Help! My Dog is Losing Hair! (Vet Answered)
This question has been answered by a vet
Veterinarian & Animal Behaviorist
With nearly two decades in veterinary medicine, Dr. Paola brings hands-on experience across multiple species. A graduate of the University of Guadalajara, she specializes in preventive care, animal welfare, and positive reinforcement training.
The Question
“My Border Collie lost hair after being put on Apoquel for allergies. He’s on Zenralia now, and the itchiness is controlled, and hair is growing back—but only the white patches, not the black spots. Vet says give it time, but I feel like something’s off. Is this normal? And is there anything I can do to help?
” – Mandy
Quick Info about Milo
Hey Mandy,
I understand this might seem confusing, but your vet is right. Coat recovery after significant itching rarely happens evenly, and the pattern you are describing is actually quite common in dogs with strong color contrast. White hairs contain very little pigment, so those follicles often resume growth more quickly once the skin becomes calm again. The black hairs require more pigment production and a longer return to their active growth stage, so they tend to lag behind. This can create the impression that something is wrong even when the skin is healing normally. Don’t worry, Apoquel is not associated with selective loss of dark hair, so the uneven regrowth likely reflects the natural recovery process rather than an adverse reaction to the medication.
If his itch is controlled on Zenralia and the skin looks healthy, from now on, patience truly becomes an important part of the treatment. Supporting the skin barrier with balanced nutrition, omega-3 fatty acids, and gentle grooming can help the follicles regain their normal rhythm.
If the darker areas fail to recover over the next few months or new thinning appears, your veterinarian can check for other potential causes, such as thyroid imbalance or persistent inflammation. If any new changes make you uncertain, at Pangovet, we would be happy to guide you through the next best steps to help you help Milo.
Kind regards,
– Dr. Paola