DEAR READERS: Here is some important information about isoxazoline parasiticides (as in Bravecto, Simparica and Nexgard) that are commonly given to dogs. This is a synopsis of the report “Survey of canine use and safety of isoxazoline parasiticides” by Valerie Palmieri, W. Jean Dodds et al. from the journal Veterinary Medicine and Science:
“A veterinarian and pet owner survey (Project Jake) examined the use and safety of isoxazoline parasiticides given to dogs. Data were received during August 2018 from a total of 2,751 survey responses. Forty-two percent reported no flea treatment or adverse events, while 58% had been treated with some parasiticide for flea control. Of those that received a parasiticide, 83% received an isoxazoline. When any flea treatment was given, adverse events were reported for 66.6% of respondents. Adverse consequences included death, seizures, shaking/tremors, behavioral issues, neurological/cognitive issues, muscular/balance issues, skin problems/itching, internal bleeding, anemia, vomiting, diarrhea and not eating or drinking.
“The Project Jake findings were compared to a retrospective analysis of publicly available Food and Drug Administration-reported and European Medicines Agency-reported adverse events. The number of total adverse events reported to FDA and EMA were comparable, although a 7- to 10-times higher occurrence of death and seizures was reported from the EMA or from outside the United States. Serious adverse events (death, seizures and neurological effects) reported in our survey were higher than the FDA reports, but moderately lower than the EMA reports. These sizable global data sets combined with this pre- and post-parasiticide administration survey indicated that isoxazoline neurotoxicity was not flea- and tick-specific. Post-marketing serious adverse effects were much higher than in Investigational New Drug submissions.
“Although the labels have recently been updated, dogs, cats and their caregivers remain impacted by their use. These aggregate data support the need for continued cross-species studies and critical review of product labeling by regulatory agencies and manufacturers.”
DEAR DR. FOX: My male German shepherd’s urine is killing my grass. I’ve had four previous German shepherds, two male and two females, and none of them spotted the grass. Should I be concerned why this one does?
We try to water the area after he urinates, but that is not always possible as sometimes he has to go out in the middle of the night (and/or sometimes the hose will not reach; we live on an acre). This will probably be our last German shepherd, as we are in our 70s and have outlived the previous four. Our dog gobbles up Nutro Essentials, and we make sure that he always has plenty of water. -- S.M. and M.M., Loxahatchee, Florida
DEAR S.M. and M.M.: There are various quack remedies that will supposedly correct this problem. However, my remedy and advice for all dog owners is not to feed the dog only dry kibble. Feeding only dry kibble is not a biologically appropriate diet for dogs (or cats). Give him a small amount of kibble, along with a rotating variety of frozen, freeze-dried and canned dog foods. This will give your dog more moisture for digestion and metabolism, which in turn will change the acidity and concentration of the urine.
It is also possible that chemicals in the kibble passed in the urine act like an herbicide -- residues of which, especially glyphosate, are present in most all commercially produced grains (which we also consume) when not USDA Certified Organic and GMO-free.
Read on for another issue from a longtime German shepherd owner.
DEAR DR. FOX: We have an 8-year-old male German shepherd who is not fixed. He has a constant drip from his penis, which leaves greenish markings throughout the house (quite annoying). He has had this since we got him at 18 months old.
He is the love our life. Best dog we have ever had. This is our fourth German shepherd, and our other dogs never had this problem. -- R.B., West Palm Beach, Florida
DEAR R.B.: I am surprised this problem has been going on for so long. Surely your dog had regular veterinary wellness evaluations, as well as anti-rabies vaccinations, heartworm tests and preventive medications. There are various glands and tissues in the sheath around your dog’s penis that can become chronically infected and inflamed, and he cannot clean himself thoroughly in this area. Horse owners will know what I am talking about.
I would waste no time and get a veterinary appointment for this condition, which is probably no less distressing for your dog than it is for you.
(Send all mail to firstname.lastname@example.org or to Dr. Michael Fox in care of Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106. The volume of mail received prohibits personal replies, but questions and comments of general interest will be discussed in future columns.
Visit Dr. Fox’s website at DrFoxOneHealth.com.)