicity.

So remember, don’t give aspirin to cats!

Also, be cognizant of other salicylate-containing medications to avoid, such as bismuth subsalicylate (Pepto Bismol). Because of the risks for cats with human NSAIDs, there are prescription NSAIDs specifically for the kitties, including robenacoxib (Onsior) and meloxicam (Mobic).

Hey, that last one looks familiar… because it’s used in humans too!

Dogs may be given particular NSAID medications when needed, but they definitely metabolize some of these quite differently than humans. For example, although dogs can be given aspirin 10-20 mg/kg twice daily for pain and inflammation, it can take them FOUR TIMES as long as a human to metabolize it! Bismuth subsalicylate may be used for canine stomach upset, including diarrhea, at 1-3 mL/kg/day. That being said, most of the time, it’s a good idea to turn to dog-specific NSAIDs from the veterinarian for pain relief, including carprofen (Rimadyl) or deracoxib (Deramaxx).

Plus, referring to the veterinarian (just like referring to a person’s primary care provider) ensures that the patient is evaluated for underlying, perhaps more serious sources of pain or inflammation. Also, when it comes to assessing your patient and determining whether an OTC is appropriate, don’t forget to check for drug interactions in our furry friends. For example, you wouldn’t want to use bismuth subsalicylate in a dog that’s already taking a canine NSAID as that could lead to double GI irritation!

Allergies

Ever had that moment - usually in slo-mo - when your dog stalks a buzzing bee that finally lands on a piece of clover? And then she lunges at the bee trying to take it out with her jaws of death?

He just couldn’t help himself…

And then this story usually ends with a swollen lump of a nose, if not a trip to the ER vet?

Yeah. Puppy-parent life.

OTC allergy medications are commonly used in dogs for a wide variety of issues, including itching, hives, runny nose or eyes, and allergic reactions. Diphenhydramine, a first generation antihistamine, may be used at a dose of 2 mg/kg for dogs. Because it has relatively stronger anticholinergic properties, it is also quite sedating and may be useful for the anxious furball who needs to calm down a smidge to go on that car ride. The flip side of those anticholinergic properties is the range of side effects, including constipation, dry mouth, urinary retention, and vision changes, so it’s not a benign medication especially in dogs with underlying medical history!

Remember the anticholinergic side effects: can’t see, can’t spit, can’t pee, can’t…poop.

Second generation antihistamines may also be useful, especially if the anticholinergic properties of diphenhydramine are either undesirable or problematic. Like you want to take your dog out for a run in the morning, but he’s still zonked out on your bed on YOUR PILLOW from the Benadryl dose last night. In these cases, cetirizine 1 mg/kg up to 10-20mg once or twice daily and loratadine 0.25-1.1 mg/kg/day in dogs may be options. Of note, cats may also have cetirizine at a dose of 1mg/kg up to 5mg once or twice a day.

Hydroxyzine, although used as a prescription anti-anxiety medication in humans, is indicated in animals for allergic symptoms such as itching with dosing of 2mg/kg two to three times daily.

GI Upset

Loperamide can be used to treat diarrhea at 0.08mg/kg three to four times daily, although caution should be used in many pet populations, particularly dogs with the MDR1 mutation. This gene mutation, also known as an ABCB1-gene deletion, changes the functionality of the P-glycoprotein efflux pumps that normally keep levels of loperamide low in the CNS. With higher loperamide levels in the CNS comes unwanted opiate adverse effects, including increased salivation, lethargy, and ataxia.

But who actually has their pups tested for this specific gene mutation…so how do you know?

Most of the time, you won’t. So log this away: although it’s not a hard and fast rule, some of the breeds in which the MDR1 mutation is more prevalent include Australian Shepherds, Collies, and Old English Sheepdogs. Just like in humans, loperamide also shouldn’t be used in cases of infectious diarrhea. Interestingly, cats seem to be far more sensitive to the CNS effects of loperamide, so it shouldn’t be used in our feline friends.

On the other hand, polyethylene glycol (MiraLAX) can be used for constipation or surgical preparation, similar to human use. Dosing is based on the size of the dog, given below. For cats, MiraLAX is given 0.5-1 gram twice daily on the cat’s food. 

Common Prescription Medications in Pets

Anxiolytics and Neurological Disorders

You know the spaz dog that chases joggers down the street? Or the one who runs, hides, pants, and cries during every thunderstorm? (And that’s with a Thundershirt?)

Or all the puppies adopted during COVID who will have never spent any time away from their owners - until the day when all of a sudden they have to go back to being physically present at work?

COVID puppy syndrome. Coin it, it’s real. And the risk of separation anxiety is looming!

There are veterinary specific medications that can be used for dogs, but common human medications may also be used off label in many situations. For example, trazodone can be used in dogs for both short term and long term anxiety. The average dose in dogs is 3.5mg/lb/day, though doses can increase to 15 mg/lb/day in certain cases. Usually the dose is tapered up after 3-5 days, with a minimum of 2 weeks to determine effectiveness. Another dosing strategy is listed in the chart below, based on total mg rather than specific mg/weight:

Another anti-anxiety medication that can be used in dogs is paroxetine. Dosing is 1-2mg/kg/day for conditions such as anxiety or fear-based behaviors. Other SSRIs like fluoxetine and sertraline may be used in both dogs and cats, and even some of the older tricyclic antidepressants like amitriptyline can be useful in both species. Although not as common these days due to concerns of abuse, benzodiazepines may be prescribed for our furry family members to aid with anxiety: alprazolam is used up to 0.1 mg/kg twice daily in dogs.  

In contrast to the long term use of anxiolytics sometimes seen in canine patients, anxiety treatment in felines is usually given short term; however, the medications themselves are the same. Trazodone is used very infrequently in felines, although documentation lists 50-100 mg per dose for short term situations, such as being nervous at the veterinarian. SSRIs and tricyclics are also used at lower doses compared with canines. Alprazolam is dosed lower at 0.125-0.25 mg twice a day. 

Wake up to this spazzy face in the middle of the night…!!! (Image)

Gabapentin can be used for seizure treatment, cluster seizures, and pain control in dogs. Dosing for seizure prevention starts at 10-20mg/kg every 6-12 hours, while cluster seizure dosing is 10 mg/kg every 8 hours for 3 days. Pain control dosing is 3-10 mg/kg every 24 hours. Although therapeutic blood monitoring is not usually recommended, the target range is 4-16 micrograms per mL. 

Other canine and feline seizure medications that cross over from the human world include carbamazepine, levetiracetam, and even phenobarbital!

Anti-Infective Medications

Antibiotic medications also cross the line from humans to animals. Azithromycin, commonly used for dermatologic, respiratory, or urogenital infections, can be used in both dogs and cats. For dogs, azithromycin should be dosed as 5-10 mg/kg/day for up to 7 days. Amoxicillin/clavulanate (Augmentin or Clavamox) is used for a variety of infections and is commonly given as 13.75 mg/kg twice daily (range 10-25 mg/kg two to three times daily). Metronidazole, which has activity against protozoal and anaerobic bacterial infections, is often used in dogs with giardiasis, trichomoniasis, abdominal abscesses, periodontitis (and the list goes on, just like in humans). The dose of metronidazole ranges up to 66 mg/kg/day in dogs with trichomoniasis!

Anti-infective medications in cats are dosed very similarly to other animals. For example, amoxicillin/clavulanate comparatively has the same average dose of 13.75 mg/kg twice daily. On the other hand, one key difference is that azithromycin has a higher upper limit in felines compared to canines: 5-15 mg/kg daily for up to 7 days depending on the infection. Metronidazole may also be used in cats. Fun fact, metronidazole tablets are really bitter, so crushing them often doesn’t work when trying to administer to a squirmy fur ball. Luckily, it can be compounded into a different formulation, metronidazole benzoate, to make it more palatable.

Even though you wouldn’t encounter it in community pharmacy, another interesting cross over for antimicrobials is amphotericin B for fungal infections. For dogs, amphotericin B is given in both slow (0.25 mg/kg IV over 4-6 hours) or rapid (0.25 mg/kg IV over 5 minutes). Whichever dosing is chosen, therapy continues with 0.5 mg/kg IV three times a week until a total dose of 9-12mg/kg is given. For cats with life-threatening fungal infections, amphotericin B only has one dosing strategy: 0.25 mg/kg IV three times weekly until a total dose of 9-12 mg/kg is reached.

Take Aways for Veterinary Pharmacy

Additional references can be found in many places. Professional monographs for different medications or medical information sites are great resources to help answer side effect questions or other dosing questions. Information for how to help animals take their medications or cooperate are also a huge help for the community pharmacist.

By using the dosing tips and recommendations within this guide, you can expand your pharmacy knowledge into the world of animals. Hopefully, when that next customer comes in with a script for trazodone for their spazzy canine, you won’t be caught off guard!