Cat pheromones: do they work?

I can’t speak for all pet owners but pet pheromone products have been pushed at me from all quarters – pet shop associates, veterinarians, trainers, and even other pet owners! I was initially recommended pheromone products due to car- and moving-induced stress in my pets but if you pick up any brand pheromone dispenser and you will discover a  multitude of potential applications. (Urine marking, inappropriate scratching, multicat tension, excessive barking, hiding, etc.) These products cost a pretty penny too – around $30 for a diffuser or spray, $15 for a pheromone-infused collar. So it begs the question: do pheromone products work?

Photo credit: Trish Hamme via / CC B

What are pheromones anyway?

Pheromones are a means of chemical communication. Although not completely understood, it is thought that animals perceive pheromones through a specialized receptor in roof animal’s snouts called the vomeronasal organ (VNO). The VNO does not always pick up pheromones, however – it has to be activated by the animal. Have you ever seen a cat, intrigued by a new smell or etc., open her mouth and “pant” with her tongue out? That behavior is called “flehmen” and it’s function is to suck pheromones into the VNO.

Animals use pheromones to communicate a wide array of messages: territorial marking, sexual receptivity, spatial orientation and emotional stabilization, assertion of social status, alarm marking during fear reactions, appeasement of infant animals – and those are just the pheromones that scientists understand (and there are loads whose functions are unknown).

Scientists and pet product companies have developed synthetic pheromones that can be purchased at many pet stores and veterinary offices. Several types of pheromone dispensation products are available: passive diffusers that are plugged into a wall outlet, pheromone-infused collars, pheromone-infused wipes, and pheromone sprays.

What could pheromones do for cats?

Photo credit: Sander van der Wel via / CC BY-NC-SA

Considering that our pets live in a world full of smells, veterinarians and behaviorists have  been exploring the application of pheromones to treat animal behavior problems because, when used correctly, they are completely non-toxic, have no side effects, and involve little effort on the part of owner or pet. The therapeutic use of pheromones to treat behavior problems in pets is called pheromonotherapy.

The principle of pheromonotherapy is pretty simple: use synthetic pheromones to communicate a useful message to a pet displaying a behavior problem. Many behavior problems are the result of fear and anxiety in pets, so using a pheromone with an emotional stabilization function – like the pheromone cats release when they rub their chin on something to distinguish it as “known”. Reduction of feline spraying has been a target of numerous pheromonotheray studies – no doubt because this is a common and extremely aggravating behavior problem for cat owners. Scientists have also evaluated cat pheromones in calming cats during transport, prior to intravenous catheterization, in preventing stress-induced anorexia, and facilitating the peaceful introduction of unsocialized cats.

So…do pheromones work?

There are real barriers to the success of pheromonotherapy. First, animals generally do not communicate by pheromones alone. Usually there would be a multitude of body signals or vocalizations that would accompany (and emphasize) the pheromone message and open up the VNO so that the animal perceives the message.  Secondly, pheromones may “prime” an animal’s emotional state to be receptive to a behavior modification program but it is unlikely that pheromones alone will completely address behavior problems.

Thus the importance of the scientific evaluation of pheromonotherapy! All of the studies that I read about the use of pheromones for emotional stabilization, i.e. for behavior problems like urine marking, inter-act aggression, transport-induced stress, stress-induced anorexia (see Sources below), were all suggestive of a positive effect. The general consensus is that the longer pheromones were used (4+ weeks), the better the effect. Additionally, many cats maintained improved behavior after pheromones were removed.

I did find a very critical meta-analysis, which is a study of studies. This meta-analysis looked at all available pheromone studies and found that most studies had significant problems with design and/or analysis, such as small sample size, the absence of blinding or randomization, and the lack of a control sample. These problems prevented the authors from agreeing with the positive findings of the individual studies. However…I had problems with the meta-analysis’s problems! The principles of “robust” clinical research aren’t always ethical – especially in a situation where, say, you’ve got an owner whose cat is spraying all over the house and euthanasia is seriously on the table. Furthermore, the funding opportunities for these studies don’t seem to be abundant so gathering huge sample sizes may not be possible. I did not find any study over stating its findings and hopefully the examination of pheromonotherapy will continue to provide additional information.

Photo credit: jenny downing via / CC BY


We have reasonable evidence to suggest human-applied pheromones (or pheromonotherapy) can be helpful as part of a behavior modification program for a cat displaying certain behavior problems, especially urine marking and inter-cat aggression. Best results have been seen in prolonged use (4+ weeks) of pheromonotherapy.




  1. Frank, Diane, Guy Beauchamp, and Clara Palestrini. “Systematic review of the use of pheromones for treatment of undesirable behavior in cats and dogs.” Journal of the American Veterinary Medical Association 236.12 (2010): 1308-1316.
  2. Mills, Daniel S., Sarah E. Redgate, and Gary M. Landsberg. “A meta-analysis of studies of treatments for feline urine spraying.” PloS one 6.4 (2011): e18448.
  3. Griffith, Cerissa A., Elizabeth S. Steigerwald, and CA Tony Buffington. “Effects of a synthetic facial pheromone on behavior of cats.” Journal of the American Veterinary Medical Association 217.8 (2000): 1154-1156.
  4. Mills, D. S., and C. B. Mills. “Evaluation of a novel method for delivering a synthetic analogue of feline facial pheromone to control urine spraying by cats.” RIVISTA DI ZOOTECNIA E VETERINARIA 30.1 (2002): 50-51.
  5. Kronen, Peter W., et al. “A synthetic fraction of feline facial pheromones calms but does not reduce struggling in cats before venous catheterization1.”Veterinary anaesthesia and analgesia 33.4 (2006): 258-265.
  6. Gunn-Moore, D. A., and M. E. Cameron. “A pilot study using synthetic feline facial pheromone for the management of feline idiopathic cystitis.” Journal of feline medicine and surgery 6.3 (2004): 133-138.
  7. Frank, D. F., H. N. Erb, and K. A. Houpt. “Urine spraying in cats: presence of concurrent disease and effects of a pheromone treatment.” Applied Animal Behaviour Science 61.3 (1999): 263-272.
  8. Pageat, Patrick, and Emmanuel Gaultier. “Current research in canine and feline pheromones.” Veterinary Clinics of North America: Small Animal Practice 33.2 (2003): 187-211.

Private: Suds & Cheese: Tips for a minimally painful & non-human-soaking dog bath!

Wisconsin recently treated me to a few days of shockingly warm weather – on the weekend, no less! I try not to bathe my dogs in the winter as much as possible but it can get a little stinky so I took full advantage of the freakish warmth! Below are my tried and true tips for a maximally peaceful, minimally self-bathing dog bath!

Tip 1: Gather your supplies. My pup cleansing supplies are 2 full sized towels, 2 hand towels, a high-quality conditioning shampoo, and cheese. Yes, CHEESE is vital. Few dogs like baths and the ample application of cheese before, during, as after baths can really make everything much more enjoyable for everyone.

Tip 2: Consider your dog’s preferences. 
One of my dog’s prefers warm-to-hot bath water, especially when it is not warm outside. Neither of my pups want to stay in the tub very long. So I trial-and-error water temperature for my pups (lucky for me, Allie will give me a *snappy comeback if the temp isn’t right). And I make sure bath time goes as fast as possible by having purchased a shower head with a long hose and getting together all my supplies before asking the pup to get in the tub. (Also, I have used the cheese tip so much that my dogs both climb in the tub willingly – so no wrestling my 85lb!)

Okay, I know the point of giving your dog a bath is to make her smell nice but puppy noses are approximately 1,000-10,000 times more sensitive than our pathetic human schnozes. And if your dog could pick a smell that was 1,000 times stronger to her than it is to you, do you think it would be tropical mango? Probably not!

Tip 3: Strategize. So you may have read my first tip and thought, Why on earth does she need so many towels?  The answer is strategy:

Exhibit A: Two towels for stability/grip.
  • Possibly the best dog bathing tip I have ever found was from Dr. Marty Becker’s book, “Your Dog: The Owner’s Manual”. He calls it the three towel tip but I have modified it slightly. I put the two hand towels in the bottom of the tub pre-pup. Slipping in the tub can be a real source of bath hatred for dogs, and the wet towels underneath the dog can provide much-appreciated stability.I used two hand towels because I’ve noticed that putting a regular towel in the tub –
    as Dr. Becker suggests – can

    Exhibit B: The after bath splash zone minimizer

    get bunched up and pushed out of the way easily. As soon as I’m done rinsing the pup, I put the first large towel over the dog (see Exhibit B) to decrease my likelihood of ending up in the splash zone of the after-bath shake. I use the second large towel to actually dry the dog.

  • Reconsider washing your dog’s head. The thing is, your dog’s head isn’t really that smelly. Or at least, if your dog doesn’t have an ear infection or bad teeth, your dog’s head shouldn’t be smelly. Most dogs dislike water pouring over their heads and it can even increase the risk of an ear infection with water gets trapped in their ear canals. So skip the head washing! I used grooming wipes on my pup’s heads if I feel so inclined but honestly, even that is generally unnecessary!


Journal Article: How to Not be a D#@% to Your Cat

IMG_2540Have you ever considered that cats, creatures that we commonly deem to call “owned”,  are a totally different species to ours?  Because cats are relatively common aspects of our households, the fact that their needs to totally unrelated to our own frequently goes overlooked. Dr. Meghan Herron and Dr. Tony Buffington published recommendations for cat owners to provide good health and welfare for their feline friends. Furthermore, ensuring good health and welfare can pre-empt or ameliorate many cat behavior problems! The authors divide their advice into five systems in a cat’s world: physical resources, nutrition, elimination, social, and behavior. My summary of these experts’ recommendations for each system is below!

  • Physical Resource System (Home!)
    • Indoor cats benefit from secure, seclusive “microenvironments”. These are spaces that a cat can go to be away from loud noises, other home inhabitants (both four- and two-legged), and removed from other things that may stress the cat.
    • Multi-cat households may experience a range of cat-on-cat sociality. Cats may prefer a social distant from other cats in the home of between 1 to 3 meters, which includes both horizontal as well as vertical distance!
    • Introducing something new to the cat – food, litter, etc. – should be offered near to the current whatever is being replaced so the cat can choose the preferred item.
  • Nutritional System (Nom noms)
    • Cats are solitary hunters of small prey, so offering food in puzzles that must be manipulated by the cat to release food away from other animals in the household may mimic cats’ natural feeding habits.
    • Cats that are “finicky” about their food may be responding to a perceived threat in their environment.
    • Offering multiple sources of water, including running water from a pet fountain, may benefit cats.
  • Elimination System (When you gotta go…)
    • Multi-cat households should have at least one litter box per cat, plus one additional, kept out of sight of other littler boxes.
    • Covered, self-cleaning, or too small litter boxes may disrupt a cat’s normal elimination behavior routine, which may cause inappropriate elimination (i.e., going outside the box)
    • Cats seem to prefer clumping litter, which should be scooped daily, the entire contents should be dumped weekly, and cleaned with mild soap and water monthly.
  • Social System (You talkin’ to me?)
    • Other living creatures in cats’ environments basically fall into three categories: threats (dogs, humans); competitors (other cats); and prey (birds, fish, pocket pets).
    • Having a perception of control can decrease stress for cats: let cats determine the timing and location of interactions with other species (as safety permits).
    • Multi-cat households may experience inter-cat aggression to due a multitude of reasons: health problems, inadequate resources/space, social status conflicts due to other animals inside or outside the home, etc.
    • Cats may prefer avoidance (silent conflict) to aggression (open conflict).
    • Cats that experience conflict may never be best friends but can usually learn to live together tolerably, sometimes with the help of a certified behaviorist.
  • Behavioral System (A cat’s gotta do…what a cat’s gotta do)
    • Cats must be permitted to display normal behavior to ensure adequate welfare but many normal cat behaviors can be “undesirable” to owners, including scratching, chewing and playing.
    • Directing otherwise “undesirable” towards desirable outlets provides an enriched environment, which can be accomplished by providing outlets that appeal to the cat’s natural behavior.
    • Cats prefer to scratch things after rest and that allow them to hook their claws into it. Poles covered in sisal rope or real wood logs may be good options, placed near common sleeping areas.
    • Cats can be enticed to chew on cat-designated plants (such as live catnip) by rubbing the plants with tuna or wet cat food, and likewise discouraged from chewing non-cat-designated plants by spraying them bitter sprays from pet stores. Pet toxic plants should be removed from cats’ access!
    • Providing a rotating variety of toys (wand toys, stuffed toys, battery-operated self-propelling toys, balls, cat-nip filled toys, laser toys, etc.) will encourage normal cat behaviors like pouncing, stalking, chasing, and biting of said toys (and discourage those same behaviors direct toward the owner’s hands/feet/etc!).

Sources Cited 

Herron ME, Buffington CAT. Environmental Enrichment for Indoor Cats.Compendium (Yardley, PA). 2010;32(12):E4.

Moving with Pets: Tips from (at this point I should be) a Pro

In my last post, I talked about my top five tips for renting with pets. Of course, moving goes hand-in-hand with renting. So here are my hard-earned top five most helpful tips for moving with pets!

  1. Keep a routine. From my internet search for moving-with-pets tips, most experts advise that disruption moving entails is the source of stress that causes most pet melt downs during relocation. To mitigate this nearly inevitable pet trauma, several weeks before and after our move, we try mightily to stick to a routine with our pets: food is doled at twice a day at the same time, walks occur precisely (more or less) on schedule, and we try to get to bed at a reasonable hour. alliebox
  2. Pack a pet overnight bag. Avoid hasty unpacking to find your cat’s food or dog’s medication by packing everything your pet needs  over the timeframe of your move (for example, 48 hours for a move occurring overnight) PLUS 50% (so 72 hours in my example). This is my method because, well, moving always takes longer than you think it will.
  3. Pheromones work (for most pets). I’m not going to lie: the only reason I tried pheromone products was my no-holds-barred approach to relocating ~450 miles a little over a year ago. I did not hold my breath for a miraculous reaction from my pets and I would say that a “miracle” has never occurred whilst my pets were exposed to pheromones. However, I will say that there was much less whining, crying, puking, and upset-potty-ing during the actual driving. When we arrived at the new rental, our cats spent far less time cowering in closets, etc. than usual. I have used pheromone products (diffusers, as well as impregnated collars, sprays, and wipes) in two subsequent moves and I will be using them for every move in the future!
  4. Talk to your vet/trainer. One of our cats gets legitimately car sick, so we talked with our vet about giving her a sedative for the 8 hour+ drive so she could sleep instead of staring out the car window and getting ill. (We just cover her kennel for shorter drives.) Conversely, one of our dogs has a real coping problem with stressful events and our trainer strongly discouraged the application of a sedative for this pet. Giving a sedative to an anxious animal doesn’t prevent the pet from feeling the anxiety – it just reduces her ability to perform her coping (or lack of coping, in our case) behaviors. So a sedated anxious animal is now trapped in a terrifyingly sluggish body that unable to do much to pacify her herself. Not a good combination! Especially when an anti-anxiety medication would actually address the pet’s real issue. So do your pets and yourself a favor: talk to a professional (and preferably more than one!).
  5. Keep your pet on leash/in a carrier and identification on your pet at all times. Typically stoic pets can get freaked about the noise and commotion of rest stops and bolt. Car accidents happen. Unfamiliar fences may have weak spots that may not go unnoticed by pets. For everyone’s safety, I always keep my pets on leash/in a carrier while traveling. In the worst case scenario that your pet does get away from you, make sure your pet has up-to-date contact information on her body. Get engraved tags from a pet store, use a sharpie to write your phone number on a collar, and/or call your pet’s microchip company to ensure your contact info is correct.

If you’re reading this in preparation of a move, I wish you smooth travels and the best of luck in your new home! Are you renting? Check out my last post about tips for renting with pets!

Renting with Pets: Tips from (at this point I should be) a Pro

IMG_2564My family of wife + husband + two dogs + two cats are about to embark on our third move in just over two years (quite a long story, with the happy ending of my husband’s PhD program and my well-paying, career-strategic job miraculously being in the same city). Since we are a such a mobile fur family, renting has been an unfortunate necessity for us! Below are some things that I’ve learn so far about renting with pets in tow.

Renting with Pets

  1. Take GREAT care of your pet. The best piece of evidence that you can provide a potential landlord that you and your pets will be great renters is a great rental and veterinary history. Give your dog enough exercise and mental stimulation so she doesn’t tear up the vinyl flooring. Get your cat to the vet regularly to head off any medical problems that may cause inappropriate elimination. Make sure everybody has enough positive human interaction, toys and activities to be healthy and happy.
  2. Find a nice person that owns a rental property. This little gem came from a dear friend. If you have more than one pet, or large dogs, or a dog that may be difficult for a property owner to insure, or an exotic pet, it’s probably best for you to skip right past ads from large property management firms or gigantic apartment complexes. Chances are, the property owner is not going to take the time to consider your individual circumstances and why you are a good renter. Instead, focus on property owners that have one or two units and provide more information that required to prove you are a great renter. Yes, this does take some trial and error if you are going primarily from Craigslist or Zillow! Ask friends or relatives for suggestions and keep at it!
  3. Make a pet resume for all your pets. A short, one-page document with your pets’ photos, veterinary history, training achievements and other charming details (age, altered status, likes/dislikes) about your furry family members can highlight just that: your pets are part of the family. Landlord don’t want to rent to pet owners that let their cats wee all over the carpet because the litter boxes are never clean or whose dog chewed all the baseboards because he never got enough exercise. If you can make the case that your pets get everything they need to be healthy and happy (because they are treated like family), a prospective landlord may be more willing to give you a shot.
  4. Take training class and get certificates. So, this may be easier for dogs: sadly, the intellectual abilities of cats are not typically advanced through organized classes. But if you have a pooch, take a few training classes and provide a certificate of completion with your rental application. This is just another piece of evidence to provide your future landlord that you are a responsible pet owner!
  5. Keep calm and keeping searching. It’s going to take some time to find a rental property that will take in your family if you have a lot of pets or unusual pets. You may encounter some unpleasantry (my choice favorites: “Can you get rid of the dogs for a year?” – where exactly would I put them?, “I would need to charge extra for the cat smell.” – my cats don’t smell, because I don’t live in filth, thanks, “Are they aggressive breeds?” – and then after I tried to explain aggressive breeds don’t exist, they hung up on me). It can be frustrating to Persevere and find the rental of your dreams! Or at least, a rental!

My next post will focus on the strategies and tips that I’ve used to making moving rentals bearable for my pets and me!

Journal Article: Hand Movements Are Mightier Than The Clicker?

Title: Clicker increases resistance to extinction but does not decrease training time of a simple operant task in domestic dogs (Canis familiaris)

Authors: Shawn M. Smith, Ellen S. Davis

Published: 2008 Applied Animal Behaviour Science


General overview:

These researchers studied the effects of using a clicker during dog training, as these devices are popular with dog owners but have not been scientifically evaluated. The authors identified three possible mechanisms that clickers may serve in the dog training process (definitions found here):

  1. A conditioned/secondary reinforcer: A neutral stimulus paired with a primary reinforcer until the neutral stimulus takes on the reinforcing properties of the primary.
  2. A marking signal: A signal used to mark desired behavior at the instant it occurs.
  3. A bridging stimulus: An event marker that identifies the desired response and “bridges” the time between the response and the delivery of the primary reinforcer.

In order to investigation the mechanism of clicker training, the authors recruited 35 basenji dogs that had never been exposed to a clicker. Eighteen dogs were assigned to the clicker group and the remaining 17 were assigned to a control group. The authors used a trainer to condition the clicker group dogs that the click was associated with food delivery in a nearby bowl, while the control group dogs were simply given rewards in the bowl with no click. Then the trainer taught the dogs a behavior (nose touch a cone) and conducted strengthening trials to reinforce the behavior where the dogs were intermittently rewarded for correct responses to the nose touch cue. These trials were followed by extinction trials in which the dogs were given the nose touch cue but not rewarded.

The authors found that there were no differences between the clicker and the control groups in the number of trials or the time needed to learn the nose touch cue, which suggested that the clicker did not serve as a marker or bridging stimulus. It did, however, the clicker group dogs significantly longer to achieve extinction – that is, to stop nose touching the cone after the nose touch cue was no longer reinforced with food. This suggested that the clicker did serve as conditioned/secondary reinforcer, possibly because the clicker dogs were facing “double extinction”: they had to unlearn both that the clicker did not result in a reward and that the nose touch did not result in a reward.

The authors noted that dogs in both groups were obviously responding to hand movements from the trainer that were associated with delivering food to the bowl, which may have interfered with the dog’s ability to associate the clicker with the food delivery instead. The authors also had a significant difference between the age of dogs and the time/number of trials needed to learn the nose touch behavior: younger dogs were faster than older dogs.

My comments

This was an interesting study because, as the authors noted, it is one of the few that scientifically evaluates the mechanism by which a clicker may facilitate learning in dogs. (How do dogs learn?Check out Crash Course Psychology Episode 11 and Episode 12.) However, I had some concerns about how the authors chose to evaluate the clicker in the context of owner-dog training.

First, the protocol that the trainer used to teach the dogs a nose touch behavior involved the reward being delivered in a dish rather than directly from the trainer. Why?? The authors did not explain this adequately. I wonder if this may have impacted the dogs’ learning based on the information I have read from Dr. Yin about the importance of timing and posture during treat delivery when training dogs. The authors even noted that the dogs were apparently watching the trainer for hand movements that indicated treat delivery to the bowl, which aligns with Dr. Yin’s assertion that treat delivery is highly influential to a dog’s learning experience. Furthermore, I have never heard of an owner training their dog in this manner – therefore, the validity of applying the results from this study to a typical owner training their dog is questionable.

Secondly, if the goal of this study was to evaluate the utility of a clicker in training by the average owner, using a professional dog trainer likely produced results that are not valid outside of that context. A dog trainer will likely have skills that the average owner does not, such as effectively applying cue-reward protocols where a regular owner may have faulty or incorrect application simply because of experience. Because owners may be less accurate during the cue-reward process of training than dog trainers, it is possible that dogs could pick up on the clicker as a marker or bridging stimulus in the absence of other effective instructions. Additionally, other researchers have found that dogs are more attuned to their owner’s social cues vs. a stranger’s behavior. If the purpose of this study was to evaluate clicker’s use for dog owners, the dog’s actual owner should have been used in the training process.

In summary, I agree with the authors that the mechanism of clickers in dog training is an interesting and useful avenue of study. Clickers may be a useful tool in promoting humane, effective dog training for the average owner but incorrect usage of the devices may frustrate owners. Understanding how clickers help (or don’t help) dogs learn could aid behaviorists and trainers to advocate effective and safe training methods to owners. While I do not believe this study’s findings can be applied to a owner/dog training scenario, it is an interesting contribution to the understanding of how clickers impact canine learning. 

Let’s Ruin: Dog Shaming – Excessive licking

I follow Dog Shaming on Tumblr. While their posts are occasionally good for a chuckle, many of the photos make me cringe (“please don’t tell me you actually believe that’s why your dog did that” or “it’s not a shame your dog did that, because she’s a dog” or “as your dog’s owner, how did you continue to let that happen? Because your dog could have been seriously injured/killed.” or “you know that’s a behavior you can work on with your dog, right?“). I totally understand the desire to publicize your dog’s odd behavior – like how my dog seems to think her collar is a cozy nap buddy – but the posts that suggest a bizarre rationale for a dog’s behavior, or complain about a perfectly normal dog behavior that could/should have been managed better by the owner, or bemoan a real problematic dog behavior that apparently is going unaddressed by the owner…it’s worrisome!

I understand that Dog Shaming is supposed to be funny, but I’ve got to ruin it. So many of us have welcomed pups into our homes and there seems to be a good portion out there that don’t really understand how dogs think or normally behave. Without understanding what normal dog behavior is and why dogs do the things they do, humans tend to resort to inefficient and potentially inhumane ways of coping with or changing the dog’s behavior – or even ignoring a behavior that is a sign of real distress or harmful to the dog.

Example #1: A recent Dog Shaming post reads:

Sadie is a Jack Russell Terrier mix that my wife and I rescued 3 years ago. She is a complete sweetheart and loves to groom herself while sunning on our bed. However, she has careless disregard for what she is licking while primping herself and always leaves a gross wet lick spot on the comforter. Fortunately, I can’t stay mad at that face for too long.

The Sign reads :
96% Comforter 4% Paw –
I think this is an acceptable lick ratio when grooming myself
– Sadie

Guess what? Far from being a eye-tongue coordination issue, excessive licking in dogs has been shown to be a pretty fair indicator of an undiagnosed gastrointestinal (GI) disorder! In a study from the University of Montreal Veterinary Teaching Hospital, researchers found that nearly 75% of dogs that excessively licked surfaces had an undiagnosed GI condition and once that condition was addressed, the excessive licking behavior resolved. The researchers hypothesized that the excessive licking may pacify feelings of nausea or abdominal discomfort for dogs.