Cytopoint™- New Hope for the Chronically Itchy Dog

Cytopoint is a new injectable medication from Zoetis that blocks a key pathway in the canine “itch” cycle.

 Cytopoint is a new injectable medication from Zoetis that blocks a key pathway in the canine “itch” cycle. Cytopoint, an inhibitor of the Interleukin-31 pathway, may be the ticket for many dogs who still itch after proper flea control, clearing up any skin infection, reducing exposure to environmental allergens, and in rare cases changing the protein source in their food. Cytopoint is compatible with many concurrent medications, and we have been able to reduce corticosteroid doses in dogs that have formerly been responsive only to high dose therapy. With subsequent doses of Cytpoint, we may be able to eliminate corticosteroid use entirely. 

One of the most common complaints that I hear, both in the clinic and during house calls is “My dog is constantly itching”. The hallmark signs of an itchy/allergic animal are:

• Licking (paws and belly), broken hairs at the base of the tail
• Reddened or eroded skin in the armpits and groin, and
• Hair loss anywhere on the body.

Flea bites are the most common trigger of allergies in California. Dogs also express inhaled allergens as skin disease, a condition called Atopy, or Atopic Dermatitis. 

Cytopoint may not be the Holy Grail of itch reduction, but it may create longer itch free intervals. 

It is a monoclonal antibody to Interleukin-31 (IL-31), and has shown excellent activity in clinical trials.
It is an injectable medication, given at 4-8 week intervals with increased length of effectiveness seen with subsequent injections.

I am following my early cases closely to determine the best dosing interval, and using it to greatly reduce my initial corticosteroid doses. So far, I have been impressed with its short-term effectiveness in some very difficult cases. After 6 months of use, I am still impressed, especially with animals that tend to have chronic ear infections as part of their allergic response. I've expanded my use to younger dogs as well. 

What is Atopic Dermatitis?

“Atopic dermatitis is an inflammatory, chronic skin disease associated with allergies. In fact, this is the second most common allergic skin disease in dogs. These allergic reactions can be brought on by normally harmless substances like grass, mold spores, house dust mites, and other environmental allergens” 

How do we “fix” an itchy dog?

We need to eliminate the easy triggers of allergies. 
The most important first step is to practice good flea control. I prefer Bravecto® (fluralaner), a three-month chewable treat that reduces the flea population in the home environment. Most dogs are allergic to flea saliva. Fleas do not live on dogs, but jump on and off to feed and lay eggs. 

We need to eliminate any active pyoderma, or skin infection.
The signs of a skin infection are redness in the armpit and groin, raised scabby lesions and in some cases, erosive lesions. Pyoderma is primarily a Staph Intermedius infection, derived from a dog’s own skin flora and triggered by self- trauma. We treat it with a specific antibiotic, and it can be quite persistent with severe cases requiring three to four weeks of medication. 

We need to eliminate environmental allergens. 
Vacuuming and keeping surface dust to a minimum in our homes is important, especially during the peak allergy season of spring and early summer. Indoor air cleaners with HEPA filtration may help. Keeping dogs away from specific tree and pollens may help as well. We can run a diagnostic panel on blood to identify the offending allergens specific to your dog. 

Topical treatments. 
We have many therapeutic shampoos and antimicrobials that can help eliminate dander by removing the dead outer layer of skin cells and superficial bacteria that may be inhaled during grooming. Many of these dogs have a characteristic odor caused by bacterial, and sometimes fungal, overgrowth with or without an increase in oily glandular secretions.

Food change.
Some dogs may be allergic to specific protein sources such as chicken and a move to a different protein source may be beneficial. In my experience, true food allergies are rare, and I have seen limited evidence of grain free, limited ingredient, or raw diets eliminating allergic symptoms in dogs. Some dogs do respond to fish oil supplements that can fix a defective fatty acid metabolic pathway.

How do we get a specific diagnosis of the source of the allergic dermatitis? We have a tiered approach to diagnosing the offending triggers. We can perform skin scrapings or skin cultures for localized lesions. If the problem is more generalized, we can draw blood and run specific allergy panels for environmental and food allergens. 

How do we treat the itchy dog? We use a multi-tiered approach to treatment of the itchy dog, ranging from systemic corticosteroids to immunosuppressive drugs in extreme cases. Apoquel is an orally administered inhibitor of an itch pathway, but only works when being ingested—it has no residual effect. Daily administration may extend the interval between corticosteroid use. I believe that it is overprescribed and it is also expensive from a cost/benefit perspective.. 

I personally do not believe that antihistamines work in dogs, except for short term use of older, sedating antihistamines such as hydroxyzine. With good flea and environmental control, judicious use of corticosteroids, both injectable and oral, can be very effective front line therapy. These drugs do suppress the overall allergic reaction, and dosed properly have no long term physiological effects. However, some dogs have a limited response to steroids, and continue to itch like clockwork 4-6 weeks after an injection and short course of oral therapy. 

Cytopoint is a new injectable medication from Zoetis that blocks a key pathway in the canine “itch” cycle. Cytopoint, an inhibitor of the Interleukin-31 pathway, may be the solution for many dogs who still itch after proper flea control, clearing up any skin infection, reducing exposure to environmental allergens, and in rare cases changing the protein source in their food. Cytopoint is compatible with many concurrent medications, and we have been able to reduce corticosteroid doses in dogs that have formerly been responsive only to high dose therapy. With subsequent doses of Cytpoint, we may be able to eliminate corticosteroid use entirely. 

Cytopoint may not be the Holy Grail of itch reduction, but it may create longer itch free intervals. 

It is a monoclonal antibody to Interleukin-31 (IL-31), and has shown excellent activity in clinical trials.
It is an injectable medication, given at 4-8 week intervals with increased length of effectiveness seen with subsequent injections. 

If you would like more information about Cytopoint, or to set up an appointment, please visit www.4Paws.vet, or call us at 650 445 4500.